We are proud to announce two new stable GnuTLS releases: Version 2.6.4
Normally we only make stable releases on the latest stable branch, i.e.,
currently 2.6.x. Many users appears to still be using the 2.4.x branch.
To make it easier for these users to upgrade to a secure version, we
have back-ported all of the X.509 chain verification fixes from the
2.6.x branch to the 2.4.x branch. These two releases should solve the
[CVE-2008-4989] security problem and fix the problems with incorrectly
rejected chains that were reported for earlier 2.6.x releases.
GnuTLS is a modern C library that implement the standard network
security protocol Transport Layer Security (TLS), for use by network
applications. GnuTLS is developed for GNU/Linux, but works on many
Unix-like systems and comes with a binary installer for Windows.
The GnuTLS library is distributed under the terms of the GNU Lesser
General Public License version 2.1 (or later). The "extra" GnuTLS
library (which contains TLS/IA support, LZO compression and Libgcrypt
FIPS-mode handler), the OpenSSL compatibility library, the self tests
and the command line tools are all distributed under the GNU General
Public License version 3.0 (or later). The manual is distributed under
the GNU Free Documentation License version 1.3 (or later).
The project page of the library is available at:
Version 2.6.4 is a maintenance release on our stable branch.
** libgnutls: Accept chains where intermediary certs are trusted.
Before GnuTLS needed to validate the entire chain back to a
self-signed certificate. GnuTLS will now stop looking when it has
found an intermediary trusted certificate. The new behaviour is
useful when chains, for example, contains a top-level CA, an
intermediary CA signed using RSA-MD5, and an end-entity certificate.
To avoid chain validation errors due to the RSA-MD5 cert, you can
explicitly add the intermediary RSA-MD5 cert to your trusted certs.
The signature on trusted certificates are not checked, so the chain
has a chance to validate correctly. Reported by "Douglas E. Engert"
** libgnutls: result_size in gnutls_hex_encode now holds
the size of the result. Report by John Brooks .
** libgnutls: gnutls_handshake when sending client hello during a
rehandshake, will not offer a version number larger than the current.
Reported by Tristan Hill .
** libgnutls: Permit V1 Certificate Authorities properly.
Before they were mistakenly rejected even though
GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT were supplied. Reported by
"Douglas E. Engert" in
** libgnutls: deprecate X.509 validation chains using MD5 and MD2
This is a bugfix -- the previous attempt to do this from internal x509
certificate verification procedures did not return the correct value
for certificates using a weak hash. Reported by Daniel Kahn Gillmor
debugged and patch by Tomas Mraz and Daniel Kahn
** libgnutls: Fix compile error with Sun CC.
Reported by Jeff Cai <[email protected]> in
** API and ABI modifications:
No changes since last version.
Getting the Software
GnuTLS may be downloaded from one of the mirror sites or direct from
The list of mirrors can be found at
Here are the BZIP2 compressed sources (4.9MB):
Here are OpenPGP detached signatures signed using key 0xB565716F:
Note, that we don't distribute gzip compressed tarballs.
In order to check that the version of GnuTLS which you are going to
install is an original and unmodified one, you should verify the OpenPGP
signature. You can use the command
gpg --verify gnutls-2.6.4.tar.bz2.sig
This checks whether the signature file matches the source file. You
should see a message indicating that the signature is good and made by
that signing key. Make sure that you have the right key, either by
checking the fingerprint of that key with other sources or by checking
that the key has been signed by a trustworthy other key. The signing
key can be identified with the following information:
pub 1280R/B565716F 2002-05-05 [expires: 2009-04-21]
Key fingerprint = 0424 D4EE 81A0 E3D1 19C6 F835 EDA2 1E94 B565 716F
uid Simon Josefsson
uid Simon Josefsson <[email protected]>
sub 1280R/4D5D40AE 2002-05-05 [expires: 2009-04-21]
The key is available from:
Alternatively, after successfully verifying the OpenPGP signature of
this announcement, you could verify that the files match the following
checksum values. The values are for SHA-1 and SHA-224 respectively:
The manual is available online at:
In particular the following formats are available:
For developers there is a GnuTLS API reference manual formatted using
the GTK-DOC tools:
If you need help to use GnuTLS, or want to help others, you are invited
to join our help-gnutls mailing list, see:
If you wish to participate in the development of GnuTLS, you are invited
to join our gnutls-dev mailing list, see:
GnuTLS has been ported to the Windows operating system, and a binary
installer is available. The installer contains DLLs for application
development, manuals, examples, and source code. The installer uses
libgpg-error v1.7, libgcrypt v1.4.4, libtasn1 v1.8, and GnuTLS v2.6.4.
For more information about GnuTLS for Windows:
The Windows binary installer and PGP signature:
The checksum values for SHA-1 and SHA-224 are:
Thanks to Enrico Tassi, we also have mingw32 *.deb's available:
The checksum values for SHA-1 and SHA-224 are:
GnuTLS messages have been translated into Dutch, French, German,
Malay, Polish, Swedish, and Vietnamese. We welcome the addition of
Improving GnuTLS is costly, but you can help! We are looking for
organizations that find GnuTLS useful and wish to contribute back.
You can contribute by reporting bugs, improve the software, or donate
money or equipment.
Commercial support contracts for GnuTLS are available, and they help
finance continued maintenance. Simon Josefsson Datakonsult AB, a
Stockholm based privately held company, is currently funding GnuTLS
maintenance. We are always looking for interesting development
projects. See http://josefsson.org/ for more details.
The GnuTLS service directory is available at: