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.
5 #include <openssl/aes.h>
6 #include <openssl/evp.h>
16 bool CCrypter::SetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod)
18 if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
21 // Try to keep the keydata out of swap (and be a bit over-careful to keep the IV that we don't even use out of swap)
22 // Note that this does nothing about suspend-to-disk (which will put all our key data on disk)
23 // 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.
24 mlock(&chKey[0], sizeof chKey);
25 mlock(&chIV[0], sizeof chIV);
28 if (nDerivationMethod == 0)
29 i = EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha512(), &chSalt[0],
30 (unsigned char *)&strKeyData[0], strKeyData.size(), nRounds, chKey, chIV);
32 if (i != (int)WALLET_CRYPTO_KEY_SIZE)
34 memset(&chKey, 0, sizeof chKey);
35 memset(&chIV, 0, sizeof chIV);
43 bool CCrypter::SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV)
45 if (chNewKey.size() != WALLET_CRYPTO_KEY_SIZE || chNewIV.size() != WALLET_CRYPTO_KEY_SIZE)
48 // Try to keep the keydata out of swap
49 // Note that this does nothing about suspend-to-disk (which will put all our key data on disk)
50 // 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.
51 mlock(&chKey[0], sizeof chKey);
52 mlock(&chIV[0], sizeof chIV);
54 memcpy(&chKey[0], &chNewKey[0], sizeof chKey);
55 memcpy(&chIV[0], &chNewIV[0], sizeof chIV);
61 bool CCrypter::Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext)
66 // max ciphertext len for a n bytes of plaintext is
67 // n + AES_BLOCK_SIZE - 1 bytes
68 int nLen = vchPlaintext.size();
69 int nCLen = nLen + AES_BLOCK_SIZE, nFLen = 0;
70 vchCiphertext = std::vector<unsigned char> (nCLen);
76 EVP_CIPHER_CTX_init(&ctx);
77 if (fOk) fOk = EVP_EncryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV);
78 if (fOk) fOk = EVP_EncryptUpdate(&ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen);
79 if (fOk) fOk = EVP_EncryptFinal_ex(&ctx, (&vchCiphertext[0])+nCLen, &nFLen);
80 EVP_CIPHER_CTX_cleanup(&ctx);
82 if (!fOk) return false;
84 vchCiphertext.resize(nCLen + nFLen);
88 bool CCrypter::Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext)
93 // plaintext will always be equal to or lesser than length of ciphertext
94 int nLen = vchCiphertext.size();
95 int nPLen = nLen, nFLen = 0;
97 vchPlaintext = CKeyingMaterial(nPLen);
103 EVP_CIPHER_CTX_init(&ctx);
104 if (fOk) fOk = EVP_DecryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV);
105 if (fOk) fOk = EVP_DecryptUpdate(&ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen);
106 if (fOk) fOk = EVP_DecryptFinal_ex(&ctx, (&vchPlaintext[0])+nPLen, &nFLen);
107 EVP_CIPHER_CTX_cleanup(&ctx);
109 if (!fOk) return false;
111 vchPlaintext.resize(nPLen + nFLen);
116 bool EncryptSecret(CKeyingMaterial& vMasterKey, const CSecret &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext)
118 CCrypter cKeyCrypter;
119 std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
120 memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
121 if(!cKeyCrypter.SetKey(vMasterKey, chIV))
123 return cKeyCrypter.Encrypt((CKeyingMaterial)vchPlaintext, vchCiphertext);
126 bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CSecret& vchPlaintext)
128 CCrypter cKeyCrypter;
129 std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
130 memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
131 if(!cKeyCrypter.SetKey(vMasterKey, chIV))
133 return cKeyCrypter.Decrypt(vchCiphertext, *((CKeyingMaterial*)&vchPlaintext));