KeyManager.h

Go to the documentation of this file.

/*
 This file is part of cpp-ethereum.

 cpp-ethereum is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 cpp-ethereum is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
 */
#pragma once

#include <functional>
#include <mutex>
#include <libdevcore/FileSystem.h>
#include <libdevcore/CommonData.h>
#include <libdevcrypto/SecretStore.h>

namespace dev
{
namespace eth
{
class PasswordUnknown: public Exception {};

struct KeyInfo
{
        KeyInfo() = default;
        KeyInfo(h256 const& _passHash, std::string const& _accountName, std::string const& _passwordHint = std::string()): passHash(_passHash), accountName(_accountName), passwordHint(_passwordHint) {}

        h256 passHash;
        std::string accountName;
        std::string passwordHint;
};

static h256 const UnknownPassword;
static auto const DontKnowThrow = [](){ throw PasswordUnknown(); return std::string(); };

enum class SemanticPassword
{
        Existing,
        Master
};

// TODO: This one is specifically for Ethereum, but we can make it generic in due course.
// TODO: hidden-partition style key-store.
class KeyManager
{
public:
        enum class NewKeyType { DirectICAP = 0, NoVanity, FirstTwo, FirstTwoNextTwo, FirstThree, FirstFour };

        KeyManager(std::string const& _keysFile = defaultPath(), std::string const& _secretsPath = SecretStore::defaultPath());
        ~KeyManager();

        void setSecretsPath(std::string const& _secretsPath) { m_store.setPath(_secretsPath); }
        void setKeysFile(std::string const& _keysFile) { m_keysFile = _keysFile; }
        std::string const& keysFile() const { return m_keysFile; }

        bool exists() const;
        void create(std::string const& _pass);
        bool load(std::string const& _pass);
        void save(std::string const& _pass) const { write(_pass, m_keysFile); }

        void notePassword(std::string const& _pass) { m_cachedPasswords[hashPassword(_pass)] = _pass; }
        void noteHint(std::string const& _pass, std::string const& _hint) { if (!_hint.empty()) m_passwordHint[hashPassword(_pass)] = _hint; }
        bool haveHint(std::string const& _pass) const { auto h = hashPassword(_pass); return m_cachedPasswords.count(h) && !m_cachedPasswords.at(h).empty(); }

        Addresses accounts() const;
        AddressHash accountsHash() const { return AddressHash() + accounts(); }
        bool hasAccount(Address const& _address) const;
        std::string const& accountName(Address const& _address) const;
        std::string const& passwordHint(Address const& _address) const;
        void changeName(Address const& _address, std::string const& _name);

        bool haveKey(Address const& _a) const { return m_addrLookup.count(_a); }
        h128 uuid(Address const& _a) const;
        Address address(h128 const& _uuid) const;

        h128 import(Secret const& _s, std::string const& _accountName, std::string const& _pass, std::string const& _passwordHint);
        h128 import(Secret const& _s, std::string const& _accountName) { return import(_s, _accountName, defaultPassword(), std::string()); }
        Address importBrain(std::string const& _seed, std::string const& _accountName, std::string const& _seedHint);
        void importExistingBrain(Address const& _a, std::string const& _accountName, std::string const& _seedHint);

        SecretStore& store() { return m_store; }
        void importExisting(h128 const& _uuid, std::string const& _accountName, std::string const& _pass, std::string const& _passwordHint);
        void importExisting(h128 const& _uuid, std::string const& _accountName) { importExisting(_uuid, _accountName, defaultPassword(), std::string()); }
        void importExisting(h128 const& _uuid, std::string const& _accountName, Address const& _addr, h256 const& _passHash = h256(), std::string const& _passwordHint = std::string());

        Secret secret(Address const& _address, std::function<std::string()> const& _pass = DontKnowThrow, bool _usePasswordCache = true) const;
        Secret secret(h128 const& _uuid, std::function<std::string()> const& _pass = DontKnowThrow, bool _usePasswordCache = true) const;

        bool recode(Address const& _address, SemanticPassword _newPass, std::function<std::string()> const& _pass = DontKnowThrow, KDF _kdf = KDF::Scrypt);
        bool recode(Address const& _address, std::string const& _newPass, std::string const& _hint, std::function<std::string()> const& _pass = DontKnowThrow, KDF _kdf = KDF::Scrypt);

        void kill(h128 const& _id) { kill(address(_id)); }
        void kill(Address const& _a);

        static std::string defaultPath() { return getDataDir("ethereum") + "/keys.info"; }

        static KeyPair presaleSecret(std::string const& _json, std::function<std::string(bool)> const& _password);

        static Secret brain(std::string const& _seed);

        static Secret subkey(Secret const& _s, unsigned _index);

        static  KeyPair newKeyPair(NewKeyType _type);
private:
        std::string getPassword(h128 const& _uuid, std::function<std::string()> const& _pass = DontKnowThrow) const;
        std::string getPassword(h256 const& _passHash, std::function<std::string()> const& _pass = DontKnowThrow) const;
        std::string defaultPassword(std::function<std::string()> const& _pass = DontKnowThrow) const { return getPassword(m_master, _pass); }
        h256 hashPassword(std::string const& _pass) const;

        void cachePassword(std::string const& _password) const;

        // Only use if previously loaded ok.
        // @returns false if wasn't previously loaded ok.
        bool write() const { return write(m_keysFile); }
        bool write(std::string const& _keysFile) const;
        void write(std::string const& _pass, std::string const& _keysFile) const;       // TODO: all passwords should be a secure string.
        void write(SecureFixedHash<16> const& _key, std::string const& _keysFile) const;

        // Ethereum keys.

        std::unordered_map<h128, Address> m_uuidLookup;
        std::unordered_map<Address, h128> m_addrLookup;
        std::unordered_map<Address, KeyInfo> m_keyInfo;
        std::unordered_map<h256, std::string> m_passwordHint;

        // Passwords that we're storing. Mapping password hash -> password.
        mutable std::unordered_map<h256, std::string> m_cachedPasswords;

        // DEPRECATED.
        // Used to be the default password for keys in the keystore, stored in the keys file.
        // Now the default password is based off the key of the keys file directly, so this is redundant
        // except for the fact that people have existing keys stored with it. Leave for now until/unless
        // we have an upgrade strategy.
        std::string m_defaultPasswordDeprecated;

        mutable std::string m_keysFile;
        mutable SecureFixedHash<16> m_keysFileKey;
        mutable h256 m_master;
        SecretStore m_store;
};

}
}