[webcryto] Validate key usages during key creation.

content/child/webcrypto/webcrypto_util.h

 // 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.
 
 #ifndef CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 #define CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 
 #include <string>
 #include <vector>
 #include "base/basictypes.h"
@@ skipping 53 matching lines @@
 // Creates an import algorithm for RSA algorithms that take a hash.
 // It is an error to call this with a hash_id that is not a SHA*.
 CONTENT_EXPORT blink::WebCryptoAlgorithm CreateRsaHashedImportAlgorithm(
     blink::WebCryptoAlgorithmId id,
     blink::WebCryptoAlgorithmId hash_id);
 
 bool CreateSecretKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
                               unsigned int keylen_bytes,
                               blink::WebCryptoKeyAlgorithm* key_algorithm);
 
+// Returns true if the set bits in b make up a subset of the set bits in a.
+bool ContainsKeyUsages(blink::WebCryptoKeyUsageMask a,
+                       blink::WebCryptoKeyUsageMask b);
+
 bool IsAlgorithmRsa(blink::WebCryptoAlgorithmId alg_id);
+bool IsAlgorithmAsymmetric(blink::WebCryptoAlgorithmId alg_id);
 
 }  // namespace webcrypto
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_