wallet: move crypter to wallet

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"