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<title>GnuTLS 3.5.3: The TLS record protocol</title>
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<a name="The-TLS-record-protocol"></a>
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<p>
Next: <a href="The-TLS-Alert-Protocol.html#The-TLS-Alert-Protocol" accesskey="n" rel="next">The TLS Alert Protocol</a>, Previous: <a href="The-transport-layer.html#The-transport-layer" accesskey="p" rel="prev">The transport layer</a>, Up: <a href="Introduction-to-TLS.html#Introduction-to-TLS" accesskey="u" rel="up">Introduction to TLS</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Function-and-Data-Index.html#Function-and-Data-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="The-TLS-record-protocol-1"></a>
<h3 class="section">3.3 The TLS record protocol</h3>
<a name="index-record-protocol"></a>
<p>The record protocol is the secure communications provider. Its purpose
is to encrypt, authenticate and —optionally— compress packets.
The record layer functions can be called at any time after
the handshake process is finished, when there is need to receive
or send data. In <acronym>DTLS</acronym> however, due to re-transmission
timers used in the handshake out-of-order handshake data might
be received for some time (maximum 60 seconds) after the handshake
process is finished.
</p>
<p>The functions to access the record protocol are limited to send
and receive functions, which might, given
the importance of this protocol in <acronym>TLS</acronym>, seem awkward. This is because
the record protocol’s parameters are all set by the handshake protocol.
The record protocol initially starts with NULL parameters, which means
no encryption, and no MAC is used. Encryption and authentication begin
just after the handshake protocol has finished.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">• <a href="Encryption-algorithms-used-in-the-record-layer.html#Encryption-algorithms-used-in-the-record-layer" accesskey="1">Encryption algorithms used in the record layer</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="Compression-algorithms-used-in-the-record-layer.html#Compression-algorithms-used-in-the-record-layer" accesskey="2">Compression algorithms used in the record layer</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="Weaknesses-and-countermeasures.html#Weaknesses-and-countermeasures" accesskey="3">Weaknesses and countermeasures</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="On-Record-Padding.html#On-Record-Padding" accesskey="4">On Record Padding</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
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