AC_LANG_POP([C])

	TCLTLS_SSL_OPENSSL_CHECK_PROTO_VER([tcltls_ssl_ssl2], [SSLv2_method], [sslv2], [NO_SSL2])
	TCLTLS_SSL_OPENSSL_CHECK_PROTO_VER([tcltls_ssl_ssl3], [SSLv3_method], [sslv3], [NO_SSL3])
	TCLTLS_SSL_OPENSSL_CHECK_PROTO_VER([tcltls_ssl_tls1_0], [TLSv1_method], [tlsv1.0], [NO_TLS1])
	TCLTLS_SSL_OPENSSL_CHECK_PROTO_VER([tcltls_ssl_tls1_1], [TLSv1_1_method], [tlsv1.1], [NO_TLS1_1])
	TCLTLS_SSL_OPENSSL_CHECK_PROTO_VER([tcltls_ssl_tls1_2], [TLSv1_2_method], [tlsv1.2], [NO_TLS1_2])
	TCLTLS_SSL_OPENSSL_CHECK_PROTO_VER([tcltls_ssl_tls1_3], [TLSv1_3_method], [tlsv1.3], [NO_TLS1_3])

	AC_CACHE_VAL([tcltls_cv_func_tlsext_hostname], [
		AC_LANG_PUSH(C)
		AC_MSG_CHECKING([for SSL_set_tlsext_host_name])
		AC_LINK_IFELSE([AC_LANG_PROGRAM([
#include <openssl/ssl.h>
#if (SSLEAY_VERSION_NUMBER >= 0x0907000L)

	if test "$enableval" = "yes"; then
		tcltls_ssl_tls1_1='force'
	else
		tcltls_ssl_tls1_1='false'
	fi
])

dnl ## TLSv1.2: Enabled by default
tcltls_ssl_tls1_2='true'
AC_ARG_ENABLE([tlsv1.2], AS_HELP_STRING([--disable-tlsv1.2], [disable TLSv1.2 protocol]), [
	if test "$enableval" = "yes"; then
		tcltls_ssl_tls1_2='force'
	else
		tcltls_ssl_tls1_2='false'
	fi
])

dnl ## TLSv1.3: Enabled by default
tcltls_ssl_tls1_3='true'
AC_ARG_ENABLE([tlsv1.3], AS_HELP_STRING([--disable-tlsv1.3], [disable TLSv1.3 protocol]), [
	if test "$enableval" = "yes"; then
		tcltls_ssl_tls1_3='force'
	else
		tcltls_ssl_tls1_3='false'
	fi
])


dnl Enable support for a debugging build
tcltls_debug='false'
AC_ARG_ENABLE([debug], AS_HELP_STRING([--enable-debug], [enable debugging parameters]), [
	if test "$enableval" = "yes"; then
		tcltls_debug='true'
	fi

CiphersObjCmd(clientData, interp, objc, objv)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;
    int objc;
    Tcl_Obj	*CONST objv[];
{
    static CONST84 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
    };
    Tcl_Obj *objPtr;
    SSL_CTX *ctx = NULL;
    SSL *ssl = NULL;
    STACK_OF(SSL_CIPHER) *sk;
    char *cp, buf[BUFSIZ];
    int index, verbose = 0;

    case TLS_TLS1_2:
#if defined(NO_TLS1_2)
		Tcl_AppendResult(interp, "protocol not supported", NULL);
		return TCL_ERROR;
#else
		ctx = SSL_CTX_new(TLSv1_2_method()); break;
#endif
    case TLS_TLS1_3:
#if defined(NO_TLS1_3)
		Tcl_AppendResult(interp, "protocol not supported", NULL);
		return TCL_ERROR;
#else
		ctx = SSL_CTX_new(TLSv1_3_method()); break;
#endif
    default:
		break;
    }
    if (ctx == NULL) {
	Tcl_AppendResult(interp, REASON(), (char *) NULL);
	return TCL_ERROR;
    }

        <dd>Enable use of SSL v3. (<strong>default</strong>: <em>false</em>)</dd>
        <dt>-<strong>tls1</strong> <em>bool</em></dt>
        <dd>Enable use of TLS v1. (<strong>default</strong>: <em>true</em>)</dd>
        <dt>-<strong>tls1.1</strong> <em>bool</em></dt>
        <dd>Enable use of TLS v1.1 (<strong>default</strong>: <em>true</em>)</dd>
        <dt>-<strong>tls1.2</strong> <em>bool</em></dt>
        <dd>Enable use of TLS v1.2 (<strong>default</strong>: <em>true</em>)</dd>
        <dt>-<strong>tls1.3</strong> <em>bool</em></dt>
        <dd>Enable use of TLS v1.3 (<strong>default</strong>: <em>true</em>)</dd>
    </dl>
</blockquote>

<dl>
    <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 SSL-enabling of a regular Tcl channel.  An error

        {* -autoservername discardOpts 1}
        {* -servername iopts 1}
        {* -ssl2 iopts 1}
        {* -ssl3 iopts 1}
        {* -tls1 iopts 1}
        {* -tls1.1 iopts 1}
        {* -tls1.2 iopts 1}
        {* -tls1.3 iopts 1}
    }

    # tls::socket and tls::init options as a humane readable string
    variable socketOptionsNoServer
    variable socketOptionsServer

    # Internal [switch] body to validate options