Introduce a ssl_cipher_has_server_public_key to save the repeated
NULL/PSK/RSA_PSK[*] check. Don't allow skipping to ServerKeyExchange when
expecting Certificate; the messages expected are determined by the cipher
suite. The ssl3_get_server_public_key call is already guarded.
As the previous test demonstrates, this is safe because of the
ssl3_check_cert_and_algorithm call, but avoid the looseness in the parsing
there.
[*] NB: we don't implement RSA_PSK, and OpenSSL has never implemented it.
Change-Id: I0571e6bcbeb8eb883f77878bdc98d1aa3a287cf3
Reviewed-on: https://boringssl-review.googlesource.com/1156
Reviewed-by: Adam Langley <agl@google.com>
e8f3d666cc