crypto: support ML-KEM in Web Cryptography

PR-URL: nodejs/node#59569
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: panva

src/ncrypto.cpp

@@ -2312,21 +2312,34 @@ DataPointer EVPKeyPointer::rawPublicKey() const {
 #if OPENSSL_WITH_PQC
 DataPointer EVPKeyPointer::rawSeed() const {
   if (!pkey_) return {};
+
+  // Determine seed length and parameter name based on key type
+  size_t seed_len;
+  const char* param_name;
+
   switch (id()) {
     case EVP_PKEY_ML_DSA_44:
     case EVP_PKEY_ML_DSA_65:
     case EVP_PKEY_ML_DSA_87:
+      seed_len = 32;  // ML-DSA uses 32-byte seeds
+      param_name = OSSL_PKEY_PARAM_ML_DSA_SEED;
+      break;
+    case EVP_PKEY_ML_KEM_512:
+    case EVP_PKEY_ML_KEM_768:
+    case EVP_PKEY_ML_KEM_1024:
+      seed_len = 64;  // ML-KEM uses 64-byte seeds
+      param_name = OSSL_PKEY_PARAM_ML_KEM_SEED;
       break;
     default:
       unreachable();
   }
 
-  size_t seed_len = 32;
   if (auto data = DataPointer::Alloc(seed_len)) {
     const Buffer<unsigned char> buf = data;
     size_t len = data.size();
+
     if (EVP_PKEY_get_octet_string_param(
-            get(), OSSL_PKEY_PARAM_ML_DSA_SEED, buf.data, len, &seed_len) != 1)
+            get(), param_name, buf.data, len, &seed_len) != 1)
       return {};
     return data;
   }