Commit Graph

3 Commits

Author SHA1 Message Date
Clemens Lang
efdb8c60a3 Allow MD5-SHA1 in LEGACY c-p to fix TLS 1.0
Fedora supports TLS down to 1.0 in LEGACY crypto-policy, but TLS 1.0
defaults to rsa_pkcs1_md5_sha1 with RSA certificates by default.
However, MD5-SHA1 would require SECLEVEL=0, because its 67 bits of
security do not meet SECLEVEL=1's requirement of 80 bits.

Instead of setting SECLEVEL to 0 in the LEGACY crypto-policy (which
would include all algorithms, regardless of their security level), allow
MD5-SHA1 if rh-allow-sha1-signatures is yes and SECLEVEL is 1.

Related: rhbz#2069239
2022-04-27 12:24:38 +02:00
Clemens Lang
0eaa0014c9 Fix a FIXME in the openssl.cnf(5) manpage
Signed-off-by: Clemens Lang <cllang@redhat.com>
2022-04-20 15:47:59 +02:00
Clemens Lang
432cfa2baa Allow disabling of SHA1 signatures
NOTE: This patch is ported from CentOS 9 / RHEL 9, where it defaults to
denying SHA1 signatures. On Fedora, the default is – for now – to allow
SHA1 signatures.

In order to phase out SHA1 signatures, introduce a new configuration
option in the alg_section named 'rh-allow-sha1-signatures'. This option
defaults to true. If set to false, any signature creation or
verification operations that involve SHA1 as digest will fail.

This also affects TLS, where the signature_algorithms extension of any
ClientHello message sent by OpenSSL will no longer include signatures
with the SHA1 digest if rh-allow-sha1-signatures is false. For servers
that request a client certificate, the same also applies for
CertificateRequest messages sent by them.

Resolves: rhbz#2070977
Related: rhbz#2031742, rhbz#2062640
Signed-off-by: Clemens Lang <cllang@redhat.com>
2022-04-07 18:14:04 +02:00