src/crypter.cpp

   1 // Copyright (c) 2009-2013 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.
   4
   5 #include "crypter.h"
   6
   7 #include "script.h"
   8
   9 #include <string>
  10 #include <vector>
  11 #include <boost/foreach.hpp>
  12 #include <openssl/aes.h>
  13 #include <openssl/evp.h>
  14
  15 bool CCrypter::SetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod)
  16 {
  17     if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
  18         return false;
  19
  20     int i = 0;
  21     if (nDerivationMethod == 0)
  22         i = EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha512(), &chSalt[0],
  23                           (unsigned char *)&strKeyData[0], strKeyData.size(), nRounds, chKey, chIV);
  24
  25     if (i != (int)WALLET_CRYPTO_KEY_SIZE)
  26     {
  27         OPENSSL_cleanse(chKey, sizeof(chKey));
  28         OPENSSL_cleanse(chIV, sizeof(chIV));
  29         return false;
  30     }
  31
  32     fKeySet = true;
  33     return true;
  34 }
  35
  36 bool CCrypter::SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV)
  37 {
  38     if (chNewKey.size() != WALLET_CRYPTO_KEY_SIZE || chNewIV.size() != WALLET_CRYPTO_KEY_SIZE)
  39         return false;
  40
  41     memcpy(&chKey[0], &chNewKey[0], sizeof chKey);
  42     memcpy(&chIV[0], &chNewIV[0], sizeof chIV);
  43
  44     fKeySet = true;
  45     return true;
  46 }
  47
  48 bool CCrypter::Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext)
  49 {
  50     if (!fKeySet)
  51         return false;
  52
  53     // max ciphertext len for a n bytes of plaintext is
  54     // n + AES_BLOCK_SIZE - 1 bytes
  55     int nLen = vchPlaintext.size();
  56     int nCLen = nLen + AES_BLOCK_SIZE, nFLen = 0;
  57     vchCiphertext = std::vector<unsigned char> (nCLen);
  58
  59     EVP_CIPHER_CTX ctx;
  60
  61     bool fOk = true;
  62
  63     EVP_CIPHER_CTX_init(&ctx);
  64     if (fOk) fOk = EVP_EncryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV);
  65     if (fOk) fOk = EVP_EncryptUpdate(&ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen);
  66     if (fOk) fOk = EVP_EncryptFinal_ex(&ctx, (&vchCiphertext[0])+nCLen, &nFLen);
  67     EVP_CIPHER_CTX_cleanup(&ctx);
  68
  69     if (!fOk) return false;
  70
  71     vchCiphertext.resize(nCLen + nFLen);
  72     return true;
  73 }
  74
  75 bool CCrypter::Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext)
  76 {
  77     if (!fKeySet)
  78         return false;
  79
  80     // plaintext will always be equal to or lesser than length of ciphertext
  81     int nLen = vchCiphertext.size();
  82     int nPLen = nLen, nFLen = 0;
  83
  84     vchPlaintext = CKeyingMaterial(nPLen);
  85
  86     EVP_CIPHER_CTX ctx;
  87
  88     bool fOk = true;
  89
  90     EVP_CIPHER_CTX_init(&ctx);
  91     if (fOk) fOk = EVP_DecryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV);
  92     if (fOk) fOk = EVP_DecryptUpdate(&ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen);
  93     if (fOk) fOk = EVP_DecryptFinal_ex(&ctx, (&vchPlaintext[0])+nPLen, &nFLen);
  94     EVP_CIPHER_CTX_cleanup(&ctx);
  95
  96     if (!fOk) return false;
  97
  98     vchPlaintext.resize(nPLen + nFLen);
  99     return true;
 100 }
 101
 102
 103 bool EncryptSecret(const CKeyingMaterial& vMasterKey, const CKeyingMaterial &vchPlaintext, const uint256& nIV, std::vector<unsigned char> &vchCiphertext)
 104 {
 105     CCrypter cKeyCrypter;
 106     std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
 107     memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
 108     if(!cKeyCrypter.SetKey(vMasterKey, chIV))
 109         return false;
 110     return cKeyCrypter.Encrypt(*((const CKeyingMaterial*)&vchPlaintext), vchCiphertext);
 111 }
 112
 113 bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CKeyingMaterial& vchPlaintext)
 114 {
 115     CCrypter cKeyCrypter;
 116     std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
 117     memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
 118     if(!cKeyCrypter.SetKey(vMasterKey, chIV))
 119         return false;
 120     return cKeyCrypter.Decrypt(vchCiphertext, *((CKeyingMaterial*)&vchPlaintext));
 121 }
 122
 123 bool CCryptoKeyStore::SetCrypted()
 124 {
 125     LOCK(cs_KeyStore);
 126     if (fUseCrypto)
 127         return true;
 128     if (!mapKeys.empty())
 129         return false;
 130     fUseCrypto = true;
 131     return true;
 132 }
 133
 134 bool CCryptoKeyStore::Lock()
 135 {
 136     if (!SetCrypted())
 137         return false;
 138
 139     {
 140         LOCK(cs_KeyStore);
 141         vMasterKey.clear();
 142     }
 143
 144     NotifyStatusChanged(this);
 145     return true;
 146 }
 147
 148 bool CCryptoKeyStore::Unlock(const CKeyingMaterial& vMasterKeyIn)
 149 {
 150     {
 151         LOCK(cs_KeyStore);
 152         if (!SetCrypted())
 153             return false;
 154
 155         bool keyPass = false;
 156         bool keyFail = false;
 157         CryptedKeyMap::const_iterator mi = mapCryptedKeys.begin();
 158         for (; mi != mapCryptedKeys.end(); ++mi)
 159         {
 160             const CPubKey &vchPubKey = (*mi).second.first;
 161             const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second;
 162             CKeyingMaterial vchSecret;
 163             if(!DecryptSecret(vMasterKeyIn, vchCryptedSecret, vchPubKey.GetHash(), vchSecret))
 164             {
 165                 keyFail = true;
 166                 break;
 167             }
 168             if (vchSecret.size() != 32)
 169             {
 170                 keyFail = true;
 171                 break;
 172             }
 173             CKey key;
 174             key.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed());
 175             if (key.GetPubKey() != vchPubKey)
 176             {
 177                 keyFail = true;
 178                 break;
 179             }
 180             keyPass = true;
 181             if (fDecryptionThoroughlyChecked)
 182                 break;
 183         }
 184         if (keyPass && keyFail)
 185         {
 186             LogPrintf("The wallet is probably corrupted: Some keys decrypt but not all.");
 187             assert(false);
 188         }
 189         if (keyFail || !keyPass)
 190             return false;
 191         vMasterKey = vMasterKeyIn;
 192         fDecryptionThoroughlyChecked = true;
 193     }
 194     NotifyStatusChanged(this);
 195     return true;
 196 }
 197
 198 bool CCryptoKeyStore::AddKeyPubKey(const CKey& key, const CPubKey &pubkey)
 199 {
 200     {
 201         LOCK(cs_KeyStore);
 202         if (!IsCrypted())
 203             return CBasicKeyStore::AddKeyPubKey(key, pubkey);
 204
 205         if (IsLocked())
 206             return false;
 207
 208         std::vector<unsigned char> vchCryptedSecret;
 209         CKeyingMaterial vchSecret(key.begin(), key.end());
 210         if (!EncryptSecret(vMasterKey, vchSecret, pubkey.GetHash(), vchCryptedSecret))
 211             return false;
 212
 213         if (!AddCryptedKey(pubkey, vchCryptedSecret))
 214             return false;
 215     }
 216     return true;
 217 }
 218
 219
 220 bool CCryptoKeyStore::AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret)
 221 {
 222     {
 223         LOCK(cs_KeyStore);
 224         if (!SetCrypted())
 225             return false;
 226
 227         mapCryptedKeys[vchPubKey.GetID()] = make_pair(vchPubKey, vchCryptedSecret);
 228     }
 229     return true;
 230 }
 231
 232 bool CCryptoKeyStore::GetKey(const CKeyID &address, CKey& keyOut) const
 233 {
 234     {
 235         LOCK(cs_KeyStore);
 236         if (!IsCrypted())
 237             return CBasicKeyStore::GetKey(address, keyOut);
 238
 239         CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
 240         if (mi != mapCryptedKeys.end())
 241         {
 242             const CPubKey &vchPubKey = (*mi).second.first;
 243             const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second;
 244             CKeyingMaterial vchSecret;
 245             if (!DecryptSecret(vMasterKey, vchCryptedSecret, vchPubKey.GetHash(), vchSecret))
 246                 return false;
 247             if (vchSecret.size() != 32)
 248                 return false;
 249             keyOut.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed());
 250             return true;
 251         }
 252     }
 253     return false;
 254 }
 255
 256 bool CCryptoKeyStore::GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const
 257 {
 258     {
 259         LOCK(cs_KeyStore);
 260         if (!IsCrypted())
 261             return CKeyStore::GetPubKey(address, vchPubKeyOut);
 262
 263         CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
 264         if (mi != mapCryptedKeys.end())
 265         {
 266             vchPubKeyOut = (*mi).second.first;
 267             return true;
 268         }
 269     }
 270     return false;
 271 }
 272
 273 bool CCryptoKeyStore::EncryptKeys(CKeyingMaterial& vMasterKeyIn)
 274 {
 275     {
 276         LOCK(cs_KeyStore);
 277         if (!mapCryptedKeys.empty() || IsCrypted())
 278             return false;
 279
 280         fUseCrypto = true;
 281         BOOST_FOREACH(KeyMap::value_type& mKey, mapKeys)
 282         {
 283             const CKey &key = mKey.second;
 284             CPubKey vchPubKey = key.GetPubKey();
 285             CKeyingMaterial vchSecret(key.begin(), key.end());
 286             std::vector<unsigned char> vchCryptedSecret;
 287             if (!EncryptSecret(vMasterKeyIn, vchSecret, vchPubKey.GetHash(), vchCryptedSecret))
 288                 return false;
 289             if (!AddCryptedKey(vchPubKey, vchCryptedSecret))
 290                 return false;
 291         }
 292         mapKeys.clear();
 293     }
 294     return true;
 295 }