[webcrypto] Properly fail-fast when importing RSA key as JWK with bad usages.

content/child/webcrypto/nss/rsa_key_nss.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/nss/rsa_key_nss.h"
 
 #include "base/logging.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/generate_key_result.h"
 #include "content/child/webcrypto/jwk.h"
@@ skipping 594 matching lines @@
 
 Status RsaHashedAlgorithm::VerifyKeyUsagesBeforeImportKey(
     blink::WebCryptoKeyFormat format,
     blink::WebCryptoKeyUsageMask usages) const {
   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:
-      return CheckKeyCreationUsages(
-          all_public_key_usages_ | all_private_key_usages_, usages);
+      // 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.
+      if (CheckKeyCreationUsages(all_private_key_usages_, usages)
+              .IsSuccess() ||
+          CheckKeyCreationUsages(all_public_key_usages_, usages)
+              .IsSuccess()) {
+        return Status::Success();
+      }
+      return Status::ErrorCreateKeyBadUsages();
     default:
       return Status::ErrorUnsupportedImportKeyFormat();
   }
 }
 
 Status RsaHashedAlgorithm::ImportKeyPkcs8(
     const CryptoData& key_data,
     const blink::WebCryptoAlgorithm& algorithm,
     bool extractable,
     blink::WebCryptoKeyUsageMask usages,
@@ skipping 208 matching lines @@
       return Status::Success();
     }
     default:
       return Status::ErrorUnexpected();
   }
 }
 
 }  // namespace webcrypto
 
 }  // namespace content