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Libgcrypt 1.6.5 with security fix released

From: Werner Koch
Subject: Libgcrypt 1.6.5 with security fix released
Date: Tue, 09 Feb 2016 16:25:04 +0100
User-agent: Gnus/5.13 (Gnus v5.13)


The GNU project is pleased to announce the availability of Libgcrypt
version 1.6.5.  This is a security fix release to mitigate a new side
channel attack.

Libgcrypt is a general purpose library of cryptographic building blocks.
It does not provide any implementation of OpenPGP or other protocols.
Thorough understanding of applied cryptography is required for proper
use Libgcrypt.

Noteworthy changes in version 1.6.5

 * Mitigate side-channel attack on ECDH with Weierstrass curves
   [CVE-2015-7511].  See for

 * Fix build problem on Solaris.


Please follow the instructions found at <> or
read on:

Libgcrypt may be downloaded from one of the GnuPG mirror sites or
From its primary FTP server.  The list of mirrors can be found at
<>.  Note that Libgcrypt is
not available at

The Libgcrypt source code compressed using BZIP2 and its OpenPGP
signature are available here: (2490k)
or here: (2490k)

The same source code but compressed with the older GZIP algorithm is
available here: (2901k)

The affected ECDH algorithm is for example used by GnuPG 2.1 (modern).
An update of Libgcrypt is sufficient to fix this for GnuPG.  We have
also updated the Windows installer of that GnuPG version to include this
fixed version of Libgcrypt:  (2630k)
or here:  (2630k)

The source used to build that Windows installer can be found in the same
directory with a ".tar.xz" suffix.

Checking the Integrity

In order to check that the version of Libgcrypt you are going to build
is an original and unmodified one, you can do it in one of the following

 * Check the supplied OpenPGP signature.  For example to check the
   signature of the file libgcrypt-1.6.5.tar.bz2 you would use this

     gpg --verify libgcrypt-1.6.5.tar.bz2.sig libgcrypt-1.6.5.tar.bz2

   This checks whether the signature file matches the source file.
   You should see a message indicating that the signature is good and
   made by one or more of the release signing keys.  Make sure that
   this is a valid key, either by matching the shown fingerprint
   against a trustworthy list of valid release signing keys or by
   checking that the key has been signed by trustworthy other keys.
   See below for information on the signing keys.

 * If you are not able to use GnuPG, you have to verify the SHA-1
   checksum.  On Unix systems the command to do this is either 
   "sha1sum" or "shasum".   Assuming you downloaded the file
   libgcrypt-1.6.5.tar.bz2, you run the command like this:

     sha1sum libgcrypt-1.6.5.tar.bz2

   and check that the output matches the first line from the
   following list:

c3a5a13e717f7b3e3895650afc1b6e0d3fe9c726  libgcrypt-1.6.5.tar.bz2
765370d9ee9e858c257dc06c3f0621bda8acaf69  libgcrypt-1.6.5.tar.gz
89bd31652d370ba69ac27b42b4d474d7edd9e0ea  gnupg-w32-2.1.11_20160209.exe
0a81d3a7b404299f651bf6f6540176b00d0a3967  gnupg-w32-2.1.11_20160209.tar.xz

Release Signing Keys

To guarantee that a downloaded Libgcrypt version has not been tampered
by malicious entities we provide signature files for all tarballs.  The
keys are also signed by the long term keys of their respective owners.
Current releases are signed by one or more of these four keys:

  2048R/4F25E3B6 2011-01-12 [expires: 2019-12-31]
  Key fingerprint = D869 2123 C406 5DEA 5E0F  3AB5 249B 39D2 4F25 E3B6
  Werner Koch (dist sig)

  rsa2048/E0856959 2014-10-29 [expires: 2019-12-31]
  Key fingerprint = 46CC 7308 65BB 5C78 EBAB  ADCF 0437 6F3E E085 6959
  David Shaw (GnuPG Release Signing Key) <dshaw 'at'>

  rsa2048/33BD3F06 2014-10-29 [expires: 2016-10-28]
  Key fingerprint = 031E C253 6E58 0D8E A286  A9F2 2071 B08A 33BD 3F06
  NIIBE Yutaka (GnuPG Release Key) <gniibe 'at'>

  rsa2048/7EFD60D9 2014-10-19 [expires: 2020-12-31]
  Key fingerprint = D238 EA65 D64C 67ED 4C30  73F2 8A86 1B1C 7EFD 60D9
  Werner Koch (Release Signing Key)

You may retrieve these keys from a keyserver using this command

  gpg --keyserver hkp:// --recv-keys  \
                  249B39D24F25E3B6 04376F3EE0856959 \
                  2071B08A33BD3F06 8A861B1C7EFD60D9

The keys are also available at <> and
in any recently released GnuPG tarball in the file g10/distsigkey.gpg .
Note that this mail has been signed by a different key.


Libgcrypt is distributed under the terms of the GNU Lesser General
Public License (LGPLv2.1+).  The helper programs as well as the
documentation are distributed under the terms of the GNU General Public
License (GPLv2+).  The file LICENSES has notices about contributions
that require these additional notices are distributed.


For help on developing with Libgcrypt you should read the included
manual and optional ask on the gcrypt-devel mailing list [1].  A
listing with commercial support offers for Libgcrypt and related
software is available at the GnuPG web site [2].

If you are a developer and you may need a certain feature for your
project, please do not hesitate to bring it to the gcrypt-devel mailing
list for discussion.

Please consult the archive of the gcrypt-devel mailing list before
reporting a bug <>.
We suggest to send bug reports for a new release to this list in favor
of filing a bug at <>.  For commercial support
requests we keep a list of known service companies at:

If you are a developer and you need a certain feature for your project,
please do not hesitate to bring it to the gcrypt-devel mailing list for

Maintenance and development of Libgcrypt is mostly financed by donations.
We currently employ 3 full-time developers, one part-timer, and one
contractor.  They all work on GnuPG and closely related software like
Libgcrypt.  Please see

on how you can help.


We have to thank all the people who helped with this release, be it
testing, coding, suggesting, auditing, administering the servers,
spreading the word, answering questions on the mailing lists, and
donating money.  Niibe Yutaka did most of the work on fixing the side
channel attack.  Special thanks to Daniel Genkin, Lev Pachmanov, Itamar
Pipman, and Eran Tromer for notifying us about their attack in advance
and testing the fix.

For the Libgcrypt hackers,


This is a announcement only mailing list.  Please send replies only to
the gcrypt-devel at mailing list.

Die Gedanken sind frei.  Ausnahmen regelt ein Bundesgesetz.

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