[WebCrypto] Throw syntaxError if keyUsage is empty in ImportKey

content/child/webcrypto/algorithm_dispatch.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 "content/child/webcrypto/algorithm_dispatch.h"
 
 #include "base/logging.h"
 #include "content/child/webcrypto/algorithm_implementation.h"
 #include "content/child/webcrypto/algorithm_registry.h"
 #include "content/child/webcrypto/crypto_data.h"
@@ skipping 111 matching lines @@
                  blink::WebCryptoKey* key) {
   const AlgorithmImplementation* impl = NULL;
   Status status = GetAlgorithmImplementation(algorithm.id(), &impl);
   if (status.IsError())
     return status;
 
   status = impl->VerifyKeyUsagesBeforeImportKey(format, usages);
   if (status.IsError())
     return status;
 
+  if (usages == 0)

[eroman, 2014/12/05 20:45:51]

This is not correct. 

Some key types are allowed to have empty usages. For instance ECDH public keys
(https://dvcs.w3.org/hg/webcrypto-api/raw-file/tip/spec/Overview.html#ecdh)

[Habib Virji, 2014/12/08 15:05:21]

Updated. Have found usages only in AES and HMAC. 
Done.

+    return Status::ErrorImportEmptyKeyUsage();
+
   switch (format) {
     case blink::WebCryptoKeyFormatRaw:
       return impl->ImportKeyRaw(key_data, algorithm, extractable, usages, key);
     case blink::WebCryptoKeyFormatSpki:
       return impl->ImportKeySpki(key_data, algorithm, extractable, usages, key);
     case blink::WebCryptoKeyFormatPkcs8:
       return impl->ImportKeyPkcs8(key_data, algorithm, extractable, usages,
                                   key);
     case blink::WebCryptoKeyFormatJwk:
       return impl->ImportKeyJwk(key_data, algorithm, extractable, usages, key);
@@ skipping 146 matching lines @@
     return false;
 
   status = impl->DeserializeKeyForClone(algorithm, type, extractable, usages,
                                         key_data, key);
   return status.IsSuccess();
 }
 
 }  // namespace webcrypto
 
 }  // namespace content