<dt><strong>peername</strong> <em>name</em></dt>
        <dd>The peername from the certificate.</dd>
        <dt><strong>sbits</strong> <em>n</em></dt>
        <dd>The number of bits used for the session key.</dd>
        <dt><strong>cipher</strong> <em>cipher</em></dt>
        <dd>The current cipher in use between the client and
            server channels.</dd>
        <dt><strong>validation</strong> <em>result</em></dt>
        <dd>Certificate validation result.</dd>
        <dt><strong>verification<em>result</em></dt>
        <dd>Certificate verification result.</dd>
        <dt><strong>alpn</strong> <em>protocol</em></dt>
        <dd>The protocol selected after Application-Layer Protocol
	    Negotiation (ALPN).</dd>
        <dt><strong>protocol</strong> <em>value</em></dt>
        <dd>The protocol version used for the connection:
	  SSLv2, SSLv3, TLSv1, TLSv1.1, TLSv1.2, TLSv1.3, or unknown</dd>
        <dt><strong>signature_hash</strong> <em>string</em></dt>
        <dd>The signature hash value.</dd>
        <dt><strong>signature_type</strong> <em>type</em></dt>
        <dd>The signature type value.</dd>
        <dt><strong>ca_names</strong> <em>list</em></dt>
        <dd>List of the Certificate Authorities used to create the certificate.</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

	additional information on the cipher. If <em>supported</em>
	is specified as true, then only the ciphers supported for protocol
	will be listed.</dd>

    <dt><a name="tls::protocols"><strong>tls::protocols</strong></a></dt>
    <dd>Returns a list of 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>.</dd>
	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>

	<dl>

	<dt>
	  <strong>alpn</strong> <em>protocol</em>
	</dt>
	<dd>
	  This form of callback is invoked when server selects the first
	  -alpn specified protocol common to the client and server. If none,
	  first client one is used.
	  For servers, this form of callback is invoked when the client ALPN
	  header is received and the first -alpn specified protocol common to
	  the both the client and server is selected. If none, the first
	  client specified protocol is used.
	</dd>

	<br>

<!--	This form of callback is disabled.

	<dt>

	<br>
-->

	<dt>
	  <strong>hello</strong> <em>servername</em>
	</dt>
	<dd>
	  This form of callback is invoked during client hello message processing.
	  For servers, this form of callback is invoked during client hello
	  message processing.
	</dd>

	<br>

	<dt>
	  <strong>info</strong> <em>channel major minor message</em>
	</dt>

	<br>

	<dt>
	  <strong>sni</strong> <em>servername</em>
	</dt>
	<dd>
	  This form of callback is invoked when the server receives the SNI
	  header from the client where <i>servername</i> is the client
	  specified servername. Used to allow multiple names for
	  same server so the right certificate can be used.
	  For servers, this form of callback is invoked when the SNI header
	  from the client is received. Where <i>servername</i> is the client
	  specified servername. This is used when a server supports multiple
	  names, so the right certificate can be used.
	</dd>

	<br>
	<br>

	<dt>
	  <strong>verify</strong> <em>channel depth cert status error</em>
	</dt>
	<dd>
	  This form of callback is invoked by the OpenSSL function
	  <code>SSL_set_verify()</code>.
	  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 result and choose whether to continue or not.
	  <br>
	  The <em>depth</em> argument is an integer representing the
	  current depth on the certificate chain, with
	  <code>0</code> as the subject certificate and higher values
	  denoting progressively more indirect issuer certificates.
	  <br>
	  The <em>cert</em> argument is a list of key-value pairs similar

    X509 *peer;
    Tcl_Obj *objPtr;
    Tcl_Channel chan;
    char *channelName, *ciphers;
    int mode;
    const unsigned char *proto;
    unsigned int len;
    int nid;

    dprintf("Called");

    switch (objc) {
	case 2:
	    channelName = Tcl_GetStringFromObj(objv[1], NULL);
	    break;

    ciphers = (char*)SSL_get_cipher(statePtr->ssl);
    if ((ciphers != NULL) && (strcmp(ciphers, "(NONE)") != 0)) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("cipher", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(SSL_get_cipher(statePtr->ssl), -1));
    }

    /* Verify the X509 certificate presented by the peer */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("validation", -1));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("verification", -1));
    if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
	/* proto = "failed"; */
	proto = REASON();
    } else {
	proto = "ok";
    }
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(proto, -1));
    Tcl_ListObjAppendElement(interp, objPtr,
	Tcl_NewStringObj(X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)), -1));

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

    /* Valid for non-RSA signature and TLS 1.3 */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("signature_hash", -1));
    if (objc == 2 ? SSL_get_peer_signature_nid(statePtr->ssl, &nid) : SSL_get_signature_nid(statePtr->ssl, &nid)) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(OBJ_nid2ln(nid), -1));
    } else {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("", -1));
    }
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("signature_type", -1));
    if (objc == 2 ? SSL_get_peer_signature_type_nid(statePtr->ssl, &nid) : SSL_get_signature_type_nid(statePtr->ssl, &nid)) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(OBJ_nid2ln(nid), -1));
    } else {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("", -1));
    }

    Tcl_SetObjResult(interp, objPtr);
    return TCL_OK;
	clientData = clientData;
}

/*

/*
 * Forward declarations
 */
Tcl_ChannelType *Tls_ChannelType(void);
Tcl_Channel     Tls_GetParent(State *statePtr, int maskFlags);

Tcl_Obj         *Tls_NewX509Obj(Tcl_Interp *interp, X509 *cert);
Tcl_Obj		*Tls_NewCAObj(Tcl_Interp *interp, const SSL *ssl, int peer);
void            Tls_Error(State *statePtr, char *msg);
void            Tls_Free(char *blockPtr);
void            Tls_Clean(State *statePtr);
int             Tls_WaitForConnect(State *statePtr, int *errorCodePtr, int handshakeFailureIsPermanent);

BIO             *BIO_new_tcl(State* statePtr, int flags);

/*
 * Copyright (C) 1997-2000 Sensus Consulting Ltd.
 * Matt Newman <[email protected]>
 * Copyright (C) 2023 Brian O'Hagan
 */
#include <tcl.h>
#include <stdio.h>
#include <openssl/bio.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/asn1.h>
#include "tlsInt.h"

/*
 *  Ensure these are not macros - known to be defined on Win32
 */
#ifdef min