/*

 * Support for the eOI card

 *

 * Copyright (C) 2022 Luka Logar <luka.logar@iname.com>

 *

 * 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.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include <stdlib.h>

#include <string.h>

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "opensc.h"

#if defined(ENABLE_SM) && defined(ENABLE_OPENPACE)

#include <openssl/aes.h>

#include <openssl/sha.h>

#include "internal.h"

#include "sm/sm-eac.h"

#include "common/compat_strlcpy.h"

#include "card-eoi.h"

static struct sc_card_operations eoi_ops;

static struct {

  int len;

  struct sc_object_id oid;

} eoi_curves[] = {

  /* secp384r1 */

  {384, {{1, 3, 132, 0, 34, -1}}}

};

static char *eoi_model = "ChipDocLite";

/* The description of the driver. */

static struct sc_card_driver eoi_drv =

{

  "eOI (Slovenian eID card)",

  "eOI",

  &eoi_ops,

  NULL, 0, NULL

};

static const struct sc_atr_table eoi_atrs[] = {

  /* Contact interface */

  { "3b:d5:18:ff:81:91:fe:1f:c3:80:73:c8:21:10:0a", NULL, NULL, SC_CARD_TYPE_EOI, 0, NULL },

  /* Contactless interface */

  { "3b:85:80:01:80:73:c8:21:10:0e", NULL, NULL, SC_CARD_TYPE_EOI_CONTACTLESS, 0, NULL },

  { NULL, NULL, NULL, 0, 0, NULL }

};

/*

 * CAN is stored encrypted in a file that (looks like) is pointed to by 'Card CAN' PIN object.

 * eoi_decrypt_can() decrypts CAN from it's encrypted form

 */

static void rol(u8 *to, const u8 *from)

{

  int i;

  u8 b = from[0] & 0x80;

  for (i = 15; i >= 0; i--) {

    u8 bo = b;

    b = from[i] & 0x80;

    to[i] = (from[i] << 1) | (bo ? 1 : 0);

    if ((i == 15) && bo)

      to[i] = (to[i] ^ 0x87) | 1;

  }

}

static int aes256_ecb_encrypt(const u8 *key, const u8 input[AES_BLOCK_SIZE], u8 output[AES_BLOCK_SIZE])

{

  EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();

  int r = 0, pos, len = pos = AES_BLOCK_SIZE;

  if (!ctx)

    goto err;

  if (!EVP_EncryptInit(ctx, EVP_aes_256_ecb(), key, NULL))

    goto err;

  /* Disable padding, otherwise EVP_EncryptFinal() will fail */

  if (!EVP_CIPHER_CTX_set_padding(ctx, 0))

    goto err;

  if (!EVP_EncryptUpdate(ctx, output, &pos, input, len))

    goto err;

  len -= pos;

  if (!EVP_EncryptFinal(ctx, output + pos, &len))

    goto err;

  r = 1;

err:

  if (ctx)

    EVP_CIPHER_CTX_free(ctx);

  return r;

}

static int aes256_ecb_decrypt(const u8 *key, const u8 input[AES_BLOCK_SIZE], u8 output[AES_BLOCK_SIZE])

{

  EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();

  int r = 0, pos, len = pos = AES_BLOCK_SIZE;

  if (!ctx)

    goto err;

  if (!EVP_DecryptInit(ctx, EVP_aes_256_ecb(), key, NULL))

    goto err;

  /* Disable padding, otherwise it will fail to decrypt non-padded inputs */

  if (!EVP_CIPHER_CTX_set_padding(ctx, 0))

    goto err;

  if (!EVP_DecryptUpdate(ctx, output, &pos, input, len))

    goto err;

  len -= pos;

  if (!EVP_DecryptFinal(ctx, output + pos, &len))

    goto err;

  r = 1;

err:

  if (ctx)

    EVP_CIPHER_CTX_free(ctx);

  return r;

}

/*

 * CAN decrypt magic...

 */

static int get_can_key(const u8 *key, const u8 round, const u8 *input, u8 *output)

{

  size_t i;

  u8 tmp[3][AES_BLOCK_SIZE];

  memset(tmp[0], 0, AES_BLOCK_SIZE);

  if (!aes256_ecb_encrypt(key, tmp[0], tmp[0]))

    return 0;

  rol(tmp[1], tmp[0]);

  rol(tmp[0], tmp[1]);

  memset(tmp[1], 0, AES_BLOCK_SIZE);

  tmp[1][11] = 4;

  tmp[1][13] = 1;

  tmp[1][15] = round;

  if (!aes256_ecb_encrypt(key, tmp[1], tmp[2]))

    return 0;

  memset(tmp[1], 0, AES_BLOCK_SIZE);

  memcpy(tmp[1], &input[AES_BLOCK_SIZE], 8);

  tmp[1][8] = 0x80;

  for (i = 0; i < AES_BLOCK_SIZE; i++)

    tmp[0][i] = tmp[0][i] ^ tmp[1][i] ^ tmp[2][i];

  if (!aes256_ecb_encrypt(key, tmp[0], output))

    return 0;

  return 1;

}

#define AES256_KEY_LEN 32

static int eoi_decrypt_can(struct sc_pkcs15_u8 *enc_can, char *can) {

  /* Magic key that is used to decrypt CAN */

  const u8 magic_key[AES256_KEY_LEN] = {0xC8, 0x12, 0x0F, 0xD8, 0x21, 0x20, 0x1F, 0x77, 0xF1, 0x83, 0x9D, 0xD8, 0x86, 0xB0, 0x5C, 0xF2, 0x4F, 0x7E, 0x52, 0x66, 0xE5, 0x87, 0x89, 0x2B, 0xF4, 0xC5, 0xE5, 0x4C, 0x54, 0xA1, 0x55, 0x30};

  u8 can_key[AES256_KEY_LEN] = { 0 };

  if (!can || !enc_can || !enc_can->value || enc_can->len != 24)

    return SC_ERROR_INVALID_ARGUMENTS;

  if (!get_can_key(magic_key, 0x01, enc_can->value, &can_key[0]))

    return SC_ERROR_INTERNAL;

  if (!get_can_key(magic_key, 0x02, enc_can->value, &can_key[AES_BLOCK_SIZE]))

    return SC_ERROR_INTERNAL;

  if (!aes256_ecb_decrypt(can_key, enc_can->value, (u8 *)can))

    return SC_ERROR_INTERNAL;

  can[AES_BLOCK_SIZE - 1] = 0;

  return SC_SUCCESS;

}

static int eoi_sm_open(struct sc_card *card)

{

  int r;

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  struct establish_pace_channel_input pace_input;

  struct establish_pace_channel_output pace_output;

  if (!privdata)

    return SC_ERROR_INTERNAL;

  if (!privdata->can[0]) {

    /* If no CAN is specified in conf, try to decrypt it from enc_can file */

    r = eoi_decrypt_can(&privdata->enc_can, privdata->can);

    sc_log_openssl(card->ctx);

    LOG_TEST_RET(card->ctx, r, "Cannot decrypt CAN");

  }

  /* CAN should be 6 chars long */

  if (strlen(privdata->can) != 6)

    return SC_ERROR_DECRYPT_FAILED;

  memset(&pace_input, 0, sizeof pace_input);

  memset(&pace_output, 0, sizeof pace_output);

  pace_input.pin_id = PACE_PIN_ID_CAN;

  pace_input.pin = (u8 *)privdata->can;

  pace_input.pin_length = strlen(privdata->can);

  /* EF.CardAccess can only be read from MF */

  r = sc_select_file(card, sc_get_mf_path(), NULL);

  LOG_TEST_RET(card->ctx, r, "sc_select_file failed");

  r = perform_pace(card, pace_input, &pace_output, EAC_TR_VERSION_2_02);

  LOG_TEST_RET(card->ctx, r, "Error verifying CAN");

  return SC_SUCCESS;

}

static int eoi_get_data(sc_card_t *card, u8 data_id, u8 *buf, size_t len)

{

  int r;

  sc_apdu_t apdu;

  sc_format_apdu(card, &apdu, SC_APDU_CASE_2_SHORT, 0xCA, 0x01, data_id);

  apdu.resp = buf;

  apdu.resplen = len;

  apdu.le = len;

  r = sc_transmit_apdu(card, &apdu);

  LOG_TEST_RET(card->ctx, r, "APDU transmit failed");

  r = sc_check_sw(card, apdu.sw1, apdu.sw2);

  return r;

}

#define ATR_MATCH 1

static int eoi_match_card(sc_card_t* card) {

  LOG_FUNC_CALLED(card->ctx);

  if (_sc_match_atr(card, eoi_atrs, &card->type) >= 0) {

    sc_log(card->ctx, "ATR recognized as Slovenian eID card");

    LOG_FUNC_RETURN(card->ctx, ATR_MATCH);

  }

  LOG_FUNC_RETURN(card->ctx, !ATR_MATCH);

}

static int eoi_init(sc_card_t* card) {

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  u8 version[6];

  size_t i, j;

  scconf_block **found_blocks, *block;

  int r;

  char *can;

  LOG_FUNC_CALLED(card->ctx);

  if (eoi_get_data(card, 0x16, version, sizeof(version)) != SC_SUCCESS)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_WRONG_CARD);

  if (privdata)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  privdata = sc_mem_secure_alloc(sizeof(struct eoi_privdata));

  if (!privdata)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_OUT_OF_MEMORY);

  /* sc_mem_secure_alloc()-ed memory may not be zeroized */

  memset(privdata, 0, sizeof(struct eoi_privdata));

  card->drv_data = privdata;

  sprintf(privdata->version, "%X%02X.%02X%02X", version[0], version[1], version[2], version[3]);

  sc_log(card->ctx, "App version: %s", privdata->version);

  memset(&card->sm_ctx, 0, sizeof card->sm_ctx);

  card->sm_ctx.ops.open = eoi_sm_open;

  card->max_send_size = SC_MAX_APDU_DATA_SIZE;

  card->max_recv_size = SC_MAX_APDU_RESP_SIZE;

  for (i = 0; i < sizeof eoi_curves / sizeof * eoi_curves; ++i) {

    r = _sc_card_add_ec_alg(card, eoi_curves[i].len, SC_ALGORITHM_ECDSA_RAW | SC_ALGORITHM_ECDSA_HASH_NONE, 0, &eoi_curves[i].oid);

    LOG_TEST_GOTO_ERR(card->ctx, r, "Add EC alg failed");

  }

  can = getenv("EOI_CAN");

  if (can)

    strlcpy(privdata->can, can, sizeof(privdata->can));

  for (i = 0; card->ctx->conf_blocks[i]; i++) {

    found_blocks = scconf_find_blocks(card->ctx->conf, card->ctx->conf_blocks[i],

          "card_driver", "eoi");

    if (!found_blocks)

      continue;

    for (j = 0, block = found_blocks[j]; block; j++, block = found_blocks[j]) {

      if (!privdata->can[0]) {

        const char *can = scconf_get_str(block, "can", NULL);

        if (can)

          strlcpy(privdata->can, can, sizeof(privdata->can));

      }

    }

    free(found_blocks);

  }

  LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

err:

  if (privdata) {

    sc_mem_clear(privdata, sizeof(struct eoi_privdata));

    sc_mem_secure_free(privdata, sizeof(struct eoi_privdata));

  }

  card->drv_data = NULL;

  LOG_FUNC_RETURN(card->ctx, r);

}

static int eoi_finish(sc_card_t* card)

{

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  LOG_FUNC_CALLED(card->ctx);

  if (privdata) {

    sc_mem_clear(privdata, sizeof(struct eoi_privdata));

    sc_mem_secure_free(privdata, sizeof(struct eoi_privdata));

  }

  card->drv_data = NULL;

  LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

}

static int eoi_select_file(sc_card_t *card, const sc_path_t *in_path, sc_file_t **file_out)

{

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  int i;

  LOG_FUNC_CALLED(card->ctx);

  if (!privdata)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  for (i = 0; i < MAX_OBJECTS && privdata->pin_paths[i]; i++) {

    if (privdata->pin_paths[i] && sc_compare_path(privdata->pin_paths[i], in_path)) {

      LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

    }

  }

  LOG_FUNC_RETURN(card->ctx, sc_get_iso7816_driver()->ops->select_file(card, in_path, file_out));

}

static int eoi_logout(struct sc_card *card)

{

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  struct sc_apdu apdu;

  u8 buf[256];

  int r = SC_SUCCESS;

  LOG_FUNC_CALLED(card->ctx);

  if (!privdata)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  iso_sm_close(card);

  card->sm_ctx.sm_mode = SM_MODE_NONE;

  if (card->reader->flags & SC_READER_ENABLE_ESCAPE) {

    /*

     * Get the UID of the ISO 14443 A card. (see PCSC Part 3)

     * The "official" PKCS#11 does it and we do the same.

     */

    sc_format_apdu(card, &apdu, SC_APDU_CASE_2_SHORT, 0xCA, 0x00, 0x00);

    apdu.cla = 0xFF;

    apdu.resp = buf;

    apdu.resplen = 256;

    apdu.lc = 0;

    apdu.le = 256;

    r = sc_transmit_apdu(card, &apdu);

  }

  LOG_FUNC_RETURN(card->ctx, r);

}

static int eoi_pin_cmd(struct sc_card *card, struct sc_pin_cmd_data *data, int *tries_left)

{

  int r;

  LOG_FUNC_CALLED(card->ctx);

  if (data->cmd == SC_PIN_CMD_VERIFY && card->sm_ctx.sm_mode == SM_MODE_NONE) {

    /* Establish SM before any PIN VERIFY command */

    r = eoi_sm_open(card);

    if (r != SC_SUCCESS)

      LOG_FUNC_RETURN(card->ctx, r);

  }

  if (data->cmd == SC_PIN_CMD_UNBLOCK) {

    int pin_reference = data->pin_reference;

    size_t pin2_len = data->pin2.len;

    /* Verify PUK, establish SM if necessary */

    data->cmd = SC_PIN_CMD_VERIFY;

    data->pin_reference = data->puk_reference;

    r = eoi_pin_cmd(card, data, tries_left);

    if (r != SC_SUCCESS)

      LOG_FUNC_RETURN(card->ctx, r);

    /* RESET RETRY COUNTER */

    data->cmd = SC_PIN_CMD_UNBLOCK;

    data->pin_reference = 0x80|pin_reference;

    data->pin1.len = 0;

    data->pin2.len = 0;

    r = sc_get_iso7816_driver()->ops->pin_cmd(card, data, tries_left);

    if (r != SC_SUCCESS)

      LOG_FUNC_RETURN(card->ctx, r);

    /* Continue as CHANGE PIN */

    data->cmd = SC_PIN_CMD_CHANGE;

    data->pin2.len = pin2_len;

  }

  /* CHANGE PIN command does not send the old PIN as it should already be verified */

  if (data->cmd == SC_PIN_CMD_CHANGE)

    data->pin1.len = 0;

  LOG_FUNC_RETURN(card->ctx, sc_get_iso7816_driver()->ops->pin_cmd(card, data, tries_left));

}

static int

eoi_card_ctl(sc_card_t *card, unsigned long cmd, void *ptr)

{

  struct sc_card_driver *iso_driver = NULL;

  int r = SC_ERROR_NOT_SUPPORTED;

  LOG_FUNC_CALLED(card->ctx);

  switch (cmd) {

  case SC_CARDCTL_GET_MODEL:

    if (!ptr) {

      r = SC_ERROR_INVALID_ARGUMENTS;

    } else {

      *(char **)ptr = eoi_model;

      r = SC_SUCCESS;

    }

    break;

  default:

    iso_driver = sc_get_iso7816_driver();

    if (iso_driver->ops->card_ctl != NULL) {

      r = sc_get_iso7816_driver()->ops->card_ctl(card, cmd, ptr);

    }

  }

  LOG_FUNC_RETURN(card->ctx, r);

}

#define ALREADY_PROCESSED 0x80000000

static int eoi_set_security_env(struct sc_card *card, const struct sc_security_env *env, int se_num)

{

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  struct sc_apdu apdu;

  u8 sbuf[4];

  int i, r, locked = 0;

  LOG_FUNC_CALLED(card->ctx);

  if (!privdata)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  if (!card || !env)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  /* We don't know yet which hash is used. So just store the security_env data and return */

  if (!(env->algorithm_flags & ALREADY_PROCESSED)) {

    privdata->key_len = BYTES4BITS(env->algorithm_ref);

    memcpy(&privdata->sec_env, env, sizeof(struct sc_security_env));

    privdata->se_num = se_num;

    LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

  }

  if (env->operation != SC_SEC_OPERATION_SIGN)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_NOT_SUPPORTED);

  if (!(env->flags & SC_SEC_ENV_KEY_REF_PRESENT))

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  if (env->key_ref_len != 1)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  if (env->algorithm != SC_ALGORITHM_EC)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  sc_format_apdu(card, &apdu, SC_APDU_CASE_3_SHORT, 0x22, 0x81, 0xB6);

  sbuf[0] = 0x91;

  sbuf[1] = 0x02;

  if (env->algorithm_flags & SC_ALGORITHM_ECDSA_HASH_SHA1)

    sbuf[2] = 0x11;

  else if (env->algorithm_flags & SC_ALGORITHM_ECDSA_HASH_SHA256)

    sbuf[2] = 0x21;

  else if (env->algorithm_flags & (SC_ALGORITHM_ECDSA_RAW|SC_ALGORITHM_ECDSA_HASH_NONE))

    sbuf[2] = 0x22;

  else

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  for (i = 0; i < MAX_OBJECTS && privdata->prkey_mappings[i][1]; i++) {

    if (privdata->prkey_mappings[i][0] == env->key_ref[0])

      break;

  }

  if (i == MAX_OBJECTS)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  sbuf[3] = privdata->prkey_mappings[i][1];

  apdu.lc = 4;

  apdu.datalen = 4;

  apdu.data = sbuf;

  if (se_num > 0) {

    r = sc_lock(card);

    LOG_TEST_RET(card->ctx, r, "sc_lock() failed");

    locked = 1;

  }

  if (apdu.datalen) {

    r = sc_transmit_apdu(card, &apdu);

    if (r) {

      sc_log(card->ctx, "%s: APDU transmit failed", sc_strerror(r));

      goto err;

    }

    r = sc_check_sw(card, apdu.sw1, apdu.sw2);

    if (r) {

      sc_log(card->ctx, "%s: Card returned error", sc_strerror(r));

      goto err;

    }

  }

  if (se_num <= 0) {

    r = SC_SUCCESS;

    goto err;

  }

  sc_unlock(card);

  LOG_TEST_RET(card->ctx, r, "APDU transmit failed");

  LOG_FUNC_RETURN(card->ctx, sc_check_sw(card, apdu.sw1, apdu.sw2));

err:

  if (locked)

    sc_unlock(card);

  LOG_FUNC_RETURN(card->ctx, r);

}

static int eoi_compute_signature(struct sc_card *card, const u8 * data, size_t data_len, u8 *out, size_t outlen)

{

  struct eoi_privdata *privdata = (struct eoi_privdata *)card->drv_data;

  int r;

  LOG_FUNC_CALLED(card->ctx);

  if (!privdata)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  /*

   * Guess the correct mode. If the size is less than the full-key-len, it must be a hash then

   */

  if (privdata->key_len != data_len) {

    switch (data_len) {

      case SHA_DIGEST_LENGTH:

        privdata->sec_env.algorithm_flags = SC_ALGORITHM_ECDSA_HASH_SHA1;

        break;

      case SHA256_DIGEST_LENGTH:

        privdata->sec_env.algorithm_flags = SC_ALGORITHM_ECDSA_HASH_SHA256;

        break;

    }

  }

  /* Now we know which hash is used */

  privdata->sec_env.algorithm_flags |= ALREADY_PROCESSED;

  /* Perform the true set_security_env */

  r = eoi_set_security_env(card, &privdata->sec_env, privdata->se_num);

  LOG_TEST_RET(card->ctx, r, "set_security_env failed");

  LOG_FUNC_RETURN(card->ctx, sc_get_iso7816_driver()->ops->compute_signature(card, data, data_len, out, outlen));

}

struct sc_card_driver *sc_get_eoi_driver(void)

{

  eoi_ops = *sc_get_iso7816_driver()->ops;

  eoi_ops.match_card = eoi_match_card;

  eoi_ops.init = eoi_init;

  eoi_ops.finish = eoi_finish;

  eoi_ops.select_file = eoi_select_file;

  eoi_ops.logout = eoi_logout;

  eoi_ops.pin_cmd = eoi_pin_cmd;

  eoi_ops.card_ctl = eoi_card_ctl;

  eoi_ops.set_security_env = eoi_set_security_env;

  eoi_ops.compute_signature = eoi_compute_signature;

  return &eoi_drv;

}

#else

struct sc_card_driver* sc_get_eoi_driver(void) {

  return NULL;

}

#endif