/**
 *  Copyright (C) 2018  Juho Vähä-Herttua
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 */

#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "fairplay.h"
#include "playfair/playfair.h"

char reply_message[4][142] = {{0x46,0x50,0x4c,0x59,0x03,0x01,0x02,0x00,0x00,0x00,0x00,0x82,0x02,0x00,0x0f,0x9f,0x3f,0x9e,0x0a,0x25,0x21,0xdb,0xdf,0x31,0x2a,0xb2,0xbf,0xb2,0x9e,0x8d,0x23,0x2b,0x63,0x76,0xa8,0xc8,0x18,0x70,0x1d,0x22,0xae,0x93,0xd8,0x27,0x37,0xfe,0xaf,0x9d,0xb4,0xfd,0xf4,0x1c,0x2d,0xba,0x9d,0x1f,0x49,0xca,0xaa,0xbf,0x65,0x91,0xac,0x1f,0x7b,0xc6,0xf7,0xe0,0x66,0x3d,0x21,0xaf,0xe0,0x15,0x65,0x95,0x3e,0xab,0x81,0xf4,0x18,0xce,0xed,0x09,0x5a,0xdb,0x7c,0x3d,0x0e,0x25,0x49,0x09,0xa7,0x98,0x31,0xd4,0x9c,0x39,0x82,0x97,0x34,0x34,0xfa,0xcb,0x42,0xc6,0x3a,0x1c,0xd9,0x11,0xa6,0xfe,0x94,0x1a,0x8a,0x6d,0x4a,0x74,0x3b,0x46,0xc3,0xa7,0x64,0x9e,0x44,0xc7,0x89,0x55,0xe4,0x9d,0x81,0x55,0x00,0x95,0x49,0xc4,0xe2,0xf7,0xa3,0xf6,0xd5,0xba},
                              {0x46,0x50,0x4c,0x59,0x03,0x01,0x02,0x00,0x00,0x00,0x00,0x82,0x02,0x01,0xcf,0x32,0xa2,0x57,0x14,0xb2,0x52,0x4f,0x8a,0xa0,0xad,0x7a,0xf1,0x64,0xe3,0x7b,0xcf,0x44,0x24,0xe2,0x00,0x04,0x7e,0xfc,0x0a,0xd6,0x7a,0xfc,0xd9,0x5d,0xed,0x1c,0x27,0x30,0xbb,0x59,0x1b,0x96,0x2e,0xd6,0x3a,0x9c,0x4d,0xed,0x88,0xba,0x8f,0xc7,0x8d,0xe6,0x4d,0x91,0xcc,0xfd,0x5c,0x7b,0x56,0xda,0x88,0xe3,0x1f,0x5c,0xce,0xaf,0xc7,0x43,0x19,0x95,0xa0,0x16,0x65,0xa5,0x4e,0x19,0x39,0xd2,0x5b,0x94,0xdb,0x64,0xb9,0xe4,0x5d,0x8d,0x06,0x3e,0x1e,0x6a,0xf0,0x7e,0x96,0x56,0x16,0x2b,0x0e,0xfa,0x40,0x42,0x75,0xea,0x5a,0x44,0xd9,0x59,0x1c,0x72,0x56,0xb9,0xfb,0xe6,0x51,0x38,0x98,0xb8,0x02,0x27,0x72,0x19,0x88,0x57,0x16,0x50,0x94,0x2a,0xd9,0x46,0x68,0x8a},
                              {0x46,0x50,0x4c,0x59,0x03,0x01,0x02,0x00,0x00,0x00,0x00,0x82,0x02,0x02,0xc1,0x69,0xa3,0x52,0xee,0xed,0x35,0xb1,0x8c,0xdd,0x9c,0x58,0xd6,0x4f,0x16,0xc1,0x51,0x9a,0x89,0xeb,0x53,0x17,0xbd,0x0d,0x43,0x36,0xcd,0x68,0xf6,0x38,0xff,0x9d,0x01,0x6a,0x5b,0x52,0xb7,0xfa,0x92,0x16,0xb2,0xb6,0x54,0x82,0xc7,0x84,0x44,0x11,0x81,0x21,0xa2,0xc7,0xfe,0xd8,0x3d,0xb7,0x11,0x9e,0x91,0x82,0xaa,0xd7,0xd1,0x8c,0x70,0x63,0xe2,0xa4,0x57,0x55,0x59,0x10,0xaf,0x9e,0x0e,0xfc,0x76,0x34,0x7d,0x16,0x40,0x43,0x80,0x7f,0x58,0x1e,0xe4,0xfb,0xe4,0x2c,0xa9,0xde,0xdc,0x1b,0x5e,0xb2,0xa3,0xaa,0x3d,0x2e,0xcd,0x59,0xe7,0xee,0xe7,0x0b,0x36,0x29,0xf2,0x2a,0xfd,0x16,0x1d,0x87,0x73,0x53,0xdd,0xb9,0x9a,0xdc,0x8e,0x07,0x00,0x6e,0x56,0xf8,0x50,0xce},
                              {0x46,0x50,0x4c,0x59,0x03,0x01,0x02,0x00,0x00,0x00,0x00,0x82,0x02,0x03,0x90,0x01,0xe1,0x72,0x7e,0x0f,0x57,0xf9,0xf5,0x88,0x0d,0xb1,0x04,0xa6,0x25,0x7a,0x23,0xf5,0xcf,0xff,0x1a,0xbb,0xe1,0xe9,0x30,0x45,0x25,0x1a,0xfb,0x97,0xeb,0x9f,0xc0,0x01,0x1e,0xbe,0x0f,0x3a,0x81,0xdf,0x5b,0x69,0x1d,0x76,0xac,0xb2,0xf7,0xa5,0xc7,0x08,0xe3,0xd3,0x28,0xf5,0x6b,0xb3,0x9d,0xbd,0xe5,0xf2,0x9c,0x8a,0x17,0xf4,0x81,0x48,0x7e,0x3a,0xe8,0x63,0xc6,0x78,0x32,0x54,0x22,0xe6,0xf7,0x8e,0x16,0x6d,0x18,0xaa,0x7f,0xd6,0x36,0x25,0x8b,0xce,0x28,0x72,0x6f,0x66,0x1f,0x73,0x88,0x93,0xce,0x44,0x31,0x1e,0x4b,0xe6,0xc0,0x53,0x51,0x93,0xe5,0xef,0x72,0xe8,0x68,0x62,0x33,0x72,0x9c,0x22,0x7d,0x82,0x0c,0x99,0x94,0x45,0xd8,0x92,0x46,0xc8,0xc3,0x59}};

char fp_header[] = {0x46, 0x50, 0x4c, 0x59, 0x03, 0x01, 0x04, 0x00, 0x00, 0x00, 0x00, 0x14};

struct fairplay_s {
    logger_t *logger;

    unsigned char keymsg[164];
    unsigned int keymsglen;
};

fairplay_t *
fairplay_init(logger_t *logger)
{
    fairplay_t *fp;

    fp = calloc(1, sizeof(fairplay_t));
    if (!fp) {
        return NULL;
    }
    fp->logger = logger;

    return fp;
}

int
fairplay_setup(fairplay_t *fp, const unsigned char req[16], unsigned char res[142])
{
    int mode;

    assert(fp);

    if (req[4] != 0x03) {
        /* Unsupported fairplay version */
        return -1;
    }

    mode = req[14];
    memcpy(res, reply_message[mode], 142);
    fp->keymsglen = 0;
    return 0;
}

int
fairplay_handshake(fairplay_t *fp, const unsigned char req[164], unsigned char res[32])
{
    assert(fp);

    if (req[4] != 0x03) {
        /* Unsupported fairplay version */
        return -1;
    }

    memcpy(fp->keymsg, req, 164);
    fp->keymsglen = 164;

    memcpy(res, fp_header, 12);
    memcpy(res + 12, req + 144, 20);
    return 0;
}

int
fairplay_decrypt(fairplay_t *fp, const unsigned char input[72], unsigned char output[16])
{
    if (fp->keymsglen != 164) {
        return -1;
    }

    playfair_decrypt(fp->keymsg, (unsigned char *) input, output);
    return 0;
}

void
fairplay_destroy(fairplay_t *fp)
{
    free(fp);
}