/**

 * PKCS15 emulation layer for Giesecke & Devrient StarCOS 3.x cards 

 * with eSign application

 *

 * Copyright (C) 2022, jozsefd

 *

 * 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 "common/compat_strlcpy.h"

#include "internal.h"

#include "log.h"

#include "pkcs15.h"

#include "cards.h"

#include <stdlib.h>

#include <string.h>

/* compile time option: define ENABLE_ESIGN_ISSUER_CONTAINERS to enable containers holding the issuer certificates */

static const char name_Card[] = "ESIGN";

static const char name_Vendor[] = "Giesecke & Devrient";

static const char name_ESign[] = "ESIGN";

static const unsigned char aid_ESIGN[] = {0xA0, 0x00, 0x00, 0x02, 0x45, 0x53, 0x69, 0x67, 0x6E};

typedef struct cdata_st {

  const char *label;

  int authority;

  const char *path;

  const char *id;

  int obj_flags;

} cdata, *pcdata;

typedef struct pdata_st {

  const char *id;

  const char *label;

  const char *path;

  int ref;

  int type;

  unsigned int maxlen;

  unsigned int minlen;

  unsigned int storedlen;

  int flags;

  int tries_left;

  int max_tries;

  const char pad_char;

  int obj_flags;

} pindata, *ppindata;

typedef struct prdata_st {

  const char *id;

  const char *label;

  unsigned int modulus_len;

  int usage;

  const char *path;

  int ref;

  const char *auth_id;

  int obj_flags;

} prdata, *pprdata;

typedef struct container_st {

  const char *id;

  const pcdata certdata;

  const ppindata pindata;

  const pprdata prdata;

} container;

#define USAGE_NONREP SC_PKCS15_PRKEY_USAGE_NONREPUDIATION

#define USAGE_KE     SC_PKCS15_PRKEY_USAGE_ENCRYPT | \

         SC_PKCS15_PRKEY_USAGE_DECRYPT | \

         SC_PKCS15_PRKEY_USAGE_WRAP | \

         SC_PKCS15_PRKEY_USAGE_UNWRAP

#define USAGE_AUT SC_PKCS15_PRKEY_USAGE_ENCRYPT | \

          SC_PKCS15_PRKEY_USAGE_DECRYPT | \

          SC_PKCS15_PRKEY_USAGE_WRAP | \

          SC_PKCS15_PRKEY_USAGE_UNWRAP | \

          SC_PKCS15_PRKEY_USAGE_SIGN

#define USER_PIN  SC_PKCS15_PIN_FLAG_INITIALIZED | \

        SC_PKCS15_PIN_FLAG_CASE_SENSITIVE | \

        SC_PKCS15_PIN_TYPE_FLAGS_PIN_GLOBAL | \

        SC_PKCS15_PIN_AUTH_TYPE_PIN

static int

get_cert_size(sc_card_t *card, sc_path_t *path, size_t *psize)

{

  int r;

  sc_file_t *file = NULL;

  r = sc_select_file(card, path, &file);

  LOG_TEST_RET(card->ctx, r, "Failed to select EF certificate");

  *psize = file->size;

  sc_file_free(file);

  return SC_SUCCESS;

}

static int

add_app(sc_pkcs15_card_t *p15card, const container *containers, int container_count)

{

  int i, containers_added = 0, r = SC_SUCCESS;

  ppindata installed_pins[4];

  size_t installed_pin_count = 0;

  sc_card_t *card = p15card->card;

  LOG_FUNC_CALLED(card->ctx);

  for (i = 0; i < container_count; i++) {

    struct sc_pkcs15_cert_info cert_info;

    struct sc_pkcs15_object cert_obj;

    size_t cert_size;

    memset(&cert_info, 0, sizeof(cert_info));

    memset(&cert_obj, 0, sizeof(cert_obj));

    sc_pkcs15_format_id(containers[i].id, &cert_info.id);

    cert_info.authority = containers[i].certdata->authority;

    sc_format_path(containers[i].certdata->path, &cert_info.path);

    r = get_cert_size(card, &cert_info.path, &cert_size);

    if ( r != SC_SUCCESS ) {

      sc_log(card->ctx, "Failed to determine size of certificate %s, ignoring container", containers[i].certdata->label);

      continue;

    }

    strlcpy(cert_obj.label, containers[i].certdata->label, sizeof(cert_obj.label));

    cert_obj.flags = containers[i].certdata->obj_flags;

    r = sc_pkcs15emu_add_x509_cert(p15card, &cert_obj, &cert_info);

    LOG_TEST_RET(card->ctx, r, "Failed to add certificate");

    if (containers[i].pindata != 0) {

      size_t j;

      int is_pin_installed = 0;

      /* A pin object could be used by more than 1 container, ensure it is added only once */

      for (j = 0; j < installed_pin_count; j++) {

        if (installed_pins[j] == containers[i].pindata) {

          is_pin_installed = 1;

          break;

        }

      }

      if (!is_pin_installed) {

        struct sc_pkcs15_auth_info pin_info;

        struct sc_pkcs15_object pin_obj;

        if (installed_pin_count < (int)(sizeof(installed_pins) / sizeof(ppindata))) {

          installed_pins[installed_pin_count++] = containers[i].pindata;

        } else {

          sc_log(card->ctx, "Warning: cannot add more than 4 pins");

          continue;

        }

        memset(&pin_info, 0, sizeof(pin_info));

        memset(&pin_obj, 0, sizeof(pin_obj));

        sc_pkcs15_format_id(containers[i].pindata->id, &pin_info.auth_id);

        pin_info.auth_type = SC_PKCS15_PIN_AUTH_TYPE_PIN;

        pin_info.attrs.pin.reference = containers[i].pindata->ref;

        pin_info.attrs.pin.flags = containers[i].pindata->flags;

        pin_info.attrs.pin.type = containers[i].pindata->type;

        pin_info.attrs.pin.min_length = containers[i].pindata->minlen;

        pin_info.attrs.pin.stored_length = containers[i].pindata->storedlen;

        pin_info.attrs.pin.max_length = containers[i].pindata->maxlen;

        pin_info.attrs.pin.pad_char = containers[i].pindata->pad_char;

        if (containers[i].pindata->path != NULL)

          sc_format_path(containers[i].pindata->path, &pin_info.path);

        pin_info.tries_left = -1;

        pin_info.max_tries = containers[i].pindata->max_tries;

        strlcpy(pin_obj.label, containers[i].pindata->label, sizeof(pin_obj.label));

        pin_obj.flags = containers[i].pindata->obj_flags;

        r = sc_pkcs15emu_add_pin_obj(p15card, &pin_obj, &pin_info);

        LOG_TEST_RET(card->ctx, r, "Failed to add PIN object");

      }

    }

    if (containers[i].prdata != 0) {

      struct sc_pkcs15_prkey_info prkey_info;

      struct sc_pkcs15_object prkey_obj;

      int modulus_len = containers[i].prdata->modulus_len;

      memset(&prkey_info, 0, sizeof(prkey_info));

      memset(&prkey_obj, 0, sizeof(prkey_obj));

      sc_pkcs15_format_id(containers[i].id, &prkey_info.id);

      prkey_info.usage = containers[i].prdata->usage;

      prkey_info.native = 1;

      prkey_info.key_reference = containers[i].prdata->ref;

      prkey_info.modulus_length = modulus_len;

      sc_format_path(containers[i].prdata->path, &prkey_info.path);

      strlcpy(prkey_obj.label, containers[i].prdata->label, sizeof(prkey_obj.label));

      prkey_obj.flags = containers[i].prdata->obj_flags;

      if (containers[i].prdata->auth_id) {

        sc_pkcs15_format_id(containers[i].prdata->auth_id, &prkey_obj.auth_id);

      }

      r = sc_pkcs15emu_add_rsa_prkey(p15card, &prkey_obj, &prkey_info);

      LOG_TEST_RET(card->ctx, r, "Failed to add RSA prkey");

    }

    containers_added++;

  }

  if (containers_added == 0) {

    r = SC_ERROR_INVALID_CARD;

  } else {

    r = SC_SUCCESS;

  }

  LOG_FUNC_RETURN(card->ctx, r);

}

/*

 * adds the PKCS15 objects of the ESIGN application. The app may contain

 * 1) Authentication container

 *  - 2048-bit RSA key

 *  - CH certificate

 * 2) Encryption container

 *  - 2048-bit RSA key

 *  - CH certificate

 * 3) Authentication Issuer container

 *  - issuer certificate

 * 3) Encryption Issuer container

 *  - issuer certificate

 * Depending on the card profile, some containers may be missing.

 * Both RSA keys are protected with the UserPIN. The app may have a PUK, not

 * supported by this emulator.

 * 

 * The issuer certificates are not included by default, define ENABLE_ESIGN_ISSUER_CONTAINERS

 * to enable them.

 */

static int

starcos_add_esign_app(sc_pkcs15_card_t *p15card)

{

  static cdata auth_cert = {"C.CH.AUT", 0, "3F00060843F1", "1", 0};

  static cdata encr_cert = {"C.CH.ENC", 0, "3F0006084301", "2", 0};

#ifdef ENABLE_ESIGN_ISSUER_CONTAINERS

  const cdata auth_root_cert = { "C.RootCA_Auth", 1, "3F00060843F0", "3", 0 };

  const cdata encr_root_cert = { "C.RootCA_Enc", 1, "3F0006084300", "4", 0 };

#endif

  static prdata auth_key = {"1", "PrK.CH.AUT", 2048, USAGE_AUT, "3F000608", 0x81, "1", SC_PKCS15_CO_FLAG_PRIVATE};

  static prdata encr_key = {"2", "PrK.CH.ENC", 2048, USAGE_KE, "3F000608", 0x83, "1", SC_PKCS15_CO_FLAG_PRIVATE};

  static pindata auth_pin = {"1", "UserPIN", "3F00", 0x01, SC_PKCS15_PIN_TYPE_UTF8, 16, 6, 0,

      USER_PIN, -1, 3, 0x00, SC_PKCS15_CO_FLAG_MODIFIABLE | SC_PKCS15_CO_FLAG_PRIVATE};

  static pindata auth_pin_v35 = {"1", "UserPIN", "3F00", 0x06, SC_PKCS15_PIN_TYPE_UTF8, 16, 6, 0,

      USER_PIN, -1, 3, 0x00, SC_PKCS15_CO_FLAG_MODIFIABLE | SC_PKCS15_CO_FLAG_PRIVATE};

  ppindata auth = (p15card->card->type == SC_CARD_TYPE_STARCOS_V3_5_ESIGN) ? &auth_pin_v35 : &auth_pin;

  const container containers[] = {

      {"1", &auth_cert, auth, &auth_key},

      {"2", &encr_cert, auth, &encr_key},

#ifdef ENABLE_ESIGN_ISSUER_CONTAINERS

      { "3", &auth_root_cert, 0, 0 },

      { "4", &encr_root_cert, 0, 0 },

#endif

  };

  return add_app(p15card, containers, sizeof(containers) / sizeof(container));

}

static int

starcos_esign_init(sc_pkcs15_card_t *p15card, struct sc_aid *aid)

{

  sc_card_t *card = p15card->card;

  sc_context_t *ctx = card->ctx;

  const char *label = name_Card;

  int r;

  int apps_added = 0;

  SC_FUNC_CALLED(ctx, SC_LOG_DEBUG_NORMAL);

  if (card->type != SC_CARD_TYPE_STARCOS_V3_4_ESIGN && card->type != SC_CARD_TYPE_STARCOS_V3_5_ESIGN) {

    return SC_ERROR_WRONG_CARD;

  }

  if (aid == NULL) {

    // no aid: in this case all emulated apps are added, currently only the esign_app

    r = starcos_add_esign_app(p15card);

    if (r == SC_SUCCESS)

      apps_added++;

  } else {

    // aid specified: only the matching app is added

    if (aid->len == sizeof(aid_ESIGN) && memcmp(aid->value, aid_ESIGN, sizeof(aid_ESIGN)) == 0) {

      r = starcos_add_esign_app(p15card);

      if (r == SC_SUCCESS) {

        label = name_ESign;

        apps_added++;

      }

    }

    if (apps_added > 0) {

      // pkcs11 requires the file_app

      struct sc_path path;

      struct sc_file *file = NULL;

      sc_path_set(&path, SC_PATH_TYPE_DF_NAME, aid->value, aid->len, 0, 0);

      r = sc_select_file(card, &path, &file);

      if (r != SC_SUCCESS || !file)

        return SC_ERROR_INTERNAL;

      sc_file_free(p15card->file_app);

      p15card->file_app = file;

    }

  }

  if (apps_added == 0) {

    LOG_TEST_RET(ctx, SC_ERROR_WRONG_CARD, "No supported app found on this card");

  }

  sc_pkcs15_free_tokeninfo(p15card->tokeninfo);

  p15card->tokeninfo = sc_pkcs15_tokeninfo_new();

  if (!p15card->tokeninfo) {

    LOG_TEST_RET(ctx, SC_ERROR_OUT_OF_MEMORY, "unable to create tokeninfo struct");

  } else {

    sc_serial_number_t serial;

    char serial_hex[SC_MAX_SERIALNR * 2 + 2];

    r = sc_card_ctl(card, SC_CARDCTL_GET_SERIALNR, &serial);

    LOG_TEST_RET(ctx, r, "Failed to query card serial number");

    r = sc_bin_to_hex(serial.value, serial.len, serial_hex, sizeof serial_hex, 0);

    LOG_TEST_RET(ctx, r, "Failed to convert S/N to hex");

    p15card->tokeninfo->serial_number = strdup(serial_hex);

    p15card->tokeninfo->label = strdup(label);

    p15card->tokeninfo->manufacturer_id = strdup(name_Vendor);

    p15card->tokeninfo->flags = SC_PKCS15_TOKEN_READONLY;

  }

  LOG_FUNC_RETURN(ctx, SC_SUCCESS);

}

int

sc_pkcs15emu_starcos_esign_init_ex(sc_pkcs15_card_t *p15card, struct sc_aid *aid)

{

  int r = SC_ERROR_WRONG_CARD;

  if (!p15card || !p15card->card || !p15card->card->ctx)

    return SC_ERROR_INVALID_ARGUMENTS;

  r = starcos_esign_init(p15card, aid);

  LOG_FUNC_RETURN(p15card->card->ctx, r);

}