tree e15264486c945480eceb30a6d9f6399109cd9ecb
parent 85a1e2e01c440953834fd739162bca8d25d0311c
author David Benjamin <davidben@google.com> 1676318409 -0500
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1677167812 +0000

Add more DSA consistency checks.

DSA private keys cannot be zero. If they are, trying to sign an all
zeros digest loops forever. Thanks to Guido Vranken who reported this in
https://github.com/openssl/openssl/issues/20268

Along the way, because OpenSSL's bad API design made constructing DSA
objects such a mess, just move all the consistency checks to
dsa_check_parameters (now dsa_check_key) so it is consistently checked
everywhere.

Ideally we'd get a better handle on DSA state, like we hope to do for
RSA state (though not there yet), so checks only happen once. But we
consider DSA deprecated so it's not worth putting much effort into it.

Update-Note: Some invalid DSA keys will be rejected by the parser and at
use. Nothing should be using DSA anymore.

Change-Id: I25d3faf145a85389c47abdd9db8e9b0056b37d8a
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/57227
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>