Refactor the interface for generating keys.

content/child/webcrypto/algorithm_dispatch.h

Index: content/child/webcrypto/algorithm_dispatch.h
diff --git a/content/child/webcrypto/algorithm_dispatch.h b/content/child/webcrypto/algorithm_dispatch.h
index a6d22bca4f73d713d19f17fb3d372e8eca5efcf5..bed1b359959d09596dc0702e2497dceaa6a8abdb 100644
--- a/content/child/webcrypto/algorithm_dispatch.h
+++ b/content/child/webcrypto/algorithm_dispatch.h
@@ -42,18 +42,16 @@ CONTENT_EXPORT Status Digest(const blink::WebCryptoAlgorithm& algorithm,
                              const CryptoData& data,
                              std::vector<uint8_t>* buffer);
 
-CONTENT_EXPORT Status
-    GenerateSecretKey(const blink::WebCryptoAlgorithm& algorithm,
-                      bool extractable,
-                      blink::WebCryptoKeyUsageMask usage_mask,
-                      blink::WebCryptoKey* key);
-
-CONTENT_EXPORT Status
-    GenerateKeyPair(const blink::WebCryptoAlgorithm& algorithm,
-                    bool extractable,
-                    blink::WebCryptoKeyUsageMask usage_mask,
-                    blink::WebCryptoKey* public_key,
-                    blink::WebCryptoKey* private_key);
+// GenerateKey() has two modes of operation:
+//   (1) If the algorithm is symmetric, a single secret key is generated and
+//       written into |*private_key|.
+//   (2) If the algorithm is asymmetric, a key pair is generated and written to
+//       |*public_key|, and |*private_key|.
+CONTENT_EXPORT Status GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
+                                  bool extractable,
+                                  blink::WebCryptoKeyUsageMask usage_mask,
+                                  blink::WebCryptoKey* public_key,
+                                  blink::WebCryptoKey* private_key);

[Ryan Sleevi, 2014/08/28 00:35:33]

From an API level, this feels wrong. I liked your original interfaces much
better.

[eroman, 2014/08/28 14:34:19]

Would you prefer:
  (1) Keep the algorithm_dispatch exported interface the same as before, but the
internal AlgorithmImplementation the way it is in this changelist
  (2) Remove this API change alltogether, and introduce a new virtual method on
AlgorithmImplementation for "bool KeysAreAsymmetric()"

[Ryan Sleevi, 2014/08/28 21:15:04]

To be clearer/explicit, I dislike the union of both symmetric and asymmetric
keys into the same interface on a C++ level.
I'm not sure why this is necessary.

 
 CONTENT_EXPORT Status ImportKey(blink::WebCryptoKeyFormat format,
                                 const CryptoData& key_data,