I do not think (but please correct me), that this version of ubuntu you're using has something like a system-wide policy, so it will not be possible to change the sha1 acceptance system-wide. In that case it will be more effective to try and change the priority string on the specific applications you are interested. The newer versions of gnutls have a more powerful configuration that can be used to implement a modifiable system-wide policy.
regards, Nikos On Mon, Jan 27, 2020 at 5:29 AM Brandon Sawyers <[email protected]> wrote: > > Sorry, I should have made it clear before. > > I've tried putting the string in both /etc/gnutls/config and > /etc/gnutls/default-priorites according to the docs I found but, neither > worked. > > Thanks, > > On Sun, Jan 26, 2020, 17:18 Brandon Sawyers <[email protected]> wrote: >> >> Thanks for the help. >> >> We are already in the process of updating so of the certs. Thanks for the >> reminder. >> >> Now I just need to figure out how to have the priority strong apply system >> wide instead of just gnutls-cli. >> >> Any tips there? >> >> Thanks again, >> Brandon >> >> >> >> On Sun, Jan 26, 2020, 16:56 Dimitri John Ledkov <[email protected]> wrote: >>> >>> On Thu, 23 Jan 2020 at 12:16, Dimitri John Ledkov <[email protected]> wrote: >>> > >>> > On Thu, 23 Jan 2020 at 14:01, Nikos Mavrogiannopoulos <[email protected]> >>> > wrote: >>> > > >>> > > On Wed, Jan 22, 2020 at 3:42 PM Brandon Sawyers <[email protected]> >>> > > wrote: >>> > > > >>> > > > Hello everyone: >>> > > > >>> > > > A recent package upgrade in ubuntu 1604 (v3.4.10-4ubuntu1.6) and 1804 >>> > > > (v3.5.18-1ubuntu1.2) has left us without SHA1 support. Since we are >>> > > > still in the process of migrating our last services off of SHA1 with >>> > > > a target date of April this has put us in a pickle. >>> > > > >>> > > > From reading the docs I expect I should be able to use priority and >>> > > > allow SHA1 to function, however making this work has been rather >>> > > > frustrating. >>> > > > >>> > > > I've tried several different versions of the following command but I >>> > > > would expect just having "NORMAL:+SIGN-RSA-SHA1:+SHA1" priority set >>> > > > should work. >>> > > > >>> > > > `gnutls-bin --x509cafile ./cachain-with-sha1-signed-cert.pem >>> > > > --priority='NORMAL:+SIGN-RSA-SHA1:+SHA1' -p 636 >>> > > > internal.directory.org` >>> > > >>> > > Have you tried appending %VERIFY_ALLOW_SIGN_WITH_SHA1? The available >>> > > priority strings are documented in: >>> > > https://gnutls.org/manual/html_node/Priority-Strings.html >>> > > >>> > >>> > From what I can tell is that the backports do not include that >>> > flag.... I'm escalating this, as this is regression-security as I do >>> > not believe that upstream code is affected as this is an issue in the >>> > patch set released in ubuntu. >>> > >>> > I hope to move this discussion downstream to >>> > https://bugs.launchpad.net/ubuntu/+source/gnutls28/+bug/1860656 >>> > >>> >>> To close this out, a further update got published to the affected >>> releases which adds support to use "%VERIFY_ALLOW_BROKEN" and >>> "%VERIFY_ALLOW_SIGN_WITH_SHA1" in the priority string option, allowing >>> one to re-enable obsoleted hashes in certificate signatures. >>> >>> But please upgrade your certificates to use SHA256 nonetheless as >>> progressively more software will start outright reject SHA1 >>> certificates without a way to turn them back on. >>> >>> -- >>> Regards, >>> >>> Dimitri. > > _______________________________________________ > Gnutls-help mailing list > [email protected] > http://lists.gnupg.org/mailman/listinfo/gnutls-help _______________________________________________ Gnutls-help mailing list [email protected] http://lists.gnupg.org/mailman/listinfo/gnutls-help
