1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
// chacha.h - written and placed in the public domain by Jeffrey Walton.
// Based on Wei Dai's Salsa20, Botan's SSE2 implementation,
// and Bernstein's reference ChaCha family implementation at
// http://cr.yp.to/chacha.html.
// The library added Bernstein's ChaCha classses at Crypto++ 5.6.4. The IETF
// uses a slightly different implementation than Bernstein, and the IETF
// classes were added at Crypto++ 8.1. We wanted to maintain ABI compatibility
// at the 8.1 release so the original ChaCha classes were not disturbed.
// Instead new classes were added for IETF ChaCha. The back-end implementation
// shares code as expected, however.
/// \file chacha.h
/// \brief Classes for ChaCha8, ChaCha12 and ChaCha20 stream ciphers
/// \details Crypto++ provides Bernstein and ECRYPT's ChaCha from <a
/// href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a
/// variant of Salsa20</a> (2008.01.28). Crypto++ also provides the
/// IETF implementation of ChaCha using the ChaChaTLS name. Bernstein's
/// implementation is _slightly_ different from the TLS working group's
/// implementation for cipher suites
/// <tt>TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>,
/// <tt>TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256</tt>,
/// and <tt>TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>.
/// \since ChaCha since Crypto++ 5.6.4, ChaChaTLS since Crypto++ 8.1
#ifndef CRYPTOPP_CHACHA_H
#define CRYPTOPP_CHACHA_H
#include "strciphr.h"
#include "secblock.h"
NAMESPACE_BEGIN(CryptoPP)
////////////////////////////// Bernstein ChaCha //////////////////////////////
/// \brief ChaCha stream cipher information
/// \since Crypto++ 5.6.4
struct ChaCha_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>
{
/// \brief The algorithm name
/// \returns the algorithm name
/// \details StaticAlgorithmName returns the algorithm's name as a static
/// member function.
/// \details Bernstein named the cipher variants ChaCha8, ChaCha12 and
/// ChaCha20. More generally, Bernstein called the family ChaCha{r}.
/// AlgorithmName() provides the exact name once rounds are set.
static const char* StaticAlgorithmName() {
return "ChaCha";
}
};
/// \brief ChaCha stream cipher implementation
/// \since Crypto++ 5.6.4
class CRYPTOPP_NO_VTABLE ChaCha_Policy : public AdditiveCipherConcretePolicy<word32, 16>
{
public:
virtual ~ChaCha_Policy() {}
ChaCha_Policy() : m_rounds(0) {}
protected:
void CipherSetKey(const NameValuePairs ¶ms, const byte *key, size_t length);
void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
bool CipherIsRandomAccess() const {return true;}
void SeekToIteration(lword iterationCount);
unsigned int GetAlignment() const;
unsigned int GetOptimalBlockSize() const;
std::string AlgorithmName() const;
std::string AlgorithmProvider() const;
FixedSizeAlignedSecBlock<word32, 16> m_state;
unsigned int m_rounds;
};
/// \brief ChaCha stream cipher
/// \details This is Bernstein and ECRYPT's ChaCha. It is _slightly_ different
/// from the IETF's version of ChaCha called ChaChaTLS.
/// \sa <a href="http://cr.yp.to/chacha/chacha-20080208.pdf">ChaCha, a variant
/// of Salsa20</a> (2008.01.28).
/// \since Crypto++ 5.6.4
struct ChaCha : public ChaCha_Info, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy, AdditiveCipherTemplate<> >, ChaCha_Info > Encryption;
typedef Encryption Decryption;
};
////////////////////////////// IETF ChaChaTLS //////////////////////////////
/// \brief ChaCha-TLS stream cipher information
/// \since Crypto++ 8.1
struct ChaChaTLS_Info : public FixedKeyLength<32, SimpleKeyingInterface::UNIQUE_IV, 12>, FixedRounds<20>
{
/// \brief The algorithm name
/// \returns the algorithm name
/// \details StaticAlgorithmName returns the algorithm's name as a static
/// member function.
/// \details This is the IETF's variant of Bernstein's ChaCha from RFC
/// 8439. IETF ChaCha is called ChaChaTLS in the Crypto++ library. It
/// is _slightly_ different from Bernstein's implementation.
static const char* StaticAlgorithmName() {
return "ChaChaTLS";
}
};
/// \brief ChaCha-TLS stream cipher implementation
/// \since Crypto++ 8.1
class CRYPTOPP_NO_VTABLE ChaChaTLS_Policy : public AdditiveCipherConcretePolicy<word32, 16>
{
public:
virtual ~ChaChaTLS_Policy() {}
ChaChaTLS_Policy() {}
protected:
void CipherSetKey(const NameValuePairs ¶ms, const byte *key, size_t length);
void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
bool CipherIsRandomAccess() const {return true;}
void SeekToIteration(lword iterationCount);
unsigned int GetAlignment() const;
unsigned int GetOptimalBlockSize() const;
std::string AlgorithmName() const;
std::string AlgorithmProvider() const;
FixedSizeAlignedSecBlock<word32, 16+1> m_state;
CRYPTOPP_CONSTANT(ROUNDS = ChaChaTLS_Info::ROUNDS)
};
/// \brief ChaCha-TLS stream cipher
/// \details This is the IETF's variant of Bernstein's ChaCha from RFC 8439.
/// IETF ChaCha is called ChaChaTLS in the Crypto++ library. It is
/// _slightly_ different from the Bernstein implementation. ChaCha-TLS
/// can be used for cipher suites
/// <tt>TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>,
/// <tt>TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256</tt>, and
/// <tt>TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>.
/// \sa <a href="https://tools.ietf.org/html/rfc8439">RFC 8439, ChaCha20 and
/// Poly1305 for IETF Protocols</a>, <A HREF="https://mailarchive.ietf.org/arch/msg/cfrg/gsOnTJzcbgG6OqD8Sc0GO5aR_tU">How
/// to handle block counter wrap in IETF's ChaCha algorithm?</A> and
/// <A HREF="https://github.com/weidai11/cryptopp/issues/790">Issue
/// 790, ChaChaTLS results when counter block wraps</A>.
/// \since Crypto++ 8.1
struct ChaChaTLS : public ChaChaTLS_Info, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaChaTLS_Policy, AdditiveCipherTemplate<> >, ChaChaTLS_Info > Encryption;
typedef Encryption Decryption;
};
NAMESPACE_END
#endif // CRYPTOPP_CHACHA_H
|
