<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::ciphers</b> <em>?protocol? ?verbose? ?supported?</em></dd>
	    <dd><b>tls::protocols</b></dd>
	    <dd><b>tls::version</b></dd>
	    <dt>&nbsp;</dt>
	    <dd><b>tls::digest</b> <em>type ?-bin|-hex? ?-key hmac_key? [-file filename | -chan channel | ?-data? data]</em></dd>
	    <dd><b>tls::digests</b></dd>
	    <dd><b>tls::md4</b> <em>data</em></dd>
	    <dd><b>tls::md5</b> <em>data</em></dd>
	    <dd><b>tls::sha1</b> <em>data</em></dd>
	    <dd><b>tls::sha256</b> <em>data</em></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>
toolkit.</p>

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

<p><b>package require Tcl 8.5</b><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::ciphers"><b>tls::ciphers</b> <i>?protocol? ?verbose? ?supported?</i></a><br>
<a href="#tls::protocols"><b>tls::protocols</b></a><br>
<a href="#tls::version"><b>tls::version</b></a><br>
<br>
<a href="#tls::digest"><b>tls::digest</b> <i>type ?-bin|-hex? ?-key hmac_key? [-file filename | -chan channel | ?-data? data]</i></a><br>
<a href="#tls::digests"><b>tls::digests</b></a><br>
<a href="#tls::md4"><b>tls::md4</b> <i>data</i></a><br>
<a href="#tls::md5"><b>tls::md5</b> <i>data</i></a><br>
<a href="#tls::sha1"><b>tls::sha1</b> <i>data</i></a><br>
<a href="#tls::sha256"><b>tls::sha256</b> <i>data</i></a><br>
</p>

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

<p>This extension provides a generic binding to <a
href="http://www.openssl.org/">OpenSSL</a>, utilizing the
<strong>Tcl_StackChannel</strong>

	<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::ciphers"><strong>tls::ciphers</strong>
    <em>?protocol? ?verbose? ?supported?</em></a></dt>
    <dd>Without any args, returns a list of all ciphers. With
	<em>protocol</em>, only the ciphers supported for that protocol
	are returned where <em>protocol</em> must be one of <b>ssl2, ssl3,
	tls1, tls1.1, tls1.2,</b> or <b>tls1.3</b>. If <em>verbose</em> is
	specified as true then a verbose, human readable list is returned
	with 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>. 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>

    <br>
    <dt><a name="tls::digest"><strong>tls::digest</strong> <em>type ?-bin|-hex?
	?-key hmac_key? [-file filename | -chan channel | ?-data? data]</em></a></dt>
    <dd>Calculate the message digest for <em>data</em> or file <em>filename</em>
	using <em>type</em> hash algorithm. Returns value as a hex string
	(default) or as a binary value with <em>-bin</em> option. Using
	<em>-chan</em> option, a stacked channel is created and data read
	from the channel is used to calculate a message digest with the result
	returned with the last read operation before EOF. Use <em>-key</em> to
	specify the key and return a Hashed Message Authentication Code (HMAC).
	Type can be any OpenSSL supported hash algorithm including: <b>md4</b>,
	<b>md5</b>, <b>sha1</b>, <b>sha256</b>, <b>sha512</b>, <b>sha3-256</b>,
	etc. See <b>tls::digests</b> command for a full list.</dd>

    <dt><a name="tls::digests"><strong>tls::digests</strong></a></dt>
    <dd>Returns a list of the hash algorithms for <b>tls::digest</b> command.</dd>

    <dt><a name="tls::md4"><strong>tls::md4</strong> <em>data</em></a></dt>
    <dd>Returns the MD4 message-digest for <em>data</em> as a hex string.</dd>

    <dt><a name="tls::md5"><strong>tls::md5</strong> <em>data</em></a></dt>
    <dd>Returns the MD5 message-digest for <em>data</em> as a hex string.</dd>

    <dt><a name="tls::sha1"><strong>tls::sha1</strong> <em>data</em></a></dt>
    <dd>Returns the SHA1 secure hash algorithm digest for <em>data</em> as a hex string.</dd>

    <dt><a name="tls::sha256"><strong>tls::sha256</strong> <em>data</em></a></dt>
    <dd>Returns the SHA-2 SHA256 secure hash algorithm digest for <em>data</em> as a hex 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