1//
2// CipherKeyImpl.cpp
3//
4// Library: Crypto
5// Package: Cipher
6// Module: CipherKeyImpl
7//
8// Copyright (c) 2008, Applied Informatics Software Engineering GmbH.
9// and Contributors.
10//
11// SPDX-License-Identifier: BSL-1.0
12//
13
14
15#include "Poco/Crypto/CipherKeyImpl.h"
16#include "Poco/Crypto/CryptoTransform.h"
17#include "Poco/Crypto/CipherFactory.h"
18#include "Poco/Exception.h"
19#include "Poco/RandomStream.h"
20#include <openssl/err.h>
21#include <openssl/evp.h>
22
23
24namespace Poco {
25namespace Crypto {
26
27
28CipherKeyImpl::CipherKeyImpl(const std::string& name,
29 const std::string& passphrase,
30 const std::string& salt,
31 int iterationCount,
32 const std::string& digest): _pCipher(0),
33 _pDigest(0),
34 _name(name),
35 _key(),
36 _iv()
37{
38 // dummy access to Cipherfactory so that the EVP lib is initilaized
39 CipherFactory::defaultFactory();
40 _pCipher = EVP_get_cipherbyname(name.c_str());
41
42 if (!_pCipher)
43 throw Poco::NotFoundException("Cipher " + name + " was not found");
44
45 _pDigest = EVP_get_digestbyname(digest.c_str());
46
47 if (!_pDigest)
48 throw Poco::NotFoundException("Digest " + name + " was not found");
49
50
51 _key = ByteVec(keySize());
52 _iv = ByteVec(ivSize());
53 generateKey(passphrase, salt, iterationCount);
54}
55
56
57CipherKeyImpl::CipherKeyImpl(const std::string& name,
58 const ByteVec& key,
59 const ByteVec& iv): _pCipher(0),
60 _pDigest(0),
61 _name(name),
62 _key(key),
63 _iv(iv)
64{
65 // dummy access to Cipherfactory so that the EVP lib is initilaized
66 CipherFactory::defaultFactory();
67 _pCipher = EVP_get_cipherbyname(name.c_str());
68
69 if (!_pCipher)
70 throw Poco::NotFoundException("Cipher " + name + " was not found");
71}
72
73
74CipherKeyImpl::CipherKeyImpl(const std::string& name): _pCipher(0),
75 _pDigest(0),
76 _name(name),
77 _key(),
78 _iv()
79{
80 // dummy access to Cipherfactory so that the EVP lib is initilaized
81 CipherFactory::defaultFactory();
82 _pCipher = EVP_get_cipherbyname(name.c_str());
83
84 if (!_pCipher)
85 throw Poco::NotFoundException("Cipher " + name + " was not found");
86 _key = ByteVec(keySize());
87 _iv = ByteVec(ivSize());
88 generateKey();
89}
90
91
92CipherKeyImpl::~CipherKeyImpl()
93{
94}
95
96
97CipherKeyImpl::Mode CipherKeyImpl::mode() const
98{
99 switch (EVP_CIPHER_mode(_pCipher))
100 {
101 case EVP_CIPH_STREAM_CIPHER:
102 return MODE_STREAM_CIPHER;
103
104 case EVP_CIPH_ECB_MODE:
105 return MODE_ECB;
106
107 case EVP_CIPH_CBC_MODE:
108 return MODE_CBC;
109
110 case EVP_CIPH_CFB_MODE:
111 return MODE_CFB;
112
113 case EVP_CIPH_OFB_MODE:
114 return MODE_OFB;
115 }
116 throw Poco::IllegalStateException("Unexpected value of EVP_CIPHER_mode()");
117}
118
119
120void CipherKeyImpl::generateKey()
121{
122 ByteVec vec;
123
124 getRandomBytes(vec, keySize());
125 setKey(vec);
126
127 getRandomBytes(vec, ivSize());
128 setIV(vec);
129}
130
131
132void CipherKeyImpl::getRandomBytes(ByteVec& vec, std::size_t count)
133{
134 Poco::RandomInputStream random;
135
136 vec.clear();
137 vec.reserve(count);
138
139 for (int i = 0; i < count; ++i)
140 vec.push_back(static_cast<unsigned char>(random.get()));
141}
142
143
144void CipherKeyImpl::generateKey(
145 const std::string& password,
146 const std::string& salt,
147 int iterationCount)
148{
149 unsigned char keyBytes[EVP_MAX_KEY_LENGTH];
150 unsigned char ivBytes[EVP_MAX_IV_LENGTH];
151
152 // OpenSSL documentation specifies that the salt must be an 8-byte array.
153 unsigned char saltBytes[8];
154 if (!salt.empty())
155 {
156 int len = static_cast<int>(salt.size());
157 // Create the salt array from the salt string
158 for (int i = 0; i < 8; ++i)
159 saltBytes[i] = salt.at(i % len);
160 for (int i = 8; i < len; ++i)
161 saltBytes[i % 8] ^= salt.at(i);
162 }
163
164 // Now create the key and IV, using the digest set in the constructor.
165 int keySize = EVP_BytesToKey(
166 _pCipher,
167 _pDigest ? _pDigest : EVP_md5(),
168 (salt.empty() ? 0 : saltBytes),
169 reinterpret_cast<const unsigned char*>(password.data()),
170 static_cast<int>(password.size()),
171 iterationCount,
172 keyBytes,
173 ivBytes);
174
175 // Copy the buffers to our member byte vectors.
176 _key.assign(keyBytes, keyBytes + keySize);
177
178 if (ivSize() == 0)
179 _iv.clear();
180 else
181 _iv.assign(ivBytes, ivBytes + ivSize());
182}
183
184
185int CipherKeyImpl::keySize() const
186{
187 return EVP_CIPHER_key_length(_pCipher);
188}
189
190
191int CipherKeyImpl::blockSize() const
192{
193 return EVP_CIPHER_block_size(_pCipher);
194}
195
196
197int CipherKeyImpl::ivSize() const
198{
199 return EVP_CIPHER_iv_length(_pCipher);
200}
201
202
203} } // namespace Poco::Crypto
204