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
|
// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <wallet/crypter.h>
#include <crypto/aes.h>
#include <crypto/sha512.h>
#include <util/system.h>
#include <vector>
int CCrypter::BytesToKeySHA512AES(const std::vector<unsigned char>& chSalt, const SecureString& strKeyData, int count, unsigned char *key,unsigned char *iv) const
{
// This mimics the behavior of openssl's EVP_BytesToKey with an aes256cbc
// cipher and sha512 message digest. Because sha512's output size (64b) is
// greater than the aes256 block size (16b) + aes256 key size (32b),
// there's no need to process more than once (D_0).
if(!count || !key || !iv)
return 0;
unsigned char buf[CSHA512::OUTPUT_SIZE];
CSHA512 di;
di.Write((const unsigned char*)strKeyData.data(), strKeyData.size());
di.Write(chSalt.data(), chSalt.size());
di.Finalize(buf);
for(int i = 0; i != count - 1; i++)
di.Reset().Write(buf, sizeof(buf)).Finalize(buf);
memcpy(key, buf, WALLET_CRYPTO_KEY_SIZE);
memcpy(iv, buf + WALLET_CRYPTO_KEY_SIZE, WALLET_CRYPTO_IV_SIZE);
memory_cleanse(buf, sizeof(buf));
return WALLET_CRYPTO_KEY_SIZE;
}
bool CCrypter::SetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod)
{
if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
return false;
int i = 0;
if (nDerivationMethod == 0)
i = BytesToKeySHA512AES(chSalt, strKeyData, nRounds, vchKey.data(), vchIV.data());
if (i != (int)WALLET_CRYPTO_KEY_SIZE)
{
memory_cleanse(vchKey.data(), vchKey.size());
memory_cleanse(vchIV.data(), vchIV.size());
return false;
}
fKeySet = true;
return true;
}
bool CCrypter::SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV)
{
if (chNewKey.size() != WALLET_CRYPTO_KEY_SIZE || chNewIV.size() != WALLET_CRYPTO_IV_SIZE)
return false;
memcpy(vchKey.data(), chNewKey.data(), chNewKey.size());
memcpy(vchIV.data(), chNewIV.data(), chNewIV.size());
fKeySet = true;
return true;
}
bool CCrypter::Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext) const
{
if (!fKeySet)
return false;
// max ciphertext len for a n bytes of plaintext is
// n + AES_BLOCKSIZE bytes
vchCiphertext.resize(vchPlaintext.size() + AES_BLOCKSIZE);
AES256CBCEncrypt enc(vchKey.data(), vchIV.data(), true);
size_t nLen = enc.Encrypt(vchPlaintext.data(), vchPlaintext.size(), vchCiphertext.data());
if(nLen < vchPlaintext.size())
return false;
vchCiphertext.resize(nLen);
return true;
}
bool CCrypter::Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext) const
{
if (!fKeySet)
return false;
// plaintext will always be equal to or lesser than length of ciphertext
int nLen = vchCiphertext.size();
vchPlaintext.resize(nLen);
AES256CBCDecrypt dec(vchKey.data(), vchIV.data(), true);
nLen = dec.Decrypt(vchCiphertext.data(), vchCiphertext.size(), vchPlaintext.data());
if(nLen == 0)
return false;
vchPlaintext.resize(nLen);
return true;
}
bool EncryptSecret(const CKeyingMaterial& vMasterKey, const CKeyingMaterial &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext)
{
CCrypter cKeyCrypter;
std::vector<unsigned char> chIV(WALLET_CRYPTO_IV_SIZE);
memcpy(chIV.data(), &nIV, WALLET_CRYPTO_IV_SIZE);
if(!cKeyCrypter.SetKey(vMasterKey, chIV))
return false;
return cKeyCrypter.Encrypt(*((const CKeyingMaterial*)&vchPlaintext), vchCiphertext);
}
bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CKeyingMaterial& vchPlaintext)
{
CCrypter cKeyCrypter;
std::vector<unsigned char> chIV(WALLET_CRYPTO_IV_SIZE);
memcpy(chIV.data(), &nIV, WALLET_CRYPTO_IV_SIZE);
if(!cKeyCrypter.SetKey(vMasterKey, chIV))
return false;
return cKeyCrypter.Decrypt(vchCiphertext, vchPlaintext);
}
bool DecryptKey(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCryptedSecret, const CPubKey& vchPubKey, CKey& key)
{
CKeyingMaterial vchSecret;
if(!DecryptSecret(vMasterKey, vchCryptedSecret, vchPubKey.GetHash(), vchSecret))
return false;
if (vchSecret.size() != 32)
return false;
key.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed());
return key.VerifyPubKey(vchPubKey);
}
|
