RHEL includes several cryptographic components who's security doesn't remain constant over time. Algorithms such as (cryptographic) hashing and encryption typically have a lifetime after which they are considered either too risky to use or plain insecure. That would mean we need to phase out such algorithms from the default settings, or completely disable if they could cause irreparable issue.
This bug is about disabling the MD5 algorithm from the OpenSSL library, while at the same hand providing a configuration method for MD5 to be allowed when needed.
For future extensibility in RHEL-7 it is recommended for any introduced configuration method to be re-usable for future algorithm or parameter deprecation (e.g., SHA1 or less than 1024-bit RSA/DH parameters), and ideally part of upstream.
I've found that it was possible to verify also certificates using MD2, MD4, and SHA0, I've disabled these together with MD5.
The system administrator can re-enable some of them with
echo 'LegacySigningMDs md5 md4' >> /etc/pki/tls/legacy-settings
For MD5 it is also possible to enable it by setting environment variable OPENSSL_ENABLE_MD5_VERIFY to any value (same method as in RHEL-7).
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.