/*
 * This file is part of the Flowee project
 * Copyright (C) 2015 The Bitcoin Core developers
 *
 * This program 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.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */
//
// C++ wrapper around ctaes, a constant-time AES implementation

#ifndef FLOWEE_CRYPTO_AES_H
#define FLOWEE_CRYPTO_AES_H

extern "C" {
#include "ctaes/ctaes.h"
}

#include <vector>

static const int AES_BLOCKSIZE = 16;
static const int AES128_KEYSIZE = 16;
static const int AES256_KEYSIZE = 32;

/** An encryption class for AES-128. */
class AES128Encrypt
{
private:
    AES128_ctx ctx;

public:
    AES128Encrypt(const char key[16]);
    ~AES128Encrypt();
    void encrypt(char ciphertext[16], const char plaintext[16]) const;
};

/** A decryption class for AES-128. */
class AES128Decrypt
{
private:
    AES128_ctx ctx;

public:
    AES128Decrypt(const char key[16]);
    ~AES128Decrypt();
    void decrypt(char plaintext[16], const char ciphertext[16]) const;
};

/** An encryption class for AES-256. */
class AES256Encrypt
{
private:
    AES256_ctx ctx;

public:
    AES256Encrypt(const char key[32]);
    ~AES256Encrypt();
    void encrypt(char ciphertext[16], const char plaintext[16]) const;
};

/** A decryption class for AES-256. */
class AES256Decrypt
{
private:
    AES256_ctx ctx;

public:
    AES256Decrypt(const char key[32]);
    ~AES256Decrypt();
    void decrypt(char plaintext[16], const char ciphertext[16]) const;
};

class AES256CBCEncrypt
{
public:
    AES256CBCEncrypt(const char key[AES256_KEYSIZE], const char ivIn[AES_BLOCKSIZE], bool padIn);
    ~AES256CBCEncrypt();
    /// encrypt the \a data using the preferences passed in the constructor.
    int encrypt(const char *data, int size, char *out) const;
    /// convenience method
    int encrypt(const std::vector<unsigned char> &data, char *out) const;
    /// convenience method
    int encrypt(const std::vector<char> &data, char *out) const;

private:
    const AES256Encrypt enc;
    const bool pad;
    unsigned char iv[AES_BLOCKSIZE];
};

class AES256CBCDecrypt
{
public:
    AES256CBCDecrypt(const char key[AES256_KEYSIZE], const char ivIn[AES_BLOCKSIZE], bool padIn);
    ~AES256CBCDecrypt();
    int decrypt(const char *data, int size, char *out) const;
    int decrypt(const std::vector<char> &data, char *out) const;
    int decrypt(const std::vector<unsigned char> &data, char *out) const;

private:
    const AES256Decrypt dec;
    const bool pad;
    char iv[AES_BLOCKSIZE];
};

class AES128CBCEncrypt
{
public:
    AES128CBCEncrypt(const char key[AES128_KEYSIZE], const char ivIn[AES_BLOCKSIZE], bool padIn);
    ~AES128CBCEncrypt();
    int encrypt(const char *data, int size, char *out) const;

private:
    const AES128Encrypt enc;
    const bool pad;
    unsigned char iv[AES_BLOCKSIZE];
};

class AES128CBCDecrypt
{
public:
    AES128CBCDecrypt(const char key[AES128_KEYSIZE], const char ivIn[AES_BLOCKSIZE], bool padIn);
    ~AES128CBCDecrypt();
    int decrypt(const char *data, int size, char *out) const;

private:
    const AES128Decrypt dec;
    const bool pad;
    char iv[AES_BLOCKSIZE];
};

#endif