LP #1462856: Newest RHEL/CentOS openssl update breaks mysql DHE
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lpjirasync January 21, 2018 at 1:41 AM
**Comment from Launchpad by: Stephen Colebrook on: 26-06-2015 18:11:56
@hrvojem Any rough timeframe on when we might see that release?
lpjirasync January 21, 2018 at 1:41 AM
**Comment from Launchpad by: Hrvoje Matijakovic on: 26-06-2015 17:19:52
@jolan - PXC will be fixed in the next/upcoming release.
lpjirasync January 21, 2018 at 1:41 AM
**Comment from Launchpad by: jolan on: 25-06-2015 13:52:38
Are xtradb cluster builds being done by a different team? I don't see an update for that in the testing repo.
lpjirasync January 21, 2018 at 1:41 AM
**Comment from Launchpad by: Hrvoje Matijakovic on: 25-06-2015 06:08:33
Packages are now available in our testing repos (https://www.percona.com/doc/percona-server/5.5/installation/apt_repo.html#percona-apt-testing-repository) so you can give them a try.
lpjirasync January 21, 2018 at 1:40 AM
**Comment from Launchpad by: Dan Benton on: 24-06-2015 11:27:19
Thank you for fixing this issue. Any ideas when a new package will be released to the repo's so we can test it?
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**Reported in Launchpad by Jacques Grove last update 20-07-2015 20:33:33
This is a problem in upstream as well, I am pretty sure:
The newest RHEL/CentOS/SL 6.6 openssl package (1.0.1e-30.el6_6.9 ; published around 6/4/2015) contains a fix for CVE-2015-4000 . RedHat's fix for this was to limit the use of any SSL DH key sizes to a minimum of 768 bits. This breaks any DHE SSL ciphers for MySQL clients as soon as you install the openssl update, since in vio/viosslfactories.c , the default DHPARAM is a 512 bit one. As far as I can tell this cannot be changed in configuration/runtime; and needs a recompile.
We should probably include and/or upstream this patch:
https://lists.fedoraproject.org/pipermail/scm-commits/2012-December/910767.html
Example:
If a user in a Percona 5.6.23-72.1-log server is setup with grant "require SSL", and the client (using the updated openssl package) executes:
mysql -u user -h serverhostname --ssl --ssl-cipher=DHE-RSA-AES256-SHA -p
Enter password:
ERROR 2026 (HY000): SSL connection error: error:00000001:lib(0):func(0):reason(1)
This will occur for any DHE cipher. Using a non-DHE cipher will work as expected.
Workaround:
Downgrade the client openssl package to any version before 1.0.1e-30.el6_6.9; e.g. 0:1.0.1e-30.el6_6.8
Alternatively, do not use DH ciphers. This is not acceptable because the supported non-DH ciphers do not afford any PFS protection.
Solution is for the server to present a 1024 bit DH param. This would:
Avoid the problem with "fixed" client libraries.
Still be small enough to avoid problems with some clients (e.g. older Java versions do not like DH params > 1024 bit)
Improve security in general.