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Subject: [FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-14:11.crypt
From: FreeBSD Errata Notices <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Date: Wed, 22 Oct 2014 21:07:49 GMT

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FreeBSD-EN-14:11.crypt                                          Errata Notice
                                                          The FreeBSD Project

Topic:          crypt(3) default hashing algorithm

Category:       core
Module:         libcrypt
Announced:      2014-10-22
Affects:        FreeBSD 9.3 and FreeBSD 10.0-STABLE after 2014-05-11 and 
                before 2014-10-16.
Corrected:      2014-10-13 15:56:47 UTC (stable/10, 10.1-PRERELEASE)
                2014-10-16 21:39:04 UTC (releng/10.1, 10.1-RC3)
                2014-10-16 21:39:04 UTC (releng/10.1, 10.1-RC2-p2)
                2014-10-16 21:39:04 UTC (releng/10.1, 10.1-RC1-p2)
                2014-10-16 21:39:04 UTC (releng/10.1, 10.1-BETA3-p2)
                2014-10-21 21:09:54 UTC (stable/9, 9.3-STABLE)
                2014-10-21 23:50:46 UTC (releng/9.3, 9.3-RELEASE-p4)

For general information regarding FreeBSD Errata Notices and Security
Advisories, including descriptions of the fields above, security
branches, and the following sections, please visit

I.   Background

The crypt(3) function performs password hashing.  Different algorithms
of varying strength are available, with older, weaker algorithms being
retained for compatibility.

The crypt(3) function was originally based on the DES encryption
algorithm and generated a 13-character hash from an eight-character
password (longer passwords were truncated) and a two-character salt.

II.  Problem Description

In recent FreeBSD releases, the default algorithm for crypt(3) was
changed to SHA-512, which generates a much longer hash than the
traditional DES-based algorithm.

III. Impact

Many applications assume that crypt(3) always returns a traditional DES
hash, and blindly copy it into a short buffer without bounds checks. This
may lead to a variety of undesirable results including, at worst, crashing
the application.

IV.  Workaround

No workaround is available.

V.   Solution

Perform one of the following:

1) Upgrade your system to a supported FreeBSD stable or release / security
branch (releng) dated after the correction date.

2) To update your present system via a source code patch:

The following patches have been verified to apply to the applicable
FreeBSD release branches.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch
# fetch
# gpg --verify crypt.patch.asc

b) Apply the patch.  Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

c) Recompile the operating system using buildworld and installworld as
described in <URL:>.

Restart all deamons using the library, or reboot the system.

3) To update your system via a binary patch:

Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

VI.  Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

Branch/path                                                      Revision
- -------------------------------------------------------------------------
stable/9/                                                         r273425
releng/9.3/                                                       r273438
stable/10/                                                        r273043
releng/10.1/                                                      r273187
- -------------------------------------------------------------------------

To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:

# svn diff -cNNNNNN --summarize svn://

Or visit the following URL, replacing NNNNNN with the revision number:


VII. References

The latest revision of this Errata Notice is available at

Version: GnuPG v2.0

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