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

components/webcrypto/algorithms/aes.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 "components/webcrypto/algorithms/aes.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "components/webcrypto/algorithms/secret_key_util.h"
+#include "components/webcrypto/algorithms/util.h"
 #include "components/webcrypto/blink_key_handle.h"
 #include "components/webcrypto/crypto_data.h"
 #include "components/webcrypto/jwk.h"
 #include "components/webcrypto/status.h"
 #include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
 #include "third_party/WebKit/public/platform/WebCryptoKeyAlgorithm.h"
 
 namespace webcrypto {
 
 namespace {
@@ skipping 31 matching lines @@
                       blink::WebCryptoKeyUsageDecrypt |
                       blink::WebCryptoKeyUsageWrapKey |
                       blink::WebCryptoKeyUsageUnwrapKey),
       jwk_suffix_(jwk_suffix) {
 }
 
 Status AesAlgorithm::GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
                                  bool extractable,
                                  blink::WebCryptoKeyUsageMask usages,
                                  GenerateKeyResult* result) const {
-  Status status = CheckSecretKeyCreationUsages(all_key_usages_, usages);
+  Status status = CheckKeyCreationUsages(all_key_usages_, usages);
   if (status.IsError())
     return status;
 
   unsigned int keylen_bits = algorithm.aesKeyGenParams()->lengthBits();
 
   // 192-bit AES is intentionally unsupported (http://crbug.com/533699).
   if (keylen_bits == 192)
     return Status::ErrorAes192BitUnsupported();
 
   if (keylen_bits != 128 && keylen_bits != 256)
     return Status::ErrorGenerateAesKeyLength();
 
   return GenerateWebCryptoSecretKey(
       blink::WebCryptoKeyAlgorithm::createAes(algorithm.id(), keylen_bits),
       extractable, usages, keylen_bits, result);
 }
 
-Status AesAlgorithm::VerifyKeyUsagesBeforeImportKey(
-    blink::WebCryptoKeyFormat format,
-    blink::WebCryptoKeyUsageMask usages) const {
+Status AesAlgorithm::ImportKey(blink::WebCryptoKeyFormat format,
+                               const CryptoData& key_data,
+                               const blink::WebCryptoAlgorithm& algorithm,
+                               bool extractable,
+                               blink::WebCryptoKeyUsageMask usages,
+                               blink::WebCryptoKey* key) const {
   switch (format) {
     case blink::WebCryptoKeyFormatRaw:
+      return ImportKeyRaw(key_data, algorithm, extractable, usages, key);
     case blink::WebCryptoKeyFormatJwk:
-      return CheckSecretKeyCreationUsages(all_key_usages_, usages);
+      return ImportKeyJwk(key_data, algorithm, extractable, usages, key);
     default:
       return Status::ErrorUnsupportedImportKeyFormat();
   }
 }
 
+Status AesAlgorithm::ExportKey(blink::WebCryptoKeyFormat format,
+                               const blink::WebCryptoKey& key,
+                               std::vector<uint8_t>* buffer) const {
+  switch (format) {
+    case blink::WebCryptoKeyFormatRaw:
+      return ExportKeyRaw(key, buffer);
+    case blink::WebCryptoKeyFormatJwk:
+      return ExportKeyJwk(key, buffer);
+    default:
+      return Status::ErrorUnsupportedExportKeyFormat();
+  }
+}
+
 Status AesAlgorithm::ImportKeyRaw(const CryptoData& key_data,
                                   const blink::WebCryptoAlgorithm& algorithm,
                                   bool extractable,
                                   blink::WebCryptoKeyUsageMask usages,
                                   blink::WebCryptoKey* key) const {
+  Status status = CheckKeyCreationUsages(all_key_usages_, usages);
+  if (status.IsError())
+    return status;
+
   const unsigned int keylen_bytes = key_data.byte_length();
 
   // 192-bit AES is intentionally unsupported (http://crbug.com/533699).
   if (keylen_bytes == 24)
     return Status::ErrorAes192BitUnsupported();
 
   if (keylen_bytes != 16 && keylen_bytes != 32)
     return Status::ErrorImportAesKeyLength();
 
   // No possibility of overflow.
   unsigned int keylen_bits = keylen_bytes * 8;
 
   return CreateWebCryptoSecretKey(
       key_data,
       blink::WebCryptoKeyAlgorithm::createAes(algorithm.id(), keylen_bits),
       extractable, usages, key);
 }
 
 Status AesAlgorithm::ImportKeyJwk(const CryptoData& key_data,
                                   const blink::WebCryptoAlgorithm& algorithm,
                                   bool extractable,
                                   blink::WebCryptoKeyUsageMask usages,
                                   blink::WebCryptoKey* key) const {
-  std::vector<uint8_t> raw_data;
-  JwkReader jwk;
-  Status status = ReadSecretKeyNoExpectedAlgJwk(key_data, extractable, usages,
-                                                &raw_data, &jwk);
+  Status status = CheckKeyCreationUsages(all_key_usages_, usages);
   if (status.IsError())
     return status;
 
+  std::vector<uint8_t> raw_data;
+  JwkReader jwk;
+  status = ReadSecretKeyNoExpectedAlgJwk(key_data, extractable, usages,
+                                         &raw_data, &jwk);
+  if (status.IsError())
+    return status;
+
   bool has_jwk_alg;
   std::string jwk_alg;
   status = jwk.GetAlg(&jwk_alg, &has_jwk_alg);
   if (status.IsError())
     return status;
 
   if (has_jwk_alg) {
     std::string expected_algorithm_name =
         MakeJwkAesAlgorithmName(jwk_suffix_, raw_data.size());
 
@@ skipping 51 matching lines @@
     return Status::Success();
 
   // 192-bit AES is intentionally unsupported (http://crbug.com/533699).
   if (*length_bits == 192)
     return Status::ErrorAes192BitUnsupported();
 
   return Status::ErrorGetAesKeyLength();
 }
 
 }  // namespace webcrypto