diff options
Diffstat (limited to 'src/wallet')
| -rw-r--r-- | src/wallet/crypter.cpp | 292 | ||||
| -rw-r--r-- | src/wallet/crypter.h | 196 | ||||
| -rw-r--r-- | src/wallet/wallet.h | 2 |
3 files changed, 489 insertions, 1 deletions
diff --git a/src/wallet/crypter.cpp b/src/wallet/crypter.cpp new file mode 100644 index 0000000000..c7f7e21679 --- /dev/null +++ b/src/wallet/crypter.cpp @@ -0,0 +1,292 @@ +// Copyright (c) 2009-2013 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include "crypter.h" + +#include "script/script.h" +#include "script/standard.h" +#include "util.h" + +#include <string> +#include <vector> +#include <boost/foreach.hpp> +#include <openssl/aes.h> +#include <openssl/evp.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) + { + memory_cleanse(chKey, sizeof(chKey)); + memory_cleanse(chIV, 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) != 0; + if (fOk) fOk = EVP_EncryptUpdate(&ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen) != 0; + if (fOk) fOk = EVP_EncryptFinal_ex(&ctx, (&vchCiphertext[0]) + nCLen, &nFLen) != 0; + 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) != 0; + if (fOk) fOk = EVP_DecryptUpdate(&ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen) != 0; + if (fOk) fOk = EVP_DecryptFinal_ex(&ctx, (&vchPlaintext[0]) + nPLen, &nFLen) != 0; + EVP_CIPHER_CTX_cleanup(&ctx); + + if (!fOk) return false; + + vchPlaintext.resize(nPLen + nFLen); + return true; +} + + +static bool EncryptSecret(const CKeyingMaterial& vMasterKey, const CKeyingMaterial &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(*((const CKeyingMaterial*)&vchPlaintext), vchCiphertext); +} + +static bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CKeyingMaterial& 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)); +} + +static bool DecryptKey(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCryptedSecret, const CPubKey& vchPubKey, CKey& key) +{ + CKeyingMaterial vchSecret; + if(!DecryptSecret(vMasterKey, vchCryptedSecret, vchPubKey.GetHash(), vchSecret)) + return false; + + if (vchSecret.size() != 32) + return false; + + key.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed()); + return key.VerifyPubKey(vchPubKey); +} + +bool CCryptoKeyStore::SetCrypted() +{ + LOCK(cs_KeyStore); + if (fUseCrypto) + return true; + if (!mapKeys.empty()) + return false; + fUseCrypto = true; + return true; +} + +bool CCryptoKeyStore::Lock() +{ + if (!SetCrypted()) + return false; + + { + LOCK(cs_KeyStore); + vMasterKey.clear(); + } + + NotifyStatusChanged(this); + return true; +} + +bool CCryptoKeyStore::Unlock(const CKeyingMaterial& vMasterKeyIn) +{ + { + LOCK(cs_KeyStore); + if (!SetCrypted()) + return false; + + bool keyPass = false; + bool keyFail = false; + CryptedKeyMap::const_iterator mi = mapCryptedKeys.begin(); + for (; mi != mapCryptedKeys.end(); ++mi) + { + const CPubKey &vchPubKey = (*mi).second.first; + const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second; + CKey key; + if (!DecryptKey(vMasterKeyIn, vchCryptedSecret, vchPubKey, key)) + { + keyFail = true; + break; + } + keyPass = true; + if (fDecryptionThoroughlyChecked) + break; + } + if (keyPass && keyFail) + { + LogPrintf("The wallet is probably corrupted: Some keys decrypt but not all."); + assert(false); + } + if (keyFail || !keyPass) + return false; + vMasterKey = vMasterKeyIn; + fDecryptionThoroughlyChecked = true; + } + NotifyStatusChanged(this); + return true; +} + +bool CCryptoKeyStore::AddKeyPubKey(const CKey& key, const CPubKey &pubkey) +{ + { + LOCK(cs_KeyStore); + if (!IsCrypted()) + return CBasicKeyStore::AddKeyPubKey(key, pubkey); + + if (IsLocked()) + return false; + + std::vector<unsigned char> vchCryptedSecret; + CKeyingMaterial vchSecret(key.begin(), key.end()); + if (!EncryptSecret(vMasterKey, vchSecret, pubkey.GetHash(), vchCryptedSecret)) + return false; + + if (!AddCryptedKey(pubkey, vchCryptedSecret)) + return false; + } + return true; +} + + +bool CCryptoKeyStore::AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret) +{ + { + LOCK(cs_KeyStore); + if (!SetCrypted()) + return false; + + mapCryptedKeys[vchPubKey.GetID()] = make_pair(vchPubKey, vchCryptedSecret); + } + return true; +} + +bool CCryptoKeyStore::GetKey(const CKeyID &address, CKey& keyOut) const +{ + { + LOCK(cs_KeyStore); + if (!IsCrypted()) + return CBasicKeyStore::GetKey(address, keyOut); + + CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address); + if (mi != mapCryptedKeys.end()) + { + const CPubKey &vchPubKey = (*mi).second.first; + const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second; + return DecryptKey(vMasterKey, vchCryptedSecret, vchPubKey, keyOut); + } + } + return false; +} + +bool CCryptoKeyStore::GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const +{ + { + LOCK(cs_KeyStore); + if (!IsCrypted()) + return CKeyStore::GetPubKey(address, vchPubKeyOut); + + CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address); + if (mi != mapCryptedKeys.end()) + { + vchPubKeyOut = (*mi).second.first; + return true; + } + } + return false; +} + +bool CCryptoKeyStore::EncryptKeys(CKeyingMaterial& vMasterKeyIn) +{ + { + LOCK(cs_KeyStore); + if (!mapCryptedKeys.empty() || IsCrypted()) + return false; + + fUseCrypto = true; + BOOST_FOREACH(KeyMap::value_type& mKey, mapKeys) + { + const CKey &key = mKey.second; + CPubKey vchPubKey = key.GetPubKey(); + CKeyingMaterial vchSecret(key.begin(), key.end()); + std::vector<unsigned char> vchCryptedSecret; + if (!EncryptSecret(vMasterKeyIn, vchSecret, vchPubKey.GetHash(), vchCryptedSecret)) + return false; + if (!AddCryptedKey(vchPubKey, vchCryptedSecret)) + return false; + } + mapKeys.clear(); + } + return true; +} diff --git a/src/wallet/crypter.h b/src/wallet/crypter.h new file mode 100644 index 0000000000..32746b00df --- /dev/null +++ b/src/wallet/crypter.h @@ -0,0 +1,196 @@ +// Copyright (c) 2009-2014 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_CRYPTER_H +#define BITCOIN_CRYPTER_H + +#include "keystore.h" +#include "serialize.h" +#include "support/allocators/secure.h" + +class uint256; + +const unsigned int WALLET_CRYPTO_KEY_SIZE = 32; +const unsigned int WALLET_CRYPTO_SALT_SIZE = 8; + +/** + * 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, int nType, int nVersion) { + 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; + +/** Encryption/decryption context with key information */ +class CCrypter +{ +private: + unsigned char chKey[WALLET_CRYPTO_KEY_SIZE]; + unsigned char chIV[WALLET_CRYPTO_KEY_SIZE]; + bool fKeySet; + +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); + bool Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext); + bool SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV); + + void CleanKey() + { + memory_cleanse(chKey, sizeof(chKey)); + memory_cleanse(chIV, sizeof(chIV)); + fKeySet = false; + } + + CCrypter() + { + fKeySet = false; + + // Try to keep the key data out of swap (and be a bit over-careful to keep the IV that we don't even use out of swap) + // Note that this does nothing about suspend-to-disk (which will put all our key data on disk) + // 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. + LockedPageManager::Instance().LockRange(&chKey[0], sizeof chKey); + LockedPageManager::Instance().LockRange(&chIV[0], sizeof chIV); + } + + ~CCrypter() + { + CleanKey(); + + LockedPageManager::Instance().UnlockRange(&chKey[0], sizeof chKey); + LockedPageManager::Instance().UnlockRange(&chIV[0], sizeof chIV); + } +}; + +/** 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: + CryptedKeyMap mapCryptedKeys; + + CKeyingMaterial vMasterKey; + + //! if fUseCrypto is true, mapKeys must be empty + //! if fUseCrypto is false, vMasterKey must be empty + bool fUseCrypto; + + //! keeps track of whether Unlock has run a thorough check before + bool fDecryptionThoroughlyChecked; + +protected: + bool SetCrypted(); + + //! will encrypt previously unencrypted keys + bool EncryptKeys(CKeyingMaterial& vMasterKeyIn); + + bool Unlock(const CKeyingMaterial& vMasterKeyIn); + +public: + CCryptoKeyStore() : fUseCrypto(false), fDecryptionThoroughlyChecked(false) + { + } + + bool IsCrypted() const + { + return fUseCrypto; + } + + bool IsLocked() const + { + if (!IsCrypted()) + return false; + bool result; + { + LOCK(cs_KeyStore); + result = vMasterKey.empty(); + } + return result; + } + + bool Lock(); + + virtual bool AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret); + bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey); + bool HaveKey(const CKeyID &address) const + { + { + LOCK(cs_KeyStore); + if (!IsCrypted()) + return CBasicKeyStore::HaveKey(address); + return mapCryptedKeys.count(address) > 0; + } + return false; + } + bool GetKey(const CKeyID &address, CKey& keyOut) const; + bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const; + void GetKeys(std::set<CKeyID> &setAddress) const + { + if (!IsCrypted()) + { + CBasicKeyStore::GetKeys(setAddress); + return; + } + setAddress.clear(); + CryptedKeyMap::const_iterator mi = mapCryptedKeys.begin(); + while (mi != mapCryptedKeys.end()) + { + setAddress.insert((*mi).first); + mi++; + } + } + + /** + * Wallet status (encrypted, locked) changed. + * Note: Called without locks held. + */ + boost::signals2::signal<void (CCryptoKeyStore* wallet)> NotifyStatusChanged; +}; + +#endif // BITCOIN_CRYPTER_H diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h index 1a9feff9f3..fbcb56685e 100644 --- a/src/wallet/wallet.h +++ b/src/wallet/wallet.h @@ -9,11 +9,11 @@ #include "amount.h" #include "primitives/block.h" #include "primitives/transaction.h" -#include "crypter.h" #include "key.h" #include "keystore.h" #include "main.h" #include "ui_interface.h" +#include "wallet/crypter.h" #include "wallet/wallet_ismine.h" #include "wallet/walletdb.h" |