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net/quic/crypto/null_decrypter.cc

Index: net/quic/crypto/null_decrypter.cc
diff --git a/net/quic/crypto/null_decrypter.cc b/net/quic/crypto/null_decrypter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..072c684f94c62084f5dd3586475b0679d580905e
--- /dev/null
+++ b/net/quic/crypto/null_decrypter.cc
@@ -0,0 +1,35 @@
+// Copyright (c) 2012 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 "net/quic/crypto/null_decrypter.h"
+#include "net/quic/quic_utils.h"
+#include "net/quic/quic_data_reader.h"
+
+using base::StringPiece;
+using std::string;
+
+namespace net {
+
+QuicData* NullDecrypter::Decrypt(StringPiece associated_data,
+                                 StringPiece ciphertext) {
+  QuicDataReader reader(ciphertext.data(), ciphertext.length());
+
+  uint128 hash;
+  if (!reader.ReadUInt128(&hash)) {
+    return NULL;
+  }
+
+  StringPiece plaintext = reader.ReadRemainingPayload();
+
+  // TODO(rch): avoid buffer copy here
+  string buffer = associated_data.as_string();
+  plaintext.AppendToString(&buffer);
+
+  if (hash != QuicUtils::FNV1a_128_Hash(buffer.data(), buffer.length())) {
+    return NULL;
+  }
+  return new QuicData(plaintext.data(), plaintext.length());
+}
+
+}  // namespace net