1 // Copyright (c) 2009-2012 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.
7 #include "util.h" /* for SecureString */
10 const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
11 const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
14 Private key encryption is done based on a CMasterKey,
15 which holds a salt and random encryption key.
17 CMasterKeys are encrypted using AES-256-CBC using a key
18 derived using derivation method nDerivationMethod
19 (0 == EVP_sha512()) and derivation iterations nDeriveIterations.
20 vchOtherDerivationParameters is provided for alternative algorithms
21 which may require more parameters (such as scrypt).
23 Wallet Private Keys are then encrypted using AES-256-CBC
24 with the double-sha256 of the public key as the IV, and the
25 master key's key as the encryption key (see keystore.[ch]).
31 std::vector<unsigned char> vchCryptedKey;
32 std::vector<unsigned char> vchSalt;
35 unsigned int nDerivationMethod;
36 unsigned int nDeriveIterations;
37 // Use this for more parameters to key derivation,
38 // such as the various parameters to scrypt
39 std::vector<unsigned char> vchOtherDerivationParameters;
43 READWRITE(vchCryptedKey);
45 READWRITE(nDerivationMethod);
46 READWRITE(nDeriveIterations);
47 READWRITE(vchOtherDerivationParameters);
51 // 25000 rounds is just under 0.1 seconds on a 1.86 GHz Pentium M
52 // ie slightly lower than the lowest hardware we need bother supporting
53 nDeriveIterations = 25000;
54 nDerivationMethod = 0;
55 vchOtherDerivationParameters = std::vector<unsigned char>(0);
59 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;
64 unsigned char chKey[WALLET_CRYPTO_KEY_SIZE];
65 unsigned char chIV[WALLET_CRYPTO_KEY_SIZE];
69 bool SetKeyFromPassphrase(const SecureString &strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod);
70 bool Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext);
71 bool Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext);
72 bool SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV);
76 memset(&chKey, 0, sizeof chKey);
77 memset(&chIV, 0, sizeof chIV);
78 munlock(&chKey, sizeof chKey);
79 munlock(&chIV, sizeof chIV);
94 bool EncryptSecret(CKeyingMaterial& vMasterKey, const CSecret &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext);
95 bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char> &vchCiphertext, const uint256& nIV, CSecret &vchPlaintext);