net/quic/crypto/chacha20_poly1305_decrypter.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_QUIC_CRYPTO_CHACHA20_POLY1305_DECRYPTER_H_
   6 #define NET_QUIC_CRYPTO_CHACHA20_POLY1305_DECRYPTER_H_
   7
   8 #include "net/quic/crypto/aead_base_decrypter.h"
   9
  10 namespace net {
  11
  12 // A ChaCha20Poly1305Decrypter is a QuicDecrypter that implements the
  13 // AEAD_CHACHA20_POLY1305 algorithm specified in
  14 // draft-agl-tls-chacha20poly1305-04, except that it truncates the Poly1305
  15 // authenticator to 12 bytes. Create an instance by calling
  16 // QuicDecrypter::Create(kCC12).
  17 //
  18 // It uses an authentication tag of 16 bytes (128 bits). There is no
  19 // fixed nonce prefix.
  20 class NET_EXPORT_PRIVATE ChaCha20Poly1305Decrypter : public AeadBaseDecrypter {
  21  public:
  22   enum {
  23     kAuthTagSize = 12,
  24   };
  25
  26   ChaCha20Poly1305Decrypter();
  27   virtual ~ChaCha20Poly1305Decrypter();
  28
  29   // Returns true if the underlying crypto library supports ChaCha20+Poly1305.
  30   static bool IsSupported();
  31
  32 #if !defined(USE_OPENSSL)
  33  protected:
  34   // AeadBaseDecrypter methods:
  35   virtual void FillAeadParams(base::StringPiece nonce,
  36                               base::StringPiece associated_data,
  37                               size_t auth_tag_size,
  38                               AeadParams* aead_params) const OVERRIDE;
  39 #endif
  40
  41  private:
  42   DISALLOW_COPY_AND_ASSIGN(ChaCha20Poly1305Decrypter);
  43 };
  44
  45 }  // namespace net
  46
  47 #endif  // NET_QUIC_CRYPTO_CHACHA20_POLY1305_DECRYPTER_H_