Date: Sat, 03 Jan 2009 22:54:44 +0100 From: "O. Hartmann" <ohartman@mail.zedat.fu-berlin.de> To: freebsd-questions@freebsd.org Subject: MD5 vs. SHA1: hashed passwords in /etc/master.passwd - can we configure SHA1 as default in /etc/login.conf? Message-ID: <495FDEA4.6010301@mail.zedat.fu-berlin.de>
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This is a multi-part message in MIME format. --------------020604060008010902050109 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit MD5 seems to be compromised by potential collision attacks. So I tried to figure out how I can use another hash for security purposes when hashing passwords for local users on a FreeBSD 7/8 box, like root or local box administration. Looking at man login.conf reveals only three possible hash algorithms selectable: md5 (recommended), des and blf. Changing /etc/login.conf's tag default:\ :passwd_format=sha1:\ followed by a obligatory "cap_mkdb" seems to do something - changing root's password results in different hashes when selecting different hash algorithms like des, md5, sha1, blf or even sha256. Well, I never digged deep enough into the source code to reveal the magic and truth, so I will ask here for some help. Is it possible to change the md5-algorithm by default towards sha1 as recommended after the md5-collisions has been published? Thanks in advance, Oliver --------------020604060008010902050109 Content-Type: message/rfc822; name="Attached Message" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="Attached Message" Message-ID: <495FDC97.4090301@mail.zedat.fu-berlin.de> Date: Sat, 03 Jan 2009 22:45:59 +0100 From: "O. Hartmann" <ohartman@mail.zedat.fu-berlin.de> User-Agent: Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: freebsd-security@freebsd.org Subject: MD5 vs. SHA1 hashed passwords in /etc/master.passwd: can we configure SHA1 in /etc/login.conf? X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit MD5 seems to be compromised by potential collision attacks. So I tried to figure out how I can use another hash for security purposes when hashing passwords for local users on a FreeBSD 7/8 box, like root or local box administration. Looking at man login.conf reveals only three possible hash algorithms selectable: md5 (recommended), des and blf. Changing /etc/login.conf's tag default:\ :passwd_format=sha1:\ followed by a obligatory "cap_mkdb" seems to do something - changing root's password results in different hashes when selecting different hash algorithms like des, md5, sha1, blf or even sha256. Well, I never digged deep enough into the source code to reveal the magic and truth, so I will ask here for some help. Is it possible to change the md5-algorithm by default towards sha1 as recommended after the md5-collisions has been published? Thanks in advance, Oliver --------------020604060008010902050109--
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