[webcrypto] Make the import algorithm a required parameter.

public/platform/WebCrypto.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 129 matching lines @@
     // -----------------------
     //
     //   * Data buffers are passed as (basePointer, byteLength) pairs.
     //     These buffers are only valid during the call itself. Asynchronous
     //     implementations wishing to access it after the function returns
     //     should make a copy.
     //
     //   * All WebCryptoKeys are guaranteeed to be !isNull().
     //
     //   * All WebCryptoAlgorithms are guaranteed to be !isNull()
-    //     unless noted otherwise. Being "null" means that it was unspecified
-    //     by the caller.
     //
     //   * Look to the Web Crypto spec for an explanation of the parameter. The
     //     method names here have a 1:1 correspondence with those of
     //     crypto.subtle, with the exception of "verify" which is here called
     //     "verifySignature".
     //
     // -----------------------
     // Guarantees on input validity
     // -----------------------
     //
     // Implementations MUST carefully sanitize algorithm inputs before using
     // them, as they come directly from the user. Few checks have been done on
     // algorithm parameters prior to passing to the embedder.
     //
     // Only the following checks can be assumed as having alread passed:
     //
     //  * The key is extractable when calling into exportKey/wrapKey.
     //  * The key usages permit the operation being requested.
     //  * The key's algorithm matches that of the requested operation.
     //
     virtual void encrypt(const WebCryptoAlgorithm&, const WebCryptoKey&, const unsigned char* data, unsigned dataSize, WebCryptoResult result) { result.completeWithError(); }
     virtual void decrypt(const WebCryptoAlgorithm&, const WebCryptoKey&, const unsigned char* data, unsigned dataSize, WebCryptoResult result) { result.completeWithError(); }
     virtual void sign(const WebCryptoAlgorithm&, const WebCryptoKey&, const unsigned char* data, unsigned dataSize, WebCryptoResult result) { result.completeWithError(); }
     virtual void verifySignature(const WebCryptoAlgorithm&, const WebCryptoKey&, const unsigned char* signature, unsigned signatureSize, const unsigned char* data, unsigned dataSize, WebCryptoResult result) { result.completeWithError(); }
     virtual void digest(const WebCryptoAlgorithm&, const unsigned char* data, unsigned dataSize, WebCryptoResult result) { result.completeWithError(); }
     virtual void generateKey(const WebCryptoAlgorithm&, bool extractable, WebCryptoKeyUsageMask, WebCryptoResult result) { result.completeWithError(); }
-    // It is possible for the WebCryptoAlgorithm to be "isNull()"
     virtual void importKey(WebCryptoKeyFormat, const unsigned char* keyData, unsigned keyDataSize, const WebCryptoAlgorithm&, bool extractable, WebCryptoKeyUsageMask, WebCryptoResult result) { result.completeWithError(); }
     virtual void exportKey(WebCryptoKeyFormat, const WebCryptoKey&, WebCryptoResult result) { result.completeWithError(); }
     virtual void wrapKey(WebCryptoKeyFormat, const WebCryptoKey& key, const WebCryptoKey& wrappingKey, const WebCryptoAlgorithm&, WebCryptoResult result) { result.completeWithError(); }
-    // It is possible that unwrappedKeyAlgorithm.isNull()
     virtual void unwrapKey(WebCryptoKeyFormat, const unsigned char* wrappedKey, unsigned wrappedKeySize, const WebCryptoKey&, const WebCryptoAlgorithm& unwrapAlgorithm, const WebCryptoAlgorithm& unwrappedKeyAlgorithm, bool extractable, WebCryptoKeyUsageMask, WebCryptoResult result) { result.completeWithError(); }
 
     // This is the one exception to the "Completing the request" guarantees
     // outlined above. digestSynchronous must provide the result into result
     // synchronously. It must return |true| on successful calculation of the
     // digest and |false| otherwise. This is useful for Blink internal crypto
     // and is not part of the WebCrypto standard.
     virtual bool digestSynchronous(const WebCryptoAlgorithmId algorithmId, const unsigned char* data, unsigned dataSize, WebArrayBuffer& result) { return false; }
 
 protected:
     virtual ~WebCrypto() { }
 };
 
 } // namespace blink
 
 #endif