/*

 * Driver for EstEID card issued from December 2018.

 *

 * Copyright (C) 2019, Martin Paljak <martin@martinpaljak.net>

 *

 * 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

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <ctype.h>

#include <stdlib.h>

#include <string.h>

#include "asn1.h"

#include "gp.h"

#include "internal.h"

/* Helping defines */

#define SIGNATURE_PAYLOAD_SIZE 0x30

#define AUTH_REF         0x81

#define SIGN_REF         0x9f

#define PIN1_REF         0x01

#define PIN2_REF         0x85

#define PUK_REF          0x02

static const struct sc_atr_table esteid_atrs[] = {

    {"3b:db:96:00:80:b1:fe:45:1f:83:00:12:23:3f:53:65:49:44:0f:90:00:f1",    NULL, "EstEID 2018",    SC_CARD_TYPE_ESTEID_2018,       0, NULL},

    {"3b:dc:96:00:80:b1:fe:45:1f:83:00:12:23:3f:54:65:49:44:32:0f:90:00:c3", NULL, "EstEID 2018 v2", SC_CARD_TYPE_ESTEID_2018_V2_2025, 0, NULL},

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

};

static const struct sc_aid IASECC_AID = {

    {0xA0, 0x00, 0x00, 0x00, 0x77, 0x01, 0x08, 0x00, 0x07, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x01, 0x00},

    16

};

static const struct sc_path MF = {

    {0x3f, 0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},

    2, 0, 0, SC_PATH_TYPE_PATH, {{0}, 0}

};

static const struct sc_path adf2 = {

    {0x3f, 0x00, 0xAD, 0xF2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},

    4, 0, 0, SC_PATH_TYPE_PATH, {{0}, 0}

};

static const struct sc_card_operations *iso_ops = NULL;

static struct sc_card_operations esteid_ops;

static struct sc_card_driver esteid2018_driver = {"EstEID 2018", "esteid2018", &esteid_ops, NULL, 0, NULL};

struct esteid_priv_data {

  sc_security_env_t sec_env; /* current security environment */

};

#define DRVDATA(card) ((struct esteid_priv_data *)((card)->drv_data))

#define SC_TRANSMIT_TEST_RET(card, apdu, text) \

  do { \

    LOG_TEST_RET(card->ctx, sc_transmit_apdu(card, &apdu), "APDU transmit failed"); \

    LOG_TEST_RET(card->ctx, sc_check_sw(card, apdu.sw1, apdu.sw2), text); \

  } while (0)

static int esteid_match_card(sc_card_t *card) {

  int i = _sc_match_atr(card, esteid_atrs, &card->type);

  if (i >= 0 && gp_select_aid(card, &IASECC_AID) == SC_SUCCESS) {

    card->name = esteid_atrs[i].name;

    return 1;

  }

  return 0;

}

static int esteid_select_file(struct sc_card *card, const struct sc_path *in_path, struct sc_file **file_out) {

  const u8 *path = in_path->value;

  u8 resp[SC_MAX_APDU_RESP_SIZE];

  size_t resplen = sizeof(resp);

  int r;

  struct sc_file *file = NULL;

  struct sc_apdu apdu;

  LOG_FUNC_CALLED(card->ctx);

  // Only support full paths

  if (in_path->type != SC_PATH_TYPE_PATH) {

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  }

  if (in_path->len % 2 != 0) {

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  }

  for (size_t pathlen = in_path->len; pathlen >= 2; pathlen -= 2, path += 2) {

    if (memcmp(path, "\x3F\x00", 2) == 0) {

      sc_format_apdu_ex(&apdu, card->cla, 0xA4, 0x00, 0x0C, path, 0, NULL, 0);

      SC_TRANSMIT_TEST_RET(card, apdu, "MF select failed");

    } else if (pathlen == 2 && path[0] == 0xAD) {

      sc_format_apdu_ex(&apdu, card->cla, 0xA4, 0x01, 0x0C, path, 2, NULL, 0);

      SC_TRANSMIT_TEST_RET(card, apdu, "DF select failed");

    } else {

      sc_format_apdu_ex(&apdu, card->cla, 0xA4, 0x09, 0x04, path, pathlen, resp, resplen);

      SC_TRANSMIT_TEST_RET(card, apdu, "EF select failed");

      if (file_out != NULL) {

        file = sc_file_new();

        if (file == NULL)

          LOG_FUNC_RETURN(card->ctx, SC_ERROR_OUT_OF_MEMORY);

        r = iso_ops->process_fci(card, file, resp, resplen);

        if (r != SC_SUCCESS) {

          sc_file_free(file);

        }

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

        *file_out = file;

      }

      break;

    }

  }

  LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

}

static int esteid_set_security_env(sc_card_t *card, const sc_security_env_t *env, int se_num) {

  struct esteid_priv_data *priv;

  struct sc_apdu apdu;

  static const u8 cse_crt_aut[] = {0x80, 0x04, 0xFF, 0x20, 0x08, 0x00, 0x84, 0x01, AUTH_REF};

  static const u8 cse_crt_sig[] = {0x80, 0x04, 0xFF, 0x15, 0x08, 0x00, 0x84, 0x01, SIGN_REF};

  static const u8 cse_crt_dec[] = {0x80, 0x04, 0xFF, 0x30, 0x04, 0x00, 0x84, 0x01, AUTH_REF};

  LOG_FUNC_CALLED(card->ctx);

  if (env == NULL || env->key_ref_len != 1)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  sc_log(card->ctx, "algo: %lu operation: %d keyref: %d", env->algorithm, env->operation, env->key_ref[0]);

  if (env->algorithm == SC_ALGORITHM_EC && env->operation == SC_SEC_OPERATION_SIGN && env->key_ref[0] == AUTH_REF) {

    sc_format_apdu_ex(&apdu, 0x00, 0x22, 0x41, 0xA4, cse_crt_aut, sizeof(cse_crt_aut), NULL, 0);

  } else if (env->algorithm == SC_ALGORITHM_EC && env->operation == SC_SEC_OPERATION_SIGN && env->key_ref[0] == SIGN_REF) {

    sc_format_apdu_ex(&apdu, 0x00, 0x22, 0x41, 0xB6, cse_crt_sig, sizeof(cse_crt_sig), NULL, 0);

  } else if (env->algorithm == SC_ALGORITHM_EC && env->operation == SC_SEC_OPERATION_DERIVE && env->key_ref[0] == AUTH_REF) {

    sc_format_apdu_ex(&apdu, 0x00, 0x22, 0x41, 0xB8, cse_crt_dec, sizeof(cse_crt_dec), NULL, 0);

  } else {

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_NOT_SUPPORTED);

  }

  SC_TRANSMIT_TEST_RET(card, apdu, "SET SECURITY ENV failed");

  priv = DRVDATA(card);

  priv->sec_env = *env;

  LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

}

static int esteid_compute_signature(sc_card_t *card, const u8 *data, size_t datalen, u8 *out, size_t outlen) {

  struct esteid_priv_data *priv = DRVDATA(card);

  struct sc_security_env *env = NULL;

  struct sc_apdu apdu;

  u8 sbuf[SIGNATURE_PAYLOAD_SIZE] = {0};

  size_t le = MIN(SC_MAX_APDU_RESP_SIZE, MIN(SIGNATURE_PAYLOAD_SIZE * 2, outlen));

  LOG_FUNC_CALLED(card->ctx);

  if (data == NULL || out == NULL || datalen > SIGNATURE_PAYLOAD_SIZE)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INVALID_ARGUMENTS);

  env = &priv->sec_env;

  // left-pad if necessary

  memcpy(&sbuf[SIGNATURE_PAYLOAD_SIZE - datalen], data, MIN(datalen, SIGNATURE_PAYLOAD_SIZE));

  datalen = SIGNATURE_PAYLOAD_SIZE;

  switch (env->key_ref[0]) {

  case AUTH_REF:

    sc_format_apdu_ex(&apdu, 0x00, 0x88, 0, 0, sbuf, datalen, out, le);

    break;

  default:

    sc_format_apdu_ex(&apdu, 0x00, 0x2A, 0x9E, 0x9A, sbuf, datalen, out, le);

  }

  SC_TRANSMIT_TEST_RET(card, apdu, "PSO CDS/INTERNAL AUTHENTICATE failed");

  LOG_FUNC_RETURN(card->ctx, (int)apdu.resplen);

}

static int esteid_get_pin_remaining_tries(sc_card_t *card, int pin_reference) {

  const u8 get_pin_info[] = {0x4D, 0x08, 0x70, 0x06, 0xBF, 0x81, pin_reference & 0x0F, 0x02, 0xA0, 0x80}; // mask out local/global

  struct sc_apdu apdu;

  u8 apdu_resp[SC_MAX_APDU_RESP_SIZE];

  LOG_FUNC_CALLED(card->ctx);

  // We don't get the file information here, so we need to be ugly

  if (pin_reference == PIN1_REF || pin_reference == PUK_REF) {

    LOG_TEST_RET(card->ctx, esteid_select_file(card, &MF, NULL), "Cannot select MF");

  } else if (pin_reference == PIN2_REF) {

    LOG_TEST_RET(card->ctx, esteid_select_file(card, &adf2, NULL), "Cannot select QSCD AID");

  } else {

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  }

  sc_format_apdu_ex(&apdu, 0x00, 0xCB, 0x3F, 0xFF, get_pin_info, sizeof(get_pin_info), apdu_resp, sizeof(apdu_resp));

  SC_TRANSMIT_TEST_RET(card, apdu, "GET DATA(pin info) failed");

  if (apdu.resplen < 32) {

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_INTERNAL);

  }

  // XXX: sc_asn1_find_tag with the following payload (to get to tag 0x9B):

  // https://lapo.it/asn1js/#cB6_gQEaoBiaAQObAQOhEIwG8wAAc0MAnAbzAABzQwA

  return (int)apdu_resp[13];

}

static int esteid_pin_cmd(sc_card_t *card, struct sc_pin_cmd_data *data, int *tries_left) {

  int r;

  struct sc_pin_cmd_data tmp;

  LOG_FUNC_CALLED(card->ctx);

  sc_log(card->ctx, "PIN CMD is %d", data->cmd);

  if (data->cmd == SC_PIN_CMD_GET_INFO) {

    sc_log(card->ctx, "SC_PIN_CMD_GET_INFO for %d", data->pin_reference);

    r = esteid_get_pin_remaining_tries(card, data->pin_reference);

    LOG_TEST_RET(card->ctx, r, "GET DATA(pin info) failed");

    data->pin1.tries_left = r;

    data->pin1.max_tries = -1; // "no support, which means the one set in PKCS#15 emulation sticks

    data->pin1.logged_in = SC_PIN_STATE_UNKNOWN;

    LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

  } else if (data->cmd == SC_PIN_CMD_UNBLOCK) {

    // Verify PUK, then issue UNBLOCK

    // VERIFY

    tmp = *data;

    tmp.cmd = SC_PIN_CMD_VERIFY;

    tmp.pin_reference = PUK_REF;

    tmp.pin2.len = 0;

    r = iso_ops->pin_cmd(card, &tmp, tries_left);

    LOG_TEST_RET(card->ctx, r, "VERIFY during unblock failed");

    if (data->pin_reference == PIN2_REF) {

      LOG_TEST_RET(card->ctx, esteid_select_file(card, &adf2, NULL), "Cannot select QSCD AID");

    }

    // UNBLOCK

    tmp = *data;

    tmp.cmd = SC_PIN_CMD_UNBLOCK;

    tmp.pin1.len = 0;

    r = iso_ops->pin_cmd(card, &tmp, tries_left);

    sc_mem_clear(&tmp, sizeof(tmp));

    LOG_FUNC_RETURN(card->ctx, r);

  }

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

}

static int esteid_init(sc_card_t *card) {

  unsigned long flags, ext_flags;

  struct esteid_priv_data *priv;

  priv = calloc(1, sizeof *priv);

  if (!priv)

    LOG_FUNC_RETURN(card->ctx, SC_ERROR_OUT_OF_MEMORY);

  card->drv_data = priv;

  card->max_recv_size = 233; // XXX: empirical, not documented

  // Workaround for the 2018 v2 card, with reader Alcor Micro AU9540

  if (card->type == SC_CARD_TYPE_ESTEID_2018_V2_2025) {

    card->max_recv_size = 0xC0;

  }

  flags = SC_ALGORITHM_ECDSA_RAW | SC_ALGORITHM_ECDH_CDH_RAW | SC_ALGORITHM_ECDSA_HASH_NONE;

  ext_flags = SC_ALGORITHM_EXT_EC_NAMEDCURVE | SC_ALGORITHM_EXT_EC_UNCOMPRESES;

  _sc_card_add_ec_alg(card, 384, flags, ext_flags, NULL);

  LOG_FUNC_RETURN(card->ctx, SC_SUCCESS);

}

static int esteid_finish(sc_card_t *card) {

  if (card != NULL)

    free(DRVDATA(card));

  return 0;

}

static int esteid_logout(sc_card_t *card) {

  return gp_select_aid(card, &IASECC_AID);

}

struct sc_card_driver *sc_get_esteid2018_driver(void) {

  struct sc_card_driver *iso_drv = sc_get_iso7816_driver();

  if (iso_ops == NULL)

    iso_ops = iso_drv->ops;

  esteid_ops = *iso_drv->ops;

  esteid_ops.match_card = esteid_match_card;

  esteid_ops.init = esteid_init;

  esteid_ops.finish = esteid_finish;

  esteid_ops.select_file = esteid_select_file;

  esteid_ops.set_security_env = esteid_set_security_env;

  esteid_ops.compute_signature = esteid_compute_signature;

  esteid_ops.pin_cmd = esteid_pin_cmd;

  esteid_ops.logout = esteid_logout;

  return &esteid2018_driver;

}