[Announce] Libgcrypt 1.7.8 released to fix CVE-2017-7526
wk at gnupg.org
Thu Jun 29 09:28:20 CEST 2017
The GnuPG Project is pleased to announce the availability of Libgcrypt
version 1.7.8. This release fixes a local side-channel attack.
Libgcrypt is a general purpose library of cryptographic building blocks.
It is originally based on code used by GnuPG. It does not provide any
implementation of OpenPGP or other protocols. Thorough understanding of
applied cryptography is required to use Libgcrypt.
Noteworthy changes in version 1.7.8 (2017-06-29) [C21/A1/R8]
* Bug fixes:
- Mitigate a flush+reload side-channel attack on RSA secret keys
dubbed "Sliding right into disaster". For details see
Note that this side-channel attack requires that the attacker can run
arbitrary software on the hardware where the private RSA key is used.
Allowing execute access to a box with private keys should be considered
as a game over condition, anyway. Thus in practice there are easier
ways to access the private keys than to mount this side-channel attack.
However, on boxes with virtual machines this attack may be used by one
VM to steal private keys from another VM.
Source code is hosted at the GnuPG FTP server and its mirrors as listed
at <https://gnupg.org/download/mirrors.html>. On the primary server
the source tarball and its digital signature are:
That file is bzip2 compressed. A gzip compressed version is here:
The same files are also available via HTTP:
In order to check that the version of Libgcrypt you downloaded is an
original and unmodified file please follow the instructions found at
<https://gnupg.org/download/integrity_check.html>. In short, you may
use one of the following methods:
- Check the supplied OpenPGP signature. For example to check the
signature of the file libgcrypt-1.7.8.tar.bz2 you would use this
gpg --verify libgcrypt-1.7.8.tar.bz2.sig libgcrypt-1.7.8.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 the end of this mail for information on the signing keys.
- If you are not able to use an existing version of 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-1.7.8.tar.bz2, you run the command like this:
and check that the output matches the first line from the
You should also verify that the checksums above are authentic by
matching them with copies of this announcement. Those copies can be
found at other mailing lists, web sites, and search engines.
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 that 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 . A
listing with commercial support offers for Libgcrypt and related
software is available at the GnuPG web site .
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.
Maintenance and development of Libgcrypt is mostly financed by
donations; see <https://gnupg.org/donate/>. We currently employ
4 full-time developers, one part-timer, and one contractor to work on
GnuPG and closely related software like Libgcrypt.
We like to thank all the people who helped with this release, be it
testing, coding, translating, suggesting, auditing, administering the
servers, spreading the word, and answering questions on the mailing
lists. Also many thanks to all our donors .
The GnuPG Team
This is an announcement only mailing list. Please send replies only to
the gcrypt-devel 'at' gnupg.org mailing list.
List of Release Signing Keys:
To guarantee that a downloaded GnuPG version has not been tampered by
malicious entities we provide signature files for all tarballs and
binary versions. The keys are also signed by the long term keys of
their respective owners. Current releases are signed by one or more
of these five 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' jabberwocky.com>
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' fsij.org>
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)
rsa3072/4B092E28 2017-03-17 [expires: 2027-03-15]
Key fingerprint = 5B80 C575 4298 F0CB 55D8 ED6A BCEF 7E29 4B09 2E28
Andre Heinecke (Release Signing Key)
You may retrieve these keys from a keyserver using this command
gpg --keyserver hkp://keys.gnupg.net --recv-keys \
249B39D24F25E3B6 04376F3EE0856959 \
2071B08A33BD3F06 8A861B1C7EFD60D9 BCEF7E294B092E28
The keys are also available at https://gnupg.org/signature_key.html and
in any recently released GnuPG tarball in the file g10/distsigkey.gpg .
Note that this mail has been signed by a different key.
Die Gedanken sind frei. Ausnahmen regelt ein Bundesgesetz.
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