1// Copyright (c) 2013 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_AEAD_BASE_DECRYPTER_H_
6#define NET_QUIC_CRYPTO_AEAD_BASE_DECRYPTER_H_
7
8#include "base/compiler_specific.h"
9#include "net/quic/crypto/quic_decrypter.h"
10
11#if defined(USE_OPENSSL)
12#include "net/quic/crypto/scoped_evp_aead_ctx.h"
13#else
14#include <pkcs11t.h>
15#include <seccomon.h>
16typedef struct PK11SymKeyStr PK11SymKey;
17typedef SECStatus (*PK11_DecryptFunction)(
18      PK11SymKey* symKey, CK_MECHANISM_TYPE mechanism, SECItem* param,
19      unsigned char* out, unsigned int* outLen, unsigned int maxLen,
20      const unsigned char* enc, unsigned encLen);
21#endif
22
23namespace net {
24
25// AeadBaseDecrypter is the base class of AEAD QuicDecrypter subclasses.
26class NET_EXPORT_PRIVATE AeadBaseDecrypter : public QuicDecrypter {
27 public:
28#if defined(USE_OPENSSL)
29  AeadBaseDecrypter(const EVP_AEAD* aead_alg,
30                    size_t key_size,
31                    size_t auth_tag_size,
32                    size_t nonce_prefix_size);
33#else
34  AeadBaseDecrypter(CK_MECHANISM_TYPE aead_mechanism,
35                    PK11_DecryptFunction pk11_decrypt,
36                    size_t key_size,
37                    size_t auth_tag_size,
38                    size_t nonce_prefix_size);
39#endif
40  virtual ~AeadBaseDecrypter();
41
42  // QuicDecrypter implementation
43  virtual bool SetKey(base::StringPiece key) OVERRIDE;
44  virtual bool SetNoncePrefix(base::StringPiece nonce_prefix) OVERRIDE;
45  virtual bool Decrypt(base::StringPiece nonce,
46                       base::StringPiece associated_data,
47                       base::StringPiece ciphertext,
48                       unsigned char* output,
49                       size_t* output_length) OVERRIDE;
50  virtual QuicData* DecryptPacket(QuicPacketSequenceNumber sequence_number,
51                                  base::StringPiece associated_data,
52                                  base::StringPiece ciphertext) OVERRIDE;
53  virtual base::StringPiece GetKey() const OVERRIDE;
54  virtual base::StringPiece GetNoncePrefix() const OVERRIDE;
55
56 protected:
57  // Make these constants available to the subclasses so that the subclasses
58  // can assert at compile time their key_size_ and nonce_prefix_size_ do not
59  // exceed the maximum.
60  static const size_t kMaxKeySize = 32;
61  static const size_t kMaxNoncePrefixSize = 4;
62
63#if !defined(USE_OPENSSL)
64  struct AeadParams {
65    unsigned int len;
66    union {
67      CK_GCM_PARAMS gcm_params;
68#if !defined(USE_NSS)
69      // USE_NSS means we are using system NSS rather than our copy of NSS.
70      // The system NSS <pkcs11n.h> header doesn't define this type yet.
71      CK_NSS_AEAD_PARAMS nss_aead_params;
72#endif
73    } data;
74  };
75
76  virtual void FillAeadParams(base::StringPiece nonce,
77                              base::StringPiece associated_data,
78                              size_t auth_tag_size,
79                              AeadParams* aead_params) const = 0;
80#endif  // !defined(USE_OPENSSL)
81
82 private:
83#if defined(USE_OPENSSL)
84  const EVP_AEAD* const aead_alg_;
85#else
86  const CK_MECHANISM_TYPE aead_mechanism_;
87  const PK11_DecryptFunction pk11_decrypt_;
88#endif
89  const size_t key_size_;
90  const size_t auth_tag_size_;
91  const size_t nonce_prefix_size_;
92
93  // The key.
94  unsigned char key_[kMaxKeySize];
95  // The nonce prefix.
96  unsigned char nonce_prefix_[kMaxNoncePrefixSize];
97
98#if defined(USE_OPENSSL)
99  ScopedEVPAEADCtx ctx_;
100#endif
101
102  DISALLOW_COPY_AND_ASSIGN(AeadBaseDecrypter);
103};
104
105}  // namespace net
106
107#endif  // NET_QUIC_CRYPTO_AEAD_BASE_DECRYPTER_H_
108