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net/quic/crypto/null_encrypter.cc

Index: net/quic/crypto/null_encrypter.cc
diff --git a/net/quic/crypto/null_encrypter.cc b/net/quic/crypto/null_encrypter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fda844b90ff02ed3e10581a936a73404f6435804
--- /dev/null
+++ b/net/quic/crypto/null_encrypter.cc
@@ -0,0 +1,37 @@
+// 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_encrypter.h"
+#include "net/quic/quic_data_writer.h"
+#include "net/quic/quic_utils.h"
+
+using base::StringPiece;
+using std::string;
+
+namespace net {
+
+const size_t kHashSize = 16;  // size of uint128 serialized
+
+QuicData* NullEncrypter::Encrypt(StringPiece associated_data,
+                                 StringPiece plaintext) {
+  // TODO(rch): avoid buffer copy here
+  string buffer = associated_data.as_string();
+  plaintext.AppendToString(&buffer);
+  uint128 hash = QuicUtils::FNV1a_128_Hash(buffer.data(), buffer.length());
+  QuicDataWriter writer(plaintext.length() + kHashSize);
+  writer.WriteUInt128(hash);
+  writer.WriteBytes(plaintext.data(), plaintext.length());
+  size_t len = writer.length();
+  return new QuicData(writer.take(), len, true);
+}
+
+size_t NullEncrypter::GetMaxPlaintextSize(size_t ciphertext_size) {
+  return ciphertext_size - kHashSize;
+}
+
+size_t NullEncrypter::GetCiphertextSize(size_t plaintext_size) {
+  return plaintext_size + kHashSize;
+}
+
+}  // namespace net