commit 480344d4fa03319efa29cdca41f051c41f5bf95a
author Adam Langley <agl@google.com> Thu Apr 13 02:09:12 2023 +0000
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon Apr 17 16:39:03 2023 +0000
tree 049b241a3374b63957b777b61f53bb400057e1cb
parent d3acd45456450f7e8091f0f56084bc2da93e48fe

Move TLS 1.3 KDF functions into the FIPS module.

Change-Id: I32a40a73f96e029ac9096af826d15b22d9dcad28
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/58745
Auto-Submit: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

ssl/tls13_enc.cc

diff --git a/ssl/tls13_enc.cc b/ssl/tls13_enc.cc
index ad023ef..3de10f4 100644
--- a/ssl/tls13_enc.cc
+++ b/ssl/tls13_enc.cc
@@ -27,6 +27,7 @@
 #include <openssl/hmac.h>
 #include <openssl/mem.h>
 
+#include "../crypto/fipsmodule/tls/internal.h"
 #include "../crypto/internal.h"
 #include "internal.h"
 
@@ -95,27 +96,10 @@
                               Span<const uint8_t> secret,
                               Span<const char> label,
                               Span<const uint8_t> hash) {
-  Span<const char> protocol_label = label_to_span("tls13 ");
-  ScopedCBB cbb;
-  CBB child;
-  Array<uint8_t> hkdf_label;
-  if (!CBB_init(cbb.get(), 2 + 1 + protocol_label.size() + label.size() + 1 +
-                               hash.size()) ||
-      !CBB_add_u16(cbb.get(), out.size()) ||
-      !CBB_add_u8_length_prefixed(cbb.get(), &child) ||
-      !CBB_add_bytes(&child,
-                     reinterpret_cast<const uint8_t *>(protocol_label.data()),
-                     protocol_label.size()) ||
-      !CBB_add_bytes(&child, reinterpret_cast<const uint8_t *>(label.data()),
-                     label.size()) ||
-      !CBB_add_u8_length_prefixed(cbb.get(), &child) ||
-      !CBB_add_bytes(&child, hash.data(), hash.size()) ||
-      !CBBFinishArray(cbb.get(), &hkdf_label)) {
-    return false;
-  }
-
-  return HKDF_expand(out.data(), out.size(), digest, secret.data(),
-                     secret.size(), hkdf_label.data(), hkdf_label.size());
+  return CRYPTO_tls13_hkdf_expand_label(
+      out.data(), out.size(), digest, secret.data(), secret.size(),
+      reinterpret_cast<const uint8_t *>(label.data()), label.size(),
+      hash.data(), hash.size()) == 1;
 }
 
 static const char kTLS13LabelDerived[] = "derived";