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<title>GnuTLS 3.5.3: Introduction to GnuTLS</title>
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<a name="Introduction-to-GnuTLS"></a>
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<p>
Next: <a href="Introduction-to-TLS.html#Introduction-to-TLS" accesskey="n" rel="next">Introduction to TLS</a>, Previous: <a href="Preface.html#Preface" accesskey="p" rel="prev">Preface</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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>
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<hr>
<a name="Introduction-to-GnuTLS-1"></a>
<h2 class="chapter">2 Introduction to GnuTLS</h2>
<p>In brief <acronym>GnuTLS</acronym> can be described as a library which offers an API
to access secure communication protocols. These protocols provide
privacy over insecure lines, and were designed to prevent
eavesdropping, tampering, or message forgery.
</p>
<p>Technically <acronym>GnuTLS</acronym> is a portable ANSI C based library which
implements the protocols ranging from SSL 3.0 to TLS 1.2 (see <a href="Introduction-to-TLS.html#Introduction-to-TLS">Introduction to TLS</a>,
for a detailed description of the protocols), accompanied
with the required framework for authentication and public key
infrastructure. Important features of the <acronym>GnuTLS</acronym> library
include:
</p>
<ul>
<li> Support for TLS 1.2, TLS 1.1, TLS 1.0 and SSL 3.0 protocols.
</li><li> Support for Datagram TLS 1.0 and 1.2.
</li><li> Support for handling and verification of <acronym>X.509</acronym> and <acronym>OpenPGP</acronym> certificates.
</li><li> Support for password authentication using <acronym>TLS-SRP</acronym>.
</li><li> Support for keyed authentication using <acronym>TLS-PSK</acronym>.
</li><li> Support for TPM, <acronym>PKCS</acronym> #11 tokens and smart-cards.
</li></ul>
<p>The <acronym>GnuTLS</acronym> library consists of three independent parts, namely the “TLS
protocol part”, the “Certificate part”, and the “Cryptographic
back-end” part. The “TLS protocol part” is the actual protocol
implementation, and is entirely implemented within the
<acronym>GnuTLS</acronym> library. The “Certificate part” consists of the
certificate parsing, and verification functions and it uses
functionality from the
libtasn1 library.
The “Cryptographic back-end” is provided by the nettle
and gmplib libraries.
</p>
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