[NOT FOR REVIEW] Ensure contributory behaviour for Web Push encryption.

components/gcm_driver/crypto/gcm_message_cryptographer_openssl.cc

 // Copyright 2015 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 "components/gcm_driver/crypto/gcm_message_cryptographer.h"
 
 #include <openssl/aead.h>
 
 #include "base/logging.h"
 #include "base/numerics/safe_math.h"
@@ skipping 19 matching lines @@
     const base::StringPiece& nonce,
     std::string* output) const {
   DCHECK(output);
 
   const EVP_AEAD* aead = EVP_aead_aes_128_gcm();
 
   EVP_AEAD_CTX context;
   if (!EVP_AEAD_CTX_init(&context, aead,
                          reinterpret_cast<const uint8_t*>(key.data()),
                          key.size(), EVP_AEAD_DEFAULT_TAG_LENGTH, nullptr)) {
+    LOG(INFO) << "--b1";
     return false;
   }
 
   base::CheckedNumeric<size_t> maximum_output_length(input.size());
   if (mode == ENCRYPT)
     maximum_output_length += kAuthenticationTagBytes;
 
   // WriteInto requires the buffer to finish with a NULL-byte.
   maximum_output_length += 1;
 
   size_t output_length = 0;
   uint8_t* raw_output = reinterpret_cast<uint8_t*>(
       base::WriteInto(output, maximum_output_length.ValueOrDie()));
 
   EVP_AEAD_CTX_TransformFunction* transform_function =
       mode == ENCRYPT ? EVP_AEAD_CTX_seal : EVP_AEAD_CTX_open;
 
   if (!transform_function(
           &context, raw_output, &output_length, output->size(),
           reinterpret_cast<const uint8_t*>(nonce.data()), nonce.size(),
           reinterpret_cast<const uint8_t*>(input.data()), input.size(),
           nullptr, 0)) {
+    LOG(INFO) << "--b2";
     EVP_AEAD_CTX_cleanup(&context);
     return false;
   }
 
   EVP_AEAD_CTX_cleanup(&context);
 
   base::CheckedNumeric<size_t> expected_output_length(input.size());
   if (mode == ENCRYPT)
     expected_output_length += kAuthenticationTagBytes;
   else
     expected_output_length -= kAuthenticationTagBytes;
 
   DCHECK_EQ(expected_output_length.ValueOrDie(), output_length);
 
   output->resize(output_length);
   return true;
 }
 
 }  // namespace gcm