Remove TLS strict mode.

It's new in OpenSSL 1.0.2 so it's never set by existing code. This removes gobs
and gobs of complexity from tls1_check_chain. It only checks the local
certificate, not the peer certificate. The uses appear to be:

- Sanity-check configuration. Not worth the complexity.

- Guide in selecting ciphers based on ClientHello parameters and which
  certificates in the CERT_PKEY are compatible. This isn't very useful one its
  own since the CERT_PKEY array only stores one slot per type (e.g. you cannot
  configure RSA/SHA-1 and RSA/SHA-256).

- For the (currently removed) SSL_check_chain to return more information based
  on ClientHello parameters and guide selecting a certificate. This is
  potentially useful but, as noted in the commit which removed it, redundant
  with ssl_early_callback_ctx.

This CL is largely mechanical removing of dead codepaths. The follow-up will
clean up the now unnecessary parts of this function.

Change-Id: I2ebfa17e4f73e59aa1ee9e4ae7f615af2c6cf590
Reviewed-on: https://boringssl-review.googlesource.com/2285
Reviewed-by: Adam Langley <agl@google.com>
3 files changed