[webcrypto] Add deriveBits key_op to JWK import/export.

content/child/webcrypto/jwk.cc

 // Copyright 2014 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 "jwk.h"
 
 #include <algorithm>
 #include <functional>
 #include <map>
 
@@ skipping 53 matching lines @@
 //   the table below, and describes the operations for which this key may be
 //   used.
 //   +-------+--------------------------------------------------------------+
 //   | "encrypt"    | encrypt operations                                    |
 //   | "decrypt"    | decrypt operations                                    |
 //   | "sign"       | sign (MAC) operations                                 |
 //   | "verify"     | verify (MAC) operations                               |
 //   | "wrapKey"    | key wrap                                              |
 //   | "unwrapKey"  | key unwrap                                            |
 //   | "deriveKey"  | key derivation                                        |
-//   | "deriveBits" | key derivation TODO(padolph): not currently supported |
+//   | "deriveBits" | key derivation                                        |
 //   +-------+--------------------------------------------------------------+
 //
 // - use (Key Use)
 //   The use field contains a single entry from the table below.
 //   +-------+--------------------------------------------------------------+
 //   | "sig"     | equivalent to key_ops of [sign, verify]                  |
 //   | "enc"     | equivalent to key_ops of [encrypt, decrypt, wrapKey,     |
 //   |           | unwrapKey, deriveKey, deriveBits]                        |
 //   +-------+--------------------------------------------------------------+
 //
@@ skipping 107 matching lines @@
 
 // Creates an RSA-OAEP algorithm. It is an error to call this with a hash_id
 // that is not a SHA*.
 blink::WebCryptoAlgorithm CreateRsaOaepImportAlgorithm(
     blink::WebCryptoAlgorithmId hash_id) {
   return CreateRsaHashedImportAlgorithm(blink::WebCryptoAlgorithmIdRsaOaep,
                                         hash_id);
 }
 
 // Web Crypto equivalent usage mask for JWK 'use' = 'enc'.
-// TODO(padolph): Add 'deriveBits' once supported by Blink.
 const blink::WebCryptoKeyUsageMask kJwkEncUsage =
     blink::WebCryptoKeyUsageEncrypt | blink::WebCryptoKeyUsageDecrypt |
     blink::WebCryptoKeyUsageWrapKey | blink::WebCryptoKeyUsageUnwrapKey |
-    blink::WebCryptoKeyUsageDeriveKey;
+    blink::WebCryptoKeyUsageDeriveKey | blink::WebCryptoKeyUsageDeriveBits;
 // Web Crypto equivalent usage mask for JWK 'use' = 'sig'.
 const blink::WebCryptoKeyUsageMask kJwkSigUsage =
     blink::WebCryptoKeyUsageSign | blink::WebCryptoKeyUsageVerify;
 
 typedef blink::WebCryptoAlgorithm (*AlgorithmCreationFunc)();
 
 class JwkAlgorithmInfo {
  public:
   JwkAlgorithmInfo()
       : creation_func_(NULL),
@@ skipping 611 matching lines @@
 
   std::string json;
   base::JSONWriter::Write(&jwk_dict, &json);
   buffer->assign(json.data(), json.data() + json.size());
   return Status::Success();
 }
 
 }  // namespace webcrypto
 
 }  // namespace content