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
212
213
214
215
216
217
218
219
220
221
222
223
224
|
//
// CipherKeyImpl.cpp
//
// Library: Crypto
// Package: Cipher
// Module: CipherKeyImpl
//
// Copyright (c) 2008, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#include "Poco/Crypto/CipherKeyImpl.h"
#include "Poco/Crypto/CryptoTransform.h"
#include "Poco/Crypto/CipherFactory.h"
#include "Poco/Exception.h"
#include "Poco/RandomStream.h"
#include <openssl/err.h>
#include <openssl/evp.h>
namespace Poco {
namespace Crypto {
CipherKeyImpl::CipherKeyImpl(const std::string& name,
const std::string& passphrase,
const std::string& salt,
int iterationCount,
const std::string& digest):
_pCipher(0),
_pDigest(0),
_name(name),
_key(),
_iv()
{
// dummy access to Cipherfactory so that the EVP lib is initilaized
CipherFactory::defaultFactory();
_pCipher = EVP_get_cipherbyname(name.c_str());
if (!_pCipher)
throw Poco::NotFoundException("Cipher " + name + " was not found");
_pDigest = EVP_get_digestbyname(digest.c_str());
if (!_pDigest)
throw Poco::NotFoundException("Digest " + name + " was not found");
_key = ByteVec(keySize());
_iv = ByteVec(ivSize());
generateKey(passphrase, salt, iterationCount);
}
CipherKeyImpl::CipherKeyImpl(const std::string& name,
const ByteVec& key,
const ByteVec& iv):
_pCipher(0),
_pDigest(0),
_name(name),
_key(key),
_iv(iv)
{
// dummy access to Cipherfactory so that the EVP lib is initialized
CipherFactory::defaultFactory();
_pCipher = EVP_get_cipherbyname(name.c_str());
if (!_pCipher)
throw Poco::NotFoundException("Cipher " + name + " was not found");
}
CipherKeyImpl::CipherKeyImpl(const std::string& name):
_pCipher(0),
_pDigest(0),
_name(name),
_key(),
_iv()
{
// dummy access to Cipherfactory so that the EVP lib is initilaized
CipherFactory::defaultFactory();
_pCipher = EVP_get_cipherbyname(name.c_str());
if (!_pCipher)
throw Poco::NotFoundException("Cipher " + name + " was not found");
_key = ByteVec(keySize());
_iv = ByteVec(ivSize());
generateKey();
}
CipherKeyImpl::~CipherKeyImpl()
{
}
CipherKeyImpl::Mode CipherKeyImpl::mode() const
{
switch (EVP_CIPHER_mode(_pCipher))
{
case EVP_CIPH_STREAM_CIPHER:
return MODE_STREAM_CIPHER;
case EVP_CIPH_ECB_MODE:
return MODE_ECB;
case EVP_CIPH_CBC_MODE:
return MODE_CBC;
case EVP_CIPH_CFB_MODE:
return MODE_CFB;
case EVP_CIPH_OFB_MODE:
return MODE_OFB;
#if OPENSSL_VERSION_NUMBER >= 0x10001000L
case EVP_CIPH_CTR_MODE:
return MODE_CTR;
case EVP_CIPH_GCM_MODE:
return MODE_GCM;
case EVP_CIPH_CCM_MODE:
return MODE_CCM;
#endif
}
throw Poco::IllegalStateException("Unexpected value of EVP_CIPHER_mode()");
}
void CipherKeyImpl::generateKey()
{
ByteVec vec;
getRandomBytes(vec, keySize());
setKey(vec);
getRandomBytes(vec, ivSize());
setIV(vec);
}
void CipherKeyImpl::getRandomBytes(ByteVec& vec, std::size_t count)
{
Poco::RandomInputStream random;
vec.clear();
vec.reserve(count);
for (int i = 0; i < count; ++i)
vec.push_back(static_cast<unsigned char>(random.get()));
}
void CipherKeyImpl::generateKey(
const std::string& password,
const std::string& salt,
int iterationCount)
{
unsigned char keyBytes[EVP_MAX_KEY_LENGTH];
unsigned char ivBytes[EVP_MAX_IV_LENGTH];
// OpenSSL documentation specifies that the salt must be an 8-byte array.
unsigned char saltBytes[8];
if (!salt.empty())
{
int len = static_cast<int>(salt.size());
// Create the salt array from the salt string
for (int i = 0; i < 8; ++i)
saltBytes[i] = salt.at(i % len);
for (int i = 8; i < len; ++i)
saltBytes[i % 8] ^= salt.at(i);
}
// Now create the key and IV, using the MD5 digest algorithm.
int keySize = EVP_BytesToKey(
_pCipher,
_pDigest ? _pDigest : EVP_md5(),
(salt.empty() ? 0 : saltBytes),
reinterpret_cast<const unsigned char*>(password.data()),
static_cast<int>(password.size()),
iterationCount,
keyBytes,
ivBytes);
// Copy the buffers to our member byte vectors.
_key.assign(keyBytes, keyBytes + keySize);
if (ivSize() == 0)
_iv.clear();
else
_iv.assign(ivBytes, ivBytes + ivSize());
}
int CipherKeyImpl::keySize() const
{
return EVP_CIPHER_key_length(_pCipher);
}
int CipherKeyImpl::blockSize() const
{
return EVP_CIPHER_block_size(_pCipher);
}
int CipherKeyImpl::ivSize() const
{
return EVP_CIPHER_iv_length(_pCipher);
}
void CipherKeyImpl::setIV(const ByteVec& iv)
{
poco_assert(mode() == MODE_GCM || iv.size() == static_cast<ByteVec::size_type>(ivSize()));
_iv = iv;
}
} } // namespace Poco::Crypto
|
