Change the error message in WebCrypto when using a key that has BOTH

third_party/WebKit/Source/modules/crypto/CryptoKey.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 160 matching lines @@
     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
         WebCryptoKeyUsage usage = keyUsageMappings[i].value;
         if (m_key.usages() & usage)
             result.append(keyUsageToString(usage));
     }
     return result;
 }
 
 bool CryptoKey::canBeUsedForAlgorithm(const WebCryptoAlgorithm& algorithm, WebCryptoKeyUsage usage, CryptoResult* result) const
 {
-    if (!(m_key.usages() & usage)) {
-        result->completeWithError(WebCryptoErrorTypeInvalidAccess, "key.usages does not permit this operation");
-        return false;
-    }
+    // This order of tests on keys is done throughout the WebCrypto spec when
+    // testing if a key can be used for an algorithm.
+    //
+    // For instance here are the steps as written for encrypt():
+    //
+    // https://w3c.github.io/webcrypto/Overview.html#dfn-SubtleCrypto-method-encrypt
+    //
+    // (8) If the name member of normalizedAlgorithm is not equal to the name
+    //     attribute of the [[algorithm]] internal slot of key then throw an
+    //     InvalidAccessError.
+    //
+    // (9) If the [[usages]] internal slot of key does not contain an entry
+    //     that is "encrypt", then throw an InvalidAccessError.
 
     if (m_key.algorithm().id() != algorithm.id()) {
         result->completeWithError(WebCryptoErrorTypeInvalidAccess, "key.algorithm does not match that of operation");
         return false;
     }
 
+    if (!(m_key.usages() & usage)) {
+        result->completeWithError(WebCryptoErrorTypeInvalidAccess, "key.usages does not permit this operation");
+        return false;
+    }
+
     return true;
 }
 
 bool CryptoKey::parseFormat(const String& formatString, WebCryptoKeyFormat& format, CryptoResult* result)
 {
     // There are few enough values that testing serially is fast enough.
     if (formatString == "raw") {
         format = WebCryptoKeyFormatRaw;
         return true;
     }
@@ skipping 22 matching lines @@
         if (!usage) {
             result->completeWithError(WebCryptoErrorTypeType, "Invalid keyUsages argument");
             return false;
         }
         mask |= usage;
     }
     return true;
 }
 
 } // namespace blink