Merge pull request #101 from ErwanLegrand/side-channel

Fix side-channel in HMACSign<Hasher>::verify
arun11299 · Feb 11, 2024 · 4a970bc · 4a970bc
2 parents 10ef573 + 2c329d2
commit 4a970bc
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/include/jwt/impl/algorithm.ipp b/include/jwt/impl/algorithm.ipp
@@ -63,7 +63,7 @@ verify_result_t HMACSign<Hasher>::verify(
   auto new_len = jwt::base64_uri_encode(&b64_enc_str[0], b64_enc_str.length());
   b64_enc_str.resize(new_len);
 
-  bool ret = (jwt::string_view{b64_enc_str} == jwt_sign);
+  bool ret = (new_len == jwt_sign.size()) && (CRYPTO_memcmp(b64_enc_str.data(), jwt_sign.data(), new_len) == 0);
 
   return { ret, ec };
 }