dash/src/crypter.cpp
Wladimir J. van der Laan 0b886ad1bd Make CCrypter use LockedPageManager to manage locked pages
Replace direct calls to mlock.

Also, change the class to lock the memory areas in the constructor and unlock them again in the destructor. This makes sure that locked pages won't leak.
2012-08-23 06:55:35 +02:00

122 lines
3.8 KiB
C++

// Copyright (c) 2009-2012 The Bitcoin Developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <openssl/aes.h>
#include <openssl/evp.h>
#include <vector>
#include <string>
#ifdef WIN32
#include <windows.h>
#endif
#include "crypter.h"
bool CCrypter::SetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod)
{
if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
return false;
int i = 0;
if (nDerivationMethod == 0)
i = EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha512(), &chSalt[0],
(unsigned char *)&strKeyData[0], strKeyData.size(), nRounds, chKey, chIV);
if (i != (int)WALLET_CRYPTO_KEY_SIZE)
{
memset(&chKey, 0, sizeof chKey);
memset(&chIV, 0, sizeof chIV);
return false;
}
fKeySet = true;
return true;
}
bool CCrypter::SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV)
{
if (chNewKey.size() != WALLET_CRYPTO_KEY_SIZE || chNewIV.size() != WALLET_CRYPTO_KEY_SIZE)
return false;
memcpy(&chKey[0], &chNewKey[0], sizeof chKey);
memcpy(&chIV[0], &chNewIV[0], sizeof chIV);
fKeySet = true;
return true;
}
bool CCrypter::Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext)
{
if (!fKeySet)
return false;
// max ciphertext len for a n bytes of plaintext is
// n + AES_BLOCK_SIZE - 1 bytes
int nLen = vchPlaintext.size();
int nCLen = nLen + AES_BLOCK_SIZE, nFLen = 0;
vchCiphertext = std::vector<unsigned char> (nCLen);
EVP_CIPHER_CTX ctx;
bool fOk = true;
EVP_CIPHER_CTX_init(&ctx);
if (fOk) fOk = EVP_EncryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV);
if (fOk) fOk = EVP_EncryptUpdate(&ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen);
if (fOk) fOk = EVP_EncryptFinal_ex(&ctx, (&vchCiphertext[0])+nCLen, &nFLen);
EVP_CIPHER_CTX_cleanup(&ctx);
if (!fOk) return false;
vchCiphertext.resize(nCLen + nFLen);
return true;
}
bool CCrypter::Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext)
{
if (!fKeySet)
return false;
// plaintext will always be equal to or lesser than length of ciphertext
int nLen = vchCiphertext.size();
int nPLen = nLen, nFLen = 0;
vchPlaintext = CKeyingMaterial(nPLen);
EVP_CIPHER_CTX ctx;
bool fOk = true;
EVP_CIPHER_CTX_init(&ctx);
if (fOk) fOk = EVP_DecryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV);
if (fOk) fOk = EVP_DecryptUpdate(&ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen);
if (fOk) fOk = EVP_DecryptFinal_ex(&ctx, (&vchPlaintext[0])+nPLen, &nFLen);
EVP_CIPHER_CTX_cleanup(&ctx);
if (!fOk) return false;
vchPlaintext.resize(nPLen + nFLen);
return true;
}
bool EncryptSecret(CKeyingMaterial& vMasterKey, const CSecret &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext)
{
CCrypter cKeyCrypter;
std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
if(!cKeyCrypter.SetKey(vMasterKey, chIV))
return false;
return cKeyCrypter.Encrypt((CKeyingMaterial)vchPlaintext, vchCiphertext);
}
bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CSecret& vchPlaintext)
{
CCrypter cKeyCrypter;
std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
if(!cKeyCrypter.SetKey(vMasterKey, chIV))
return false;
return cKeyCrypter.Decrypt(vchCiphertext, *((CKeyingMaterial*)&vchPlaintext));
}