Fix the error message when generating an AES key using a length other…

… than 128, 192, 256.

Also changes the error type to OperationError to match the spec update:
https://dvcs.w3.org/hg/webcrypto-api/rev/5e7ba79bdf36

BUG=436581,425670

Review URL: https://codereview.chromium.org/762593003

Cr-Commit-Position: refs/heads/master@{#305769}

content/child/webcrypto/status.cc

@@ -146,10 +146,17 @@ Status Status::ErrorUnsupportedExportKeyFormat() {
 }
 
 Status Status::ErrorImportAesKeyLength() {
+  // TODO(eroman): Mention only 128 and 256 bits since 192 is unsupported.
+  // http://crbug.com/425670
   return Status(blink::WebCryptoErrorTypeData,
                 "AES key data must be 128, 192 or 256 bits");
 }
 
+Status Status::ErrorGenerateAesKeyLength() {
+  return Status(blink::WebCryptoErrorTypeOperation,
+                "AES key length must be 128 or 256 bits");
+}
+
 Status Status::ErrorAes192BitUnsupported() {
   return Status(blink::WebCryptoErrorTypeNotSupported,
                 "192-bit AES keys are not supported");
@@ -241,12 +248,23 @@ Status Status::ErrorKeyNotExtractable() {
                 "They key is not extractable");
 }
 
-Status Status::ErrorGenerateKeyLength() {
+Status Status::ErrorGenerateHmacKeyLengthPartialByte() {
+  // TODO(eroman): This message needs to be fixed (however appears in a
+  // LayoutTest).
+  //   * The error type is no longer spec compliant
+  //   * The message text is poor
+  //   * In fact the spec no longer requires key lengths to be multiples of 8
+  //     bits so this message is bogus (http://crbug.com/431085)
   return Status(blink::WebCryptoErrorTypeData,
                 "Invalid key length: it is either zero or not a multiple of 8 "
                 "bits");
 }
 
+Status Status::ErrorGenerateHmacKeyLengthZero() {
+  return Status(blink::WebCryptoErrorTypeOperation,
+                "HMAC key length must be not be zero");
+}
+
 Status Status::ErrorCreateKeyBadUsages() {
   return Status(blink::WebCryptoErrorTypeSyntax,
                 "Cannot create a key using the specified key usages.");

content/child/webcrypto/status.h

@@ -136,6 +136,9 @@ class CONTENT_EXPORT Status {
   // AES.
   static Status ErrorImportAesKeyLength();
 
+  // Attempted to generate an AES key with an invalid length.
+  static Status ErrorGenerateAesKeyLength();
+
   // 192-bit AES keys are valid, however unsupported.
   static Status ErrorAes192BitUnsupported();
 
@@ -205,9 +208,12 @@ class CONTENT_EXPORT Status {
   // An unextractable key was used by an operation which exports the key data.
   static Status ErrorKeyNotExtractable();
 
-  // The key length specified when generating a key was invalid. Either it was
-  // zero, or it was not a multiple of 8 bits.
-  static Status ErrorGenerateKeyLength();
+  // Attempted to generate an HMAC key with a key length in bits that was not a
+  // multiple of 8.
+  static Status ErrorGenerateHmacKeyLengthPartialByte();
+
+  // Attempted to generate an HMAC key using a key length of 0.
+  static Status ErrorGenerateHmacKeyLengthZero();
 
   // Attempted to create a key (either by importKey(), generateKey(), or
   // unwrapKey()) however the key usages were not applicable for the key type

content/child/webcrypto/test/aes_cbc_unittest.cc

@@ -193,7 +193,7 @@ TEST(WebCryptoAesCbcTest, GenerateKeyBadLength) {
   blink::WebCryptoKey key;
   for (size_t i = 0; i < arraysize(kKeyLen); ++i) {
     SCOPED_TRACE(i);
-    EXPECT_EQ(Status::ErrorGenerateKeyLength(),
+    EXPECT_EQ(Status::ErrorGenerateAesKeyLength(),
               GenerateSecretKey(CreateAesCbcKeyGenAlgorithm(kKeyLen[i]), true,
                                 0, &key));
   }

content/child/webcrypto/test/aes_gcm_unittest.cc

@@ -109,7 +109,7 @@ TEST(WebCryptoAesGcmTest, GenerateKeyBadLength) {
   blink::WebCryptoKey key;
   for (size_t i = 0; i < arraysize(kKeyLen); ++i) {
     SCOPED_TRACE(i);
-    EXPECT_EQ(Status::ErrorGenerateKeyLength(),
+    EXPECT_EQ(Status::ErrorGenerateAesKeyLength(),
               GenerateSecretKey(CreateAesGcmKeyGenAlgorithm(kKeyLen[i]), true,
                                 0, &key));
   }

content/child/webcrypto/test/aes_kw_unittest.cc

@@ -28,7 +28,7 @@ TEST(WebCryptoAesKwTest, GenerateKeyBadLength) {
   blink::WebCryptoKey key;
   for (size_t i = 0; i < arraysize(kKeyLen); ++i) {
     SCOPED_TRACE(i);
-    EXPECT_EQ(Status::ErrorGenerateKeyLength(),
+    EXPECT_EQ(Status::ErrorGenerateAesKeyLength(),
               GenerateSecretKey(CreateAesKwKeyGenAlgorithm(kKeyLen[i]), true, 0,
                                 &key));
   }

content/child/webcrypto/webcrypto_util.cc

@@ -183,7 +183,7 @@ Status GetAesKeyGenLengthInBits(const blink::WebCryptoAesKeyGenParams* params,
   if (*keylen_bits == 192)
     return Status::ErrorAes192BitUnsupported();
 
-  return Status::ErrorGenerateKeyLength();
+  return Status::ErrorGenerateAesKeyLength();
 }
 
 Status GetHmacKeyGenLengthInBits(const blink::WebCryptoHmacKeyGenParams* params,
@@ -203,14 +203,16 @@ Status GetHmacKeyGenLengthInBits(const blink::WebCryptoHmacKeyGenParams* params,
     }
   }
 
+  // TODO(eroman): Non multiple of 8 bit keylengths should be allowed:
+  // http://crbug.com/431085.
   if (params->optionalLengthBits() % 8)
-    return Status::ErrorGenerateKeyLength();
+    return Status::ErrorGenerateHmacKeyLengthPartialByte();
 
   *keylen_bits = params->optionalLengthBits();
 
-  // TODO(eroman): NSS fails when generating a zero-length secret key.
+  // Zero-length HMAC keys are disallowed by the spec.
   if (*keylen_bits == 0)
-    return Status::ErrorGenerateKeyLength();
+    return Status::ErrorGenerateHmacKeyLengthZero();
 
   return Status::Success();
 }