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
|
// Copyright (c) 2009-2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_WALLET_CRYPTER_H
#define BITCOIN_WALLET_CRYPTER_H
#include <keystore.h>
#include <serialize.h>
#include <support/allocators/secure.h>
#include <atomic>
const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
const unsigned int WALLET_CRYPTO_IV_SIZE = 16;
/**
* 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;
ADD_SERIALIZE_METHODS;
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
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;
namespace wallet_crypto_tests
{
class TestCrypter;
}
/** Encryption/decryption context with key information */
class CCrypter
{
friend class wallet_crypto_tests::TestCrypter; // for test access to chKey/chIV
private:
std::vector<unsigned char, secure_allocator<unsigned char>> vchKey;
std::vector<unsigned char, secure_allocator<unsigned char>> vchIV;
bool fKeySet;
int BytesToKeySHA512AES(const std::vector<unsigned char>& chSalt, const SecureString& strKeyData, int count, unsigned char *key,unsigned char *iv) const;
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) const;
bool Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext) const;
bool SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV);
void CleanKey()
{
memory_cleanse(vchKey.data(), vchKey.size());
memory_cleanse(vchIV.data(), vchIV.size());
fKeySet = false;
}
CCrypter()
{
fKeySet = false;
vchKey.resize(WALLET_CRYPTO_KEY_SIZE);
vchIV.resize(WALLET_CRYPTO_IV_SIZE);
}
~CCrypter()
{
CleanKey();
}
};
/** 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:
CKeyingMaterial vMasterKey GUARDED_BY(cs_KeyStore);
//! if fUseCrypto is true, mapKeys must be empty
//! if fUseCrypto is false, vMasterKey must be empty
std::atomic<bool> fUseCrypto;
//! keeps track of whether Unlock has run a thorough check before
bool fDecryptionThoroughlyChecked;
protected:
using CryptedKeyMap = std::map<CKeyID, std::pair<CPubKey, std::vector<unsigned char>>>;
bool SetCrypted();
//! will encrypt previously unencrypted keys
bool EncryptKeys(CKeyingMaterial& vMasterKeyIn);
bool Unlock(const CKeyingMaterial& vMasterKeyIn);
CryptedKeyMap mapCryptedKeys GUARDED_BY(cs_KeyStore);
public:
CCryptoKeyStore() : fUseCrypto(false), fDecryptionThoroughlyChecked(false)
{
}
bool IsCrypted() const { return fUseCrypto; }
bool IsLocked() const;
bool Lock();
virtual bool AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret);
bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
bool HaveKey(const CKeyID &address) const override;
bool GetKey(const CKeyID &address, CKey& keyOut) const override;
bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const override;
std::set<CKeyID> GetKeys() const override;
/**
* Wallet status (encrypted, locked) changed.
* Note: Called without locks held.
*/
boost::signals2::signal<void (CCryptoKeyStore* wallet)> NotifyStatusChanged;
};
#endif // BITCOIN_WALLET_CRYPTER_H
|
