Refactor: Extract some duplicated code for verifying usages during import of asymmetric key.

content/child/webcrypto/webcrypto_util.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/webcrypto_util.h"
 
 #include <set>
 
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
@@ skipping 244 matching lines @@
   }
 
   // OpenSSL hangs when given bad public exponents, whereas NSS simply fails. To
   // avoid feeding OpenSSL data that will hang use a whitelist.
   if (*public_exponent != 3 && *public_exponent != 65537)
     return Status::ErrorGenerateKeyPublicExponent();
 
   return Status::Success();
 }
 
+Status VerifyUsagesBeforeImportAsymmetricKey(
+    blink::WebCryptoKeyFormat format,
+    blink::WebCryptoKeyUsageMask all_public_key_usages,
+    blink::WebCryptoKeyUsageMask all_private_key_usages,
+    blink::WebCryptoKeyUsageMask usages) {
+  switch (format) {
+    case blink::WebCryptoKeyFormatSpki:
+      return CheckKeyCreationUsages(all_public_key_usages, usages);
+    case blink::WebCryptoKeyFormatPkcs8:
+      return CheckKeyCreationUsages(all_private_key_usages, usages);
+    case blink::WebCryptoKeyFormatJwk: {
+      // The JWK could represent either a public key or private key. The usages
+      // must make sense for one of the two. The usages will be checked again by
+      // ImportKeyJwk() once the key type has been determined.
+      Status status = CheckKeyCreationUsages(all_public_key_usages, usages);
+      if (status.IsError())
+        return status;

[davidben, 2014/12/09 20:36:39]

I think this got inverted from the original code. It used to be valid if either
was success, but now it requires both be success.

[eroman, 2014/12/09 20:41:54]

Ugh you are right! I will restore the original code.
I should have run the tests before sending this, sorry!

[eroman, 2014/12/09 20:46:40]

OK Fixed.

I reordered it a bit from the original version to match the early-return style
of other functions.

+
+      status = CheckKeyCreationUsages(all_private_key_usages, usages);
+      if (status.IsError())
+        return status;
+      return Status::Success();
+    }
+    default:
+      return Status::ErrorUnsupportedImportKeyFormat();
+  }
+}
+
 }  // namespace webcrypto
 
 }  // namespace content