Support delegated credentials verison 06

This version adds signature algorithms to the extension

Change-Id: I91dc78d33ee81cb7a6221c7bdeefc8ea460a2d6c
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42424
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/ssl/ssl_cert.cc b/ssl/ssl_cert.cc
index 6bac3a9..c64303a 100644
--- a/ssl/ssl_cert.cc
+++ b/ssl/ssl_cert.cc
@@ -821,16 +821,13 @@
   }
 
   // Check that the DC signature algorithm is supported by the peer.
-  Span<const uint16_t> peer_sigalgs = tls1_get_peer_verify_algorithms(hs);
-  bool sigalg_found = false;
+  Span<const uint16_t> peer_sigalgs = hs->peer_delegated_credential_sigalgs;
   for (uint16_t peer_sigalg : peer_sigalgs) {
     if (dc->expected_cert_verify_algorithm == peer_sigalg) {
-      sigalg_found = true;
-      break;
+      return true;
     }
   }
-
-  return sigalg_found;
+  return false;
 }
 
 bool ssl_signing_with_dc(const SSL_HANDSHAKE *hs) {