Add Aes128GcmEncrypter and Aes128GcmDecrypter

net/quic/crypto/scoped_evp_cipher_ctx.h

+// Copyright (c) 2013 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.
+
+#ifndef NET_QUIC_CRYPTO_SCOPED_EVP_CIPHER_CTX_H_
+#define NET_QUIC_CRYPTO_SCOPED_EVP_CIPHER_CTX_H_
+
+#include <openssl/evp.h>
+
+#include "base/logging.h"
+
+namespace net {
+
+// TODO(wtc): this is the same as the ScopedCipherCTX class defined in
+// crypto/encryptor_openssl.cc.  Eliminate the duplicate code.
+// crypto::ScopedOpenSSL is not suitable for EVP_CIPHER_CTX because
+// there are no EVP_CIPHER_CTX_create and EVP_CIPHER_CTX_destroy
+// functions.
+class ScopedEVPCipherCtx {
+ public:
+  ScopedEVPCipherCtx() {
+    EVP_CIPHER_CTX_init(&ctx_);
+  }
+
+  ~ScopedEVPCipherCtx() {
+    int rv = EVP_CIPHER_CTX_cleanup(&ctx_);
+    DCHECK_EQ(rv, 1);
+  }
+
+  EVP_CIPHER_CTX* get() { return &ctx_; }
+
+ private:
+  EVP_CIPHER_CTX ctx_;
+};
+
+}  // namespace net
+
+#endif  // NET_QUIC_CRYPTO_SCOPED_EVP_CIPHER_CTX_H_