[webcrypto] Add key generation for AES-GCM and AES-KW for NSS.

content/renderer/webcrypto/webcrypto_impl_nss.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/webcrypto/webcrypto_impl.h"
 
 #include <cryptohi.h>
 #include <pk11pub.h>
 #include <sechash.h>
 
@@ skipping 167 matching lines @@
   }
 
   webcrypto::ShrinkBuffer(buffer, final_output_chunk_len + output_len);
   return true;
 }
 
 CK_MECHANISM_TYPE WebCryptoAlgorithmToGenMechanism(
     const blink::WebCryptoAlgorithm& algorithm) {
   switch (algorithm.id()) {
     case blink::WebCryptoAlgorithmIdAesCbc:
+    case blink::WebCryptoAlgorithmIdAesGcm:
+    case blink::WebCryptoAlgorithmIdAesKw:
       return CKM_AES_KEY_GEN;
     case blink::WebCryptoAlgorithmIdHmac:
       return WebCryptoHashToHMACMechanism(algorithm.hmacKeyParams()->hash());
     default:
       return CKM_INVALID_MECHANISM;
   }
 }
 
 // Converts a (big-endian) WebCrypto BigInteger, with or without leading zeros,
 // to unsigned long.
@@ skipping 439 matching lines @@
 
   CK_MECHANISM_TYPE mech = WebCryptoAlgorithmToGenMechanism(algorithm);
   unsigned int keylen_bytes = 0;
   blink::WebCryptoKeyType key_type = blink::WebCryptoKeyTypeSecret;
 
   if (mech == CKM_INVALID_MECHANISM) {
     return false;
   }
 
   switch (algorithm.id()) {
-    case blink::WebCryptoAlgorithmIdAesCbc: {
+    case blink::WebCryptoAlgorithmIdAesCbc:
+    case blink::WebCryptoAlgorithmIdAesGcm:
+    case blink::WebCryptoAlgorithmIdAesKw: {
       const blink::WebCryptoAesKeyGenParams* params =
           algorithm.aesKeyGenParams();
       DCHECK(params);
+      // Ensure the key length is a multiple of 8 bits. Let NSS verify further
+      // algorithm-specific length restrictions.
       if (params->lengthBits() % 8)
         return false;
       keylen_bytes = params->lengthBits() / 8;
       key_type = blink::WebCryptoKeyTypeSecret;
       break;
     }
     case blink::WebCryptoAlgorithmIdHmac: {
       const blink::WebCryptoHmacKeyParams* params = algorithm.hmacKeyParams();
       DCHECK(params);
       if (params->hasLengthBytes()) {
@@ skipping 325 matching lines @@
 
   *key = blink::WebCryptoKey::create(new PublicKeyHandle(pubkey.Pass()),
                                      blink::WebCryptoKeyTypePublic,
                                      extractable,
                                      algorithm,
                                      usage_mask);
   return true;
 }
 
 }  // namespace content