Package: inn2
Version: 2.6.3-1
Hi,
There is a TLS-related issue with INN 2.6.3 if the "security level"
feature of OpenSSL 1.1 is used: negotiations for ciphersuites using DHE
key exchange fail if the security level is set to something beyond 1.
The upcoming Debian 10 (Buster) seems to do this by default:
https://wiki.debian.org/ContinuousIntegration/TriagingTips/openssl-1.1.1
INN 2.6.3 negotiates 1028-bit parameters with for instance the
"DHE-RSA-AES256-GCM-SHA384" cipher suite, which is disallowed by the
security level 2 enforced by Debian Buster. At least 2048-bit
parameters are expected.
According to OpenSSL documentation:
https://www.openssl.org/docs/man1.1.1/man3/SSL_CTX_set_security_level.html
"WARNING at this time setting the security level higher than 1 for
general internet use is likely to cause considerable interoperability
issues and is not recommended. This is because the SHA1 algorithm is
very widely used in certificates and will be rejected at levels higher
than 1 because it only offers 80 bits of security."
Here is a patch to improve how INN selects appropriate parameters:
https://inn.eyrie.org/trac/changeset/10344/
Could it please be included in the inn2 package shipped with Buster?
P.-S.: This issue was found by Michael Bäuerle, and reported in the
news.software.nntp newsgroup.
--
Julien ÉLIE
« Qui joue des flûtes perd sa hutte ! » (Mme Agecanonix)
