[webcrypto] Check for empty key usages *after* key creation rather than before, to match the spec's…

components/webcrypto/algorithms/aes.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 COMPONENTS_WEBCRYPTO_ALGORITHMS_AES_H_
 #define COMPONENTS_WEBCRYPTO_ALGORITHMS_AES_H_
 
 #include <stdint.h>
 
 #include "components/webcrypto/algorithm_implementation.h"
@@ skipping 15 matching lines @@
   // This is the same as the other AesAlgorithm constructor where
   // |all_key_usages| is pre-filled to values for encryption/decryption
   // algorithms (supports usages for: encrypt, decrypt, wrap, unwrap).
   explicit AesAlgorithm(const std::string& jwk_suffix);
 
   Status GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
                      bool extractable,
                      blink::WebCryptoKeyUsageMask usages,
                      GenerateKeyResult* result) const override;
 
-  Status VerifyKeyUsagesBeforeImportKey(
-      blink::WebCryptoKeyFormat format,
-      blink::WebCryptoKeyUsageMask usages) const override;
+  Status ImportKey(blink::WebCryptoKeyFormat format,
+                   const CryptoData& key_data,
+                   const blink::WebCryptoAlgorithm& algorithm,
+                   bool extractable,
+                   blink::WebCryptoKeyUsageMask usages,
+                   blink::WebCryptoKey* key) const override;
 
-  Status ImportKeyRaw(const CryptoData& key_data,
-                      const blink::WebCryptoAlgorithm& algorithm,
-                      bool extractable,
-                      blink::WebCryptoKeyUsageMask usages,
-                      blink::WebCryptoKey* key) const override;
-
-  Status ImportKeyJwk(const CryptoData& key_data,
-                      const blink::WebCryptoAlgorithm& algorithm,
-                      bool extractable,
-                      blink::WebCryptoKeyUsageMask usages,
-                      blink::WebCryptoKey* key) const override;
-
-  Status ExportKeyRaw(const blink::WebCryptoKey& key,
-                      std::vector<uint8_t>* buffer) const override;
-
-  Status ExportKeyJwk(const blink::WebCryptoKey& key,
-                      std::vector<uint8_t>* buffer) const override;
+  Status ExportKey(blink::WebCryptoKeyFormat format,
+                   const blink::WebCryptoKey& key,
+                   std::vector<uint8_t>* buffer) const override;
 
   Status DeserializeKeyForClone(const blink::WebCryptoKeyAlgorithm& algorithm,
                                 blink::WebCryptoKeyType type,
                                 bool extractable,
                                 blink::WebCryptoKeyUsageMask usages,
                                 const CryptoData& key_data,
                                 blink::WebCryptoKey* key) const override;
 
   Status GetKeyLength(const blink::WebCryptoAlgorithm& key_length_algorithm,
                       bool* has_length_bits,
                       unsigned int* length_bits) const override;
 
  private:
+  Status ImportKeyRaw(const CryptoData& key_data,
+                      const blink::WebCryptoAlgorithm& algorithm,
+                      bool extractable,
+                      blink::WebCryptoKeyUsageMask usages,
+                      blink::WebCryptoKey* key) const;
+
+  Status ImportKeyJwk(const CryptoData& key_data,
+                      const blink::WebCryptoAlgorithm& algorithm,
+                      bool extractable,
+                      blink::WebCryptoKeyUsageMask usages,
+                      blink::WebCryptoKey* key) const;
+
+  Status ExportKeyRaw(const blink::WebCryptoKey& key,
+                      std::vector<uint8_t>* buffer) const;
+
+  Status ExportKeyJwk(const blink::WebCryptoKey& key,
+                      std::vector<uint8_t>* buffer) const;
+
   const blink::WebCryptoKeyUsageMask all_key_usages_;
   const std::string jwk_suffix_;
 };
 
 }  // namespace webcrypto
 
 #endif  // COMPONENTS_WEBCRYPTO_ALGORITHMS_AES_H_