Add |SSL_CIPHER_get_value| to get the IANA number of a cipher suite.

Change-Id: I1d642e0bf319421d49b48f25803280046a85a176
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/37585
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

include/openssl/ssl.h

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index d3ca63c..dbf9293 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -1247,10 +1247,14 @@
 // https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4.
 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
 
-// SSL_CIPHER_get_id returns |cipher|'s id. It may be cast to a |uint16_t| to
-// get the cipher suite value.
+// SSL_CIPHER_get_id returns |cipher|'s non-IANA id. This is not its
+// IANA-assigned number, which is called the "value" here, although it may be
+// cast to a |uint16_t| to get it.
 OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
 
+// SSL_CIPHER_get_value returns |cipher|'s IANA-assigned number.
+OPENSSL_EXPORT uint16_t SSL_CIPHER_get_value(const SSL_CIPHER *cipher);
+
 // SSL_CIPHER_is_aead returns one if |cipher| uses an AEAD cipher.
 OPENSSL_EXPORT int SSL_CIPHER_is_aead(const SSL_CIPHER *cipher);
 

ssl/ssl_cipher.cc

diff --git a/ssl/ssl_cipher.cc b/ssl/ssl_cipher.cc
index a420f4d..30037f6 100644
--- a/ssl/ssl_cipher.cc
+++ b/ssl/ssl_cipher.cc
@@ -1377,6 +1377,10 @@
 
 uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher) { return cipher->id; }
 
+uint16_t SSL_CIPHER_get_value(const SSL_CIPHER *cipher) {
+  return static_cast<uint16_t>(cipher->id);
+}
+
 int SSL_CIPHER_is_aead(const SSL_CIPHER *cipher) {
   return (cipher->algorithm_mac & SSL_AEAD) != 0;
 }