[webcrypto] Reject AES-GCM tag lengths other than 32, 64, 96, 104, 112, 120, 128.

content/renderer/webcrypto/shared_crypto_unittest.cc

Index: content/renderer/webcrypto/shared_crypto_unittest.cc
diff --git a/content/renderer/webcrypto/shared_crypto_unittest.cc b/content/renderer/webcrypto/shared_crypto_unittest.cc
index d5d0e0c1f91e7449deded98d690f46c61c5dcd34..1f437366de617bb7169cacf48a6aa025a2935aea 100644
--- a/content/renderer/webcrypto/shared_crypto_unittest.cc
+++ b/content/renderer/webcrypto/shared_crypto_unittest.cc
@@ -1996,7 +1996,7 @@ TEST_F(SharedCryptoTest, MAYBE(AesGcmSampleSets)) {
                                 &plain_text));
 
     // Try different incorrect tag lengths
-    uint8 kAlternateTagLengths[] = {8, 96, 120, 128, 160, 255};
+    uint8 kAlternateTagLengths[] = {0, 8, 96, 120, 128, 160, 255};

[eroman, 2014/02/20 01:28:22]

Previously, decrypting with taglength=0 would succeed, so added it to the
failure tests.

     for (size_t tag_i = 0; tag_i < arraysize(kAlternateTagLengths); ++tag_i) {
       unsigned int wrong_tag_size_bits = kAlternateTagLengths[tag_i];
       if (test_tag_size_bits == wrong_tag_size_bits)