1 // Copyright (c) 2011 The Bitcoin Developers
2 // Distributed under the MIT/X11 software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
9 const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
10 const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
13 Private key encryption is done based on a CMasterKey,
14 which holds a salt and random encryption key.
16 CMasterKeys is encrypted using AES-256-CBC using a key
17 derived using derivation method nDerivationMethod
18 (0 == EVP_sha512()) and derivation iterations nDeriveIterations.
19 vchOtherDerivationParameters is provided for alternative algorithms
20 which may require more parameters (such as scrypt).
22 Wallet Private Keys are then encrypted using AES-256-CBC
23 with the double-sha256 of the private key as the IV, and the
24 master key's key as the encryption key.
30 std::vector<unsigned char> vchCryptedKey;
31 std::vector<unsigned char> vchSalt;
34 unsigned int nDerivationMethod;
35 unsigned int nDeriveIterations;
36 // Use this for more parameters to key derivation,
37 // such as the various parameters to scrypt
38 std::vector<unsigned char> vchOtherDerivationParameters;
42 READWRITE(vchCryptedKey);
44 READWRITE(nDerivationMethod);
45 READWRITE(nDeriveIterations);
46 READWRITE(vchOtherDerivationParameters);
50 // 25000 rounds is just under 0.1 seconds on a 1.86 GHz Pentium M
51 // ie slightly lower than the lowest hardware we need bother supporting
52 nDeriveIterations = 25000;
53 nDerivationMethod = 0;
54 vchOtherDerivationParameters = std::vector<unsigned char>(0);
58 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;
63 unsigned char chKey[WALLET_CRYPTO_KEY_SIZE];
64 unsigned char chIV[WALLET_CRYPTO_KEY_SIZE];
68 bool SetKeyFromPassphrase(const std::string &strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod);
69 bool Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext);
70 bool Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext);
71 bool SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV);
75 memset(&chKey, 0, sizeof chKey);
76 memset(&chIV, 0, sizeof chIV);
77 munlock(&chKey, sizeof chKey);
78 munlock(&chIV, sizeof chIV);
93 bool EncryptSecret(CKeyingMaterial& vMasterKey, const CSecret &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext);
94 bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char> &vchCiphertext, const uint256& nIV, CSecret &vchPlaintext);