forked from juliushekkala/cryptopp-pqc
-
Notifications
You must be signed in to change notification settings - Fork 2
/
chachapoly.cpp
211 lines (179 loc) · 8.39 KB
/
chachapoly.cpp
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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
// chachapoly.cpp - written and placed in the public domain by Jeffrey Walton
// RFC 8439, Section 2.8, AEAD Construction, http://tools.ietf.org/html/rfc8439
#include "pch.h"
#include "chachapoly.h"
#include "algparam.h"
#include "misc.h"
#if CRYPTOPP_MSC_VERSION
# pragma warning(disable: 4244)
#endif
NAMESPACE_BEGIN(CryptoPP)
////////////////////////////// IETF ChaChaTLS //////////////////////////////
// RekeyCipherAndMac is heavier-weight than we like. The Authenc framework was
// predicated on BlockCiphers, where the key and key schedule could be
// calculated independent of the IV being used. However, the ChaCha and
// ChaCha20Poly1305 construction combines key setup and IV. That is, both are
// needed to key or rekey the cipher. Even a simple Resync() requires us to
// regenerate the initial state for both ChaCha20 and Poly1305.
void ChaCha20Poly1305_Base::RekeyCipherAndMac(const byte *userKey, size_t keylength, const NameValuePairs ¶ms)
{
// Derive MAC key
AlgorithmParameters block0 = MakeParameters("InitialBlock", (word64)0, true);
AccessSymmetricCipher().SetKey(userKey, keylength, CombinedNameValuePairs(params, block0));
// Only the first 256-bits are used to key the MAC
SecByteBlock derived(NULLPTR, 32);
AccessSymmetricCipher().ProcessString(derived, derived.size());
// Key the Poly1305 MAC
AccessMAC().SetKey(derived, derived.size(), params);
// Key the ChaCha20 cipher
AlgorithmParameters block1 = MakeParameters("InitialBlock", (word64)1, true);
AccessSymmetricCipher().SetKey(userKey, keylength, CombinedNameValuePairs(params, block1));
}
void ChaCha20Poly1305_Base::SetKeyWithoutResync(const byte *userKey, size_t userKeyLength, const NameValuePairs ¶ms)
{
CRYPTOPP_ASSERT(userKey && userKeyLength == 32);
m_userKey.Assign(userKey, userKeyLength);
// ChaCha/Poly1305 initial state depends on both the key and IV. The
// IV may or may not be present during the call to SetKeyWithoutResync.
// If the IV is present, the framework will call SetKeyWithoutResync
// followed by Resynchronize which calls Resync. In this case we defer
// calculating the initial state until the call to Resynchronize.
// If the IV is not present, it avoids calling ChaCha's SetKey without
// an IV, which results in an exception. In this case the user will need
// to call Resynchronize to key ChaCha and Poly1305.
// RekeyCipherAndMac(userKey, userKeyLength, params);
CRYPTOPP_UNUSED(params);
}
void ChaCha20Poly1305_Base::Resync(const byte *iv, size_t len)
{
CRYPTOPP_ASSERT(iv && len == 12);
RekeyCipherAndMac(m_userKey, m_userKey.SizeInBytes(),
MakeParameters(Name::IV(), ConstByteArrayParameter(iv,len)));
}
size_t ChaCha20Poly1305_Base::AuthenticateBlocks(const byte *data, size_t len)
{
AccessMAC().Update(data, len);
return 0;
}
void ChaCha20Poly1305_Base::AuthenticateLastHeaderBlock()
{
// Pad to a multiple of 16 or 0
const byte zero[16] = {0};
size_t pad = (16U - (m_totalHeaderLength % 16)) % 16;
AccessMAC().Update(zero, pad);
}
void ChaCha20Poly1305_Base::AuthenticateLastConfidentialBlock()
{
// Pad to a multiple of 16 or 0
const byte zero[16] = {0};
size_t pad = (16U - (m_totalMessageLength % 16)) % 16;
AccessMAC().Update(zero, pad);
}
void ChaCha20Poly1305_Base::AuthenticateLastFooterBlock(byte *mac, size_t macSize)
{
CRYPTOPP_ALIGN_DATA(8) byte length[2*sizeof(word64)];
PutWord(true, LITTLE_ENDIAN_ORDER, length+0, m_totalHeaderLength);
PutWord(true, LITTLE_ENDIAN_ORDER, length+8, m_totalMessageLength);
AccessMAC().Update(length, sizeof(length));
AccessMAC().TruncatedFinal(mac, macSize);
m_state = State_KeySet;
}
void ChaCha20Poly1305_Base::EncryptAndAuthenticate(byte *ciphertext, byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *message, size_t messageLength)
{
Resynchronize(iv, ivLength);
Update(aad, aadLength);
ProcessString(ciphertext, message, messageLength);
TruncatedFinal(mac, macSize);
}
bool ChaCha20Poly1305_Base::DecryptAndVerify(byte *message, const byte *mac, size_t macLength, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *ciphertext, size_t ciphertextLength)
{
Resynchronize(iv, ivLength);
Update(aad, aadLength);
ProcessString(message, ciphertext, ciphertextLength);
return TruncatedVerify(mac, macLength);
}
////////////////////////////// IETF XChaCha20 draft //////////////////////////////
// RekeyCipherAndMac is heavier-weight than we like. The Authenc framework was
// predicated on BlockCiphers, where the key and key schedule could be
// calculated independent of the IV being used. However, the ChaCha and
// ChaCha20Poly1305 construction combines key setup and IV. That is, both are
// needed to key or rekey the cipher. Even a simple Resync() requires us to
// regenerate the initial state for both ChaCha20 and Poly1305.
void XChaCha20Poly1305_Base::RekeyCipherAndMac(const byte *userKey, size_t keylength, const NameValuePairs ¶ms)
{
// Derive MAC key
AlgorithmParameters block0 = MakeParameters("InitialBlock", (word64)0, true);
AccessSymmetricCipher().SetKey(userKey, keylength, CombinedNameValuePairs(params, block0));
// Only the first 256-bits are used to key the MAC
SecByteBlock derived(NULLPTR, 32);
AccessSymmetricCipher().ProcessString(derived, derived.size());
// Key the Poly1305 MAC
AccessMAC().SetKey(derived, derived.size(), params);
// Key the ChaCha20 cipher
AlgorithmParameters block1 = MakeParameters("InitialBlock", (word64)1, true);
AccessSymmetricCipher().SetKey(userKey, keylength, CombinedNameValuePairs(params, block1));
}
void XChaCha20Poly1305_Base::SetKeyWithoutResync(const byte *userKey, size_t userKeyLength, const NameValuePairs ¶ms)
{
CRYPTOPP_ASSERT(userKey && userKeyLength == 32);
m_userKey.Assign(userKey, userKeyLength);
// XChaCha20/Poly1305 initial state depends on both the key and IV. The
// IV may or may not be present during the call to SetKeyWithoutResync.
// If the IV is present, the framework will call SetKeyWithoutResync
// followed by Resynchronize which calls Resync. In this case we defer
// calculating the initial state until the call to Resynchronize.
// If the IV is not present, it avoids calling ChaCha's SetKey without
// an IV, which results in an exception. In this case the user will need
// to call Resynchronize to key ChaCha and Poly1305.
// RekeyCipherAndMac(userKey, userKeyLength, params);
CRYPTOPP_UNUSED(params);
}
void XChaCha20Poly1305_Base::Resync(const byte *iv, size_t len)
{
CRYPTOPP_ASSERT(iv && len == 24);
RekeyCipherAndMac(m_userKey, m_userKey.SizeInBytes(),
MakeParameters(Name::IV(), ConstByteArrayParameter(iv,len)));
}
size_t XChaCha20Poly1305_Base::AuthenticateBlocks(const byte *data, size_t len)
{
AccessMAC().Update(data, len);
return 0;
}
void XChaCha20Poly1305_Base::AuthenticateLastHeaderBlock()
{
// Pad to a multiple of 16 or 0
const byte zero[16] = {0};
size_t pad = (16 - (m_totalHeaderLength % 16)) % 16;
AccessMAC().Update(zero, pad);
}
void XChaCha20Poly1305_Base::AuthenticateLastConfidentialBlock()
{
// Pad to a multiple of 16 or 0
const byte zero[16] = {0};
size_t pad = (16 - (m_totalMessageLength % 16)) % 16;
AccessMAC().Update(zero, pad);
}
void XChaCha20Poly1305_Base::AuthenticateLastFooterBlock(byte *mac, size_t macSize)
{
CRYPTOPP_ALIGN_DATA(8) byte length[2*sizeof(word64)];
PutWord(true, LITTLE_ENDIAN_ORDER, length+0, m_totalHeaderLength);
PutWord(true, LITTLE_ENDIAN_ORDER, length+8, m_totalMessageLength);
AccessMAC().Update(length, sizeof(length));
AccessMAC().TruncatedFinal(mac, macSize);
m_state = State_KeySet;
}
void XChaCha20Poly1305_Base::EncryptAndAuthenticate(byte *ciphertext, byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *message, size_t messageLength)
{
Resynchronize(iv, ivLength);
Update(aad, aadLength);
ProcessString(ciphertext, message, messageLength);
TruncatedFinal(mac, macSize);
}
bool XChaCha20Poly1305_Base::DecryptAndVerify(byte *message, const byte *mac, size_t macLength, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *ciphertext, size_t ciphertextLength)
{
Resynchronize(iv, ivLength);
Update(aad, aadLength);
ProcessString(message, ciphertext, ciphertextLength);
return TruncatedVerify(mac, macLength);
}
NAMESPACE_END