Remove SSL_get_server_key_exchange_hash.

Chromium no longer uses it.

Change-Id: I50cc55bad4124305686d299032a2e8ed2cb9d0d7
Reviewed-on: https://boringssl-review.googlesource.com/8691
Reviewed-by: David Benjamin <davidben@google.com>

include/openssl/ssl.h

@@ -3212,14 +3212,6 @@ OPENSSL_EXPORT void SSL_load_error_strings(void);
 OPENSSL_EXPORT int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx,
                                                const char *profiles);
 
-/* SSL_get_server_key_exchange_hash, on a client, returns the hash the server
- * used to sign the ServerKeyExchange in TLS 1.2. If not applicable, it returns
- * |TLSEXT_hash_none|.
- *
- * TODO(davidben): Remove once Chromium switches to
- * |SSL_get_peer_signature_algorithm|. */
-OPENSSL_EXPORT uint8_t SSL_get_server_key_exchange_hash(const SSL *ssl);
-
 /* SSL_set_tlsext_use_srtp calls |SSL_set_srtp_profiles|. It returns zero on
  * success and one on failure.
  *

ssl/ssl_lib.c

@@ -2716,10 +2716,6 @@ uint16_t SSL_get_peer_signature_algorithm(const SSL *ssl) {
   return ssl->s3->tmp.peer_signature_algorithm;
 }
 
-uint8_t SSL_get_server_key_exchange_hash(const SSL *ssl) {
-  return (uint8_t) (SSL_get_peer_signature_algorithm(ssl) >> 8);
-}
-
 size_t SSL_get_client_random(const SSL *ssl, uint8_t *out, size_t max_out) {
   if (max_out == 0) {
     return sizeof(ssl->s3->client_random);