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
|
// Copyright (c) 2009-2013 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef __CRYPTER_H__
#define __CRYPTER_H__
#include "allocators.h"
#include "serialize.h"
#include "keystore.h"
class uint256;
const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
/*
Private key encryption is done based on a CMasterKey,
which holds a salt and random encryption key.
CMasterKeys are encrypted using AES-256-CBC using a key
derived using derivation method nDerivationMethod
(0 == EVP_sha512()) and derivation iterations nDeriveIterations.
vchOtherDerivationParameters is provided for alternative algorithms
which may require more parameters (such as scrypt).
Wallet Private Keys are then encrypted using AES-256-CBC
with the double-sha256 of the public key as the IV, and the
master key's key as the encryption key (see keystore.[ch]).
*/
/** Master key for wallet encryption */
class CMasterKey
{
public:
std::vector<unsigned char> vchCryptedKey;
std::vector<unsigned char> vchSalt;
// 0 = EVP_sha512()
// 1 = scrypt()
unsigned int nDerivationMethod;
unsigned int nDeriveIterations;
// Use this for more parameters to key derivation,
// such as the various parameters to scrypt
std::vector<unsigned char> vchOtherDerivationParameters;
IMPLEMENT_SERIALIZE;
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
READWRITE(vchCryptedKey);
READWRITE(vchSalt);
READWRITE(nDerivationMethod);
READWRITE(nDeriveIterations);
READWRITE(vchOtherDerivationParameters);
}
CMasterKey()
{
// 25000 rounds is just under 0.1 seconds on a 1.86 GHz Pentium M
// ie slightly lower than the lowest hardware we need bother supporting
nDeriveIterations = 25000;
nDerivationMethod = 0;
vchOtherDerivationParameters = std::vector<unsigned char>(0);
}
};
typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;
/** Encryption/decryption context with key information */
class CCrypter
{
private:
unsigned char chKey[WALLET_CRYPTO_KEY_SIZE];
unsigned char chIV[WALLET_CRYPTO_KEY_SIZE];
bool fKeySet;
public:
bool SetKeyFromPassphrase(const SecureString &strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod);
bool Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext);
bool Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext);
bool SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV);
void CleanKey()
{
OPENSSL_cleanse(chKey, sizeof(chKey));
OPENSSL_cleanse(chIV, sizeof(chIV));
fKeySet = false;
}
CCrypter()
{
fKeySet = false;
// Try to keep the key data out of swap (and be a bit over-careful to keep the IV that we don't even use out of swap)
// Note that this does nothing about suspend-to-disk (which will put all our key data on disk)
// Note as well that at no point in this program is any attempt made to prevent stealing of keys by reading the memory of the running process.
LockedPageManager::Instance().LockRange(&chKey[0], sizeof chKey);
LockedPageManager::Instance().LockRange(&chIV[0], sizeof chIV);
}
~CCrypter()
{
CleanKey();
LockedPageManager::Instance().UnlockRange(&chKey[0], sizeof chKey);
LockedPageManager::Instance().UnlockRange(&chIV[0], sizeof chIV);
}
};
bool EncryptSecret(const CKeyingMaterial& vMasterKey, const CKeyingMaterial &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext);
bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CKeyingMaterial& vchPlaintext);
/** Keystore which keeps the private keys encrypted.
* It derives from the basic key store, which is used if no encryption is active.
*/
class CCryptoKeyStore : public CBasicKeyStore
{
private:
CryptedKeyMap mapCryptedKeys;
CKeyingMaterial vMasterKey;
// if fUseCrypto is true, mapKeys must be empty
// if fUseCrypto is false, vMasterKey must be empty
bool fUseCrypto;
// keeps track of whether Unlock has run a thourough check before
bool fDecryptionThoroughlyChecked;
protected:
bool SetCrypted();
// will encrypt previously unencrypted keys
bool EncryptKeys(CKeyingMaterial& vMasterKeyIn);
bool Unlock(const CKeyingMaterial& vMasterKeyIn);
public:
CCryptoKeyStore() : fUseCrypto(false), fDecryptionThoroughlyChecked(false)
{
}
bool IsCrypted() const
{
return fUseCrypto;
}
bool IsLocked() const
{
if (!IsCrypted())
return false;
bool result;
{
LOCK(cs_KeyStore);
result = vMasterKey.empty();
}
return result;
}
bool Lock();
virtual bool AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret);
bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
bool HaveKey(const CKeyID &address) const
{
{
LOCK(cs_KeyStore);
if (!IsCrypted())
return CBasicKeyStore::HaveKey(address);
return mapCryptedKeys.count(address) > 0;
}
return false;
}
bool GetKey(const CKeyID &address, CKey& keyOut) const;
bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const;
void GetKeys(std::set<CKeyID> &setAddress) const
{
if (!IsCrypted())
{
CBasicKeyStore::GetKeys(setAddress);
return;
}
setAddress.clear();
CryptedKeyMap::const_iterator mi = mapCryptedKeys.begin();
while (mi != mapCryptedKeys.end())
{
setAddress.insert((*mi).first);
mi++;
}
}
/* Wallet status (encrypted, locked) changed.
* Note: Called without locks held.
*/
boost::signals2::signal<void (CCryptoKeyStore* wallet)> NotifyStatusChanged;
};
#endif
|
