Refactor: Extract common code for generating asymmetric keys to a helper.

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 GetUsagesForGenerateAsymmetricKey(
+    blink::WebCryptoKeyUsageMask combined_usages,
+    blink::WebCryptoKeyUsageMask all_public_usages,
+    blink::WebCryptoKeyUsageMask all_private_usages,
+    blink::WebCryptoKeyUsageMask* public_usages,
+    blink::WebCryptoKeyUsageMask* private_usages) {
+  *public_usages = combined_usages & all_public_usages;
+  *private_usages = combined_usages & all_private_usages;
+
+  Status status = CheckKeyCreationUsages(all_public_usages, *public_usages);
+  if (status.IsError())
+    return status;
+
+  status = CheckKeyCreationUsages(all_private_usages, *private_usages);
+  if (status.IsError())
+    return status;
+
+  if (private_usages == 0)
+    return Status::ErrorCreateKeyEmptyUsages();
+
+  return Status::Success();
+}
+
 }  // namespace webcrypto
 
 }  // namespace content