INSTALL_LIBRARY	= @INSTALL_LIBRARY@

PACKAGE_NAME	= @PACKAGE_NAME@
PACKAGE_VERSION	= @PACKAGE_VERSION@
CC		= @CC@
CCLD		= @CCLD@
CFLAGS_DEFAULT	= @CFLAGS_DEFAULT@
CFLAGS_WARNING	= @CFLAGS_WARNING@
EXEEXT		= @EXEEXT@
LDFLAGS_DEFAULT	= @LDFLAGS_DEFAULT@
MAKE_LIB	= @MAKE_LIB@
MAKE_STUB_LIB	= @MAKE_STUB_LIB@
OBJEXT		= @OBJEXT@
RANLIB		= @RANLIB@
RANLIB_STUB	= @RANLIB_STUB@

# TCL_DEFS is not strictly need here, but if you remove it, then you
# must make sure that configure.ac checks for the necessary components
# that your library may use.  TCL_DEFS can actually be a problem if
# you do not compile with a similar machine setup as the Tcl core was
# compiled with.
#DEFS		= $(TCL_DEFS) @DEFS@ $(PKG_CFLAGS)
DEFS		= @DEFS@ $(PKG_CFLAGS)

# Move pkgIndex.tcl to 'BINARIES' var if it is generated in the Makefile
CONFIG_CLEAN_FILES = Makefile pkgIndex.tcl generic/tls.tcl.h
CLEANFILES	= @CLEANFILES@

CPPFLAGS	= @CPPFLAGS@
LIBS		= @PKG_LIBS@ @LIBS@

# this extension
tls.tcl.h: @srcdir@/library/tls.tcl Makefile
	od -A n -v -t xC < '@srcdir@/library/tls.tcl' > tls.tcl.h.new.1
	sed 's@[^0-9A-Fa-f]@@g;s@..@0x&, @g' < tls.tcl.h.new.1 > tls.tcl.h.new.2
	rm -f tls.tcl.h.new.1
	mv tls.tcl.h.new.2 @srcdir@/generic/tls.tcl.h








$(srcdir)/manifest.uuid:
	printf "git-" >$(srcdir)/manifest.uuid
	(cd $(srcdir); git rev-parse HEAD >>$(srcdir)/manifest.uuid || \
	    (printf "svn-r" >$(srcdir)/manifest.uuid ; \
	    svn info --show-item last-changed-revision >>$(srcdir)/manifest.uuid) || \
	    printf "unknown" >$(srcdir)/manifest.uuid)

Tool Command Language (TCL) Transport Layer Security (TLS) Extension

Intro
=====

This package provides an extension which implements Secure Socket Layer (SSL)
and Transport Layer Security (TLS) over Transmission Control Protocol (TCP)
network communication channels. It utilizes either the OpenSSL or LibreSSL
software library.

Version 2.0 also provides a cryptography library providing TCL scripts access
to the crypto capabilities of the OpenSSL library.


Description
===========

This extension works by creating a layered TCL Channel on top of an existing
bi-directional channel created by the TLS socket command. All existing socket
functionality is supported, in addition to several new options. Both client
and server modes are supported.


Documentation
=============

See the doc directory for the full usage documentation.


Compatibility
=============

This package requires TCL 8.5 or later.

This package is compatible with:
- OpenSSL v1.1.1 or later. See (http://www.openssl.org/
- LibreSSL (TBD version)


Installation
============

This package uses the Tcl Extension Architecture (TEA) to build and install on
any supported Unix, Mac, or MS Windows system. Either the OpenSSL or LibreSSL
software libraries must be built and available prior to building TCL TLS.

UNIX and Linux
--------------

The standard TEA config, make and install process is supported.

	$ cd tcltls
	$ ./configure --enable-64bit --enable-deterministic --with-builtin-dh-params-size=2048
	$ make
	$ make test
	$ make install

The supported configure options include all of the standard TEA configure script
options, plus:

  --disable-tls1          disable TLS1 protocol
  --disable-tls1_1        disable TLS1.1 protocol
  --disable-tls1_2        disable TLS1.2 protocol
  --disable-tls1_3        disable TLS1.3 protocol
  --enable-deterministic  enable deterministic DH parameters
  --enable-ssl-fastpath   enable using the underlying file descriptor for talking directly to the SSL library
  --enable-hardening      enable hardening attempts
  --enable-static-ssl     enable static linking to the SSL library
  --with-builtin-dh-params-size=<bits>	specify the size of the built-in, precomputed, DH params

If either TCL or OpenSSL are installed in non-standard locations, the following
configure options are available. For all options, see ./configure --help.

  --with-tcl=<dir>			path to where tclCondig.sh file resides
  --with-tclinclude=<dir>		directory containing the public Tcl header files
  --with-openssl-dir=<dir>		path to root directory of OpenSSL or LibreSSL installation
  --with-openssl-includedir=<dir>	path to include directory of OpenSSL or LibreSSL installation
  --with-openssl-libdir=<dir>		path to lib directory of OpenSSL or LibreSSL installation
  --with-openssl-pkgconfig=<dir>	path to root directory of OpenSSL or LibreSSL pkgconfigdir


MacOS
-----

The standard TEA installation process is supported. Use the --with-tcl option
to set the TCL path if the ActiveState or other non-Apple version of TCL is to
be used.

	$ cd tcltls
	$ ./configure --with-tcl=/Library/Frameworks/Tcl.framework/
	$ make
	$ make test
	$ make install


Windows
-------

If installing with MinGW, use the TEA build process. If using MS Visual C
(MSVC), see the win/README.txt file for the installation instructions.


Copyrights
==========

Original TLS Copyright (C) 1997-2000 Matt Newman <[email protected]>
TLS 1.4.1    Copyright (C) 2000 Ajuba Solutions
TLS 1.6      Copyright (C) 2008 ActiveState Software Inc.
TLS 1.7      Copyright (C) 2016 Matt Newman, Ajuba Solutions, ActiveState
                                Software Inc, Roy Keene <[email protected]>
TLS 1.9-2.0  Copyright (C) 2023 Brian O'Hagan




Acknowledgments


===============









Non-exclusive credits for TLS are:
   Original work: Matt Newman @ Novadigm
   Updates: Jeff Hobbs @ ActiveState
   Tcl Channel mechanism: Andreas Kupries
   Impetus/Related work: tclSSL (Colin McCormack, Shared Technology)
                         SSLtcl (Peter Antman)

License
=======

This code is licensed under the same terms as the Tcl Core.

#
# Include the TEA standard macro set
#

builtin(include,tclconfig/tcl.m4)

#
# Add here whatever m4 macros you want to define for your package
#

AC_DEFUN([TCLTLS_SSL_OPENSSL], [
	AC_CHECK_TOOL([PKG_CONFIG], [pkg-config])

	dnl Disable support for TLS 1.0 protocol
	AC_ARG_ENABLE([tls1], AS_HELP_STRING([--disable-tls1], [disable TLS1 protocol]), [
		if test "${enableval}" = "no"; then
			AC_DEFINE([NO_TLS1], [1], [Disable TLS1 protocol])
			AC_MSG_CHECKING([for disable TLS1 protocol])
			AC_MSG_RESULT('yes')
		fi
	])

	dnl Disable support for TLS 1.1 protocol
	AC_ARG_ENABLE([tls1_1], AS_HELP_STRING([--disable-tls1_1], [disable TLS1.1 protocol]), [
		if test "${enableval}" = "no"; then
			AC_DEFINE([NO_TLS1_1], [1], [Disable TLS1.1 protocol])
			AC_MSG_CHECKING([for disable TLS1.1 protocol])
			AC_MSG_RESULT('yes')
		fi
	])

	dnl Disable support for TLS 1.2 protocol
	AC_ARG_ENABLE([tls1_2], AS_HELP_STRING([--disable-tls1_2], [disable TLS1.2 protocol]), [
		if test "${enableval}" = "no"; then
			AC_DEFINE([NO_TLS1_2], [1], [Disable TLS1.2 protocol])
			AC_MSG_CHECKING([for disable TLS1.2 protocol])
			AC_MSG_RESULT('yes')
		fi
	])

	dnl Disable support for TLS 1.3 protocol
	AC_ARG_ENABLE([tls1_3], AS_HELP_STRING([--disable-tls1_3], [disable TLS1.3 protocol]), [
		if test "${enableval}" = "no"; then
			AC_DEFINE([NO_TLS1_3], [1], [Disable TLS1.3 protocol])
			AC_MSG_CHECKING([for disable TLS1.3 protocol])
			AC_MSG_RESULT('yes')
		fi
	])


	dnl Determine if we have been asked to use a fast path if possible
	AC_ARG_ENABLE([ssl-fastpath], AS_HELP_STRING([--enable-ssl-fastpath],
		[enable using the underlying file descriptor for talking directly to the SSL library]), [
		tcltls_ssl_fastpath="$enableval"
	], [
		tcltls_ssl_fastpath='no'
	])
	if test "$tcltls_ssl_fastpath" = 'yes'; then
		AC_DEFINE(TCLTLS_SSL_USE_FASTPATH, [1], [Enable SSL library direct use of the underlying file descriptor])
	fi
	AC_MSG_CHECKING([for fast path])
	AC_MSG_RESULT([$tcltls_ssl_fastpath])


	dnl Enable hardening
	AC_ARG_ENABLE([hardening], AS_HELP_STRING([--enable-hardening], [enable hardening attempts]), [
		tcltls_enable_hardening="$enableval"
	], [
		tcltls_enable_hardening='yes'
	])
	if test "$tcltls_enable_hardening" = 'yes'; then
		if test "$GCC" = 'yes' -o "$CC" = 'clang'; then
			TEA_ADD_CFLAGS([-fstack-protector-all])
			TEA_ADD_CFLAGS([-fno-strict-overflow])
			AC_DEFINE([_FORTIFY_SOURCE], [2], [Enable fortification])
		fi
	fi
	AC_MSG_CHECKING([for enable hardening])
	AC_MSG_RESULT([$tcltls_enable_hardening])


	dnl Determine if we have been asked to statically link to the SSL library
	AC_ARG_ENABLE([static-ssl], AS_HELP_STRING([--enable-static-ssl], [enable static linking to the SSL library]), [
		TCLEXT_TLS_STATIC_SSL="$enableval"
	], [
		TCLEXT_TLS_STATIC_SSL='no'
	])
	AC_MSG_CHECKING([for static linking of openSSL libraries])
	AC_MSG_RESULT([$TCLEXT_TLS_STATIC_SSL])


	dnl Set SSL files root path
	AC_ARG_WITH([openssl-dir],
		AS_HELP_STRING([--with-openssl-dir=<dir>],
			[path to root directory of OpenSSL or LibreSSL installation]
		), [
			openssldir="$withval"
		], [
			openssldir=''
		]
	)

	dnl Set SSL include files path
	AC_ARG_WITH([openssl-includedir],
		AS_HELP_STRING([--with-openssl-includedir=<dir>],
			[path to include directory of OpenSSL or LibreSSL installation]
		), [
			opensslincludedir="$withval"
		], [
			if test -n "$openssldir"; then
				opensslincludedir="$openssldir/include/openssl"
			else
				opensslincludedir=''
			fi
		]
	)
	AC_MSG_CHECKING([for OpenSSL include directory])
	AC_MSG_RESULT($opensslincludedir)

	dnl Set SSL include vars
	if test -n "$opensslincludedir"; then
		if test -f "$opensslincludedir/ssl.h"; then
			TCLTLS_SSL_CFLAGS="-I$opensslincludedir"
			TCLTLS_SSL_INCLUDES="-I$opensslincludedir"
		else
			AC_MSG_ERROR([Unable to locate ssl.h])
		fi
	else
		TCLTLS_SSL_CFLAGS="-I$(includedir)/openssl"
		TCLTLS_SSL_INCLUDES="-I$(includedir)/openssl"
	fi

	dnl Set SSL lib files path
	AC_ARG_WITH([openssl-libdir],
		AS_HELP_STRING([--with-openssl-libdir=<dir>],
			[path to lib directory of OpenSSL or LibreSSL installation]
		), [
			openssllibdir="$withval"
		], [
			if test -n "$openssldir"; then
				if test "$do64bit" == 'yes'; then
					openssllibdir="$openssldir/lib64"
				else
					openssllibdir="$openssldir/lib"
				fi
			else
				openssllibdir=''
			fi
		]
	)
	AC_MSG_CHECKING([for OpenSSL lib directory])
	AC_MSG_RESULT($openssllibdir)

	dnl Set SSL lib vars
	if test -n "$openssllibdir"; then
		if test -f "$openssllibdir/libssl${SHLIB_SUFFIX}"; then
			if test "${TCLEXT_TLS_STATIC_SSL}" == 'no'; then
				TCLTLS_SSL_LIBS="-L$openssllibdir -lcrypto -lssl"
			else
				# Linux and Solaris
				TCLTLS_SSL_LIBS="-Wl,-Bstatic `$PKG_CONFIG --static --libs crypto ssl` -Wl,-Bdynamic"
				# HPUX
				# -Wl,-a,archive ... -Wl,-a,shared_archive
			fi
		else
			AC_MSG_ERROR([Unable to locate libssl${SHLIB_SUFFIX}])
		fi
	else
		TCLTLS_SSL_LIBS="-lcrypto -lssl"
	fi


	dnl Include config variables in --help list and make available to be substituted via AC_SUBST.
	AC_ARG_VAR([TCLTLS_SSL_CFLAGS], [C compiler flags for OpenSSL or LibreSSL])
	AC_ARG_VAR([TCLTLS_SSL_INCLUDES], [C compiler include paths for OpenSSL or LibreSSL])
	AC_ARG_VAR([TCLTLS_SSL_LIBS], [libraries to pass to the linker for OpenSSL or LibreSSL])


	dnl Set location of pkgconfig files
	AC_ARG_WITH([openssl-pkgconfig],
		AS_HELP_STRING([--with-openssl-pkgconfig=<dir>],
			[path to root directory of OpenSSL or LibreSSL pkgconfigdir]
		), [
			opensslpkgconfigdir="$withval"
		], [
			opensslpkgconfigdir=''
		]
	)
	AC_MSG_CHECKING([for OpenSSL pkgconfig])
	AC_MSG_RESULT($opensslpkgconfigdir)


	# Use Package Config tool to get config
	pkgConfigExtraArgs=''
	if test "${SHARED_BUILD}" == 0 -o "$TCLEXT_TLS_STATIC_SSL" = 'yes'; then
		pkgConfigExtraArgs='--static'
	fi

	dnl Use pkg-config to find the libraries
	if test -n "${PKG_CONFIG}"; then
		dnl Temporarily update PKG_CONFIG_PATH
		PKG_CONFIG_PATH_SAVE="${PKG_CONFIG_PATH}"
		if test -n "${opensslpkgconfigdir}"; then
			if ! test -f "${opensslpkgconfigdir}/openssl.pc"; then
				AC_MSG_ERROR([Unable to locate ${opensslpkgconfigdir}/openssl.pc])
			fi

			PKG_CONFIG_PATH="${opensslpkgconfigdir}${PATH_SEPARATOR}${PKG_CONFIG_PATH}"
			export PKG_CONFIG_PATH
		fi
		if test -z "$TCLTLS_SSL_LIBS"; then
			TCLTLS_SSL_LIBS="`"${PKG_CONFIG}" openssl --libs $pkgConfigExtraArgs`" || AC_MSG_ERROR([Unable to get OpenSSL Configuration])
		fi
		if test -z "$TCLTLS_SSL_CFLAGS"; then
			TCLTLS_SSL_CFLAGS="`"${PKG_CONFIG}" openssl --cflags-only-other $pkgConfigExtraArgs`" || AC_MSG_ERROR([Unable to get OpenSSL Configuration])
		fi
		if test -z "$TCLTLS_SSL_INCLUDES"; then
			TCLTLS_SSL_INCLUDES="`"${PKG_CONFIG}" openssl --cflags-only-I $pkgConfigExtraArgs`" || AC_MSG_ERROR([Unable to get OpenSSL Configuration])
		fi
		PKG_CONFIG_PATH="${PKG_CONFIG_PATH_SAVE}"
	fi
])

<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type"
content="text/html; charset=iso-8859-1">
<meta name="Copyright" content="1999 Matt Newman / 2004 Starfish Systems">
<title>TLS (SSL) TCL Commands</title>
<link rel="stylesheet" href="docs.css" type="text/css" media="all">
</head>

<body class="vsc-initialized">

<h2>Tcl Tls Extension Documentation</h2>

<dl>
    <dd><a href="#NAME">NAME</a>
    <dl>
	<dd><b>tls</b> - binding to <b>OpenSSL</b> library
	for socket and I/O channel communications.</dd>
    </dl>
    </dd>
    <dd><a href="#SYNOPSIS">SYNOPSIS</a> </dd>
    <dd><dl>
	    <dd><b>package require Tcl</b> <em>?<b>8.5</b>?</em></dd>
	    <dd><b>package require tls</b></dd>
	    <dt>&nbsp;</dt>
	    <dd><b>tls::init</b> <em>?options?</em> </dd>
	    <dd><b>tls::socket</b> <em>?options? host port</em></dd>
	    <dd><b>tls::socket</b> <em>?-server command? ?options? port</em></dd>
	    <dd><b>tls::handshake</b> <em> channel</em></dd>
	    <dd><b>tls::status</b> <em>?-local? channel</em></dd>
	    <dd><b>tls::connection</b> <em>channel</em></dd>
	    <dd><b>tls::import</b> <em>channel ?options?</em></dd>
	    <dd><b>tls::unimport</b> <em>channel</em></dd>
	    <dt>&nbsp;</dt>
	    <dd><b>tls::protocols</b></dd>
	    <dd><b>tls::version</b></dd>
	</dl>
    </dd>
    <dd><a href="#COMMANDS">COMMANDS</a></dd>
    <dd><a href="#CALLBACK OPTIONS">CALLBACK OPTIONS</a></dd>
    <dd><a href="#HTTPS EXAMPLE">HTTPS EXAMPLE</a></dd>
    <dd><a href="#SEE ALSO">SPECIAL CONSIDERATIONS</a></dd>
    <dd><a href="#SEE ALSO">SEE ALSO</a></dd>
</dl>

<hr>

<h3><a name="NAME">NAME</a></h3>

<p><strong>tls</strong> - binding to <strong>OpenSSL</strong> library
for socket and I/O channel communications.</p>

<h3><a name="SYNOPSIS">SYNOPSIS</a></h3>

<p><b>package require Tcl</b> <em>?<b>8.5</b>?</em><br>
<b>package require tls</b><br>
<br>
<a href="#tls::init"><b>tls::init</b> <i>?options?</i></a><br>
<a href="#tls::socket"><b>tls::socket</b> <i>?options? host port</i><br>
<a href="#tls::socket"><b>tls::socket</b> <i>?-server command? ?options? port</i></a><br>
<a href="#tls::status"><b>tls::status</b> <i>?-local? channel</i></a><br>
<a href="#tls::connection"><b>tls::connection</b> <i>channel</i></a><br>
<a href="#tls::handshake"><b>tls::handshake</b> <i>channel</i></a><br>
<a href="#tls::import"><b>tls::import</b> <i>channel ?options?</i></a><br>
<a href="#tls::unimport"><b>tls::unimport</b> <i>channel</i></a><br>
<br>
<a href="#tls::protocols"><b>tls::protocols</b></a><br>
<a href="#tls::version"><b>tls::version</b></a><br>
</p>

<h3><a name="DESCRIPTION">DESCRIPTION</a></h3>

<p>This extension provides TCL script access to secure socket communications
using the Transport Layer Security (TLS) protocol. It provides a generic
binding to <a href="http://www.openssl.org/">OpenSSL</a>, utilizing the
<strong>Tcl_StackChannel</strong> API in Tcl 8.4 and higher.
These sockets behave exactly the same as channels created using the built-in
<strong>socket</strong> command, along with additional options for controlling
the SSL session.
</p>

<h3><a name="COMMANDS">COMMANDS</a></h3>

<p>Typically one would use the <strong>tls::socket </strong>command
which provides compatibility with the native Tcl <strong>socket</strong>
command. In such cases <strong>tls::import</strong> should not be
used directly.</p>

<dl>
    <dt><a name="tls::init"><b>tls::init </b><i>?options?</i></a></dt>
    <dd>Optional function to set the default options used by
	<strong>tls::socket</strong>. If you call <strong>tls::import</strong>
	directly this routine has no effect. Any of the options
	that <strong>tls::socket</strong> accepts can be set
	using this command, though you should limit your options
	to only TLS related ones.</dd>
    <dt>&nbsp;</dt>
    <dt><a name="tls::socket"><b>tls::socket </b><em>?options?
	host port</em></a></dt>
    <dt><b>tls::socket</b><em> ?-server command? ?options? port</em></dt>
    <dd>This is a helper function that utilizes the underlying
	commands (<strong>tls::import</strong>). It behaves
	exactly the same as the native Tcl <strong>socket</strong>
	command except the options can also include any of the
	applicable <a href="#tls::import"><strong>tls:import</strong></a>
	options with one additional option:</dd>
<blockquote>
    <dl>
	<dt><strong>-autoservername</strong> <em>bool</em></dt>
	<dd>Automatically set the -servername argument to the <em>host</em>
	    argument (default is <em>false</em>).</dd>
    </dl>
</blockquote>

    <dt><a name="tls::import"><b>tls::import </b><i>channel
	?options?</i></a></dt>
    <dd>Add SSL/TLS encryption to a regular Tcl channel. It need
	not be a socket, but must provide bi-directional flow. Also
	set session parameters for SSL handshake.</dd>

<blockquote>
    <dl>
	<dt><strong>-alpn</strong> <em>list</em></dt>
	<dd>List of protocols to offer during Application-Layer
	    Protocol Negotiation (ALPN). For example: <em>h2</em> and
	    <em>http/1.1</em>, but not <em>h3</em> or <em>quic</em>.</dd>
	<dt><strong>-cadir</strong> <em>dir</em></dt>
	<dd>Set the CA certificates path. The default directory is platform
	    specific and can be set at compile time. This can be overridden
	    via the <b>SSL_CERT_DIR</b> environment variable.</dd>
	<dt><strong>-cafile </strong><em>filename</em></dt>
	<dd>Set the certificate authority (CA) certificates file. The default
	    is the cert.pem file in the OpsnSSL directory. This can also be
	    overridden via the <b>SSL_CERT_FILE</b> environment variable.</dd>
	<dt><strong>-certfile</strong> <em>filename</em></dt>
	<dd>Specify the filename with the certificate to use.</dd>
	<dt><strong>-cert</strong> <em>filename</em></dt>
	<dd>Specify the contents of a certificate to use, as a DER
	    encoded binary value (X.509 DER).</dd>
	<dt><strong>-cipher</strong> <em>string</em></dt>
	<dd>List of ciphers to use. String is a colon (":") separated list
	    of ciphers. Ciphers can be combined
	    using the <b>+</b> character. Prefixes can be used to permanently
	    remove ("!"), delete ("-"), or move a cypher to the end of
	    the list ("+"). Keywords <b>@STRENGTH</b> (sort by algorithm
	    key length), <b>@SECLEVEL=</b><i>n</i> (set security level to
	    n), and <b>DEFAULT</b> (use default cipher list, at start only)
	    can also be specified. See OpenSSL documentation for the full
	    list of valid values. (TLS 1.2 and earlier only)</dd>
	<dt><strong>-ciphersuites</strong> <em>string</em></dt>
	<dd>List of cipher suites to use. String is a colon (":")
	    separated list of cipher suite names. (TLS 1.3 only)</dd>
	<dt><strong>-command</strong> <em>callback</em></dt>
	<dd>Callback command to invoke at several points during the handshake.
	    This is used to pass errors and tracing information, and
	    it can allow Tcl scripts to perform their own certificate
	    validation in place of the default validation provided by
	    OpenSSL. See <a href="#CALLBACK OPTIONS">CALLBACK OPTIONS</a>
	    for further discussion.</dd>
	<dt><strong>-dhparams </strong><em>filename</em></dt>
	<dd>Specify the Diffie-Hellman parameters file.</dd>
	<dt><strong>-keyfile</strong> <em>filename</em></dt>
	<dd>Specify the private key file. (default is
	    value of -certfile)</dd>
	<dt><strong>-key</strong> <em>filename</em></dt>
	<dd>Specify the private key to use as a DER encoded value (PKCS#1 DER)</dd>
	<dt><strong>-model</strong> <em>channel</em></dt>
	<dd>Force this channel to share the same <em><strong>SSL_CTX</strong></em>
	    structure as the specified <em>channel</em>, and
	    therefore share callbacks etc.</dd>
	<dt><strong>-password</strong> <em>callback</em></dt>
	<dd>Callback command to invoke when OpenSSL needs to obtain a password.
	    Typically used to unlock the private key of a certificate. The
	    callback should return a string which represents the password
	    to be used. See <a href="#CALLBACK OPTIONS">CALLBACK OPTIONS</a>
	    for further discussion.</dd>
	<dt><strong>-post_handshake</strong> <em>bool</em></dt>
	<dd>Allow post-handshake ticket updates.</dd>
	<dt><strong>-request </strong><em>bool</em></dt>
	<dd>Request a certificate from peer during SSL handshake.
	    (default is <em>true</em>)</dd>
	<dt><strong>-require</strong> <em>bool</em></dt>
	<dd>Require a valid certificate from peer during SSL handshake.
	    If this is set to true, then <strong>-request</strong> must
	    also be set to true and a either a -cadir, -cafile, or platform
	    default must be provided in order to validate against.
	    (default is <em>false</em>)</dd>
	<dt><strong>-security_level</strong> <em>integer</em></dt>
	<dd>Set security level. Must be 0 to 5. The security level affects
	    the cipher suite encryption algorithms, supported ECC curves,
	    supported signature algorithms, DH parameter sizes, certificate
	    key sizes and signature algorithms. The default is 1.
	    Level 3 and higher disable support for session tickets and only
	    accept cipher suites that provide forward secrecy.</dd>
	<dt><strong>-server</strong> <em>bool</em></dt>
	<dd>Set to act as a server and respond with a server handshake when
	    a client connects and provides a client handshake.
	    (default is <em>false</em>)</dd>
	<dt><strong>-servername</strong> <em>host</em></dt>
	<dd>Specify server's hostname. Used to set the TLS 'Server Name
	    Indication' (SNI) extension. Set to the expected servername
	    in the server's certificate or one of the subjectAltName
	    alternates.</dd>
	<dt><strong>-session_id</strong> <em>string</em></dt>
	<dd>Session id to resume session.</dd>
	<dt><strong>-ssl2</strong> <em>bool</em></dt>
	<dd>Enable use of SSL v2. (default is <em>false</em>)</dd>
	<dt><strong>-ssl3 </strong><em>bool</em></dt>
	<dd>Enable use of SSL v3. (default is <em>false</em>)</dd>
	<dt>-<strong>tls1</strong> <em>bool</em></dt>
	<dd>Enable use of TLS v1. (default is <em>true</em>)</dd>
	<dt>-<strong>tls1.1</strong> <em>bool</em></dt>
	<dd>Enable use of TLS v1.1 (default is <em>true</em>)</dd>
	<dt>-<strong>tls1.2</strong> <em>bool</em></dt>
	<dd>Enable use of TLS v1.2 (default is <em>true</em>)</dd>
	<dt>-<strong>tls1.3</strong> <em>bool</em></dt>
	<dd>Enable use of TLS v1.3 (default is <em>true</em>)</dd>
	<dt><strong>-validatecommand</strong> <em>callback</em></dt>
	<dd>Callback command to invoke to verify or validate protocol config
	    parameters during the protocol negotiation phase. See
	    <a href="#CALLBACK OPTIONS">CALLBACK OPTIONS</a>
	    for further discussion.</dd>
    </dl>
</blockquote>

    <dt><a name="tls::unimport"><b>tls::unimport </b><i>channel</i></a></dt>
    <dd>Provided for symmetry to <strong>tls::import</strong>, this
      unstacks the encryption of a regular Tcl channel. An error
      is thrown if TLS is not the top stacked channel type.</dd>
    <dt>&nbsp;</dt>
    <dt><a name="tls::handshake"><strong>tls::handshake</strong>
	<em>channel</em></a></dt>
    <dd>Forces handshake to take place, and returns 0 if
	handshake is still in progress (non-blocking), or 1 if
	the handshake was successful. If the handshake failed
	this routine will throw an error.</dd>
    <dt>&nbsp;</dt>
    <dt><a name="tls::status"><strong>tls::status</strong>
    <em>?</em><b>-local</b><em>? channel</em></a></dt>
    <dd>Returns the current status of an SSL channel. The result is a list
	of key-value pairs describing the SSL, certificate, and certificate
	verification status. If the SSL handshake has not yet completed,
	an empty list is returned. If <b>-local</b> is specified, then the
	local certificate is used.</dd>
<blockquote>
	<b>SSL Status</b>
    <dl>
	<dt><strong>alpn</strong> <em>protocol</em></dt>
	<dd>The protocol selected after Application-Layer Protocol
	    Negotiation (ALPN).</dd>
	<dt><strong>cipher</strong> <em>cipher</em></dt>
	<dd>The current cipher in use between for the channel.</dd>
	<dt><strong>peername</strong> <em>name</em></dt>
	<dd>The peername from the certificate.</dd>
	<dt><strong>protocol</strong> <em>version</em></dt>
	<dd>The protocol version used for the connection:
	    SSL2, SSL3, TLS1, TLS1.1, TLS1.2, TLS1.3, or unknown.</dd>
	<dt><strong>sbits</strong> <em>n</em></dt>
	<dd>The number of bits used for the session key.</dd>
	<dt><strong>signatureHashAlgorithm</strong> <em>algorithm</em></dt>
	<dd>The signature hash algorithm.</dd>
	<dt><strong>signatureType</strong> <em>type</em></dt>
	<dd>The signature type value.</dd>
	<dt><strong>verifyDepth</strong> <em>n</em></dt>
	<dd>Maximum depth for the certificate chain verification.
	    Default is -1, to check all.</dd>
	<dt><strong>verifyMode</strong> <em>list</em></dt>
	<dd>List of certificate verification modes.</dd>
	<dt><strong>verifyResult</strong> <em>result</em></dt>
	<dd>Certificate verification result.</dd>
	<dt><strong>ca_names</strong> <em>list</em></dt>
	<dd>List of the Certificate Authorities used to create the certificate.</dd>
    </dl>
</blockquote>
<blockquote>
	<b>Certificate Status</b>
    <dl>
	<dt><strong>all</strong> <em>string</em></dt>
	<dd>Dump of all certificate info.</dd>

	<dt><strong>version</strong> <em>value</em></dt>
	<dd>The certificate version.</dd>
	<dt><strong>serialNumber</strong> <em>n</em></dt>
	<dd>The serial number of the certificate as a hex string.</dd>
	<dt><strong>signature</strong> <em>algorithm</em></dt>
	<dd>Cipher algorithm used for certificate signature.</dd>
	<dt><strong>issuer</strong> <em>dn</em></dt>
	<dd>The distinguished name (DN) of the certificate issuer.</dd>
	<dt><strong>notBefore</strong> <em>date</em></dt>
	<dd>The begin date for the validity of the certificate.</dd>
	<dt><strong>notAfter</strong> <em>date</em></dt>
	<dd>The expiration date for the certificate.</dd>
	<dt><strong>subject</strong> <em>dn</em></dt>
	<dd>The distinguished name (DN) of the certificate subject.
	    Fields include: Common Name (CN), Organization (O), Locality
	    or City (L), State or Province (S), and Country Name (C).</dd>
	<dt><strong>issuerUniqueID</strong> <em>string</em></dt>
	<dd>The issuer unique id.</dd>
	<dt><strong>subjectUniqueID</strong> <em>string</em></dt>
	<dd>The subject unique id.</dd>

	<dt><strong>num_extensions</strong> <em>n</em></dt>
	<dd>Number of certificate extensions.</dd>
	<dt><strong>extensions</strong> <em>list</em></dt>
	<dd>List of certificate extension names.</dd>
	<dt><strong>authorityKeyIdentifier</strong> <em>string</em></dt>
	<dd>(AKI) Key identifier of the Issuing CA certificate that signed
	    the SSL certificate as a hex string. This value matches the SKI
	    value of the Intermediate CA certificate.</dd>
	<dt><strong>subjectKeyIdentifier</strong> <em>string</em></dt>
	<dd>(SKI) Hash of the public key inside the certificate as a hex
	   string. Used to identify certificates that contain a particular
	   public key.</dd>
	<dt><strong>subjectAltName</strong> <em>list</em></dt>
	<dd>List of all of the alternative domain names, sub domains,
	    and IP addresses that are secured by the certificate.</dd>
	<dt><strong>ocsp</strong> <em>list</em></dt>
	<dd>List of all Online Certificate Status Protocol (OCSP) URLs.</dd>

	<dt><strong>certificate</strong> <em>cert</em></dt>
	<dd>The PEM encoded certificate.</dd>

	<dt><strong>signatureAlgorithm</strong> <em>algorithm</em></dt>
	<dd>Cipher algorithm used for the certificate signature.</dd>
	<dt><strong>signatureValue</strong> <em>string</em></dt>
	<dd>Certificate signature as a hex string.</dd>
	<dt><strong>signatureDigest</strong> <em>version</em></dt>
	<dd>Certificate signing digest as a hex string.</dd>
	<dt><strong>publicKeyAlgorithm</strong> <em>algorithm</em></dt>
	<dd>Certificate signature public key algorithm.</dd>
	<dt><strong>publicKey</strong> <em>string</em></dt>
	<dd>Certificate signature public key as a hex string.</dd>
	<dt><strong>bits</strong> <em>n</em></dt>
	<dd>Number of bits used for certificate signature key.</dd>
	<dt><strong>self_signed</strong> <em>boolean</em></dt>
	<dd>Whether the certificate signature is self signed.</dd>

	<dt><strong>sha1_hash</strong> <em>hash</em></dt>
	<dd>The SHA1 hash of the certificate as a hex string.</dd>
	<dt><strong>sha256_hash</strong> <em>hash</em></dt>
	<dd>The SHA256 hash of the certificate as a hex string.</dd>
    </dl>
</blockquote>

    <dt><a name="tls::connection"><strong>tls::connection</strong>
    <em>channel</em></a></dt>
    <dd>Returns the current connection status of an SSL channel. The
	result is a list of key-value pairs describing the connection.</dd>
<blockquote>
	<b>SSL Status</b>
    <dl>
	<dt><strong>state</strong> <em>state</em></dt>
	<dd>State of the connection.</dd>
	<dt><strong>servername</strong> <em>name</em></dt>
	<dd>The name of the connected to server.</dd>
	<dt><strong>protocol</strong> <em>version</em></dt>
	<dd>The protocol version used for the connection:
	    SSL2, SSL3, TLS1, TLS1.1, TLS1.2, TLS1.3, or unknown.</dd>
	<dt><strong>renegotiation_allowed</strong> <em>boolean</em></dt>
	<dd>Whether protocol renegotiation is supported or not.</dd>
	<dt><strong>security_level</strong> <em>level</em></dt>
	<dd>The security level used for selection of ciphers, key size, etc.</dd>
	<dt><strong>session_reused</strong> <em>boolean</em></dt>
	<dd>Whether the session has been reused or not.</dd>
	<dt><strong>is_server</strong> <em>boolean</em></dt>
	<dd>Whether the connection is configured as a server (1) or client (0).</dd>
	<dt><strong>compression</strong> <em>mode</em></dt>
	<dd>Compression method.</dd>
	<dt><strong>expansion</strong> <em>mode</em></dt>
	<dd>Expansion method.</dd>
	<dt><strong>caList</strong> <em>list</em></dt>
	<dd>List of Certificate Authorities (CA) for X.509 certificate.</dd>
    </dl>
</blockquote>
<blockquote>
	<b>Cipher Info</b>
    <dl>
	<dt><strong>cipher</strong> <em>cipher</em></dt>
	<dd>The current cipher in use for the connection.</dd>
	<dt><strong>standard_name</strong> <em>name</em></dt>
	<dd>The standard RFC name of cipher.</dd>
	<dt><strong>algorithm_bits</strong> <em>n</em></dt>
	<dd>The number of processed bits used for cipher.</dd>
	<dt><strong>secret_bits</strong> <em>n</em></dt>
	<dd>The number of secret bits used for cipher.</dd>
	<dt><strong>min_version</strong> <em>version</em></dt>
	<dd>The minimum protocol version for cipher.</dd>
	<dt><strong>cipher_is_aead</strong> <em>boolean</em></dt>
	<dd>Whether the cipher is Authenticated Encryption with
	Associated Data (AEAD).</dd>
	<dt><strong>cipher_id</strong> <em>id</em></dt>
	<dd>The OpenSSL cipher id.</dd>
	<dt><strong>description</strong> <em>string</em></dt>
	<dd>A text description of the cipher.</dd>
	<dt><strong>handshake_digest</strong> <em>boolean</em></dt>
	<dd>Digest used during handshake.</dd>
    </dl>
</blockquote>
<blockquote>
	<b>Session Info</b>
    <dl>
	<dt><strong>alpn</strong> <em>protocol</em></dt>
	<dd>The protocol selected after Application-Layer Protocol
	    Negotiation (ALPN).</dd>
	<dt><strong>resumable</strong> <em>boolean</em></dt>
	<dd>Whether the session can be resumed or not.</dd>
	<dt><strong>start_time</strong> <em>seconds</em></dt>
	<dd>Time since session started in seconds since epoch.</dd>
	<dt><strong>timeout</strong> <em>seconds</em></dt>
	<dd>Max duration of session in seconds before time-out.</dd>
	<dt><strong>lifetime</strong> <em>seconds</em></dt>
	<dd>Session ticket lifetime hint in seconds.</dd>
	<dt><strong>session_id</strong> <em>binary_string</em></dt>
	<dd>Unique session id for use in resuming the session.</dd>
	<dt><strong>session_ticket</strong> <em>binary_string</em></dt>
	<dd>Unique session ticket for use in resuming the session.</dd>
	<dt><strong>ticket_app_data</strong> <em>binary_string</em></dt>
	<dd>Unique session ticket application data.</dd>
	<dt><strong>master_key</strong> <em>binary_string</em></dt>
	<dd>Unique session master key.</dd>
	<dt><strong>session_cache_mode</strong> <em>mode</em></dt>
	<dd>Server cache mode (client, server, or both).</dd>
    </dl>
</blockquote>

    <dt><a name="tls::protocols"><strong>tls::protocols</strong></a></dt>
    <dd>Returns a list of the supported protocols. Valid values are:
	<b>ssl2</b>, <b>ssl3</b>, <b>tls1</b>, <b>tls1.1</b>, <b>tls1.2</b>,
	and <b>tls1.3</b>. Exact list depends on OpenSSL version and
	compile time flags.</dd>

    <dt><a name="tls::version"><strong>tls::version</strong></a></dt>
    <dd>Returns the OpenSSL version string.</dd>
</dl>

<h3><a name="CALLBACK OPTIONS">CALLBACK OPTIONS</a></h3>

<p>
As indicated above, individual channels can be given their own callbacks
to handle intermediate processing by the OpenSSL library, using the
<strong>-command</strong>, <strong>-password</strong>, and
<strong>-validate_command</strong> options passed to either of
<strong>tls::socket</strong> or <strong>tls::import</strong>.
If the callback generates an error, the <b>bgerror</b> command will be
invoked with the error information.
</p>

<blockquote>
<dl>

    <dt><strong>-command</strong> <em>callback</em></dt>
    <dd>
	Invokes the specified <em>callback</em> script at several points
	during the OpenSSL handshake and use. See below for the possible
	arguments passed to the callback script. Values returned from the
	callback are ignored.

	<br>
	<br>

	<dl>

	<dt>
	  <strong>error</strong> <em>channelId message</em>
	</dt>
	<dd>
	  This form of callback is invoked whenever an error occurs during the
	  initial connection, handshake, or I/O operations. The <em>message</em>
	  argument can be from the Tcl_ErrnoMsg, OpenSSL function
	  <code>ERR_reason_error_string()</code>, or a custom message.
	</dd>

	<br>

	<dt>
	  <strong>info</strong> <em>channelId major minor message type</em>
	</dt>
	<dd>
	  This form of callback is invoked by the OpenSSL function
	  <code>SSL_set_info_callback()</code> during the initial connection
	  and handshake operations. The <em>type</em> argument is new for
	  TLS 1.8. The arguments are:
	  <br>
	  <ul>
	  <li>Possible values for <em>major</em> are:
	  <code>handshake, alert, connect, accept</code>.</li>
	  <li>Possible values for <em>minor</em> are:
	  <code>start, done, read, write, loop, exit</code>.</li>
	  <li>The <em>message</em> argument is a descriptive string which may
	  be generated either by <code>SSL_state_string_long()</code> or by
	  <code>SSL_alert_desc_string_long()</code>, depending on the context.</li>
	  <li>For alerts, the possible values for <em>type</em> are:
	  <code>warning, fatal, and unknown</code>. For others,
	  <code>info</code> is used.</li>
	  </ul>
	</dd>

	<dt>
	  <strong>message</strong> <em>channelId direction version content_type message</em>
	</dt>
	<dd>
	  This form of callback is invoked by the OpenSSL function
	  <code>SSL_set_msg_callback()</code> whenever a message is sent or
	  received during the initial connection, handshake, or I/O operations.
	  It is only available when OpenSSL is complied with the
	  <em>enable-ssl-trace</em> option. Arguments are: <em>direction</em>
	  is <b>Sent</b> or <b>Received</b>, <em>version</em> is the protocol
	  version, <em>content_type</em> is the message content type, and
	  <em>message</em> is more info from the <code>SSL_trace</code> API.
	  This callback is new for TLS 1.8.
	</dd>
	<br>

	<dt>
	  <strong>session</strong> <em>channelId session_id ticket lifetime</em>
	</dt>
	<dd>
	  This form of callback is invoked by the OpenSSL function
	  <code>SSL_CTX_sess_set_new_cb()</code> whenever a new session id is
	  sent by the server during the initial connection and handshake, but
	  can also be received later if the <b>-post_handshake</b> option is
	  used. Arguments are: <em>session_id</em> is the current
	  session identifier, <em>ticket</em> is the session ticket info, and
	  <em>lifetime</em> is the the ticket lifetime in seconds.
	  This callback is new for TLS 1.8.
	</dd>
	<br>
	</dl>
    </dd>

    <br>

    <dt><strong>-password</strong> <em>callback</em></dt>
    <dd>
	Invokes the specified <em>callback</em> script when OpenSSL needs to
	obtain a password. See below for the possible arguments passed to
	the callback script. See below for valid return values.

	<br>
	<br>

	<dl>

	<dt>
	  <strong>password</strong> <em>rwflag size</em>
	</dt>
	<dd>
	  Invoked when loading or storing a PEM certificate with encryption.
	  Where <em>rwflag</em> is 0 for reading/decryption or 1 for
	  writing/encryption (can prompt user to confirm) and
	  <em>size</em> is the max password length in bytes.
	  The callback should return the password as a string.
	  Both arguments are new for TLS 1.8.
	</dd>
    </dd>

    <br>


    <dt><strong>-validatecommand</strong> <em>callback</em></dt>
    <dd>
	Invokes the specified <em>callback</em> script during handshake in
	order to validate the provided value(s). See below for the possible
	arguments passed to the callback script. If not specified, OpenSSL
	will accept valid certificates and extensions.
	To reject the value and abort the connection, the callback should return 0.
	To accept the value and continue the connection, it should return 1.
	To reject the value, but continue the connection, it should return 2.

	<br>
	<br>

	<dl>

	<dt>
	  <strong>alpn</strong> <em>channelId protocol match</em>
	</dt>
	<dd>
	  For servers, this form of callback is invoked when the client ALPN
	  extension is received. If <em>match</em> is true, <em>protocol</em>
	  is the first <b>-alpn</b> option specified protocol common to both
	  the client and server. If not, the first client specified protocol is
	  used. It is called after the hello and ALPN callbacks.
	  This callback is new for TLS 1.8.
	</dd>

	<br>

	<dt>
	  <strong>hello</strong> <em>channelId servername</em>
	</dt>
	<dd>
	  For servers, this form of callback is invoked during client hello
	  message processing. The purpose is so the server can select the
	  appropriate certificate to present to the client, and to make other
	  configuration adjustments relevant to that server name and its
	  configuration. It is called before the SNI and ALPN callbacks.
	  This callback is new for TLS 1.8.
	</dd>

	<br>

	<dt>
	  <strong>sni</strong> <em>channelId servername</em>
	</dt>
	<dd>
	  For servers, this form of callback is invoked when the Server Name
	  Indication (SNI) extension is received. The <em>servername</em>
	  argument is the client provided server name in the <b>-servername</b>
	  option. The purpose is so when a server supports multiple names, the
	  right certificate can be used. It is called after the hello callback
	  but before the ALPN callback.
	  This callback is new for TLS 1.8.
	</dd>

	<br>

	<dt>
	  <strong>verify</strong> <em>channelId depth cert status error</em>
	</dt>
	<dd>
	  This form of callback is invoked by OpenSSL when a new certificate
	  is received from the peer. It allows the client to check the
	  certificate verification results and choose whether to continue
	  or not. It is called for each certificate in the certificate chain.
	  <ul>
	  <li>The <em>depth</em> argument is the integer depth of the
	  certificate in the certificate chain, where 0 is the peer certificate
	  and higher values going up to the Certificate Authority (CA).</li>
	  <li>The <em>cert</em> argument is a list of key-value pairs similar
	  to those returned by
	  <a href="#tls::status"><strong>tls::status</strong></a>.</li>
	  <li>The <em>status</em> argument is the boolean validity of the
	  current certificate where 0 is invalid and 1 is valid.</li>
	  <li>The <em>error</em> argument is the error message, if any, generated
	  by <code>X509_STORE_CTX_get_error()</code>.</li>
	  </ul>
	</dd>
	<br>
	</dl>
    </dd>
</dl>
</blockquote>

<p>
Reference implementations of these callbacks are provided in the
distribution as <strong>tls::callback</strong>, <strong>tls::password</strong>,
and <strong>tls::validate_command</strong> respectively.  Note that these are
<em>sample</em> implementations only.  In a more realistic deployment
you would specify your own callback scripts on each TLS channel using the
<strong>-command</strong>, <strong>-password</strong>, and <strong>-validate_command</strong> options.
</p>

<p>
The default behavior when the <strong>-command</strong> and <strong>-validate_command</strong>
options are not specified is for TLS to process the associated library callbacks
internally. The default behavior when the <strong>-password</strong> option is not
specified is for TLS to process the associated library callbacks by attempting
to call <strong>tls::password</strong>.
The difference between these two behaviors is a consequence of maintaining
compatibility with earlier implementations.
</p>

<p>
<em>
The use of the reference callbacks <strong>tls::callback</strong>,
<strong>tls::password</strong>, and <strong>tls::validate_command</strong>
is not recommended.  They may be removed from future releases.
</em>
</p>

<h3><a name="DEBUG">DEBUG</a></h3>

TLS key logging can be enabled by setting the environment variable
<b>SSLKEYLOGFILE</b> to the name of the file to log to. Then whenever TLS
key material is generated or received it will be logged to the file. This
is useful for logging key data for network logging tools to use to
decrypt the data.

<p>
The <strong>tls::debug</strong> variable provides some additional
control over these reference callbacks.  Its value is zero by default.
Higher values produce more diagnostic output, and will also force the
verify method in <strong>tls::callback</strong> to accept the
certificate, even when it is invalid if the <b>tls::validate_command</b>
callback is used for the <b>-validatecommand</b> option.
</p>

<p>
<em>
The use of the variable <strong>tls::debug</strong> is not recommended.
It may be removed from future releases.
</em>
</p>

<h4><a name="DEBUG_EXAMPLES">Debug Examples</a></h4>

<p>These examples use the default Unix platform SSL certificates. For standard
installations, -cadir and -cafile should not be needed. If your certificates
are in non-standard locations, update -cadir or use -cafile as needed.</p>
<br>
Example #1: Use HTTP package


<pre><code>
package require http
package require tls
set url "https://www.tcl.tk/"

http::register https 443 [list ::tls::socket -autoservername true -require true -cadir /etc/ssl/certs \
    -command ::tls::callback -password ::tls::password -validatecommand ::tls::validate_command]

# Check for error
set token [http::geturl $url]
if {[http::status $token] ne "ok"} {
    puts [format "Error %s" [http::status $token]]
}

# Get web page
set data [http::data $token]
puts [string length $data]

# Cleanup
::http::cleanup $token
</code></pre>

Example #2: Use raw socket
<pre><code>
package require tls

set url "www.tcl-lang.org"
set port 443

set ch [tls::socket -autoservername 1 -servername $url -request 1 -require 1 \
    -alpn {http/1.1} -cadir /etc/ssl/certs -command ::tls::callback \
    -password ::tls::password -validatecommand ::tls::validate_command $url $port]
chan configure $ch -buffersize 65536
tls::handshake $ch

puts $ch "GET / HTTP/1.1"
flush $ch
after 500
set data [read $ch]

array set status [tls::status $ch]
array set conn [tls::connection $ch]
array set chan [chan configure $ch]
close $ch
parray status
parray conn
parray chan
</code></pre>


<h3><a name="HTTPS EXAMPLE">HTTPS EXAMPLE</a></h3>

<p>These examples use the default Unix platform SSL certificates. For standard
installations, -cadir and -cafile should not be needed. If your certificates
are in non-standard locations, update -cadir or use -cafile as needed.</p>

Example #1: Get web page

<pre><code>
package require http
package require tls
set url "https://www.tcl.tk/"

http::register https 443 [list ::tls::socket -autoservername true -require true -cadir /etc/ssl/certs]

# Check for error
set token [http::geturl $url]
if {[http::status $token] ne "ok"} {
    puts [format "Error %s" [http::status $token]]
}

# Get web page
set data [http::data $token]
puts $data

# Cleanup
::http::cleanup $token
</code></pre>

Example #2: Download file

<pre><code>
package require http
package require tls

set url "https://wiki.tcl-lang.org/sitemap.xml"
set filename [file tail $url]

http::register https 443 [list ::tls::socket -autoservername true -require true -cadir /etc/ssl/certs]

# Get file
set ch [open $filename wb]
set token [::http::geturl $url -blocksize 65536 -channel $ch]

# Cleanup
close $ch
::http::cleanup $token
</code></pre>

<h3><a name="SPECIAL CONSIDERATIONS">SPECIAL CONSIDERATIONS</a></h3>

<p>The capabilities of this package can vary enormously based upon how the
linked to OpenSSL library was configured and built. New versions may obsolete
older protocol versions, add or remove ciphers, change default values, etc.
Use the <strong>tls::protocols</strong> commands to obtain the supported
protocol versions.</p>

<h3><a name="SEE ALSO">SEE ALSO</a></h3>

<p><strong>socket</strong>, <strong>fileevent</strong>, <strong>http</strong>,
<a href="http://www.openssl.org/"><strong>OpenSSL</strong></a></p>

<hr>

<pre>
Copyright &copy; 1999 Matt Newman.
Copyright &copy; 2004 Starfish Systems.
Copyright &copy; 2023 Brian O'Hagan.
</pre>
</body>
</html>

/*
 * Copyright (C) 1997-1999 Matt Newman <[email protected]>
 * some modifications:
 *	Copyright (C) 2000 Ajuba Solutions
 *	Copyright (C) 2002 ActiveState Corporation
 *	Copyright (C) 2004 Starfish Systems
 *	Copyright (C) 2023 Brian O'Hagan
 *
 * TLS (aka SSL) Channel - can be layered on any bi-directional
 * Tcl_Channel (Note: Requires Trf Core Patch)
 *
 * This was built (almost) from scratch based upon observation of
 * OpenSSL 0.9.2B
 *
 * Addition credit is due for Andreas Kupries ([email protected]), for
 * providing the Tcl_ReplaceChannel mechanism and working closely with me
 * to enhance it to support full fileevent semantics.
 *
 * Also work done by the follow people provided the impetus to do this "right":
 *	tclSSL (Colin McCormack, Shared Technology)
 *	SSLtcl (Peter Antman)
 *
 */

#include "tlsInt.h"
#include "tclOpts.h"
#include <stdio.h>
#include <stdlib.h>
#include <openssl/rsa.h>
#include <openssl/safestack.h>

/* Min OpenSSL version */
#if OPENSSL_VERSION_NUMBER < 0x10101000L
#error "Only OpenSSL v1.1.1 or later is supported"
#endif

/*
 * External functions
 */

/*
 * Forward declarations
 */

#define F2N(key, dsp) \
	(((key) == NULL) ? (char *) NULL : \
		Tcl_TranslateFileName(interp, (key), (dsp)))












static SSL_CTX *CTX_Init(State *statePtr, int isServer, int proto, char *key,
		char *certfile, unsigned char *key_asn1, unsigned char *cert_asn1,
		int key_asn1_len, int cert_asn1_len, char *CApath, char *CAfile,
		char *ciphers, char *ciphersuites, int level, char *DHparams);

static int	TlsLibInit(int uninitialize);

#define TLS_PROTO_SSL2		0x01
#define TLS_PROTO_SSL3		0x02
#define TLS_PROTO_TLS1		0x04
#define TLS_PROTO_TLS1_1	0x08
#define TLS_PROTO_TLS1_2	0x10
#define TLS_PROTO_TLS1_3	0x20
#define ENABLED(flag, mask)	(((flag) & (mask)) == (mask))




#define SSLKEYLOGFILE		"SSLKEYLOGFILE"























/*
 * Thread-Safe TLS Code
 */

#ifdef TCL_THREADS
#define OPENSSL_THREAD_DEFINES
#include <openssl/opensslconf.h>

#ifdef OPENSSL_THREADS
#include <openssl/crypto.h>
#include <openssl/ssl.h>

/*
 * Threaded operation requires locking callbacks
 * Based from /crypto/cryptlib.c of OpenSSL and NSOpenSSL.
 */

static Tcl_Mutex *locks = NULL;
static int locksCount = 0;
static Tcl_Mutex init_mx;






























#endif /* OPENSSL_THREADS */
#endif /* TCL_THREADS */


/********************/
/* Callbacks        */
/********************/

/*
 *-------------------------------------------------------------------
 *
 * Eval Callback Command --
 *
 *	Eval callback command and catch any errors
 *
 * Results:
 *	0 = Command returned fail or eval returned TCL_ERROR
 *	1 = Command returned success or eval returned TCL_OK
 *
 * Side effects:
 *	Evaluates callback command
 *
 *-------------------------------------------------------------------
 */
static int
EvalCallback(Tcl_Interp *interp, State *statePtr, Tcl_Obj *cmdPtr) {
    int code, ok = 0;

    dprintf("Called");

    Tcl_Preserve((ClientData) interp);
    Tcl_Preserve((ClientData) statePtr);

    /* Eval callback with success for ok or return value 1, fail for error or return value 0 */
    Tcl_ResetResult(interp);
    code = Tcl_EvalObjEx(interp, cmdPtr, TCL_EVAL_GLOBAL);
    dprintf("EvalCallback: %d", code);
    if (code == TCL_OK) {
	/* Check result for return value */
	Tcl_Obj *result = Tcl_GetObjResult(interp);
	if (result == NULL || Tcl_GetIntFromObj(interp, result, &ok) != TCL_OK) {
	    ok = 1;
	}
	dprintf("Result: %d", ok);
    } else {
	/* Error - reject the certificate */
	dprintf("Tcl_BackgroundError");
#if (TCL_MAJOR_VERSION == 8) && (TCL_MINOR_VERSION < 6)
	Tcl_BackgroundError(interp);
#else
	Tcl_BackgroundException(interp, code);
#endif
    }

    Tcl_Release((ClientData) statePtr);
    Tcl_Release((ClientData) interp);
    return ok;
}

/*
 *-------------------------------------------------------------------
 *
 * InfoCallback --
 *
 *	Monitors SSL connection process
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 *-------------------------------------------------------------------
 */
static void
InfoCallback(const SSL *ssl, int where, int ret) {

    State *statePtr = (State*)SSL_get_app_data((SSL *)ssl);
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    char *major; char *minor;

    dprintf("Called");

    if (statePtr->callback == (Tcl_Obj*)NULL)
	return;












    if (where & SSL_CB_HANDSHAKE_START) {
	major = "handshake";
	minor = "start";
    } else if (where & SSL_CB_HANDSHAKE_DONE) {
	major = "handshake";
	minor = "done";
    } else {
	if (where & SSL_CB_ALERT)		major = "alert";
	else if (where & SSL_ST_CONNECT)	major = "connect";
	else if (where & SSL_ST_ACCEPT)		major = "accept";
	else					major = "unknown";

	if (where & SSL_CB_READ)		minor = "read";
	else if (where & SSL_CB_WRITE)		minor = "write";
	else if (where & SSL_CB_LOOP)		minor = "loop";
	else if (where & SSL_CB_EXIT)		minor = "exit";
	else					minor = "unknown";
    }



    /* Create command to eval with fn, chan, major, minor, message, and type args */
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);

    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("info", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));

    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(major, -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(minor, -1));

    if (where & SSL_CB_ALERT) {
	Tcl_ListObjAppendElement(interp, cmdPtr,


	    Tcl_NewStringObj(SSL_alert_desc_string_long(ret), -1));

	Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(SSL_alert_type_string_long(ret), -1));
    } else {
	Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(SSL_state_string_long(ssl), -1));
	Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("info", -1));
    }

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    EvalCallback(interp, statePtr, cmdPtr);
    Tcl_DecrRefCount(cmdPtr);
}

/*
 *-------------------------------------------------------------------
 *
 * MessageCallback --
 *
 *	Monitors SSL protocol messages
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 *-------------------------------------------------------------------
 */
#ifndef OPENSSL_NO_SSL_TRACE
static void
MessageCallback(int write_p, int version, int content_type, const void *buf, size_t len, SSL *ssl, void *arg) {
    State *statePtr = (State*)arg;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    char *ver, *type;
    BIO *bio;
    char buffer[15000];
    buffer[0] = 0;

    dprintf("Called");

    if (statePtr->callback == (Tcl_Obj*)NULL)
	return;

    switch(version) {
#if OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(NO_SSL2) && !defined(OPENSSL_NO_SSL2)
    case SSL2_VERSION:
	ver = "SSLv2";
	break;
#endif
#if !defined(NO_SSL3) && !defined(OPENSSL_NO_SSL3)
    case SSL3_VERSION:
	ver = "SSLv3";
	break;
#endif
    case TLS1_VERSION:
	ver = "TLSv1";
	break;
    case TLS1_1_VERSION:
	ver = "TLSv1.1";
	break;
    case TLS1_2_VERSION:
	ver = "TLSv1.2";
	break;
    case TLS1_3_VERSION:
	ver = "TLSv1.3";
	break;
    case 0:
	ver = "none";
	break;
    default:
	ver = "unknown";
	break;
    }

    switch (content_type) {
    case SSL3_RT_HEADER:
	type = "Header";
	break;
    case SSL3_RT_INNER_CONTENT_TYPE:
	type = "Inner Content Type";
	break;
    case SSL3_RT_CHANGE_CIPHER_SPEC:
	type = "Change Cipher";
	break;
    case SSL3_RT_ALERT:
	type = "Alert";
	break;
    case SSL3_RT_HANDSHAKE:
	type = "Handshake";
	break;
    case SSL3_RT_APPLICATION_DATA:
	type = "App Data";
	break;
#if OPENSSL_VERSION_NUMBER < 0x30000000L
    case DTLS1_RT_HEARTBEAT:
	type = "Heartbeat";
	break;
#endif
    default:
	type = "unknown";
    }

    /* Needs compile time option "enable-ssl-trace". */
    if ((bio = BIO_new(BIO_s_mem())) != NULL) {
	int n;
	SSL_trace(write_p, version, content_type, buf, len, ssl, (void *)bio);
	n = BIO_read(bio, buffer, BIO_pending(bio) < 15000 ? BIO_pending(bio) : 14999);
	n = (n<0) ? 0 : n;
	buffer[n] = 0;
	(void)BIO_flush(bio);
	BIO_free(bio);
   }

    /* Create command to eval with fn, chan, direction, version, type, and message args */
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("message", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(write_p ? "Sent" : "Received", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(ver, -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(type, -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(buffer, -1));

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    EvalCallback(interp, statePtr, cmdPtr);
    Tcl_DecrRefCount(cmdPtr);
}
#endif

/*
 *-------------------------------------------------------------------
 *
 * VerifyCallback --
 *
 *	Monitors SSL certificate validation process. Used to control the
 *	behavior when the SSL_VERIFY_PEER flag is set. This is called
 *	whenever a certificate is inspected or decided invalid. Called for
 *	each certificate in the cert chain.
 *
 * Checks:
 *	certificate chain is checked starting with the deepest nesting level
 *	  (the root CA certificate) and worked upward to the peer's certificate.
 *	All signatures are valid, current time is within first and last validity time.
 *	Check that the certificate is issued by the issuer certificate issuer.
 *	Check the revocation status for each certificate.
 *	Check the validity of the given CRL and the cert revocation status.
 *	Check the policies of all the certificates
 *
 * Args
 *	preverify_ok indicates whether the certificate verification passed (1) or not (0)
 *
 * Results:
 *	A callback bound to the socket may return one of:
 *	    0			- the certificate is deemed invalid, send verification
 *				  failure alert to peer, and terminate handshake.
 *	    1			- the certificate is deemed valid, continue with handshake.
 *	    empty string	- no change to certificate validation
 *
 * Side effects:
 *	The err field of the currently operative State is set
 *	  to a string describing the SSL negotiation failure reason
 *
 *-------------------------------------------------------------------
 */
static int
VerifyCallback(int ok, X509_STORE_CTX *ctx) {

    Tcl_Obj *cmdPtr;


    SSL   *ssl		= (SSL*)X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
    X509  *cert		= X509_STORE_CTX_get_current_cert(ctx);
    State *statePtr	= (State*)SSL_get_app_data(ssl);
    Tcl_Interp *interp	= statePtr->interp;
    int depth		= X509_STORE_CTX_get_error_depth(ctx);
    int err		= X509_STORE_CTX_get_error(ctx);

    dprintf("Called");
    dprintf("VerifyCallback: %d", ok);






    if (statePtr->vcmd == (Tcl_Obj*)NULL) {
	/* Use ok value if verification is required */
	if (statePtr->vflags & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
	    return ok;
	} else {
	    return 1;
	}
    } else if (cert == NULL || ssl == NULL) {
	return 0;
    }



    dprintf("VerifyCallback: eval callback");



    /* Create command to eval with fn, chan, depth, cert info list, status, and error args */
    cmdPtr = Tcl_DuplicateObj(statePtr->vcmd);

    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("verify", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewIntObj(depth));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tls_NewX509Obj(interp, cert));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewIntObj(ok));

    Tcl_ListObjAppendElement(interp, cmdPtr,

	Tcl_NewStringObj((char*)X509_verify_cert_error_string(err), -1));





    /* Prevent I/O while callback is in progress */


    /* statePtr->flags |= TLS_TCL_CALLBACK; */












    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    ok = EvalCallback(interp, statePtr, cmdPtr);
    Tcl_DecrRefCount(cmdPtr);


    dprintf("VerifyCallback: command result = %d", ok);



    /* statePtr->flags &= ~(TLS_TCL_CALLBACK); */
    return(ok);	/* By default, leave verification unchanged. */
}

/*
 *-------------------------------------------------------------------
 *
 * Tls_Error --
 *
 *	Calls callback with list of errors.

 *
 * Side effects:
 *	The err field of the currently operative State is set
 *	  to a string describing the SSL negotiation failure reason
 *
 *-------------------------------------------------------------------
 */
void
Tls_Error(State *statePtr, char *msg) {

    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr, *listPtr;
    unsigned long err;
    statePtr->err = msg;

    dprintf("Called");








    if (statePtr->callback == (Tcl_Obj*)NULL)





	return;

    /* Create command to eval with fn, chan, and message args */
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("error", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));
    if (msg != NULL) {
	Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(msg, -1));

    } else if ((msg = Tcl_GetStringFromObj(Tcl_GetObjResult(interp), (Tcl_Size *) NULL)) != NULL) {
	Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(msg, -1));

    } else {
	listPtr = Tcl_NewListObj(0, NULL);
	while ((err = ERR_get_error()) != 0) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj(ERR_reason_error_string(err), -1));
	}
	Tcl_ListObjAppendElement(interp, cmdPtr, listPtr);

    }



    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    EvalCallback(interp, statePtr, cmdPtr);
    Tcl_DecrRefCount(cmdPtr);
}

/*
 *-------------------------------------------------------------------
 *
 * KeyLogCallback --
 *
 *	Write received key data to log file.
 *
 * Side effects:
 *	none
 *
 *-------------------------------------------------------------------
 */
void KeyLogCallback(const SSL *ssl, const char *line) {
    char *str = getenv(SSLKEYLOGFILE);
    FILE *fd;

    dprintf("Called");

    if (str) {
	fd = fopen(str, "a");
	fprintf(fd, "%s\n",line);
	fclose(fd);
    }
}

/*
 *-------------------------------------------------------------------
 *
 * Password Callback --
 *
 *	Called when a password for a private key loading/storing a PEM
 *	certificate with encryption. Evals callback script and returns
 *	the result as the password string in buf.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 * Returns:
 *	Password size in bytes or -1 for an error.
 *
 *-------------------------------------------------------------------
 */





static int
PasswordCallback(char *buf, int size, int rwflag, void *udata) {










    State *statePtr	= (State *) udata;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    int code;

    dprintf("Called");

    /* If no callback, use default callback */
    if (statePtr->password == NULL) {
	if (Tcl_EvalEx(interp, "tls::password", -1, TCL_EVAL_GLOBAL) == TCL_OK) {

	    char *ret = (char *) Tcl_GetStringResult(interp);
	    strncpy(buf, ret, (size_t) size);
	    return (int)strlen(ret);
	} else {
	    return -1;
	}
    }

    /* Create command to eval with fn, rwflag, and size args */
    cmdPtr = Tcl_DuplicateObj(statePtr->password);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("password", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewIntObj(rwflag));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewIntObj(size));

    Tcl_Preserve((ClientData) interp);
    Tcl_Preserve((ClientData) statePtr);

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    code = Tcl_EvalObjEx(interp, cmdPtr, TCL_EVAL_GLOBAL);
    if (code != TCL_OK) {
#if (TCL_MAJOR_VERSION == 8) && (TCL_MINOR_VERSION < 6)
	Tcl_BackgroundError(interp);
#else
	Tcl_BackgroundException(interp, code);
#endif
    }
    Tcl_DecrRefCount(cmdPtr);

    Tcl_Release((ClientData) statePtr);


    /* If successful, pass back password string and truncate if too long */
    if (code == TCL_OK) {
	Tcl_Size len;
	char *ret = (char *) Tcl_GetStringFromObj(Tcl_GetObjResult(interp), &len);
	if (len > (Tcl_Size) size-1) {
	    len = (Tcl_Size) size-1;
	}
	strncpy(buf, ret, (size_t) len);
	buf[len] = '\0';
	Tcl_Release((ClientData) interp);
	return((int) len);
    }
    Tcl_Release((ClientData) interp);
    return -1;
}

/*
 *-------------------------------------------------------------------
 *
 * Session Callback for Clients --
 *
 *	Called when a new session is added to the cache. In TLS 1.3
 *	this may be received multiple times after the handshake. For
 *	earlier versions, this will be received during the handshake.
 *	This is the preferred way to obtain a resumable session.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 * Return codes:
 *	0 = error where session will be immediately removed from the internal cache.
 *	1 = success where app retains session in session cache, and must call SSL_SESSION_free() when done.
 *
 *-------------------------------------------------------------------
 */
static int
SessionCallback(SSL *ssl, SSL_SESSION *session) {
    State *statePtr = (State*)SSL_get_app_data((SSL *)ssl);
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    const unsigned char *ticket;
    const unsigned char *session_id;
    size_t len2;
    unsigned int ulen;

    dprintf("Called");

    if (statePtr->callback == (Tcl_Obj*)NULL) {
	return SSL_TLSEXT_ERR_OK;
    } else if (ssl == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    /* Create command to eval with fn, chan, session id, session ticket, and lifetime args */
    cmdPtr = Tcl_DuplicateObj(statePtr->callback);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("session", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));

    /* Session id */
    session_id = SSL_SESSION_get_id(session, &ulen);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewByteArrayObj(session_id, (Tcl_Size) ulen));

    /* Session ticket */
    SSL_SESSION_get0_ticket(session, &ticket, &len2);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewByteArrayObj(ticket, (Tcl_Size) len2));

    /* Lifetime - number of seconds */
    Tcl_ListObjAppendElement(interp, cmdPtr,
	Tcl_NewLongObj((long) SSL_SESSION_get_ticket_lifetime_hint(session)));

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    EvalCallback(interp, statePtr, cmdPtr);
    Tcl_DecrRefCount(cmdPtr);
    return 0;
}

/*
 *-------------------------------------------------------------------
 *
 * ALPN Callback for Servers and NPN Callback for Clients --
 *
 *	Perform protocol (http/1.1, h2, h3, etc.) selection for the
 *	incoming connection. Called after Hello and server callbacks.
 *	Where 'out' is selected protocol and 'in' is the peer advertised list.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 * Return codes:
 *	SSL_TLSEXT_ERR_OK: ALPN protocol selected. The connection continues.
 *	SSL_TLSEXT_ERR_ALERT_FATAL: There was no overlap between the client's
 *	    supplied list and the server configuration. The connection will be aborted.
 *	SSL_TLSEXT_ERR_NOACK: ALPN protocol not selected, e.g., because no ALPN
 *	    protocols are configured for this connection. The connection continues.
 *
 *-------------------------------------------------------------------
 */
static int
ALPNCallback(SSL *ssl, const unsigned char **out, unsigned char *outlen,
	const unsigned char *in, unsigned int inlen, void *arg) {
    State *statePtr = (State*)arg;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    int code, res;

    dprintf("Called");

    if (ssl == NULL || arg == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    /* Select protocol */
    if (SSL_select_next_proto((unsigned char **) out, outlen, statePtr->protos, statePtr->protos_len,
	in, inlen) == OPENSSL_NPN_NEGOTIATED) {
	/* Match found */
	res = SSL_TLSEXT_ERR_OK;
    } else {
	/* OPENSSL_NPN_NO_OVERLAP = No overlap, so use first item from client protocol list */
	res = SSL_TLSEXT_ERR_NOACK;
    }

    if (statePtr->vcmd == (Tcl_Obj*)NULL) {
	return res;
    }

    /* Create command to eval with fn, chan, depth, cert info list, status, and error args */
    cmdPtr = Tcl_DuplicateObj(statePtr->vcmd);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("alpn", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj((const char *) *out, -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewBooleanObj(res == SSL_TLSEXT_ERR_OK));

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    if ((code = EvalCallback(interp, statePtr, cmdPtr)) > 1) {
	res = SSL_TLSEXT_ERR_NOACK;
    } else if (code == 1) {
	res = SSL_TLSEXT_ERR_OK;
    } else {
	res = SSL_TLSEXT_ERR_ALERT_FATAL;
    }
    Tcl_DecrRefCount(cmdPtr);
    return res;
}

/*
 *-------------------------------------------------------------------
 *
 * Advertise Protocols Callback for Next Protocol Negotiation (NPN) in ServerHello --
 *
 *	called when a TLS server needs a list of supported protocols for Next
 *	Protocol Negotiation.
 *
 * Results:
 *	None
 *
 * Side effects:
 *
 * Return codes:
 *	SSL_TLSEXT_ERR_OK: NPN protocol selected. The connection continues.
 *	SSL_TLSEXT_ERR_NOACK: NPN protocol not selected. The connection continues.
 *
 *-------------------------------------------------------------------
 */
#ifdef USE_NPN
static int
NPNCallback(const SSL *ssl, const unsigned char **out, unsigned int *outlen, void *arg) {
    State *statePtr = (State*)arg;

    dprintf("Called");

    if (ssl == NULL || arg == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    /* Set protocols list */
    if (statePtr->protos != NULL) {
	*out = statePtr->protos;
	*outlen = statePtr->protos_len;
    } else {
	*out = NULL;
	*outlen = 0;
	return SSL_TLSEXT_ERR_NOACK;
    }
    return SSL_TLSEXT_ERR_OK;
}
#endif

/*
 *-------------------------------------------------------------------
 *
 * SNI Callback for Servers --
 *
 *	Perform server-side SNI hostname selection after receiving SNI extension
 *	in Client Hello. Called after hello callback but before ALPN callback.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 * Return codes:
 *	SSL_TLSEXT_ERR_OK: SNI hostname is accepted. The connection continues.
 *	SSL_TLSEXT_ERR_ALERT_FATAL: SNI hostname is not accepted. The connection
 *	    is aborted. Default for alert is SSL_AD_UNRECOGNIZED_NAME.
 *	SSL_TLSEXT_ERR_ALERT_WARNING: SNI hostname is not accepted, warning alert
 *	    sent (not supported in TLSv1.3). The connection continues.
 *	SSL_TLSEXT_ERR_NOACK: SNI hostname is not accepted and not acknowledged,
 *	    e.g. if SNI has not been configured. The connection continues.
 *
 *-------------------------------------------------------------------
 */
static int
SNICallback(const SSL *ssl, int *alert, void *arg) {
    State *statePtr = (State*)arg;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    int code, res;
    const char *servername = NULL;

    dprintf("Called");

    if (ssl == NULL || arg == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    /* Only works for TLS 1.2 and earlier */
    servername = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
    if (!servername || servername[0] == '\0') {
	return SSL_TLSEXT_ERR_NOACK;
    }

    if (statePtr->vcmd == (Tcl_Obj*)NULL) {
	return SSL_TLSEXT_ERR_OK;
    }

    /* Create command to eval with fn, chan, and server name args */
    cmdPtr = Tcl_DuplicateObj(statePtr->vcmd);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("sni", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(servername , -1));

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    if ((code = EvalCallback(interp, statePtr, cmdPtr)) > 1) {
	res = SSL_TLSEXT_ERR_ALERT_WARNING;
	*alert = SSL_AD_UNRECOGNIZED_NAME; /* Not supported by TLS 1.3 */
    } else if (code == 1) {
	res = SSL_TLSEXT_ERR_OK;
    } else {
	res = SSL_TLSEXT_ERR_ALERT_FATAL;
	*alert = SSL_AD_UNRECOGNIZED_NAME; /* Not supported by TLS 1.3 */
    }
    Tcl_DecrRefCount(cmdPtr);
    return res;
}

/*
 *-------------------------------------------------------------------
 *
 * ClientHello Handshake Callback for Servers --
 *
 *	Used by server to examine the server name indication (SNI) extension
 *	provided by the client in order to select an appropriate certificate to
 *	present, and make other configuration adjustments relevant to that server
 *	name and its configuration. This includes swapping out the associated
 *	SSL_CTX pointer, modifying the server's list of permitted TLS versions,
 *	changing the server's cipher list in response to the client's cipher list, etc.
 *	Called before SNI and ALPN callbacks.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 * Return codes:
 *	SSL_CLIENT_HELLO_RETRY: suspend the handshake, and the handshake function will return immediately
 *	SSL_CLIENT_HELLO_ERROR: failure, terminate connection. Set alert to error code.
 *	SSL_CLIENT_HELLO_SUCCESS: success
 *
 *-------------------------------------------------------------------
 */
static int
HelloCallback(SSL *ssl, int *alert, void *arg) {
    State *statePtr = (State*)arg;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    int code, res;
    const char *servername;
    const unsigned char *p;
    size_t len, remaining;

    dprintf("Called");

    if (statePtr->vcmd == (Tcl_Obj*)NULL) {
	return SSL_CLIENT_HELLO_SUCCESS;
    } else if (ssl == (const SSL *)NULL || arg == (void *)NULL) {
	return SSL_CLIENT_HELLO_ERROR;
    }

    /* Get names */
    if (!SSL_client_hello_get0_ext(ssl, TLSEXT_TYPE_server_name, &p, &remaining) || remaining <= 2) {
	*alert = SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER;
	return SSL_CLIENT_HELLO_ERROR;
    }

    /* Extract the length of the supplied list of names. */
    len = (*(p++) << 8);
    len += *(p++);
    if (len + 2 != remaining) {
	*alert = SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER;
	return SSL_CLIENT_HELLO_ERROR;
    }
    remaining = len;

    /* The list in practice only has a single element, so we only consider the first one. */
    if (remaining == 0 || *p++ != TLSEXT_NAMETYPE_host_name) {
	*alert = SSL_R_TLSV1_ALERT_INTERNAL_ERROR;
	return SSL_CLIENT_HELLO_ERROR;
    }
    remaining--;

    /* Now we can finally pull out the byte array with the actual hostname. */
    if (remaining <= 2) {
	*alert = SSL_R_TLSV1_ALERT_INTERNAL_ERROR;
	return SSL_CLIENT_HELLO_ERROR;
    }
    len = (*(p++) << 8);
    len += *(p++);
    if (len + 2 > remaining) {
	*alert = SSL_R_TLSV1_ALERT_INTERNAL_ERROR;
	return SSL_CLIENT_HELLO_ERROR;
    }
    remaining = len;
    servername = (const char *)p;

    /* Create command to eval with fn, chan, and server name args */
    cmdPtr = Tcl_DuplicateObj(statePtr->vcmd);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("hello", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	    Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(servername, (Tcl_Size) len));

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    if ((code = EvalCallback(interp, statePtr, cmdPtr)) > 1) {
	res = SSL_CLIENT_HELLO_RETRY;
	*alert = SSL_R_TLSV1_ALERT_USER_CANCELLED;
    } else if (code == 1) {
	res = SSL_CLIENT_HELLO_SUCCESS;
    } else {
	res = SSL_CLIENT_HELLO_ERROR;
	*alert = SSL_R_TLSV1_ALERT_INTERNAL_ERROR;
    }
    Tcl_DecrRefCount(cmdPtr);
    return res;
}


/********************/
/* Commands         */
/********************/

/*
 *-------------------------------------------------------------------
 *
 * CiphersObjCmd -- list available ciphers
 *
 *	This procedure is invoked to process the "tls::ciphers" command
 *	to list available ciphers, based upon protocol selected.
 *
 * Results:
 *	A standard Tcl result list.
 *
 * Side effects:
 *	constructs and destroys SSL context (CTX)
 *
 *-------------------------------------------------------------------
 */







static const char *protocols[] = {
	"ssl2", "ssl3", "tls1", "tls1.1", "tls1.2", "tls1.3", NULL
};
enum protocol {
    TLS_SSL2, TLS_SSL3, TLS_TLS1, TLS_TLS1_1, TLS_TLS1_2, TLS_TLS1_3, TLS_NONE
};

static int
CiphersObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    Tcl_Obj *objPtr = NULL;
    SSL_CTX *ctx = NULL;
    SSL *ssl = NULL;
    STACK_OF(SSL_CIPHER) *sk;
    char *cp, buf[BUFSIZ];
    int index, verbose = 0, use_supported = 0;
    const SSL_METHOD *method;
    (void) clientData;

    dprintf("Called");

    if ((objc < 2) || (objc > 4)) {
	Tcl_WrongNumArgs(interp, 1, objv, "protocol ?verbose? ?supported?");
	return TCL_ERROR;
    }
    if (Tcl_GetIndexFromObj(interp, objv[1], protocols, "protocol", 0, &index) != TCL_OK) {
	return TCL_ERROR;
    }
    if ((objc > 2) && Tcl_GetBooleanFromObj(interp, objv[2], &verbose) != TCL_OK) {
	return TCL_ERROR;
    }
    if ((objc > 3) && Tcl_GetBooleanFromObj(interp, objv[3], &use_supported) != TCL_OK) {

	return TCL_ERROR;
    }

    ERR_clear_error();

    switch ((enum protocol)index) {
	case TLS_SSL2:
#if OPENSSL_VERSION_NUMBER >= 0x10100000L || defined(NO_SSL2) || defined(OPENSSL_NO_SSL2)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = SSLv2_method(); break;
#endif
	case TLS_SSL3:
#if defined(NO_SSL3) || defined(OPENSSL_NO_SSL3) || defined(OPENSSL_NO_SSL3_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = SSLv3_method(); break;
#endif
	case TLS_TLS1:
#if defined(NO_TLS1) || defined(OPENSSL_NO_TLS1) || defined(OPENSSL_NO_TLS1_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLSv1_method(); break;
#endif
	case TLS_TLS1_1:
#if defined(NO_TLS1_1) || defined(OPENSSL_NO_TLS1_1) || defined(OPENSSL_NO_TLS1_1_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLSv1_1_method(); break;
#endif
	case TLS_TLS1_2:
#if defined(NO_TLS1_2) || defined(OPENSSL_NO_TLS1_2) || defined(OPENSSL_NO_TLS1_2_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLSv1_2_method(); break;
#endif
	case TLS_TLS1_3:
#if defined(NO_TLS1_3) || defined(OPENSSL_NO_TLS1_3)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLS_method();
	    SSL_CTX_set_min_proto_version(ctx, TLS1_3_VERSION);
	    SSL_CTX_set_max_proto_version(ctx, TLS1_3_VERSION);
	    break;
#endif
	default:
	    method = TLS_method();
	    break;
    }

    ctx = SSL_CTX_new(method);
    if (ctx == NULL) {
	Tcl_AppendResult(interp, GET_ERR_REASON(), NULL);
	return TCL_ERROR;
    }

    ssl = SSL_new(ctx);
    if (ssl == NULL) {
	Tcl_AppendResult(interp, GET_ERR_REASON(), NULL);
	SSL_CTX_free(ctx);
	return TCL_ERROR;
    }

    /* Use list and order as would be sent in a ClientHello or all available ciphers */
    if (use_supported) {
	sk = SSL_get1_supported_ciphers(ssl);
    } else {
	sk = SSL_get_ciphers(ssl);
    }

    if (sk != NULL) {
	if (!verbose) {
	    objPtr = Tcl_NewListObj(0, NULL);
	    for (int i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
		const SSL_CIPHER *c = sk_SSL_CIPHER_value(sk, i);
		if (c == NULL) continue;

		/* cipher name or (NONE) */
		cp = SSL_CIPHER_get_name(c);
		if (cp == NULL) break;
		Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(cp, -1));

	    }

	} else {
	    objPtr = Tcl_NewStringObj("",0);
	    for (int i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
		const SSL_CIPHER *c = sk_SSL_CIPHER_value(sk, i);
		if (c == NULL) continue;



		/* textual description of the cipher */
		if (SSL_CIPHER_description(c, buf, sizeof(buf)) != NULL) {
		    Tcl_AppendToObj(objPtr, buf, (Tcl_Size) strlen(buf));



		} else {

		    Tcl_AppendToObj(objPtr, "UNKNOWN\n", 8);
		}
	    }


	}
	if (use_supported) {
	    sk_SSL_CIPHER_free(sk);
	}
    }
    SSL_free(ssl);
    SSL_CTX_free(ctx);

    Tcl_SetObjResult(interp, objPtr);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *
 * ProtocolsObjCmd -- list available protocols
 *
 *	This procedure is invoked to process the "tls::protocols" command
 *	to list available protocols.
 *
 * Results:
 *	A standard Tcl result list.
 *
 * Side effects:
 *	none
 *
 *-------------------------------------------------------------------
 */
static int
ProtocolsObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    Tcl_Obj *objPtr;
    (void) clientData;

    dprintf("Called");

    if (objc != 1) {
	Tcl_WrongNumArgs(interp, 1, objv, "");
	return TCL_ERROR;
    }

    ERR_clear_error();

    objPtr = Tcl_NewListObj(0, NULL);

#if OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(NO_SSL2) && !defined(OPENSSL_NO_SSL2)
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(protocols[TLS_SSL2], -1));
#endif
#if !defined(NO_SSL3) && !defined(OPENSSL_NO_SSL3) && !defined(OPENSSL_NO_SSL3_METHOD)
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(protocols[TLS_SSL3], -1));
#endif
#if !defined(NO_TLS1) && !defined(OPENSSL_NO_TLS1) && !defined(OPENSSL_NO_TLS1_METHOD)
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(protocols[TLS_TLS1], -1));
#endif
#if !defined(NO_TLS1_1) && !defined(OPENSSL_NO_TLS1_1) && !defined(OPENSSL_NO_TLS1_1_METHOD)
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(protocols[TLS_TLS1_1], -1));
#endif
#if !defined(NO_TLS1_2) && !defined(OPENSSL_NO_TLS1_2) && !defined(OPENSSL_NO_TLS1_2_METHOD)
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(protocols[TLS_TLS1_2], -1));
#endif
#if !defined(NO_TLS1_3) && !defined(OPENSSL_NO_TLS1_3)
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(protocols[TLS_TLS1_3], -1));
#endif

    Tcl_SetObjResult(interp, objPtr);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *
 * HandshakeObjCmd --
 *
 *	This command is used to verify whether the handshake is complete
 *	or not.
 *
 * Results:
 *	A standard Tcl result. 1 means handshake complete, 0 means pending.
 *
 * Side effects:
 *	May force SSL negotiation to take place.
 *
 *-------------------------------------------------------------------
 */

static int HandshakeObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {





    Tcl_Channel chan;        /* The channel to set a mode on. */
    State *statePtr;        /* client state for ssl socket */
    const char *errStr = NULL;
    int ret = 1;
    int err = 0;
    (void) clientData;

    dprintf("Called");

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel");
	return(TCL_ERROR);
    }

    ERR_clear_error();

    chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], (Tcl_Size *) NULL), NULL);
    if (chan == (Tcl_Channel) NULL) {
	return(TCL_ERROR);
    }


    /* Make sure to operate on the topmost channel */

    chan = Tcl_GetTopChannel(chan);
    if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
	    "\": not a TLS channel", NULL);
	Tcl_SetErrorCode(interp, "TLS", "HANDSHAKE", "CHANNEL", "INVALID", (char *) NULL);
	return(TCL_ERROR);
    }
    statePtr = (State *)Tcl_GetChannelInstanceData(chan);

    dprintf("Calling Tls_WaitForConnect");
    ret = Tls_WaitForConnect(statePtr, &err, 1);
    dprintf("Tls_WaitForConnect returned: %i", ret);



    if (ret < 0 && ((statePtr->flags & TLS_TCL_ASYNC) && (err == EAGAIN))) {

	dprintf("Async set and err = EAGAIN");
	ret = 0;
    } else if (ret < 0) {
	long result;
	errStr = statePtr->err;
	Tcl_ResetResult(interp);
	Tcl_SetErrno(err);

	if (!errStr || (*errStr == 0)) {
	    errStr = Tcl_PosixError(interp);
	}

	Tcl_AppendResult(interp, "handshake failed: ", errStr, (char *) NULL);
	if ((result = SSL_get_verify_result(statePtr->ssl)) != X509_V_OK) {
	    Tcl_AppendResult(interp, " due to \"", X509_verify_cert_error_string(result), "\"", (char *) NULL);
	}
	Tcl_SetErrorCode(interp, "TLS", "HANDSHAKE", "FAILED", (char *) NULL);
	dprintf("Returning TCL_ERROR with handshake failed: %s", errStr);
	return(TCL_ERROR);
    } else {
	if (err != 0) {
	    dprintf("Got an error with a completed handshake: err = %i", err);
	}

	ret = 1;
    }

    dprintf("Returning TCL_OK with data \"%i\"", ret);
    Tcl_SetObjResult(interp, Tcl_NewIntObj(ret));
    return(TCL_OK);
}

/*
 *-------------------------------------------------------------------
 *
 * ImportObjCmd --
 *
 *	This procedure is invoked to process the "ssl" command
 *
 *	The ssl command pushes SSL over a (newly connected) tcp socket
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	May modify the behavior of an IO channel.
 *
 *-------------------------------------------------------------------
 */

static int




ImportObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {

    Tcl_Channel chan;		/* The channel to set a mode on. */
    State *statePtr;		/* client state for ssl socket */
    SSL_CTX *ctx		= NULL;
    Tcl_Obj *script		= NULL;
    Tcl_Obj *password		= NULL;
    Tcl_Obj *vcmd		= NULL;
    Tcl_DString upperChannelTranslation, upperChannelBlocking, upperChannelEncoding, upperChannelEOFChar;
    int idx;
    Tcl_Size len;
    int flags			= TLS_TCL_INIT;
    int server			= 0;	/* is connection incoming or outgoing? */
    char *keyfile		= NULL;
    char *certfile		= NULL;
    unsigned char *key		= NULL;
    Tcl_Size key_len		= 0;
    unsigned char *cert		= NULL;
    Tcl_Size cert_len		= 0;
    char *ciphers		= NULL;
    char *ciphersuites		= NULL;
    char *CAfile		= NULL;
    char *CApath		= NULL;
    char *DHparams		= NULL;
    char *model			= NULL;

    char *servername		= NULL;	/* hostname for Server Name Indication */

    const unsigned char *session_id = NULL;
    Tcl_Obj *alpn		= NULL;
    int ssl2 = 0, ssl3 = 0;
    int tls1 = 1, tls1_1 = 1, tls1_2 = 1, tls1_3 = 1;
    int proto = 0, level = -1;
    int verify = 0, require = 0, request = 1, post_handshake = 0;
    (void) clientData;

    dprintf("Called");







#if defined(NO_TLS1) || defined(OPENSSL_NO_TLS1)
    tls1 = 0;
#endif
#if defined(NO_TLS1_1) || defined(OPENSSL_NO_TLS1_1)
    tls1_1 = 0;
#endif
#if defined(NO_TLS1_2) || defined(OPENSSL_NO_TLS1_2)
    tls1_2 = 0;
#endif
#if defined(NO_TLS1_3) || defined(OPENSSL_NO_TLS1_3)
    tls1_3 = 0;
#endif

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel ?options?");
	return TCL_ERROR;
    }

    ERR_clear_error();

    chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], (Tcl_Size *) NULL), NULL);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }


    /* Make sure to operate on the topmost channel */

    chan = Tcl_GetTopChannel(chan);

    for (idx = 2; idx < objc; idx++) {
	char *opt = Tcl_GetStringFromObj(objv[idx], (Tcl_Size *)NULL);

	if (opt[0] != '-')
	    break;

	OPTOBJ("-alpn", alpn);
	OPTSTR("-cadir", CApath);
	OPTSTR("-cafile", CAfile);
	OPTBYTE("-cert", cert, cert_len);
	OPTSTR("-certfile", certfile);
	OPTSTR("-cipher", ciphers);
	OPTSTR("-ciphers", ciphers);
	OPTSTR("-ciphersuites", ciphersuites);
	OPTOBJ("-command", script);
	OPTSTR("-dhparams", DHparams);
	OPTBYTE("-key", key, key_len);
	OPTSTR("-keyfile", keyfile);
	OPTSTR("-model", model);
	OPTOBJ("-password", password);
	OPTBOOL("-post_handshake", post_handshake);
	OPTBOOL("-request", request);
	OPTBOOL("-require", require);
	OPTINT("-security_level", level);
	OPTBOOL("-server", server);

	OPTSTR("-servername", servername);

	OPTSTR("-session_id", session_id);
	OPTBOOL("-ssl2", ssl2);
	OPTBOOL("-ssl3", ssl3);
	OPTBOOL("-tls1", tls1);
	OPTBOOL("-tls1.1", tls1_1);
	OPTBOOL("-tls1.2", tls1_2);
	OPTBOOL("-tls1.3", tls1_3);
	OPTOBJ("-validatecommand", vcmd);
	OPTOBJ("-vcmd", vcmd);


	OPTBAD("option", "-alpn, -cadir, -cafile, -cert, -certfile, -cipher, -ciphersuites, -command, -dhparams, -key, -keyfile, -model, -password, -post_handshake, -request, -require, -security_level, -server, -servername, -session_id, -ssl2, -ssl3, -tls1, -tls1.1, -tls1.2, -tls1.3, or -validatecommand");

	return TCL_ERROR;
    }
    if (request)		verify |= SSL_VERIFY_CLIENT_ONCE | SSL_VERIFY_PEER;
    if (request && require)	verify |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
    if (request && post_handshake)	verify |= SSL_VERIFY_POST_HANDSHAKE;
    if (verify == 0)		verify = SSL_VERIFY_NONE;

    proto |= (ssl2 ? TLS_PROTO_SSL2 : 0);
    proto |= (ssl3 ? TLS_PROTO_SSL3 : 0);
    proto |= (tls1 ? TLS_PROTO_TLS1 : 0);
    proto |= (tls1_1 ? TLS_PROTO_TLS1_1 : 0);
    proto |= (tls1_2 ? TLS_PROTO_TLS1_2 : 0);
    proto |= (tls1_3 ? TLS_PROTO_TLS1_3 : 0);

    /* reset to NULL if blank string provided */
    if (cert && !*cert)		        cert	        = NULL;
    if (key && !*key)		        key	        = NULL;
    if (certfile && !*certfile)         certfile	= NULL;
    if (keyfile && !*keyfile)		keyfile	        = NULL;
    if (ciphers && !*ciphers)	        ciphers	        = NULL;
    if (ciphersuites && !*ciphersuites) ciphersuites    = NULL;
    if (CAfile && !*CAfile)	        CAfile	        = NULL;
    if (CApath && !*CApath)	        CApath	        = NULL;
    if (DHparams && !*DHparams)	        DHparams        = NULL;

    /* new SSL state */
    statePtr		= (State *) ckalloc((unsigned) sizeof(State));
    memset(statePtr, 0, sizeof(State));

    statePtr->flags	= flags;

    if (password) {
	(void) Tcl_GetStringFromObj(password, &len);
	if (len) {
	    statePtr->password = password;
	    Tcl_IncrRefCount(statePtr->password);
	}
    }

    /* allocate validate command */
    if (vcmd) {
	(void) Tcl_GetStringFromObj(vcmd, &len);
	if (len) {
	    statePtr->vcmd = vcmd;
	    Tcl_IncrRefCount(statePtr->vcmd);
	}
    }

    if (model != NULL) {
	int mode;
	/* Get the "model" context */
	chan = Tcl_GetChannel(interp, model, &mode);
	if (chan == (Tcl_Channel) NULL) {
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}

	/*
	 * Make sure to operate on the topmost channel
	 */
	chan = Tcl_GetTopChannel(chan);
	if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	    Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
		"\": not a TLS channel", NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "CHANNEL", "INVALID", (char *) NULL);
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}
	ctx = ((State *)Tcl_GetChannelInstanceData(chan))->ctx;
    } else {
	if ((ctx = CTX_Init(statePtr, server, proto, keyfile, certfile, key, cert, (int) key_len,

	    (int) cert_len, CApath, CAfile, ciphers, ciphersuites, level, DHparams)) == NULL) {
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}
    }

    statePtr->ctx = ctx;

    /*

    Tcl_GetChannelOption(interp, chan, "-eofchar", &upperChannelEOFChar);
    Tcl_GetChannelOption(interp, chan, "-encoding", &upperChannelEncoding);
    Tcl_GetChannelOption(interp, chan, "-translation", &upperChannelTranslation);
    Tcl_GetChannelOption(interp, chan, "-blocking", &upperChannelBlocking);
    Tcl_SetChannelOption(interp, chan, "-translation", "binary");
    Tcl_SetChannelOption(interp, chan, "-blocking", "true");
    dprintf("Consuming Tcl channel %s", Tcl_GetChannelName(chan));
    statePtr->self = Tcl_StackChannel(interp, Tls_ChannelType(), (ClientData) statePtr,
	(TCL_READABLE | TCL_WRITABLE), chan);
    dprintf("Created channel named %s", Tcl_GetChannelName(statePtr->self));
    if (statePtr->self == (Tcl_Channel) NULL) {
	/*
	 * No use of Tcl_EventuallyFree because no possible Tcl_Preserve.
	 */
	Tls_Free((char *) statePtr);
	return TCL_ERROR;
    }

    Tcl_SetChannelOption(interp, statePtr->self, "-translation", Tcl_DStringValue(&upperChannelTranslation));
    Tcl_SetChannelOption(interp, statePtr->self, "-encoding", Tcl_DStringValue(&upperChannelEncoding));
    Tcl_SetChannelOption(interp, statePtr->self, "-eofchar", Tcl_DStringValue(&upperChannelEOFChar));
    Tcl_SetChannelOption(interp, statePtr->self, "-blocking", Tcl_DStringValue(&upperChannelBlocking));
    Tcl_DStringFree(&upperChannelTranslation);
    Tcl_DStringFree(&upperChannelEncoding);
    Tcl_DStringFree(&upperChannelEOFChar);
    Tcl_DStringFree(&upperChannelBlocking);

    /*
     * SSL Initialization
     */

    statePtr->ssl = SSL_new(statePtr->ctx);
    if (!statePtr->ssl) {
	/* SSL library error */
	Tcl_AppendResult(interp, "couldn't construct ssl session: ", GET_ERR_REASON(), (char *) NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "INIT", "FAILED", (char *) NULL);
	Tls_Free((char *) statePtr);
	return TCL_ERROR;
    }

    /* Set host server name */
    if (servername) {
	/* Sets the server name indication (SNI) in ClientHello extension */
	/* Per RFC 6066, hostname is a ASCII encoded string, though RFC 4366 says UTF-8. */
	if (!SSL_set_tlsext_host_name(statePtr->ssl, servername) && require) {
	    Tcl_AppendResult(interp, "Set SNI extension failed: ", GET_ERR_REASON(), (char *) NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "SNI", "FAILED", (char *) NULL);
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}

	/* Set hostname for peer certificate hostname verification in clients.
	   Don't use SSL_set1_host since it has limitations. */
	if (!SSL_add1_host(statePtr->ssl, servername)) {
	    Tcl_AppendResult(interp, "Set DNS hostname failed: ", GET_ERR_REASON(), (char *) NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "HOSTNAME", "FAILED", (char *) NULL);
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}
    }

    /* Resume session id */
    if (session_id && strlen(session_id) <= SSL_MAX_SID_CTX_LENGTH) {
	/* SSL_set_session() */
	if (!SSL_SESSION_set1_id_context(SSL_get_session(statePtr->ssl), session_id, (unsigned int) strlen(session_id))) {
	    Tcl_AppendResult(interp, "Resume session failed: ", GET_ERR_REASON(), (char *) NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "SESSION", "FAILED", (char *) NULL);
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}
    }

    /* Enable Application-Layer Protocol Negotiation. Examples are: http/1.0,
	http/1.1, h2, h3, ftp, imap, pop3, xmpp-client, xmpp-server, mqtt, irc, etc. */
    if (alpn) {
	/* Convert a TCL list into a protocol-list in wire-format */
	unsigned char *protos, *p;
	unsigned int protos_len = 0;
	Tcl_Size cnt, i;
	int j;
	Tcl_Obj **list;

	if (Tcl_ListObjGetElements(interp, alpn, &cnt, &list) != TCL_OK) {
	    Tls_Free((char *) statePtr);
	    return TCL_ERROR;
	}

	/* Determine the memory required for the protocol-list */
	for (i = 0; i < cnt; i++) {
	    Tcl_GetStringFromObj(list[i], &len);
	    if (len > 255) {
		Tcl_AppendResult(interp, "ALPN protocol names too long", (char *) NULL);
		Tcl_SetErrorCode(interp, "TLS", "IMPORT", "ALPN", "FAILED", (char *) NULL);
		Tls_Free((char *) statePtr);
		return TCL_ERROR;
	    }
	    protos_len += 1 + (int) len;
	}

	/* Build the complete protocol-list */
	protos = ckalloc(protos_len);
	/* protocol-lists consist of 8-bit length-prefixed, byte strings */
	for (j = 0, p = protos; j < cnt; j++) {
	    char *str = Tcl_GetStringFromObj(list[j], &len);
	    *p++ = (unsigned char) len;
	    memcpy(p, str, (size_t) len);
	    p += len;
	}

	/* SSL_set_alpn_protos makes a copy of the protocol-list */
	/* Note: This functions reverses the return value convention */
	if (SSL_set_alpn_protos(statePtr->ssl, protos, protos_len)) {
	    Tcl_AppendResult(interp, "Set ALPN protocols failed: ", GET_ERR_REASON(), (char *) NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "ALPN", "FAILED", (char *) NULL);
	    Tls_Free((char *) statePtr);
	    ckfree(protos);
	    return TCL_ERROR;
	}

	/* Store protocols list */
	statePtr->protos = protos;
	statePtr->protos_len = protos_len;
    } else {
	statePtr->protos = NULL;
	statePtr->protos_len = 0;
    }

    /*
     * SSL Callbacks
     */

    SSL_set_app_data(statePtr->ssl, (void *)statePtr);	/* point back to us */

    SSL_set_verify(statePtr->ssl, verify, VerifyCallback);
    SSL_set_info_callback(statePtr->ssl, InfoCallback);

    /* Callback for observing protocol messages */
#ifndef OPENSSL_NO_SSL_TRACE
    /* void SSL_CTX_set_msg_callback_arg(statePtr->ctx, (void *)statePtr);
    void SSL_CTX_set_msg_callback(statePtr->ctx, MessageCallback); */
    SSL_set_msg_callback_arg(statePtr->ssl, (void *)statePtr);
    SSL_set_msg_callback(statePtr->ssl, MessageCallback);
#endif

    /* Create Tcl_Channel BIO Handler */
    statePtr->p_bio	= BIO_new_tcl(statePtr, BIO_NOCLOSE);
    statePtr->bio	= BIO_new(BIO_f_ssl());

    if (server) {
	/* Server callbacks */
	SSL_CTX_set_tlsext_servername_arg(statePtr->ctx, (void *)statePtr);
	SSL_CTX_set_tlsext_servername_callback(statePtr->ctx, SNICallback);
	SSL_CTX_set_client_hello_cb(statePtr->ctx, HelloCallback, (void *)statePtr);
	if (statePtr->protos != NULL) {
	    SSL_CTX_set_alpn_select_cb(statePtr->ctx, ALPNCallback, (void *)statePtr);
#ifdef USE_NPN
	    if (tls1_2 == 0 && tls1_3 == 0) {
		SSL_CTX_set_next_protos_advertised_cb(statePtr->ctx, NPNCallback, (void *)statePtr);
	    }
#endif
	}

	/* Enable server to send cert request after handshake (TLS 1.3 only) */
	/* A write operation must take place for the Certificate Request to be
	   sent to the client, this can be done with SSL_do_handshake(). */
	if (request && post_handshake && tls1_3) {
	    SSL_verify_client_post_handshake(statePtr->ssl);
	}

	/* set automatic curve selection */
	SSL_set_ecdh_auto(statePtr->ssl, 1);

	/* Set server mode */
	statePtr->flags |= TLS_TCL_SERVER;
	SSL_set_accept_state(statePtr->ssl);
    } else {
	/* Client callbacks */
#ifdef USE_NPN
	if (statePtr->protos != NULL && tls1_2 == 0 && tls1_3 == 0) {
	    SSL_CTX_set_next_proto_select_cb(statePtr->ctx, ALPNCallback, (void *)statePtr);
	}
#endif

	/* Session caching */
	SSL_CTX_set_session_cache_mode(statePtr->ctx, SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_NO_INTERNAL_STORE);
	SSL_CTX_sess_set_new_cb(statePtr->ctx, SessionCallback);

	/* Enable post handshake Authentication extension. TLS 1.3 only, not http/2. */
	if (request && post_handshake) {
	    SSL_set_post_handshake_auth(statePtr->ssl, 1);
	}

	/* Set client mode */
	SSL_set_connect_state(statePtr->ssl);
    }
    SSL_set_bio(statePtr->ssl, statePtr->p_bio, statePtr->p_bio);
    BIO_set_ssl(statePtr->bio, statePtr->ssl, BIO_NOCLOSE);

    /*
     * End of SSL Init
     */
    dprintf("Returning %s", Tcl_GetChannelName(statePtr->self));
    Tcl_SetResult(interp, (char *) Tcl_GetChannelName(statePtr->self), TCL_VOLATILE);

    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *
 * UnimportObjCmd --
 *
 *	This procedure is invoked to remove the topmost channel filter.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	May modify the behavior of an IO channel.
 *
 *-------------------------------------------------------------------
 */

static int
UnimportObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {





    Tcl_Channel chan;		/* The channel to set a mode on. */
    (void) clientData;

    dprintf("Called");

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel");
	return TCL_ERROR;
    }

    chan = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), NULL);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }


    /* Make sure to operate on the topmost channel */

    chan = Tcl_GetTopChannel(chan);

    if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
		"\": not a TLS channel", NULL);
	    Tcl_SetErrorCode(interp, "TLS", "UNIMPORT", "CHANNEL", "INVALID", (char *) NULL);
	return TCL_ERROR;
    }

    if (Tcl_UnstackChannel(interp, chan) == TCL_ERROR) {
	return TCL_ERROR;
    }

 *	A valid SSL_CTX instance or NULL.
 *
 * Side effects:
 *	constructs SSL context (CTX)
 *
 *-------------------------------------------------------------------
 */

static SSL_CTX *

CTX_Init(State *statePtr, int isServer, int proto, char *keyfile, char *certfile,




    unsigned char *key, unsigned char *cert, int key_len, int cert_len, char *CApath,




    char *CAfile, char *ciphers, char *ciphersuites, int level, char *DHparams) {



    Tcl_Interp *interp = statePtr->interp;
    SSL_CTX *ctx = NULL;
    Tcl_DString ds;
    Tcl_DString ds1;
    int off = 0, abort = 0;
    int load_private_key;
    const SSL_METHOD *method;

    dprintf("Called");

    if (!proto) {
	Tcl_AppendResult(interp, "no valid protocol selected", (char *) NULL);
	return NULL;
    }

    /* create SSL context */
#if OPENSSL_VERSION_NUMBER >= 0x10100000L || defined(NO_SSL2) || defined(OPENSSL_NO_SSL2)
    if (ENABLED(proto, TLS_PROTO_SSL2)) {
	Tcl_AppendResult(interp, "SSL2 protocol not supported", (char *) NULL);
	return NULL;
    }
#endif
#if defined(NO_SSL3) || defined(OPENSSL_NO_SSL3)
    if (ENABLED(proto, TLS_PROTO_SSL3)) {
	Tcl_AppendResult(interp, "SSL3 protocol not supported", (char *) NULL);
	return NULL;
    }
#endif
#if defined(NO_TLS1) || defined(OPENSSL_NO_TLS1)
    if (ENABLED(proto, TLS_PROTO_TLS1)) {
	Tcl_AppendResult(interp, "TLS 1.0 protocol not supported", (char *) NULL);
	return NULL;
    }
#endif
#if defined(NO_TLS1_1) || defined(OPENSSL_NO_TLS1_1)
    if (ENABLED(proto, TLS_PROTO_TLS1_1)) {
	Tcl_AppendResult(interp, "TLS 1.1 protocol not supported", (char *) NULL);
	return NULL;
    }
#endif
#if defined(NO_TLS1_2) || defined(OPENSSL_NO_TLS1_2)
    if (ENABLED(proto, TLS_PROTO_TLS1_2)) {
	Tcl_AppendResult(interp, "TLS 1.2 protocol not supported", (char *) NULL);
	return NULL;
    }
#endif
#if defined(NO_TLS1_3) || defined(OPENSSL_NO_TLS1_3)
    if (ENABLED(proto, TLS_PROTO_TLS1_3)) {
	Tcl_AppendResult(interp, "TLS 1.3 protocol not supported", (char *) NULL);
	return NULL;
    }
#endif
    if (proto == 0) {
	/* Use full range */
	SSL_CTX_set_min_proto_version(ctx, 0);
	SSL_CTX_set_max_proto_version(ctx, 0);
    }

    switch (proto) {
#if OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(NO_SSL2) && !defined(OPENSSL_NO_SSL2)
    case TLS_PROTO_SSL2:
	method = isServer ? SSLv2_server_method() : SSLv2_client_method();
	break;
#endif
#if !defined(NO_SSL3) && !defined(OPENSSL_NO_SSL3) && !defined(OPENSSL_NO_SSL3_METHOD)
    case TLS_PROTO_SSL3:
	method = isServer ? SSLv3_server_method() : SSLv3_client_method();
	break;
#endif
#if !defined(NO_TLS1) && !defined(OPENSSL_NO_TLS1) && !defined(OPENSSL_NO_TLS1_METHOD)
    case TLS_PROTO_TLS1:
	method = isServer ? TLSv1_server_method() : TLSv1_client_method();
	break;
#endif
#if !defined(NO_TLS1_1) && !defined(OPENSSL_NO_TLS1_1) && !defined(OPENSSL_NO_TLS1_1_METHOD)
    case TLS_PROTO_TLS1_1:
	method = isServer ? TLSv1_1_server_method() : TLSv1_1_client_method();
	break;
#endif
#if !defined(NO_TLS1_2) && !defined(OPENSSL_NO_TLS1_2) && !defined(OPENSSL_NO_TLS1_2_METHOD)
    case TLS_PROTO_TLS1_2:
	method = isServer ? TLSv1_2_server_method() : TLSv1_2_client_method();
	break;
#endif
#if !defined(NO_TLS1_3) && !defined(OPENSSL_NO_TLS1_3)
    case TLS_PROTO_TLS1_3:



	/* Use the generic method and constraint range after context is created */

	method = isServer ? TLS_server_method() : TLS_client_method();
	break;
#endif
    default:
	/* Negotiate highest available SSL/TLS version */
	method = isServer ? TLS_server_method() : TLS_client_method();



#if OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(NO_SSL2) && !defined(OPENSSL_NO_SSL2)
	off |= (ENABLED(proto, TLS_PROTO_SSL2)   ? 0 : SSL_OP_NO_SSLv2);
#endif
#if !defined(NO_SSL3) && !defined(OPENSSL_NO_SSL3)
	off |= (ENABLED(proto, TLS_PROTO_SSL3)   ? 0 : SSL_OP_NO_SSLv3);
#endif
#if !defined(NO_TLS1) && !defined(OPENSSL_NO_TLS1)
	off |= (ENABLED(proto, TLS_PROTO_TLS1)   ? 0 : SSL_OP_NO_TLSv1);
#endif
#if !defined(NO_TLS1_1) && !defined(OPENSSL_NO_TLS1_1)
	off |= (ENABLED(proto, TLS_PROTO_TLS1_1) ? 0 : SSL_OP_NO_TLSv1_1);
#endif
#if !defined(NO_TLS1_2) && !defined(OPENSSL_NO_TLS1_2)
	off |= (ENABLED(proto, TLS_PROTO_TLS1_2) ? 0 : SSL_OP_NO_TLSv1_2);
#endif
#if !defined(NO_TLS1_3) && !defined(OPENSSL_NO_TLS1_3)
	off |= (ENABLED(proto, TLS_PROTO_TLS1_3) ? 0 : SSL_OP_NO_TLSv1_3);
#endif
	break;
    }

    ERR_clear_error();

    ctx = SSL_CTX_new(method);
    if (!ctx) {
	return(NULL);
    }

    if (getenv(SSLKEYLOGFILE)) {
	SSL_CTX_set_keylog_callback(ctx, KeyLogCallback);
    }

#if !defined(NO_TLS1_3) && !defined(OPENSSL_NO_TLS1_3)
    if (proto == TLS_PROTO_TLS1_3) {
	SSL_CTX_set_min_proto_version(ctx, TLS1_3_VERSION);
	SSL_CTX_set_max_proto_version(ctx, TLS1_3_VERSION);
    }
#endif

    /* Force cipher selection order by server */
    if (!isServer) {
	SSL_CTX_set_options(ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
    }

#if OPENSSL_VERSION_NUMBER < 0x10100000L
    OpenSSL_add_all_algorithms(); /* Load ciphers and digests */
#endif

    SSL_CTX_set_app_data(ctx, (void*)interp);	/* remember the interpreter */
    SSL_CTX_set_options(ctx, SSL_OP_ALL);	/* all SSL bug workarounds */
    SSL_CTX_set_options(ctx, SSL_OP_NO_COMPRESSION);	/* disable compression even if supported */
    SSL_CTX_set_options(ctx, off);		/* disable protocol versions */
#if OPENSSL_VERSION_NUMBER < 0x10101000L
    SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);	/* handle new handshakes in background. On by default in OpenSSL 1.1.1. */
#endif
    SSL_CTX_sess_set_cache_size(ctx, 128);

    /* Set user defined ciphers, cipher suites, and security level */
    if ((ciphers != NULL) && !SSL_CTX_set_cipher_list(ctx, ciphers)) {
	Tcl_AppendResult(interp, "Set ciphers failed: No valid ciphers", (char *) NULL);
	SSL_CTX_free(ctx);
	return NULL;
    }
    if ((ciphersuites != NULL) && !SSL_CTX_set_ciphersuites(ctx, ciphersuites)) {
	Tcl_AppendResult(interp, "Set cipher suites failed: No valid ciphers", (char *) NULL);
	SSL_CTX_free(ctx);
	return NULL;
    }

    /* Set security level */
    if (level > -1 && level < 6) {
	/* SSL_set_security_level */
	SSL_CTX_set_security_level(ctx, level);
    }

    /* set some callbacks */
    SSL_CTX_set_default_passwd_cb(ctx, PasswordCallback);


    SSL_CTX_set_default_passwd_cb_userdata(ctx, (void *)statePtr);


    /* read a Diffie-Hellman parameters file, or use the built-in one */
#ifdef OPENSSL_NO_DH
    if (DHparams != NULL) {

	Tcl_AppendResult(interp, "DH parameter support not available", (char *) NULL);
	SSL_CTX_free(ctx);
	return NULL;
    }
#else
    {
	DH* dh;
	if (DHparams != NULL) {
	    BIO *bio;

	    bio = BIO_new_file(F2N(DHparams, &ds), "r");
	    if (!bio) {
		Tcl_DStringFree(&ds);

		Tcl_AppendResult(interp, "Could not find DH parameters file", (char *) NULL);
		SSL_CTX_free(ctx);
		return NULL;
	    }

	    dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
	    BIO_free(bio);
	    Tcl_DStringFree(&ds);
	    if (!dh) {

		Tcl_AppendResult(interp, "Could not read DH parameters from file", (char *) NULL);
		SSL_CTX_free(ctx);
		return NULL;
	    }
	    SSL_CTX_set_tmp_dh(ctx, dh);
	    DH_free(dh);

	} else {
	    /* Use well known DH parameters that have built-in support in OpenSSL */
	    if (!SSL_CTX_set_dh_auto(ctx, 1)) {
		Tcl_AppendResult(interp, "Could not enable set DH auto: ", GET_ERR_REASON(), (char *) NULL);
		SSL_CTX_free(ctx);
		return NULL;
	    }


	}
    }
#endif

    /* set our certificate */
    load_private_key = 0;
    if (certfile != NULL) {
	load_private_key = 1;



	if (SSL_CTX_use_certificate_file(ctx, F2N(certfile, &ds), SSL_FILETYPE_PEM) <= 0) {

	    Tcl_DStringFree(&ds);

	    Tcl_AppendResult(interp, "unable to set certificate file ", certfile, ": ",
		GET_ERR_REASON(), (char *) NULL);
	    SSL_CTX_free(ctx);
	    return NULL;
	}
	Tcl_DStringFree(&ds);

    } else if (cert != NULL) {
	load_private_key = 1;
	if (SSL_CTX_use_certificate_ASN1(ctx, cert_len, cert) <= 0) {

	    Tcl_AppendResult(interp, "unable to set certificate: ",

		GET_ERR_REASON(), (char *) NULL);
	    SSL_CTX_free(ctx);
	    return NULL;
	}
    } else {
	certfile = (char*)X509_get_default_cert_file();

	if (SSL_CTX_use_certificate_file(ctx, certfile, SSL_FILETYPE_PEM) <= 0) {

#if 0


	    Tcl_AppendResult(interp, "unable to use default certificate file ", certfile, ": ",
		GET_ERR_REASON(), (char *) NULL);
	    SSL_CTX_free(ctx);
	    return NULL;
#endif
	}
    }

    /* set our private key */
    if (load_private_key) {
	if (keyfile == NULL && key == NULL) {
	    keyfile = certfile;
	}

	if (keyfile != NULL) {
	    /* get the private key associated with this certificate */
	    if (keyfile == NULL) {
		keyfile = certfile;
	    }

	    if (SSL_CTX_use_PrivateKey_file(ctx, F2N(keyfile, &ds), SSL_FILETYPE_PEM) <= 0) {
		Tcl_DStringFree(&ds);
		/* flush the passphrase which might be left in the result */
		Tcl_SetResult(interp, NULL, TCL_STATIC);

		Tcl_AppendResult(interp, "unable to set public key file ", keyfile, " ",
		    GET_ERR_REASON(), (char *) NULL);
		SSL_CTX_free(ctx);
		return NULL;
	    }

	    Tcl_DStringFree(&ds);

	} else if (key != NULL) {
	    if (SSL_CTX_use_PrivateKey_ASN1(EVP_PKEY_RSA, ctx, key,key_len) <= 0) {

		/* flush the passphrase which might be left in the result */
		Tcl_SetResult(interp, NULL, TCL_STATIC);
		Tcl_AppendResult(interp, "unable to set public key: ", GET_ERR_REASON(), (char *) NULL);


		SSL_CTX_free(ctx);
		return NULL;
	    }
	}
	/* Now we know that a key and cert have been set against
	 * the SSL context */
	if (!SSL_CTX_check_private_key(ctx)) {

	    Tcl_AppendResult(interp, "private key does not match the certificate public key",
			     (char *) NULL);
	    SSL_CTX_free(ctx);
	    return NULL;
	}
    }

    /* Set to use default location and file for Certificate Authority (CA) certificates. The
     * verify path and store can be overridden by the SSL_CERT_DIR env var. The verify file can
     * be overridden by the SSL_CERT_FILE env var. */
    if (!SSL_CTX_set_default_verify_paths(ctx)) {
	abort++;
    }

    /* Overrides for the CA verify path and file */
    {
#if OPENSSL_VERSION_NUMBER < 0x30000000L
	if (CApath != NULL || CAfile != NULL) {
	    Tcl_DString ds1;
	    if (!SSL_CTX_load_verify_locations(ctx, F2N(CAfile, &ds), F2N(CApath, &ds1))) {


		abort++;
	    }
	    Tcl_DStringFree(&ds);
	    Tcl_DStringFree(&ds1);

	    /* Set list of CAs to send to client when requesting a client certificate */
	    /* https://sourceforge.net/p/tls/bugs/57/ */
	    /* XXX:TODO: Let the user supply values here instead of something that exists on the filesystem */
	    STACK_OF(X509_NAME) *certNames = SSL_load_client_CA_file(F2N(CAfile, &ds));
	    if (certNames != NULL) {
		SSL_CTX_set_client_CA_list(ctx, certNames);
	    }
	    Tcl_DStringFree(&ds);
	}

#else
	if (CApath != NULL) {
	    if (!SSL_CTX_load_verify_dir(ctx, F2N(CApath, &ds))) {
		abort++;
	    }
	    Tcl_DStringFree(&ds);
	}
	if (CAfile != NULL) {
	    if (!SSL_CTX_load_verify_file(ctx, F2N(CAfile, &ds))) {
		abort++;
	    }
	    Tcl_DStringFree(&ds);

	    /* Set list of CAs to send to client when requesting a client certificate */
	    STACK_OF(X509_NAME) *certNames = SSL_load_client_CA_file(F2N(CAfile, &ds));
	    if (certNames != NULL) {
		SSL_CTX_set_client_CA_list(ctx, certNames);
	    }
	    Tcl_DStringFree(&ds);
	}
#endif
    }












    return ctx;
}

/*
 *-------------------------------------------------------------------
 *
 * StatusObjCmd -- return certificate for connected peer.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------
 */
static int
StatusObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {





    State *statePtr;
    X509 *peer;
    Tcl_Obj *objPtr;
    Tcl_Channel chan;
    char *channelName, *ciphers;
    int mode;
    const unsigned char *proto;
    unsigned int len;
    int nid, res;
    (void) clientData;

    dprintf("Called");



    if (objc < 2 || objc > 3 || (objc == 3 && !strcmp(Tcl_GetString(objv[1]), "-local"))) {









	Tcl_WrongNumArgs(interp, 1, objv, "?-local? channel");
	return TCL_ERROR;
    }

    /* Get channel Id */
    channelName = Tcl_GetStringFromObj(objv[(objc == 2 ? 1 : 2)], (Tcl_Size *) NULL);
    chan = Tcl_GetChannel(interp, channelName, &mode);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }

    /* Make sure to operate on the topmost channel */

    chan = Tcl_GetTopChannel(chan);
    if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
		"\": not a TLS channel", NULL);
	Tcl_SetErrorCode(interp, "TLS", "STATUS", "CHANNEL", "INVALID", (char *) NULL);
	return TCL_ERROR;
    }
    statePtr = (State *) Tcl_GetChannelInstanceData(chan);

    /* Get certificate for peer or self */
    if (objc == 2) {
	peer = SSL_get_peer_certificate(statePtr->ssl);
    } else {
	peer = SSL_get_certificate(statePtr->ssl);
    }
    /* Get X509 certificate info */
    if (peer) {
	objPtr = Tls_NewX509Obj(interp, peer);
	if (objc == 2) {
	    X509_free(peer);
	    peer = NULL;
	}
    } else {
	objPtr = Tcl_NewListObj(0, NULL);
    }

    /* Peer name */

    LAPPEND_STR(interp, objPtr, "peername", SSL_get0_peername(statePtr->ssl), -1);
    LAPPEND_INT(interp, objPtr, "sbits", SSL_get_cipher_bits(statePtr->ssl, NULL));

    ciphers = (char*)SSL_get_cipher(statePtr->ssl);
    LAPPEND_STR(interp, objPtr, "cipher", ciphers, -1);

    /* Verify the X509 certificate presented by the peer */
    LAPPEND_STR(interp, objPtr, "verifyResult",
	X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)), -1);

    /* Verify mode */
    mode = SSL_get_verify_mode(statePtr->ssl);
    if (mode && SSL_VERIFY_NONE) {
	LAPPEND_STR(interp, objPtr, "verifyMode", "none", -1);
    } else {
	Tcl_Obj *listObjPtr = Tcl_NewListObj(0, NULL);
	if (mode && SSL_VERIFY_PEER) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("peer", -1));
	}
	if (mode && SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("fail if no peer cert", -1));
	}
	if (mode && SSL_VERIFY_CLIENT_ONCE) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("client once", -1));
	}
	if (mode && SSL_VERIFY_POST_HANDSHAKE) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("post handshake", -1));
	}
	LAPPEND_OBJ(interp, objPtr, "verifyMode", listObjPtr)
    }

    /* Verify mode depth */
    LAPPEND_INT(interp, objPtr, "verifyDepth", SSL_get_verify_depth(statePtr->ssl));

    /* Report the selected protocol as a result of the negotiation */
    SSL_get0_alpn_selected(statePtr->ssl, &proto, &len);
    LAPPEND_STR(interp, objPtr, "alpn", (char *)proto, (Tcl_Size) len);
    LAPPEND_STR(interp, objPtr, "protocol", SSL_get_version(statePtr->ssl), -1);

    /* Valid for non-RSA signature and TLS 1.3 */
    if (objc == 2) {
	res = SSL_get_peer_signature_nid(statePtr->ssl, &nid);
    } else {
	res = SSL_get_signature_nid(statePtr->ssl, &nid);
    }
    if (!res) {nid = 0;}
    LAPPEND_STR(interp, objPtr, "signatureHashAlgorithm", OBJ_nid2ln(nid), -1);

    if (objc == 2) {
	res = SSL_get_peer_signature_type_nid(statePtr->ssl, &nid);
    } else {
	res = SSL_get_signature_type_nid(statePtr->ssl, &nid);
    }
    if (!res) {nid = 0;}
    LAPPEND_STR(interp, objPtr, "signatureType", OBJ_nid2ln(nid), -1);

    Tcl_SetObjResult(interp, objPtr);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *
 * ConnectionInfoObjCmd -- return connection info from OpenSSL.
 *
 * Results:
 *	A list of connection info
  *
 *-------------------------------------------------------------------
 */

static int ConnectionInfoObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    Tcl_Channel chan;		/* The channel to set a mode on */
    State *statePtr;		/* client state for ssl socket */
    Tcl_Obj *objPtr, *listPtr;
    const SSL *ssl;
    const SSL_CIPHER *cipher;
    const SSL_SESSION *session;
    const EVP_MD *md;
    (void) clientData;

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel");
	return(TCL_ERROR);
    }

    chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], (Tcl_Size *)NULL), NULL);
    if (chan == (Tcl_Channel) NULL) {
	return(TCL_ERROR);
    }

    /* Make sure to operate on the topmost channel */
    chan = Tcl_GetTopChannel(chan);
    if (Tcl_GetChannelType(chan) != Tls_ChannelType()) {
	Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
	    "\": not a TLS channel", NULL);
	Tcl_SetErrorCode(interp, "TLS", "CONNECTION", "CHANNEL", "INVALID", (char *) NULL);
	return(TCL_ERROR);
    }

    objPtr = Tcl_NewListObj(0, NULL);

    /* Connection info */
    statePtr = (State *)Tcl_GetChannelInstanceData(chan);
    ssl = statePtr->ssl;
    if (ssl != NULL) {
	/* connection state */
	LAPPEND_STR(interp, objPtr, "state", SSL_state_string_long(ssl), -1);

	/* Get SNI requested server name */
	LAPPEND_STR(interp, objPtr, "servername", SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name), -1);

	/* Get protocol */
	LAPPEND_STR(interp, objPtr, "protocol", SSL_get_version(ssl), -1);

	/* Renegotiation allowed */
	LAPPEND_BOOL(interp, objPtr, "renegotiation_allowed", SSL_get_secure_renegotiation_support((SSL *) ssl));

	/* Get security level */
	LAPPEND_INT(interp, objPtr, "security_level", SSL_get_security_level(ssl));

	/* Session info */
	LAPPEND_BOOL(interp, objPtr, "session_reused", SSL_session_reused(ssl));

	/* Is server info */
	LAPPEND_BOOL(interp, objPtr, "is_server", SSL_is_server(ssl));

	/* Is DTLS */
	LAPPEND_BOOL(interp, objPtr, "is_dtls", SSL_is_dtls(ssl));
    }

    /* Cipher info */
    cipher = SSL_get_current_cipher(ssl);
    if (cipher != NULL) {
	char buf[BUFSIZ] = {0};
	int bits, alg_bits;

	/* Cipher name */
	LAPPEND_STR(interp, objPtr, "cipher", SSL_CIPHER_get_name(cipher), -1);

	/* RFC name of cipher */
	LAPPEND_STR(interp, objPtr, "standard_name", SSL_CIPHER_standard_name(cipher), -1);

	/* OpenSSL name of cipher */
	LAPPEND_STR(interp, objPtr, "openssl_name", OPENSSL_cipher_name(SSL_CIPHER_standard_name(cipher)), -1);

	/* number of secret bits used for cipher */
	bits = SSL_CIPHER_get_bits(cipher, &alg_bits);
	LAPPEND_INT(interp, objPtr, "secret_bits", bits);
	LAPPEND_INT(interp, objPtr, "algorithm_bits", alg_bits);
	/* alg_bits is actual key secret bits. If use bits and secret (algorithm) bits differ,
	   the rest of the bits are fixed, i.e. for limited export ciphers (bits < 56) */

	/* Indicates which SSL/TLS protocol version first defined the cipher */
	LAPPEND_STR(interp, objPtr, "min_version", SSL_CIPHER_get_version(cipher), -1);

	/* Cipher NID */
	LAPPEND_STR(interp, objPtr, "cipherNID", (char *)OBJ_nid2ln(SSL_CIPHER_get_cipher_nid(cipher)), -1);
	LAPPEND_STR(interp, objPtr, "digestNID", (char *)OBJ_nid2ln(SSL_CIPHER_get_digest_nid(cipher)), -1);
	LAPPEND_STR(interp, objPtr, "keyExchangeNID", (char *)OBJ_nid2ln(SSL_CIPHER_get_kx_nid(cipher)), -1);
	LAPPEND_STR(interp, objPtr, "authenticationNID", (char *)OBJ_nid2ln(SSL_CIPHER_get_auth_nid(cipher)), -1);

	/* message authentication code - Cipher is AEAD (e.g. GCM or ChaCha20/Poly1305) or not */
	/* Authenticated Encryption with associated data (AEAD) check */
	LAPPEND_BOOL(interp, objPtr, "cipher_is_aead", SSL_CIPHER_is_aead(cipher));

	/* Digest used during the SSL/TLS handshake when using the cipher. */
	md = SSL_CIPHER_get_handshake_digest(cipher);
	LAPPEND_STR(interp, objPtr, "handshake_digest", (char *)EVP_MD_name(md), -1);

	/* Get OpenSSL-specific ID, not IANA ID */
	LAPPEND_INT(interp, objPtr, "cipher_id", (int) SSL_CIPHER_get_id(cipher));

	/* Two-byte ID used in the TLS protocol of the given cipher */
	LAPPEND_INT(interp, objPtr, "protocol_id", (int) SSL_CIPHER_get_protocol_id(cipher));

	/* Textual description of the cipher */
	if (SSL_CIPHER_description(cipher, buf, sizeof(buf)) != NULL) {
	    LAPPEND_STR(interp, objPtr, "description", buf, -1);
	}
    }

    /* Session info */
    session = SSL_get_session(ssl);
    if (session != NULL) {
	const unsigned char *ticket;
	size_t len2;
	unsigned int ulen;
	const unsigned char *session_id, *proto;
	unsigned char buffer[SSL_MAX_MASTER_KEY_LENGTH];

	/* Report the selected protocol as a result of the ALPN negotiation */
	SSL_SESSION_get0_alpn_selected(session, &proto, &len2);
	LAPPEND_STR(interp, objPtr, "alpn", (char *) proto, (Tcl_Size) len2);

	/* Report the selected protocol as a result of the NPN negotiation */
#ifdef USE_NPN
	SSL_get0_next_proto_negotiated(ssl, &proto, &ulen);
	LAPPEND_STR(interp, objPtr, "npn", (char *) proto, (Tcl_Size) ulen);
#endif

	/* Resumable session */
	LAPPEND_BOOL(interp, objPtr, "resumable", SSL_SESSION_is_resumable(session));

	/* Session start time (seconds since epoch) */
	LAPPEND_LONG(interp, objPtr, "start_time", SSL_SESSION_get_time(session));

	/* Timeout value - SSL_CTX_get_timeout (in seconds) */
	LAPPEND_LONG(interp, objPtr, "timeout", SSL_SESSION_get_timeout(session));

	/* Session id - TLSv1.2 and below only */
	session_id = SSL_SESSION_get_id(session, &ulen);
	LAPPEND_BARRAY(interp, objPtr, "session_id", session_id, (Tcl_Size) ulen);

	/* Session context */
	session_id = SSL_SESSION_get0_id_context(session, &ulen);
	LAPPEND_BARRAY(interp, objPtr, "session_context", session_id, (Tcl_Size) ulen);

	/* Session ticket - client only */
	SSL_SESSION_get0_ticket(session, &ticket, &len2);
	LAPPEND_BARRAY(interp, objPtr, "session_ticket", ticket, (Tcl_Size) len2);

	/* Session ticket lifetime hint (in seconds) */
	LAPPEND_LONG(interp, objPtr, "lifetime", SSL_SESSION_get_ticket_lifetime_hint(session));

	/* Ticket app data */
#if OPENSSL_VERSION_NUMBER < 0x30000000L
	SSL_SESSION_get0_ticket_appdata((SSL_SESSION *) session, &ticket, &len2);
	LAPPEND_BARRAY(interp, objPtr, "ticket_app_data", ticket, (Tcl_Size) len2);
#endif

	/* Get master key */
	len2 = SSL_SESSION_get_master_key(session, buffer, SSL_MAX_MASTER_KEY_LENGTH);
	LAPPEND_BARRAY(interp, objPtr, "master_key", buffer, (Tcl_Size) len2);

	/* Compression id */
	unsigned int id = SSL_SESSION_get_compress_id(session);
	LAPPEND_STR(interp, objPtr, "compression_id", id == 1 ? "zlib" : "none", -1);
    }

    /* Compression info */
    if (ssl != NULL) {
#ifdef HAVE_SSL_COMPRESSION
	const COMP_METHOD *comp, *expn;
	comp = SSL_get_current_compression(ssl);
	expn = SSL_get_current_expansion(ssl);

	LAPPEND_STR(interp, objPtr, "compression", comp ? SSL_COMP_get_name(comp) : "none", -1);
	LAPPEND_STR(interp, objPtr, "expansion", expn ? SSL_COMP_get_name(expn) : "none", -1);
#else
	LAPPEND_STR(interp, objPtr, "compression", "none", -1);
	LAPPEND_STR(interp, objPtr, "expansion", "none", -1);
#endif
    }

    /* Server info */
    {
	long mode = SSL_CTX_get_session_cache_mode(statePtr->ctx);
	char *msg;

	if (mode & SSL_SESS_CACHE_OFF) {
	    msg = "off";
	} else if (mode & SSL_SESS_CACHE_CLIENT) {
	    msg = "client";
	} else if (mode & SSL_SESS_CACHE_SERVER) {
	    msg = "server";
	} else if (mode & SSL_SESS_CACHE_BOTH) {
	    msg = "both";
	} else {
	    msg = "unknown";
	}
	LAPPEND_STR(interp, objPtr, "session_cache_mode", msg, -1);
    }

    /* CA List */
    /* IF not a server, same as SSL_get0_peer_CA_list. If server same as SSL_CTX_get_client_CA_list */
    listPtr = Tcl_NewListObj(0, NULL);
    STACK_OF(X509_NAME) *ca_list;
    if ((ca_list = SSL_get_client_CA_list(ssl)) != NULL) {
	char buffer[BUFSIZ];
	for (int i = 0; i < sk_X509_NAME_num(ca_list); i++) {
	    X509_NAME *name = sk_X509_NAME_value(ca_list, i);
	    if (name) {
		X509_NAME_oneline(name, buffer, BUFSIZ);
		Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj(buffer, -1));

	    }
	}
    }
    LAPPEND_OBJ(interp, objPtr, "caList", listPtr);
    LAPPEND_INT(interp, objPtr, "caListCount", sk_X509_NAME_num(ca_list));

    Tcl_SetObjResult(interp, objPtr);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *
 * VersionObjCmd -- return version string from OpenSSL.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------
 */
static int
VersionObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {





    Tcl_Obj *objPtr;
    (void) clientData;
    (void) objc;
    (void) objv;

    dprintf("Called");

    objPtr = Tcl_NewStringObj(OPENSSL_VERSION_TEXT, -1);

    Tcl_SetObjResult(interp, objPtr);

    return TCL_OK;
}

/*
 *-------------------------------------------------------------------
 *
 * MiscObjCmd -- misc commands
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------
 */
static int


MiscObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {



    static const char *commands [] = { "req", "strreq", NULL };
    enum command { C_REQ, C_STRREQ, C_DUMMY };
    Tcl_Size cmd;
    int isStr;
    char buffer[16384];
    (void) clientData;

    dprintf("Called");

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "subcommand ?args?");
	return TCL_ERROR;
    }
    if (Tcl_GetIndexFromObj(interp, objv[1], commands, "command", 0, &cmd) != TCL_OK) {

	return TCL_ERROR;
    }

    ERR_clear_error();

    isStr = (cmd == C_STRREQ);
    switch ((enum command) cmd) {
	case C_REQ:
	case C_STRREQ: {
	    EVP_PKEY *pkey=NULL;
	    X509 *cert=NULL;
	    X509_NAME *name=NULL;
	    Tcl_Obj **listv;
	    Tcl_Size listc;
	    int i;

	    BIO *out=NULL;

	    char *k_C="",*k_ST="",*k_L="",*k_O="",*k_OU="",*k_CN="",*k_Email="";
	    char *keyout,*pemout,*str;
	    int keysize,serial=0,days=365;

#if OPENSSL_VERSION_NUMBER < 0x30000000L
	    BIGNUM *bne = NULL;
	    RSA *rsa = NULL;
#else
	    EVP_PKEY_CTX *ctx = NULL;
#endif

	    if ((objc<5) || (objc>6)) {
		Tcl_WrongNumArgs(interp, 2, objv, "keysize keyfile certfile ?info?");
		return TCL_ERROR;
	    }

	    if (Tcl_GetIntFromObj(interp, objv[2], &keysize) != TCL_OK) {
		return TCL_ERROR;
	    }
	    keyout=Tcl_GetString(objv[3]);
	    pemout=Tcl_GetString(objv[4]);
	    if (isStr) {
		Tcl_SetVar(interp,keyout,"",0);
		Tcl_SetVar(interp,pemout,"",0);
	    }

	    if (objc>=6) {
		if (Tcl_ListObjGetElements(interp, objv[5], &listc, &listv) != TCL_OK) {

		    return TCL_ERROR;
		}

		if ((listc%2) != 0) {
		    Tcl_SetResult(interp,"Information list must have even number of arguments",NULL);
		    return TCL_ERROR;
		}
		for (i=0; i<listc; i+=2) {
		    str=Tcl_GetString(listv[i]);
		    if (strcmp(str,"days")==0) {
			if (Tcl_GetIntFromObj(interp,listv[i+1],&days)!=TCL_OK)
			    return TCL_ERROR;



		    } else if (strcmp(str,"serial")==0) {
			if (Tcl_GetIntFromObj(interp,listv[i+1],&serial)!=TCL_OK)
			    return TCL_ERROR;
		    } else if (strcmp(str,"C")==0) {
			k_C=Tcl_GetString(listv[i+1]);
		    } else if (strcmp(str,"ST")==0) {
			k_ST=Tcl_GetString(listv[i+1]);

			k_Email=Tcl_GetString(listv[i+1]);
		    } else {
			Tcl_SetResult(interp,"Unknown parameter",NULL);
			return TCL_ERROR;
		    }
		}
	    }

#if OPENSSL_VERSION_NUMBER < 0x30000000L
	    bne = BN_new();
	    rsa = RSA_new();
	    pkey = EVP_PKEY_new();
	    if (bne == NULL || rsa == NULL || pkey == NULL || !BN_set_word(bne,RSA_F4) ||
		!RSA_generate_key_ex(rsa, keysize, bne, NULL) || !EVP_PKEY_assign_RSA(pkey, rsa)) {
		EVP_PKEY_free(pkey);
		/* RSA_free(rsa); freed by EVP_PKEY_free */
		BN_free(bne);
#else
	    pkey = EVP_RSA_gen((unsigned int) keysize);
	    ctx = EVP_PKEY_CTX_new(pkey,NULL);
	    if (pkey == NULL || ctx == NULL || !EVP_PKEY_keygen_init(ctx) ||
		!EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, keysize) || !EVP_PKEY_keygen(ctx, &pkey)) {
		EVP_PKEY_free(pkey);
		EVP_PKEY_CTX_free(ctx);
#endif
		Tcl_SetResult(interp,"Error generating private key",NULL);
		return TCL_ERROR;
	    } else {
		if (isStr) {
		    out=BIO_new(BIO_s_mem());
		    PEM_write_bio_PrivateKey(out,pkey,NULL,NULL,0,NULL,NULL);
		    i=BIO_read(out,buffer,sizeof(buffer)-1);
		    i=(i<0) ? 0 : i;
		    buffer[i]='\0';
		    Tcl_SetVar(interp,keyout,buffer,0);
		    BIO_flush(out);
		    BIO_free(out);
		} else {
		    out=BIO_new(BIO_s_file());
		    BIO_write_filename(out,keyout);
		    PEM_write_bio_PrivateKey(out,pkey,NULL,NULL,0,NULL,NULL);
		    /* PEM_write_bio_RSAPrivateKey(out, rsa, NULL, NULL, 0, NULL, NULL); */
		    BIO_free_all(out);
	 	}

		if ((cert=X509_new())==NULL) {
		    Tcl_SetResult(interp,"Error generating certificate request",NULL);
		    EVP_PKEY_free(pkey);
#if OPENSSL_VERSION_NUMBER < 0x30000000L
		    BN_free(bne);
#endif
		    return(TCL_ERROR);
		}

		X509_set_version(cert,2);
		ASN1_INTEGER_set(X509_get_serialNumber(cert),serial);
		X509_gmtime_adj(X509_getm_notBefore(cert),0);
		X509_gmtime_adj(X509_getm_notAfter(cert),(long)60*60*24*days);
		X509_set_pubkey(cert,pkey);

		name=X509_get_subject_name(cert);

		X509_NAME_add_entry_by_txt(name,"C", MBSTRING_ASC, (const unsigned char *) k_C, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"ST", MBSTRING_ASC, (const unsigned char *) k_ST, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"L", MBSTRING_ASC, (const unsigned char *) k_L, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"O", MBSTRING_ASC, (const unsigned char *) k_O, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"OU", MBSTRING_ASC, (const unsigned char *) k_OU, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"CN", MBSTRING_ASC, (const unsigned char *) k_CN, -1, -1, 0);
		X509_NAME_add_entry_by_txt(name,"Email", MBSTRING_ASC, (const unsigned char *) k_Email, -1, -1, 0);

		X509_set_subject_name(cert,name);

		if (!X509_sign(cert,pkey,EVP_sha256())) {
		    X509_free(cert);
		    EVP_PKEY_free(pkey);
#if OPENSSL_VERSION_NUMBER < 0x30000000L
		    BN_free(bne);
#endif
		    Tcl_SetResult(interp,"Error signing certificate",NULL);
		    return TCL_ERROR;
		}

		if (isStr) {
		    out=BIO_new(BIO_s_mem());
		    PEM_write_bio_X509(out,cert);
		    i=BIO_read(out,buffer,sizeof(buffer)-1);
		    i=(i<0) ? 0 : i;
		    buffer[i]='\0';
		    Tcl_SetVar(interp,pemout,buffer,0);
		    BIO_flush(out);
		    BIO_free(out);
		} else {
		    out=BIO_new(BIO_s_file());
		    BIO_write_filename(out,pemout);

		    PEM_write_bio_X509(out,cert);
		    BIO_free_all(out);
		}

		X509_free(cert);
		EVP_PKEY_free(pkey);
#if OPENSSL_VERSION_NUMBER < 0x30000000L
		BN_free(bne);
#endif


	    }
	}
	break;
    default:
	break;
    }
    return TCL_OK;
}

/********************/
/* Init             */
/********************/

/*
 *-------------------------------------------------------------------
 *
 * Tls_Free --
 *
 *	This procedure cleans up when a SSL socket based channel
 *	is closed and its reference count falls below 1
 *
 * Results:
 *	none
 *
 * Side effects:
 *	Frees all the state
 *
 *-------------------------------------------------------------------
 */
void



Tls_Free(char *blockPtr) {


    State *statePtr = (State *)blockPtr;

    dprintf("Called");

    Tls_Clean(statePtr);
    ckfree(blockPtr);
}

     * we're assuming here that we're single-threaded
     */
    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = NULL;
    }

    if (statePtr->protos) {
	ckfree(statePtr->protos);
	statePtr->protos = NULL;
    }
    if (statePtr->bio) {
	/* This will call SSL_shutdown. Bug 1414045 */
	dprintf("BIO_free_all(%p)", statePtr->bio);
	BIO_free_all(statePtr->bio);
	statePtr->bio = NULL;
    }
    if (statePtr->ssl) {

	Tcl_DecrRefCount(statePtr->callback);
	statePtr->callback = NULL;
    }
    if (statePtr->password) {
	Tcl_DecrRefCount(statePtr->password);
	statePtr->password = NULL;
    }
    if (statePtr->vcmd) {
	Tcl_DecrRefCount(statePtr->vcmd);
	statePtr->vcmd = NULL;
    }

    dprintf("Returning");
}

#if TCL_MAJOR_VERSION > 8
#define MIN_VERSION "9.0"
#else
#define MIN_VERSION "8.5"
#endif

/*
 *-------------------------------------------------------------------
 *
 * Tls_Init --
 *
 *	This is a package initialization procedure, which is called
 *	by Tcl when this package is to be added to an interpreter.
 *
 * Results:  Ssl configured and loaded
 *
 * Side effects:
 *	 create the ssl command, initialize ssl context
 *
 *-------------------------------------------------------------------
 */

DLLEXPORT int Tls_Init(Tcl_Interp *interp) {
    const char tlsTclInitScript[] = {
#include "tls.tcl.h"
	0x00
    };

    dprintf("Called");





#ifdef USE_TCL_STUBS
    if (Tcl_InitStubs(interp, MIN_VERSION, 0) == NULL) {


	return TCL_ERROR;
    }
#endif
    if (Tcl_PkgRequire(interp, "Tcl", MIN_VERSION, 0) == NULL) {
	return TCL_ERROR;
    }

    if (TlsLibInit(0) != TCL_OK) {
	Tcl_AppendResult(interp, "could not initialize SSL library", (char *) NULL);
	return TCL_ERROR;
    }

    Tcl_CreateObjCommand(interp, "tls::ciphers", CiphersObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::connection", ConnectionInfoObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::handshake", HandshakeObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::import", ImportObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::unimport", UnimportObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::status", StatusObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::version", VersionObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::misc", MiscObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::protocols", ProtocolsObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);

    if (interp) {
	Tcl_Eval(interp, tlsTclInitScript);
    }

    return Tcl_PkgProvide(interp, PACKAGE_NAME, PACKAGE_VERSION);
}

/*
 *------------------------------------------------------*
 *
 *	Tls_SafeInit --
 *
 *	------------------------------------------------*
 *	Standard procedure required by 'load'.
 *	Initializes this extension for a safe interpreter.
 *	------------------------------------------------*
 *
 *	Side effects:
 *		As of 'Tls_Init'
 *
 *	Result:
 *		A standard Tcl error code.
 *
 *------------------------------------------------------*
 */

DLLEXPORT int Tls_SafeInit(Tcl_Interp *interp) {
    dprintf("Called");
    return(Tls_Init(interp));
}

/*
 *------------------------------------------------------*
 *
 *	TlsLibInit --
 *
 *	------------------------------------------------*
 *	Initializes SSL library once per application
 *	------------------------------------------------*
 *
 *	Side effects:
 *		initializes SSL library
 *
 *	Result:
 *		none
 *
 *------------------------------------------------------*
 */
static int TlsLibInit(int uninitialize) {
    static int initialized = 0;
    int status = TCL_OK;
#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
    size_t num_locks;
#endif

    if (uninitialize) {
	if (!initialized) {
	    dprintf("Asked to uninitialize, but we are not initialized");

	    return(TCL_OK);
	}

	dprintf("Asked to uninitialize");

#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
	Tcl_MutexLock(&init_mx);




	if (locks) {
	    free(locks);
	    locks = NULL;
	    locksCount = 0;
	}
#endif
	initialized = 0;

#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
	Tcl_MutexUnlock(&init_mx);
#endif

	return(TCL_OK);
    }

    if (initialized) {
	dprintf("Called, but using cached value");
	return(status);
    }

    dprintf("Called");

#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
    Tcl_MutexLock(&init_mx);
#endif
    initialized = 1;

#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
    num_locks = 1;
    locksCount = (int) num_locks;
    locks = malloc(sizeof(*locks) * num_locks);
    memset(locks, 0, sizeof(*locks) * num_locks);



#endif



    /* Initialize BOTH libcrypto and libssl. */

    OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS | OPENSSL_INIT_LOAD_CRYPTO_STRINGS


	| OPENSSL_INIT_ADD_ALL_CIPHERS | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);

    BIO_new_tcl(NULL, 0);

#if 0
    /*
     * XXX:TODO: Remove this code and replace it with a check
     * for enough entropy and do not try to create our own
     * terrible entropy
     */
    /*
     * Seed the random number generator in the SSL library,
     * using the do/while construct because of the bug note in the
     * OpenSSL FAQ at http://www.openssl.org/support/faq.html#USER1
     *
     * The crux of the problem is that Solaris 7 does not have a
     * /dev/random or /dev/urandom device so it cannot gather enough
     * entropy from the RAND_seed() when TLS initializes and refuses
     * to go further. Earlier versions of OpenSSL carried on regardless.
     */
    srand((unsigned int) time((time_t *) NULL));
    do {
	for (i = 0; i < 16; i++) {
	    rnd_seed[i] = 1 + (char) (255.0 * rand()/(RAND_MAX+1.0));
	}
	RAND_seed(rnd_seed, sizeof(rnd_seed));
    } while (RAND_status() != 1);
#endif


#if defined(OPENSSL_THREADS) && defined(TCL_THREADS)
	Tcl_MutexUnlock(&init_mx);
#endif

    return(status);
}

 * to enhance it to support full fileevent semantics.
 *
 * Also work done by the follow people provided the impetus to do this "right":-
 *	tclSSL (Colin McCormack, Shared Technology)
 *	SSLtcl (Peter Antman)
 *
 */

#ifndef _TLS_H
#define _TLS_H

#include <tcl.h>

/*
 * Initialization routines -- our entire public C API.

/*
 * Copyright (C) 1997-2000 Matt Newman <[email protected]>
 *
 * Provides BIO layer to interface OpenSSL to TCL.
 */

#include "tlsInt.h"








/* Called by SSL_write() */
































































































static int BioWrite(BIO *bio, const char *buf, int bufLen) {
    Tcl_Channel chan;
    Tcl_Size ret;
    int tclEofChan, tclErrno;

    chan = Tls_GetParent((State *) BIO_get_data(bio), 0);

    dprintf("[chan=%p] BioWrite(%p, <buf>, %d)", (void *)chan, (void *) bio, bufLen);

    ret = Tcl_WriteRaw(chan, buf, (Tcl_Size) bufLen);

    tclEofChan = Tcl_Eof(chan);
    tclErrno = Tcl_GetErrno();

    dprintf("[chan=%p] BioWrite(%d) -> %" TCL_SIZE_MODIFIER "d [tclEof=%d; tclErrno=%d]",
	(void *) chan, bufLen, ret, tclEofChan, tclErrno);

    BIO_clear_flags(bio, BIO_FLAGS_WRITE | BIO_FLAGS_SHOULD_RETRY);

    if (tclEofChan && ret <= 0) {
	dprintf("Got EOF while reading, returning a Connection Reset error which maps to Soft EOF");
	Tcl_SetErrno(ECONNRESET);
	ret = 0;

    } else if (ret == 0) {
	dprintf("Got 0 from Tcl_WriteRaw, and EOF is not set; ret = 0");
	dprintf("Setting retry read flag");
	BIO_set_retry_read(bio);

    } else if (ret < 0) {
	dprintf("We got some kind of I/O error");

	if (tclErrno == EAGAIN) {
	    dprintf("It's EAGAIN");
	} else {
	    dprintf("It's an unexpected error: %s/%i", Tcl_ErrnoMsg(tclErrno), tclErrno);
	}

    } else {
	dprintf("Successfully wrote %" TCL_SIZE_MODIFIER "d bytes of data", ret);
    }

    if (ret != -1 || (ret == -1 && tclErrno == EAGAIN)) {
	if (BIO_should_read(bio)) {
	    dprintf("Setting should retry read flag");

	    BIO_set_retry_read(bio);
	}
    }

    return((int) ret);
}

/* Called by SSL_read()*/
static int BioRead(BIO *bio, char *buf, int bufLen) {
    Tcl_Channel chan;
    Tcl_Size ret = 0;
    int tclEofChan, tclErrno;

    chan = Tls_GetParent((State *) BIO_get_data(bio), 0);

    dprintf("[chan=%p] BioRead(%p, <buf>, %d)", (void *) chan, (void *) bio, bufLen);

    if (buf == NULL) {
	return 0;
    }

    ret = Tcl_ReadRaw(chan, buf, (Tcl_Size) bufLen);

    tclEofChan = Tcl_Eof(chan);
    tclErrno = Tcl_GetErrno();

    dprintf("[chan=%p] BioRead(%d) -> %" TCL_SIZE_MODIFIER "d [tclEof=%d; tclErrno=%d]",
	(void *) chan, bufLen, ret, tclEofChan, tclErrno);

    BIO_clear_flags(bio, BIO_FLAGS_READ | BIO_FLAGS_SHOULD_RETRY);

    if (tclEofChan && ret <= 0) {
	dprintf("Got EOF while reading, returning a Connection Reset error which maps to Soft EOF");
	Tcl_SetErrno(ECONNRESET);
	ret = 0;

    } else if (ret == 0) {
	dprintf("Got 0 from Tcl_Read or Tcl_ReadRaw, and EOF is not set; ret = 0");
	dprintf("Setting retry read flag");
	BIO_set_retry_read(bio);

    } else if (ret < 0) {
	dprintf("We got some kind of I/O error");

	if (tclErrno == EAGAIN) {
	    dprintf("It's EAGAIN");
	} else {
	    dprintf("It's an unexpected error: %s/%i", Tcl_ErrnoMsg(tclErrno), tclErrno);
	}

    } else {
	dprintf("Successfully read %" TCL_SIZE_MODIFIER "d bytes of data", ret);
    }

    if (ret != -1 || (ret == -1 && tclErrno == EAGAIN)) {
	if (BIO_should_write(bio)) {
	    dprintf("Setting should retry write flag");

	    BIO_set_retry_write(bio);
	}
    }

    dprintf("BioRead(%p, <buf>, %d) [%p] returning %" TCL_SIZE_MODIFIER "d", (void *) bio,
	bufLen, (void *) chan, ret);

    return((int) ret);
}

static int BioPuts(BIO *bio, const char *str) {
    dprintf("BioPuts(%p, <string:%p>) called", bio, str);

    return(BioWrite(bio, str, (int) strlen(str)));
}

static long BioCtrl(BIO *bio, int cmd, long num, void *ptr) {
    Tcl_Channel chan;
    long ret = 1;

    chan = Tls_GetParent((State *) BIO_get_data(bio), 0);

    dprintf("BioCtrl(%p, 0x%x, 0x%lx, %p)", (void *) bio, cmd, num, ptr);

    switch (cmd) {
	case BIO_CTRL_RESET:
		dprintf("Got BIO_CTRL_RESET");
		num = 0;
		ret = 0;
		break;
	case BIO_C_FILE_SEEK:
		dprintf("Got BIO_C_FILE_SEEK");
		ret = 0;
		break;
	case BIO_C_FILE_TELL:
		dprintf("Got BIO_C_FILE_TELL");
		ret = 0;
		break;
	case BIO_CTRL_INFO:
		dprintf("Got BIO_CTRL_INFO");
		ret = 1;
		break;
	case BIO_C_SET_FD:
		dprintf("Unsupported call: BIO_C_SET_FD");
		ret = -1;
		break;
	case BIO_C_GET_FD:
		dprintf("Unsupported call: BIO_C_GET_FD");
		ret = -1;
		break;
	case BIO_CTRL_GET_CLOSE:
		dprintf("Got BIO_CTRL_CLOSE");
		ret = BIO_get_shutdown(bio);
		break;
	case BIO_CTRL_SET_CLOSE:
		dprintf("Got BIO_SET_CLOSE");
		BIO_set_shutdown(bio, num);
		break;
	case BIO_CTRL_EOF:
		dprintf("Got BIO_CTRL_EOF");
		ret = ((chan) ? Tcl_Eof(chan) : 1);
		break;
	case BIO_CTRL_PENDING:
		dprintf("Got BIO_CTRL_PENDING");
		ret = ((chan) ? ((Tcl_InputBuffered(chan) ? 1 : 0)) : 0);
		dprintf("BIO_CTRL_PENDING(%d)", (int) ret);
		break;
	case BIO_CTRL_WPENDING:
		dprintf("Got BIO_CTRL_WPENDING");
		ret = 0;
		break;
	case BIO_CTRL_DUP:
		dprintf("Got BIO_CTRL_DUP");
		break;
	case BIO_CTRL_FLUSH:
		dprintf("Got BIO_CTRL_FLUSH");
		ret = ((chan) && (Tcl_WriteRaw(chan, "", 0) >= 0) ? 1 : -1);
		dprintf("BIO_CTRL_FLUSH returning value %li", ret);
		break;
	case BIO_CTRL_PUSH:
		dprintf("Got BIO_CTRL_PUSH");
		ret = 0;
		break;
	case BIO_CTRL_POP:
		dprintf("Got BIO_CTRL_POP");
		ret = 0;
		break;
	case BIO_CTRL_SET:
		dprintf("Got BIO_CTRL_SET");
		ret = 0;
		break;
	case BIO_CTRL_GET :
		dprintf("Got BIO_CTRL_GET ");
		ret = 0;
		break;
#ifdef BIO_CTRL_GET_KTLS_SEND
	case BIO_CTRL_GET_KTLS_SEND:
		dprintf("Got BIO_CTRL_GET_KTLS_SEND");
		ret = 0;
		break;
#endif
#ifdef BIO_CTRL_GET_KTLS_RECV
	case BIO_CTRL_GET_KTLS_RECV:
		dprintf("Got BIO_CTRL_GET_KTLS_RECV");
		ret = 0;
		break;
#endif
	default:
		dprintf("Got unknown control command (%i)", cmd);
		ret = 0;
		break;
    }

    return(ret);
}

static int BioNew(BIO *bio) {
    dprintf("BioNew(%p) called", bio);

    BIO_set_init(bio, 0);
    BIO_set_data(bio, NULL);
    BIO_clear_flags(bio, -1);

    return(1);
}

static int BioFree(BIO *bio) {
    if (bio == NULL) {
	return(0);
    }

    dprintf("BioFree(%p) called", bio);

    if (BIO_get_shutdown(bio)) {
	if (BIO_get_init(bio)) {
	    /*shutdown(bio->num, 2) */
	    /*closesocket(bio->num) */
	}

	BIO_set_init(bio, 0);
	BIO_clear_flags(bio, -1);
    }
    return(1);
}

BIO *BIO_new_tcl(State *statePtr, int flags) {
    BIO *bio;
    static BIO_METHOD *BioMethods = NULL;
#ifdef TCLTLS_SSL_USE_FASTPATH
    Tcl_Channel parentChannel;
    const Tcl_ChannelType *parentChannelType;
    void *parentChannelFdIn_p, *parentChannelFdOut_p;
    int parentChannelFdIn, parentChannelFdOut, parentChannelFd;
    int validParentChannelFd;
    int tclGetChannelHandleRet;
#endif

    dprintf("BIO_new_tcl() called");

    if (BioMethods == NULL) {
	BioMethods = BIO_meth_new(BIO_TYPE_TCL, "tcl");
	BIO_meth_set_write(BioMethods, BioWrite);
	BIO_meth_set_read(BioMethods, BioRead);
	BIO_meth_set_puts(BioMethods, BioPuts);
	BIO_meth_set_ctrl(BioMethods, BioCtrl);
	BIO_meth_set_create(BioMethods, BioNew);
	BIO_meth_set_destroy(BioMethods, BioFree);
    }

    if (statePtr == NULL) {
	dprintf("Asked to setup a NULL state, just creating the initial configuration");

	return(NULL);
    }

#ifdef TCLTLS_SSL_USE_FASTPATH
    /*
     * If the channel can be mapped back to a file descriptor, just use the file descriptor
     * with the SSL library since it will likely be optimized for this.
     */
    parentChannel = Tls_GetParent(statePtr, 0);
    parentChannelType = Tcl_GetChannelType(parentChannel);

    validParentChannelFd = 0;
    if (strcmp(parentChannelType->typeName, "tcp") == 0) {
	tclGetChannelHandleRet = Tcl_GetChannelHandle(parentChannel, TCL_READABLE, (ClientData) &parentChannelFdIn_p);
	if (tclGetChannelHandleRet == TCL_OK) {
	    tclGetChannelHandleRet = Tcl_GetChannelHandle(parentChannel, TCL_WRITABLE, (ClientData) &parentChannelFdOut_p);
	    if (tclGetChannelHandleRet == TCL_OK) {
		parentChannelFdIn = PTR2INT(parentChannelFdIn_p);
		parentChannelFdOut = PTR2INT(parentChannelFdOut_p);
		if (parentChannelFdIn == parentChannelFdOut) {
		    parentChannelFd = parentChannelFdIn;
		    validParentChannelFd = 1;
		}
	    }
	}
    }

    if (validParentChannelFd) {
	dprintf("We found a shortcut, this channel is backed by a socket: %i", parentChannelFdIn);
	bio = BIO_new_socket(parentChannelFd, flags);
	statePtr->flags |= TLS_TCL_FASTPATH;
	return(bio);
    }

    dprintf("Falling back to Tcl I/O for this channel");
#endif

    bio = BIO_new(BioMethods);
    BIO_set_data(bio, statePtr);
    BIO_set_shutdown(bio, flags);
    BIO_set_init(bio, 1);
    return(bio);
}

 * This was built from scratch based upon observation of OpenSSL 0.9.2B
 *
 * Addition credit is due for Andreas Kupries ([email protected]), for
 * providing the Tcl_ReplaceChannel mechanism and working closely with me
 * to enhance it to support full fileevent semantics.
 *
 * Also work done by the follow people provided the impetus to do this "right":
 *    tclSSL (Colin McCormack, Shared Technology)
 *    SSLtcl (Peter Antman)
 *
 */

#include "tlsInt.h"
#include <errno.h>

/*
 * Forward declarations
 */









static void TlsChannelHandlerTimer(ClientData clientData);

/*
























 *-------------------------------------------------------------------
 *



















 * TlsBlockModeProc --
 *
 *    This procedure is invoked by the generic IO level
 *       to set blocking and nonblocking modes
 *
 * Results:
 *    0 if successful or POSIX error code if failed.
 *
 * Side effects:
 *    Sets the device into blocking or nonblocking mode.
 *
 *-------------------------------------------------------------------
 */
static int TlsBlockModeProc(ClientData instanceData, int mode) {
    State *statePtr = (State *) instanceData;

    if (mode == TCL_MODE_NONBLOCKING) {
	statePtr->flags |= TLS_TCL_ASYNC;
    } else {
	statePtr->flags &= ~(TLS_TCL_ASYNC);
    }

    return(0);
}

/*
 *-------------------------------------------------------------------
 *
 * TlsCloseProc --
 *
 *    This procedure is invoked by the generic IO level to perform
 *    channel-type-specific cleanup when a SSL socket based channel
 *    is closed.
 *
 *    Note: we leave the underlying socket alone, is this right?
 *
 * Results:
 *    0 if successful or POSIX error code if failed.
 *
 * Side effects:
 *    Closes the socket of the channel.
 *
 *-------------------------------------------------------------------
 */
static int TlsCloseProc(ClientData instanceData, Tcl_Interp *interp) {
    State *statePtr = (State *) instanceData;

    dprintf("TlsCloseProc(%p)", (void *) statePtr);

    Tls_Clean(statePtr);
    Tcl_EventuallyFree((ClientData)statePtr, Tls_Free);
    return(0);
}

static int TlsClose2Proc(ClientData instanceData,    /* The socket state. */
    Tcl_Interp *interp,		/* For errors - can be NULL. */
    int flags)			/* Flags to close read and/or write side of channel */
{

    State *statePtr = (State *) instanceData;

    dprintf("TlsClose2Proc(%p)", (void *) statePtr);


    if ((flags & (TCL_CLOSE_READ|TCL_CLOSE_WRITE)) == 0) {
	return TlsCloseProc(instanceData, interp);
    }
    return EINVAL;
}

/*
 *------------------------------------------------------*
 *
 * Tls_WaitForConnect --
 *
 * Result:
 *    0 if successful, -1 if failed.
 *
 * Side effects:
 *    Issues SSL_accept or SSL_connect
 *
 *------------------------------------------------------*
 */
int Tls_WaitForConnect(State *statePtr, int *errorCodePtr, int handshakeFailureIsPermanent) {
    unsigned long backingError;
    int err, rc;
    int bioShouldRetry;
    *errorCodePtr = 0;

    dprintf("WaitForConnect(%p)", (void *) statePtr);
    dprintFlags(statePtr);

    if (!(statePtr->flags & TLS_TCL_INIT)) {
	dprintf("Tls_WaitForConnect called on already initialized channel -- returning with immediate success");

	return(0);
    }

    if (statePtr->flags & TLS_TCL_HANDSHAKE_FAILED) {
	/*
	 * Different types of operations have different requirements
	 * SSL being established
	 */
	if (handshakeFailureIsPermanent) {
	    dprintf("Asked to wait for a TLS handshake that has already failed.  Returning fatal error");
	    *errorCodePtr = ECONNABORTED;
	} else {
	    dprintf("Asked to wait for a TLS handshake that has already failed.  Returning soft error");
	    *errorCodePtr = ECONNRESET;
	}
	Tls_Error(statePtr, "Wait for failed handshake");
	return(-1);
    }

    for (;;) {
	ERR_clear_error();

	/* Not initialized yet! Also calls SSL_do_handshake. */
	if (statePtr->flags & TLS_TCL_SERVER) {
	    dprintf("Calling SSL_accept()");

	    err = SSL_accept(statePtr->ssl);

	} else {
	    dprintf("Calling SSL_connect()");

	    err = SSL_connect(statePtr->ssl);
	}

	if (err > 0) {
	    dprintf("Accept or connect was successful");

	    err = BIO_flush(statePtr->bio);

	    if (err <= 0) {
		dprintf("Flushing the lower layers failed, this will probably terminate this session");
	    }
	} else {
	    dprintf("Accept or connect failed");
	}

	rc = SSL_get_error(statePtr->ssl, err);
	backingError = ERR_get_error();
	if (rc != SSL_ERROR_NONE) {
	    dprintf("Got error: %i (rc = %i)", err, rc);
	    dprintf("Got error: %s", ERR_reason_error_string(backingError));
	}

	bioShouldRetry = 0;
	if (err <= 0) {
	    if (rc == SSL_ERROR_WANT_CONNECT || rc == SSL_ERROR_WANT_ACCEPT || rc == SSL_ERROR_WANT_READ || rc == SSL_ERROR_WANT_WRITE) {
		bioShouldRetry = 1;
	    } else if (BIO_should_retry(statePtr->bio)) {
		bioShouldRetry = 1;
	    } else if (rc == SSL_ERROR_SYSCALL && Tcl_GetErrno() == EAGAIN) {
		bioShouldRetry = 1;
	    }
	} else {
	    if (!SSL_is_init_finished(statePtr->ssl)) {
		bioShouldRetry = 1;
	    }
	}

	if (bioShouldRetry) {
	    dprintf("The I/O did not complete -- but we should try it again");

	    if (statePtr->flags & TLS_TCL_ASYNC) {
		dprintf("Returning EAGAIN so that it can be retried later");

		*errorCodePtr = EAGAIN;
		Tls_Error(statePtr, "Handshake not complete, will retry later");
		return(-1);
	    } else {
		dprintf("Doing so now");

		continue;
	    }
	}

	dprintf("We have either completely established the session or completely failed it -- there is no more need to ever retry it though");
	break;
    }




    switch (rc) {
	case SSL_ERROR_NONE:
	    /* The TLS/SSL I/O operation completed */
	    dprintf("The connection is good");
	    *errorCodePtr = 0;
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    /* The TLS/SSL peer has closed the connection for writing by sending the close_notify alert */
	    dprintf("SSL_ERROR_ZERO_RETURN: Connect returned an invalid value...");
	    *errorCodePtr = EINVAL;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    return(-1);

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */
	    dprintf("SSL_ERROR_SYSCALL");

	    if (backingError == 0 && err == 0) {
		dprintf("EOF reached")
		*errorCodePtr = ECONNRESET;
		Tls_Error(statePtr, "(unexpected) EOF reached");

	    } else if (backingError == 0 && err == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		if (*errorCodePtr == ECONNRESET) {
		    *errorCodePtr = ECONNABORTED;
		}
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		if (*errorCodePtr == ECONNRESET) {
		    *errorCodePtr = ECONNABORTED;




		}
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }

	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    return(-1);

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL_ERROR_SSL: Got permanent fatal SSL error, aborting immediately");
	    if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    }
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }
	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    *errorCodePtr = ECONNABORTED;
	    return(-1);

	case SSL_ERROR_WANT_READ:
	case SSL_ERROR_WANT_WRITE:
	case SSL_ERROR_WANT_X509_LOOKUP:
	case SSL_ERROR_WANT_CONNECT:
	case SSL_ERROR_WANT_ACCEPT:
	case SSL_ERROR_WANT_ASYNC:
	case SSL_ERROR_WANT_ASYNC_JOB:
	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
	default:
	    /* The operation did not complete and should be retried later. */
	    dprintf("Operation did not complete, call function again later: %i", rc);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);


	    Tls_Error(statePtr, "Operation did not complete, call function again later");











	    return(-1);
    }



    dprintf("Removing the \"TLS_TCL_INIT\" flag since we have completed the handshake");
    statePtr->flags &= ~TLS_TCL_INIT;

    dprintf("Returning in success");
    *errorCodePtr = 0;

    return(0);
}

/*
 *-------------------------------------------------------------------
 *
 * TlsInputProc --
 *
 *    This procedure is invoked by the generic IO level
 *       to read input from a SSL socket based channel.
 *
 * Results:
 *    Returns the number of bytes read or -1 on error. Sets errorCodePtr
 *    to a POSIX error code if an error occurred, or 0 if none.

 *
 * Side effects:
 *    Reads input from the input device of the channel.
 *
 *-------------------------------------------------------------------
 */

static int TlsInputProc(ClientData instanceData, char *buf, int bufSize, int *errorCodePtr) {
    unsigned long backingError;
    State *statePtr = (State *) instanceData;
    int bytesRead;
    int tlsConnect;
    int err;

    *errorCodePtr = 0;

    dprintf("BIO_read(%d)", bufSize);

    if (statePtr->flags & TLS_TCL_CALLBACK) {
	/* don't process any bytes while verify callback is running */
	dprintf("Callback is running, reading 0 bytes");
	return(0);
    }

    dprintf("Calling Tls_WaitForConnect");
    tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 0);
    if (tlsConnect < 0) {
	dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	Tls_Error(statePtr, strerror(*errorCodePtr));

	bytesRead = -1;
	if (*errorCodePtr == ECONNRESET) {
	    dprintf("Got connection reset");
	    /* Soft EOF */
	    *errorCodePtr = 0;
	    bytesRead = 0;
	}

	return(bytesRead);
    }

    /*
     * We need to clear the SSL error stack now because we sometimes reach
     * this function with leftover errors in the stack.  If BIO_read
     * returns -1 and intends EAGAIN, there is a leftover error, it will be
     * misconstrued as an error, not EAGAIN.
     *
     * Alternatively, we may want to handle the <0 return codes from
     * BIO_read specially (as advised in the RSA docs).  TLS's lower level BIO
     * functions play with the retry flags though, and this seems to work
     * correctly.  Similar fix in TlsOutputProc. - hobbs
     */
    ERR_clear_error();
    bytesRead = BIO_read(statePtr->bio, buf, bufSize);
    dprintf("BIO_read -> %d", bytesRead);

    err = SSL_get_error(statePtr->ssl, bytesRead);
    backingError = ERR_get_error();

#if 0
    if (bytesRead <= 0) {
	if (BIO_should_retry(statePtr->bio)) {
	    dprintf("I/O failed, will retry based on EAGAIN");
	    *errorCodePtr = EAGAIN;
	}
    }
#endif

    switch (err) {
	case SSL_ERROR_NONE:
	    dprintBuffer(buf, bytesRead);
	    break;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }
	    *errorCodePtr = ECONNABORTED;
	    bytesRead = -1;

#if OPENSSL_VERSION_NUMBER >= 0x30000000L
	    /* Unexpected EOF from the peer for OpenSSL 3.0+ */
	    if (ERR_GET_REASON(backingError) == SSL_R_UNEXPECTED_EOF_WHILE_READING) {
		dprintf("(Unexpected) EOF reached")
		*errorCodePtr = 0;
		bytesRead = 0;
		Tls_Error(statePtr, "EOF reached");
	    }
#endif
	    break;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */

	    if (backingError == 0 && bytesRead == 0) {
		/* Unexpected EOF from the peer for OpenSSL 1.1 */
		dprintf("(Unexpected) EOF reached")
		*errorCodePtr = 0;
		bytesRead = 0;






		Tls_Error(statePtr, "EOF reached");


	    } else if (backingError == 0 && bytesRead == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		bytesRead = -1;
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		bytesRead = -1;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    dprintf("Got SSL_ERROR_ZERO_RETURN, this means an EOF has been reached");
	    bytesRead = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf("Got SSL_ERROR_WANT_READ, mapping this to EAGAIN");
	    bytesRead = -1;
	    *errorCodePtr = EAGAIN;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	default:
	    dprintf("Unknown error (err = %i), mapping to EOF", err);
	    *errorCodePtr = 0;
	    bytesRead = 0;
	    Tls_Error(statePtr, "Unknown error");
	    break;
    }

    dprintf("Input(%d) -> %d [%d]", bufSize, bytesRead, *errorCodePtr);
    return(bytesRead);
}

/*
 *-------------------------------------------------------------------
 *
 * TlsOutputProc --
 *
 *    This procedure is invoked by the generic IO level
 *       to write output to a SSL socket based channel.
 *
 * Results:
 *    Returns the number of bytes written or -1 on error. Sets errorCodePtr
 *    to a POSIX error code if an error occurred, or 0 if none.
 *
 * Side effects:
 *    Writes output on the output device of the channel.
 *
 *-------------------------------------------------------------------
 */

static int TlsOutputProc(ClientData instanceData, const char *buf, int toWrite, int *errorCodePtr) {
    unsigned long backingError;
    State *statePtr = (State *) instanceData;
    int written, err;
    int tlsConnect;

    *errorCodePtr = 0;

    dprintf("BIO_write(%p, %d)", (void *) statePtr, toWrite);
    dprintBuffer(buf, toWrite);

    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Don't process output while callbacks are running");
	written = -1;
	*errorCodePtr = EAGAIN;
	return(-1);
    }

    dprintf("Calling Tls_WaitForConnect");
    tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 1);
    if (tlsConnect < 0) {
	dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	Tls_Error(statePtr, strerror(*errorCodePtr));

	written = -1;
	if (*errorCodePtr == ECONNRESET) {
	    dprintf("Got connection reset");
	    /* Soft EOF */
	    *errorCodePtr = 0;
	    written = 0;
	}

	return(written);
    }

    if (toWrite == 0) {
	dprintf("zero-write");
	err = BIO_flush(statePtr->bio);

	if (err <= 0) {
	    dprintf("Flushing failed");
	    Tls_Error(statePtr, "Flush failed");

	    *errorCodePtr = EIO;
	    written = 0;
	    return(-1);
	}

	written = 0;
	*errorCodePtr = 0;
	return(0);
    }

    /*
     * We need to clear the SSL error stack now because we sometimes reach
     * this function with leftover errors in the stack.  If BIO_write
     * returns -1 and intends EAGAIN, there is a leftover error, it will be
     * misconstrued as an error, not EAGAIN.
     *
     * Alternatively, we may want to handle the <0 return codes from
     * BIO_write specially (as advised in the RSA docs).  TLS's lower level
     * BIO functions play with the retry flags though, and this seems to
     * work correctly.  Similar fix in TlsInputProc. - hobbs
     */
    ERR_clear_error();
    written = BIO_write(statePtr->bio, buf, toWrite);
    dprintf("BIO_write(%p, %d) -> [%d]", (void *) statePtr, toWrite, written);

    err = SSL_get_error(statePtr->ssl, written);
    backingError = ERR_get_error();

    switch (err) {
	case SSL_ERROR_NONE:
	    if (written < 0) {
		written = 0;
	    }
	    break;

	case SSL_ERROR_WANT_WRITE:
	    dprintf("Got SSL_ERROR_WANT_WRITE, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    written = -1;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_WRITE");
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf(" write R BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	case SSL_ERROR_WANT_X509_LOOKUP:
	    dprintf(" write X BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_X509_LOOKUP");
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    dprintf(" closed");
	    written = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */

	    if (backingError == 0 && written == 0) {
		dprintf("EOF reached")
		*errorCodePtr = 0;
		written = 0;
		Tls_Error(statePtr, "EOF reached");

	    } else if (backingError == 0 && written == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		written = -1;
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		written = -1;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }

	    break;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }
	    *errorCodePtr = ECONNABORTED;
	    written = -1;
	    break;

	default:
	    dprintf("unknown error: %d", err);
	    Tls_Error(statePtr, "Unknown error");
	    break;
    }

    dprintf("Output(%d) -> %d", toWrite, written);
    return(written);
}

/*
 *-------------------------------------------------------------------
 *
 * TlsSetOptionProc --
 *
 *    Sets an option value for a SSL socket based channel, or a
 *    list of all options and their values.
 *
 * Results:
 *    TCL_OK if successful or TCL_ERROR if failed.
 *
 * Side effects:
 *    Updates channel option to new value.
 *
 *-------------------------------------------------------------------
 */
static int
TlsSetOptionProc(ClientData instanceData,    /* Socket state. */
    Tcl_Interp *interp,		/* For errors - can be NULL. */
    const char *optionName,	/* Name of the option to set the value for, or
				 * NULL to get all options and their values. */
    const char *optionValue)	/* Value for option. */
{
    State *statePtr = (State *) instanceData;

    Tcl_Channel downChan = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);
    Tcl_DriverSetOptionProc *setOptionProc;

    setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(downChan));
    if (setOptionProc != NULL) {
	return (*setOptionProc)(Tcl_GetChannelInstanceData(downChan), interp, optionName, optionValue);
    } else if (optionName == (char*) NULL) {
	/*
	 * Request is query for all options, this is ok.
	 */
	return TCL_OK;
    }
    /*
     * Request for a specific option has to fail, we don't have any.
     */
    return Tcl_BadChannelOption(interp, optionName, "");
}

/*
 *-------------------------------------------------------------------
 *
 * TlsGetOptionProc --
 *
 *    Gets an option value for a SSL socket based channel, or a
 *    list of all options and their values.
 *
 * Results:
 *    A standard Tcl result. The value of the specified option or a
 *    list of all options and their values is returned in the
 *    supplied DString.
 *
 * Side effects:
 *    None.
 *
 *-------------------------------------------------------------------
 */
static int
TlsGetOptionProc(ClientData instanceData,    /* Socket state. */
    Tcl_Interp *interp,		/* For errors - can be NULL. */
    const char *optionName,	/* Name of the option to retrieve the value for, or

				 * NULL to get all options and their values. */

    Tcl_DString *optionValue)	/* Where to store the computed value initialized by caller. */

{
    State *statePtr = (State *) instanceData;

    Tcl_Channel downChan = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);
    Tcl_DriverGetOptionProc *getOptionProc;

    getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(downChan));
    if (getOptionProc != NULL) {
	return (*getOptionProc)(Tcl_GetChannelInstanceData(downChan), interp, optionName, optionValue);
    } else if (optionName == (char*) NULL) {
	/*
	 * Request is query for all options, this is ok.
	 */
	return TCL_OK;
    }
    /*
     * Request for a specific option has to fail, we don't have any.
     */
    return Tcl_BadChannelOption(interp, optionName, "");
}

/*
 *-------------------------------------------------------------------
 *
 * TlsWatchProc --
 *
 *    Initialize the notifier to watch Tcl_Files from this channel.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Sets up the notifier so that a future event on the channel
 *    will be seen by Tcl.
 *
 *-------------------------------------------------------------------
 */

static void
TlsWatchProc(ClientData instanceData,    /* The socket state. */
    int mask)			/* Events of interest; an OR-ed combination of

				 * TCL_READABLE, TCL_WRITABLE and TCL_EXCEPTION. */
{
    Tcl_Channel     downChan;
    State *statePtr = (State *) instanceData;
    Tcl_DriverWatchProc *watchProc;

    dprintf("TlsWatchProc(0x%x)", mask);

    /* Pretend to be dead as long as the verify callback is running.
     * Otherwise that callback could be invoked recursively. */
    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Callback is on-going, doing nothing");
	return;
    }

    dprintFlags(statePtr);

    downChan = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);

    if (statePtr->flags & TLS_TCL_HANDSHAKE_FAILED) {
	dprintf("Asked to watch a socket with a failed handshake -- nothing can happen here");

	dprintf("Unregistering interest in the lower channel");


	watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(downChan));
	watchProc(Tcl_GetChannelInstanceData(downChan), 0);
	statePtr->watchMask = 0;

	return;
    }

    statePtr->watchMask = mask;

    /* No channel handlers any more. We will be notified automatically
     * about events on the channel below via a call to our
     * 'TransformNotifyProc'. But we have to pass the interest down now.
     * We are allowed to add additional 'interest' to the mask if we want
     * to. But this transformation has no such interest. It just passes
     * the request down, unchanged.
     */


    dprintf("Registering our interest in the lower channel (chan=%p)", (void *) downChan);
    watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(downChan));
    watchProc(Tcl_GetChannelInstanceData(downChan), mask);


    /*
     * Management of the internal timer.
     */

    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	dprintf("A timer was found, deleting it");
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = (Tcl_TimerToken) NULL;
    }

    if ((mask & TCL_READABLE) &&
	((Tcl_InputBuffered(statePtr->self) > 0) || (BIO_ctrl_pending(statePtr->bio) > 0))) {
	/*
	 * There is interest in readable events and we actually have
	 * data waiting, so generate a timer to flush that.
	 */
	dprintf("Creating a new timer since data appears to be waiting");
	statePtr->timer = Tcl_CreateTimerHandler(TLS_TCL_DELAY, TlsChannelHandlerTimer, (ClientData) statePtr);
    }

}

/*
 *-------------------------------------------------------------------
 *
 * TlsGetHandleProc --
 *
 *    Called from Tcl_GetChannelFile to retrieve o/s file handler
 *    from the SSL socket based channel.
 *
 * Results:
 *    The appropriate Tcl_File handle or NULL if none.
 *
 * Side effects:
 *    None.
 *
 *-------------------------------------------------------------------
 */
static int TlsGetHandleProc(ClientData instanceData,    /* Socket state. */
    int direction,		/* TCL_READABLE or TCL_WRITABLE */
    ClientData *handlePtr)	/* Handle associated with the channel */
{
    State *statePtr = (State *) instanceData;

    return(Tcl_GetChannelHandle(Tls_GetParent(statePtr, TLS_TCL_FASTPATH), direction, handlePtr));
}

/*
 *-------------------------------------------------------------------
 *
 * TlsNotifyProc --
 *
 *    Handler called by Tcl to inform us of activity
 *    on the underlying channel.
 *
 * Results:
 *    Type of event or 0 if failed
 *
 * Side effects:
 *    May process the incoming event by itself.
 *
 *-------------------------------------------------------------------
 */
static int TlsNotifyProc(ClientData instanceData,    /* Socket state. */
    int mask)			/* type of event that occurred:
				 * OR-ed combination of TCL_READABLE or TCL_WRITABLE */
{

    State *statePtr = (State *) instanceData;
    int errorCode;

    /*
     * An event occurred in the underlying channel.  This
     * transformation doesn't process such events thus returns the
     * incoming mask unchanged.
     */
    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	/*
	 * Delete an existing timer. It was not fired, yet we are
	 * here, so the channel below generated such an event and we
	 * don't have to. The renewal of the interest after the
	 * execution of channel handlers will eventually cause us to
	 * recreate the timer (in WatchProc).
	 */
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = (Tcl_TimerToken) NULL;
    }

    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Returning 0 due to callback");
	return 0;
    }

    dprintf("Calling Tls_WaitForConnect");
    errorCode = 0;
    if (Tls_WaitForConnect(statePtr, &errorCode, 1) < 0) {
	Tls_Error(statePtr, strerror(errorCode));
	if (errorCode == EAGAIN) {
	    dprintf("Async flag could be set (didn't check) and errorCode == EAGAIN:  Returning 0");

	    return 0;
	}

	dprintf("Tls_WaitForConnect returned an error");
    }

    dprintf("Returning %i", mask);

    return(mask);
}


/*
 *------------------------------------------------------*
 *
 *    TlsChannelHandlerTimer --
 *
 *    ------------------------------------------------*
 *    Called by the notifier (-> timer) to flush out

 *    information waiting in channel buffers.
 *    ------------------------------------------------*








































 *








































 *    Side effects:
 *        As of 'TlsChannelHandler'.
 *
 *    Result:
 *        None.
 *
 *------------------------------------------------------*
 */

static void TlsChannelHandlerTimer(ClientData clientData) {
    State *statePtr = (State *) clientData;
    int mask = 0;

    dprintf("Called");

    statePtr->timer = (Tcl_TimerToken) NULL;

    if (BIO_wpending(statePtr->bio)) {
	dprintf("[chan=%p] BIO writable", statePtr->self);

	mask |= TCL_WRITABLE;
    }

    if (BIO_pending(statePtr->bio)) {
	dprintf("[chan=%p] BIO readable", statePtr->self);

	mask |= TCL_READABLE;
    }

    dprintf("Notifying ourselves");
    Tcl_NotifyChannel(statePtr->self, mask);

    dprintf("Returning");

    return;
}

Tcl_Channel Tls_GetParent(State *statePtr, int maskFlags) {
    dprintf("Requested to get parent of channel %p", statePtr->self);

    if ((statePtr->flags & ~maskFlags) & TLS_TCL_FASTPATH) {
	dprintf("Asked to get the parent channel while we are using FastPath -- returning NULL");
	return(NULL);
    }
    return(Tcl_GetStackedChannel(statePtr->self));
}

/*
 *-------------------------------------------------------------------
 *
 * Tls_ChannelType --
 *
 *    Return the correct TLS channel driver info
 *
 * Results:
 *    The correct channel driver for the current version of Tcl.
 *
 * Side effects:
 *    None.
 *
 *-------------------------------------------------------------------
 */
static const Tcl_ChannelType tlsChannelType = {
    "tls",			/* Type name */
    TCL_CHANNEL_VERSION_5,	/* v5 channel */
    TlsCloseProc,		/* Close proc */
    TlsInputProc,		/* Input proc */
    TlsOutputProc,		/* Output proc */
    NULL,			/* Seek proc */
    TlsSetOptionProc,		/* Set option proc */
    TlsGetOptionProc,		/* Get option proc */
    TlsWatchProc,		/* Initialize notifier */
    TlsGetHandleProc,		/* Get OS handles out of channel */
    TlsClose2Proc,		/* close2proc */
    TlsBlockModeProc,		/* Set blocking/nonblocking mode*/
    NULL,			/* Flush proc */
    TlsNotifyProc,		/* Handling of events bubbling up */
    NULL,			/* Wide seek proc */
    NULL,			/* Thread action */
    NULL			/* Truncate */
};

const Tcl_ChannelType *Tls_ChannelType(void) {
    return &tlsChannelType;
}