crypter.h

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// Copyright (c) 2009-2014 The Bitcoin developers
// Copyright (c) 2017-2021 The PIVX Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef PIVX_CRYPTER_H
#define PIVX_CRYPTER_H
 
#include "keystore.h"
#include "serialize.h"
#include "streams.h"
#include "support/allocators/zeroafterfree.h"
 
class uint256;
 
#include <atomic>
 
const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
const unsigned int WALLET_CRYPTO_IV_SIZE = 16;
 
class CMasterKey
{
public:
    std::vector<unsigned char> vchCryptedKey;
    std::vector<unsigned char> vchSalt;
    unsigned int nDerivationMethod;
    unsigned int nDeriveIterations;
    std::vector<unsigned char> vchOtherDerivationParameters;
 
    SERIALIZE_METHODS(CMasterKey, obj) { READWRITE(obj.vchCryptedKey, obj.vchSalt, obj.nDerivationMethod, obj.nDeriveIterations, obj.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;
 
namespace wallet_crypto
{
    class TestCrypter;
}
 
class CSecureDataStream : public CBaseDataStream<CKeyingMaterial>
{
public:
    explicit CSecureDataStream(int nTypeIn, int nVersionIn) : CBaseDataStream(nTypeIn, nVersionIn) { }
 
    CSecureDataStream(const_iterator pbegin, const_iterator pend, int nTypeIn, int nVersionIn) :
            CBaseDataStream(pbegin, pend, nTypeIn, nVersionIn) { }
 
    CSecureDataStream(const vector_type& vchIn, int nTypeIn, int nVersionIn) :
            CBaseDataStream(vchIn, nTypeIn, nVersionIn) { }
};
 
class CCrypter
{
friend class wallet_crypto::TestCrypter; // for test access to chKey/chIV
private:
    std::vector<unsigned char, secure_allocator<unsigned char>> vchKey;
    std::vector<unsigned char, secure_allocator<unsigned char>> vchIV;
    bool fKeySet;
 
    int BytesToKeySHA512AES(const std::vector<unsigned char>& chSalt, const SecureString& strKeyData, int count, unsigned char *key,unsigned char *iv) const;
 
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) const;
    bool Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext) const;
    bool SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV);
 
    void CleanKey()
    {
        memory_cleanse(vchKey.data(), vchKey.size());
        memory_cleanse(vchIV.data(), vchIV.size());
        fKeySet = false;
    }
 
    CCrypter()
    {
        fKeySet = false;
        vchKey.resize(WALLET_CRYPTO_KEY_SIZE);
        vchIV.resize(WALLET_CRYPTO_IV_SIZE);
    }
 
    ~CCrypter()
    {
        CleanKey();
    }
};
 
bool EncryptSecret(const CKeyingMaterial& vMasterKey, const CKeyingMaterial& vchPlaintext, const uint256& nIV, std::vector<unsigned char>& vchCiphertext);
bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CKeyingMaterial& vchPlaintext);
 
 
class CCryptoKeyStore : public CBasicKeyStore
{
private:
    std::atomic<bool> fUseCrypto;
 
protected:
    // TODO: In the future, move this variable to the wallet class directly following upstream's structure.
    CKeyingMaterial vMasterKey;
    // Sapling
    CryptedSaplingSpendingKeyMap mapCryptedSaplingSpendingKeys;
 
    bool SetCrypted();
 
    bool EncryptKeys(CKeyingMaterial& vMasterKeyIn);
 
    CryptedKeyMap mapCryptedKeys;
 
    static bool DecryptKey(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCryptedSecret, const CPubKey& vchPubKey, CKey& key);
 
    // Unlock Sapling keys
    bool UnlockSaplingKeys(const CKeyingMaterial& vMasterKeyIn, bool fDecryptionThoroughlyChecked);
 
public:
    CCryptoKeyStore() : fUseCrypto(false) { }
 
    bool IsCrypted() const { return fUseCrypto; }
    bool IsLocked() const;
 
    virtual bool AddCryptedKey(const CPubKey& vchPubKey, const std::vector<unsigned char>& vchCryptedSecret);
    bool AddKeyPubKey(const CKey& key, const CPubKey& pubkey) override;
    bool HaveKey(const CKeyID& address) const override;
 
    bool GetKey(const CKeyID& address, CKey& keyOut) const override;
    bool GetPubKey(const CKeyID& address, CPubKey& vchPubKeyOut) const override;
    std::set<CKeyID> GetKeys() const override;
 
    virtual bool AddCryptedSaplingSpendingKey(const libzcash::SaplingExtendedFullViewingKey& extfvk,
                                              const std::vector<unsigned char>& vchCryptedSecret);
    bool HaveSaplingSpendingKey(const libzcash::SaplingExtendedFullViewingKey& extfvk) const override;
    bool GetSaplingSpendingKey(const libzcash::SaplingExtendedFullViewingKey& extfvk, libzcash::SaplingExtendedSpendingKey& skOut) const override;
 
    boost::signals2::signal<void(CCryptoKeyStore* wallet)> NotifyStatusChanged;
};
 
#endif // PIVX_CRYPTER_H