/*
 * card.c: General smart card functions
 *
 * Copyright (C) 2001, 2002  Juha Yrjölä <juha.yrjola@iki.fi>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#include <assert.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>

#include "internal.h"
#include "asn1.h"

int sc_check_sw(sc_card_t *card, unsigned int sw1, unsigned int sw2)
{
	if (card == NULL)
		return SC_ERROR_INVALID_ARGUMENTS;
	if (card->ops->check_sw == NULL)
		return SC_ERROR_NOT_SUPPORTED;
	return card->ops->check_sw(card, sw1, sw2);
}

void sc_format_apdu(sc_card_t *card, sc_apdu_t *apdu,
		    int cse, int ins, int p1, int p2)
{
	assert(card != NULL && apdu != NULL);
	memset(apdu, 0, sizeof(*apdu));
	apdu->cla = (u8) card->cla;
	apdu->cse = cse;
	apdu->ins = (u8) ins;
	apdu->p1 = (u8) p1;
	apdu->p2 = (u8) p2;
}

static sc_card_t * sc_card_new(sc_context_t *ctx)
{
	sc_card_t *card;

	if (ctx == NULL)
		return NULL;

	card = (sc_card_t *) calloc(1, sizeof(struct sc_card));
	if (card == NULL)
		return NULL;
	card->ops = (struct sc_card_operations *) malloc(sizeof(struct sc_card_operations));
	if (card->ops == NULL) {
		free(card);
		return NULL;
	}

	card->ctx = ctx;
	if (sc_mutex_create(ctx, &card->mutex) != SC_SUCCESS) {
		free(card->ops);
		free(card);
		return NULL;
	}

	card->type = -1;
	card->app_count = -1;
	card->magic = SC_CARD_MAGIC;

	return card;
}

static void sc_card_free(sc_card_t *card)
{
	assert(sc_card_valid(card));
	sc_free_apps(card);
	if (card->ef_dir != NULL)
		sc_file_free(card->ef_dir);
	free(card->ops);
	if (card->algorithms != NULL)
		free(card->algorithms);
	if (card->mutex != NULL) {
		int r = sc_mutex_destroy(card->ctx, card->mutex);
		if (r != SC_SUCCESS)
			sc_debug(card->ctx, "unable to destroy mutex\n");
	}
	sc_mem_clear(card, sizeof(*card));
	free(card);
}

int sc_connect_card(sc_reader_t *reader, sc_card_t **card_out)
{
	sc_card_t *card;
	sc_context_t *ctx;
	struct sc_card_driver *driver;
	int i, r = 0, idx, connected = 0;

	if (card_out == NULL || reader == NULL)
		return SC_ERROR_INVALID_ARGUMENTS;
	ctx = reader->ctx;
	SC_FUNC_CALLED(ctx, 1);
	if (reader->ops->connect == NULL)
		SC_FUNC_RETURN(ctx, 0, SC_ERROR_NOT_SUPPORTED);

	card = sc_card_new(ctx);
	if (card == NULL)
		SC_FUNC_RETURN(ctx, 1, SC_ERROR_OUT_OF_MEMORY);
	r = reader->ops->connect(reader);
	if (r)
		goto err;

	connected = 1;
	card->reader = reader;
	card->ctx = ctx;

	/* These can be overridden by the card driver */
	card->max_send_size = reader->driver->max_send_size;
	card->max_recv_size = reader->driver->max_recv_size;

	memcpy(card->atr, reader->atr, reader->atr_len);
	card->atr_len = reader->atr_len;

	_sc_parse_atr(reader);

	/* See if the ATR matches any ATR specified in the config file */
	if ((driver = ctx->forced_driver) == NULL) {
		if (ctx->debug >= 3)
			sc_debug(ctx, "matching configured ATRs\n");
		for (i = 0; ctx->card_drivers[i] != NULL; i++) {
			driver = ctx->card_drivers[i];

			if (driver->atr_map == NULL ||
			    !strcmp(driver->short_name, "default")) {
				driver = NULL;
				continue;
			}
			if (ctx->debug >= 3)
				sc_debug(ctx, "trying driver: %s\n", driver->short_name);
			idx = _sc_match_atr(card, driver->atr_map, NULL);
			if (idx >= 0) {
				struct sc_atr_table *src = &driver->atr_map[idx];

				if (ctx->debug >= 3)
					sc_debug(ctx, "matched: %s\n", driver->name);
				/* It's up to card driver to notice these correctly */
				card->name = src->name;
				card->type = src->type;
				card->flags = src->flags;
				break;
			}
			driver = NULL;
		}
	}

	if (driver != NULL) {
		/* Forced driver, or matched via ATR mapping from
		 * config file */
		card->driver = driver;
		memcpy(card->ops, card->driver->ops, sizeof(struct sc_card_operations));
		if (card->ops->init != NULL) {
			r = card->ops->init(card);
			if (r) {
				sc_debug(ctx, "driver '%s' init() failed: %s\n", card->driver->name,
				      sc_strerror(r));
				goto err;
			}
		}
	} else {
		if (ctx->debug >= 3)
			sc_debug(ctx, "matching built-in ATRs\n");
		for (i = 0; ctx->card_drivers[i] != NULL; i++) {
			struct sc_card_driver *drv = ctx->card_drivers[i];
			const struct sc_card_operations *ops = drv->ops;

			if (ctx->debug >= 3)
				sc_debug(ctx, "trying driver: %s\n", drv->short_name);
			if (ops == NULL || ops->match_card == NULL)
				continue;
			/* Needed if match_card() needs to talk with the card (e.g. card-muscle) */
			*card->ops = *ops;
			if (ops->match_card(card) != 1)
				continue;
			if (ctx->debug >= 3)
				sc_debug(ctx, "matched: %s\n", drv->name);
			memcpy(card->ops, ops, sizeof(struct sc_card_operations));
			card->driver = drv;
			r = ops->init(card);
			if (r) {
				sc_debug(ctx, "driver '%s' init() failed: %s\n", drv->name,
				      sc_strerror(r));
				if (r == SC_ERROR_INVALID_CARD) {
					card->driver = NULL;
					continue;
				}
				goto err;
			}
			break;
		}
	}
	if (card->driver == NULL) {
		sc_debug(ctx, "unable to find driver for inserted card\n");
		r = SC_ERROR_INVALID_CARD;
		goto err;
	}
	if (card->name == NULL)
		card->name = card->driver->name;
	*card_out = card;

	sc_debug(ctx, "card info: %s, %i, 0x%X\n", card->name, card->type, card->flags);
	SC_FUNC_RETURN(ctx, 1, 0);
err:
	if (connected)
		reader->ops->disconnect(reader);
	if (card != NULL)
		sc_card_free(card);
	SC_FUNC_RETURN(ctx, 1, r);
}

int sc_disconnect_card(sc_card_t *card)
{
	sc_context_t *ctx;
	assert(sc_card_valid(card));
	ctx = card->ctx;
	SC_FUNC_CALLED(ctx, 1);
	assert(card->lock_count == 0);
	if (card->ops->finish) {
		int r = card->ops->finish(card);
		if (r)
			sc_debug(card->ctx, "card driver finish() failed: %s\n",
			      sc_strerror(r));
	}
	if (card->reader->ops->disconnect) {
		int r = card->reader->ops->disconnect(card->reader);
		if (r)
			sc_debug(card->ctx, "disconnect() failed: %s\n",
			      sc_strerror(r));
	}
	sc_card_free(card);
	SC_FUNC_RETURN(ctx, 1, 0);
}

int sc_reset(sc_card_t *card)
{
	int r, r2;

	if (card == NULL)
		return SC_ERROR_INVALID_ARGUMENTS;
	if (card->reader->ops->reset == NULL)
		return SC_ERROR_NOT_SUPPORTED;

	r = sc_mutex_lock(card->ctx, card->mutex);
	if (r != SC_SUCCESS)
		return r;

	r = card->reader->ops->reset(card->reader);
	/* invalidate cache */
	memset(&card->cache, 0, sizeof(card->cache));
	card->cache_valid = 0;

	r2 = sc_mutex_unlock(card->ctx, card->mutex);
	if (r2 != SC_SUCCESS) {
		sc_debug(card->ctx, "unable to release lock\n");
		r = r != SC_SUCCESS ? r : r2;
	}

	return r;
}

int sc_lock(sc_card_t *card)
{
	int r = 0, r2 = 0;

	SC_FUNC_CALLED(card->ctx, 3);
	
	if (card == NULL)
		return SC_ERROR_INVALID_ARGUMENTS;
	r = sc_mutex_lock(card->ctx, card->mutex);
	if (r != SC_SUCCESS)
		return r;
	if (card->lock_count == 0) {
		if (card->reader->ops->lock != NULL) {
			r = card->reader->ops->lock(card->reader);
			if (r == SC_ERROR_CARD_RESET || r == SC_ERROR_READER_REATTACHED) {
				/* invalidate cache */
				memset(&card->cache, 0, sizeof(card->cache));
				card->cache_valid = 0;
				r = card->reader->ops->lock(card->reader);
			}
		}
		if (r == 0)
			card->cache_valid = 1;
	}
	if (r == 0)
		card->lock_count++;
	r2 = sc_mutex_unlock(card->ctx, card->mutex);
	if (r2 != SC_SUCCESS) {
		sc_debug(card->ctx, "unable to release lock\n");
		r = r != SC_SUCCESS ? r : r2;
	}
	return r;
}

int sc_unlock(sc_card_t *card)
{
	int r, r2;

	SC_FUNC_CALLED(card->ctx, 3);

	if (card == NULL)
		return SC_ERROR_INVALID_ARGUMENTS;
	r = sc_mutex_lock(card->ctx, card->mutex);
	if (r != SC_SUCCESS)
		return r;
	assert(card->lock_count >= 1);
	if (--card->lock_count == 0) {
		/* invalidate cache */
		memset(&card->cache, 0, sizeof(card->cache));
		card->cache_valid = 0;
		/* release reader lock */
		if (card->reader->ops->unlock != NULL)
			r = card->reader->ops->unlock(card->reader);
	}
	r2 = sc_mutex_unlock(card->ctx, card->mutex);
	if (r2 != SC_SUCCESS) {
		sc_debug(card->ctx, "unable to release lock\n");
		r = (r == SC_SUCCESS) ? r2 : r;
	}
	return r;
}

int sc_list_files(sc_card_t *card, u8 *buf, size_t buflen)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 1);
	if (card->ops->list_files == NULL)
		SC_FUNC_RETURN(card->ctx, 1, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->list_files(card, buf, buflen);
	SC_FUNC_RETURN(card->ctx, 1, r);
}

int sc_create_file(sc_card_t *card, sc_file_t *file)
{
	int r;

	assert(card != NULL);
	if (card->ctx->debug >= 1) {
		char pbuf[SC_MAX_PATH_STRING_SIZE];
		const sc_path_t *in_path = &file->path;

		r = sc_path_print(pbuf, sizeof(pbuf), in_path);
		if (r != SC_SUCCESS)
			pbuf[0] = '\0';

		sc_debug(card->ctx, "called; type=%d, path=%s, size=%u\n",
				in_path->type, pbuf, file->size);
	}
	if (card->ops->create_file == NULL)
		SC_FUNC_RETURN(card->ctx, 1, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->create_file(card, file);
	SC_FUNC_RETURN(card->ctx, 1, r);
}

int sc_delete_file(sc_card_t *card, const sc_path_t *path)
{
	int r;

	assert(card != NULL);
	if (card->ctx->debug >= 1) {
		char pbuf[SC_MAX_PATH_STRING_SIZE];

		r = sc_path_print(pbuf, sizeof(pbuf), path);
		if (r != SC_SUCCESS)
			pbuf[0] = '\0';

		sc_debug(card->ctx, "called; type=%d, path=%s\n",
				path->type, pbuf);
	}
	if (card->ops->delete_file == NULL)
		SC_FUNC_RETURN(card->ctx, 1, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->delete_file(card, path);
	SC_FUNC_RETURN(card->ctx, 1, r);
}

int sc_read_binary(sc_card_t *card, unsigned int idx,
		   unsigned char *buf, size_t count, unsigned long flags)
{
	size_t max_le = card->max_recv_size;
	int r;

	assert(card != NULL && card->ops != NULL && buf != NULL);
	if (card->ctx->debug >= 2)
		sc_debug(card->ctx, "called; %d bytes at index %d\n", count, idx);
	if (count == 0)
		return 0;
	if (card->ops->read_binary == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	if (count > max_le) {
		int bytes_read = 0;
		unsigned char *p = buf;

		r = sc_lock(card);
		SC_TEST_RET(card->ctx, r, "sc_lock() failed");
		while (count > 0) {
			size_t n = count > max_le ? max_le : count;
			r = sc_read_binary(card, idx, p, n, flags);
			if (r < 0) {
				sc_unlock(card);
				SC_TEST_RET(card->ctx, r, "sc_read_binary() failed");
			}
			p += r;
			idx += r;
			bytes_read += r;
			count -= r;
			if (r == 0) {
				sc_unlock(card);
				SC_FUNC_RETURN(card->ctx, 2, bytes_read);
			}
		}
		sc_unlock(card);
		SC_FUNC_RETURN(card->ctx, 2, bytes_read);
	}
	r = card->ops->read_binary(card, idx, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_write_binary(sc_card_t *card, unsigned int idx,
		    const u8 *buf, size_t count, unsigned long flags)
{
	size_t max_lc = card->max_send_size;
	int r;

	assert(card != NULL && card->ops != NULL && buf != NULL);
	if (card->ctx->debug >= 2)
		sc_debug(card->ctx, "called; %d bytes at index %d\n", count, idx);
	if (count == 0)
		return 0;
	if (card->ops->write_binary == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	if (count > max_lc) {
		int bytes_written = 0;
		const u8 *p = buf;

		r = sc_lock(card);
		SC_TEST_RET(card->ctx, r, "sc_lock() failed");
		while (count > 0) {
			size_t n = count > max_lc? max_lc : count;
			r = sc_write_binary(card, idx, p, n, flags);
			if (r < 0) {
				sc_unlock(card);
				SC_TEST_RET(card->ctx, r, "sc_write_binary() failed");
			}
			p += r;
			idx += r;
			bytes_written += r;
			count -= r;
			if (r == 0) {
				sc_unlock(card);
				SC_FUNC_RETURN(card->ctx, 2, bytes_written);
			}
		}
		sc_unlock(card);
		SC_FUNC_RETURN(card->ctx, 2, bytes_written);
	}
	r = card->ops->write_binary(card, idx, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_update_binary(sc_card_t *card, unsigned int idx,
		     const u8 *buf, size_t count, unsigned long flags)
{
	size_t max_lc = card->max_send_size;
	int r;

	assert(card != NULL && card->ops != NULL && buf != NULL);
	if (card->ctx->debug >= 2)
		sc_debug(card->ctx, "called; %d bytes at index %d\n", count, idx);
	if (count == 0)
		return 0;
	if (card->ops->update_binary == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	if (count > max_lc) {
		int bytes_written = 0;
		const u8 *p = buf;

		r = sc_lock(card);
		SC_TEST_RET(card->ctx, r, "sc_lock() failed");
		while (count > 0) {
			size_t n = count > max_lc? max_lc : count;
			r = sc_update_binary(card, idx, p, n, flags);
			if (r < 0) {
				sc_unlock(card);
				SC_TEST_RET(card->ctx, r, "sc_update_binary() failed");
			}
			p += r;
			idx += r;
			bytes_written += r;
			count -= r;
			if (r == 0) {
				sc_unlock(card);
				SC_FUNC_RETURN(card->ctx, 2, bytes_written);
			}
		}
		sc_unlock(card);
		SC_FUNC_RETURN(card->ctx, 2, bytes_written);
	}
	r = card->ops->update_binary(card, idx, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_select_file(sc_card_t *card,
		   const sc_path_t *in_path,
		   sc_file_t **file)
{
	int r;

	assert(card != NULL && in_path != NULL);
	if (card->ctx->debug >= 1) {
		char pbuf[SC_MAX_PATH_STRING_SIZE];

		r = sc_path_print(pbuf, sizeof(pbuf), in_path);
		if (r != SC_SUCCESS)
			pbuf[0] = '\0';

		sc_debug(card->ctx, "called; type=%d, path=%s\n",
				in_path->type, pbuf);
	}
	if (in_path->len > SC_MAX_PATH_SIZE)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_INVALID_ARGUMENTS);
	if (in_path->type == SC_PATH_TYPE_PATH) {
		/* Perform a sanity check */
		size_t i;
		if ((in_path->len & 1) != 0)
			SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_INVALID_ARGUMENTS);
		for (i = 0; i < in_path->len/2; i++) {
			u8 p1 = in_path->value[2*i],
			   p2 = in_path->value[2*i+1];
			if ((p1 == 0x3F && p2 == 0x00) && i != 0)
				SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_INVALID_ARGUMENTS);
		}
	}
	if (card->ops->select_file == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->select_file(card, in_path, file);
	/* Remember file path */
	if (r == 0 && file && *file)
		(*file)->path = *in_path;
	SC_FUNC_RETURN(card->ctx, 1, r);
}

int sc_get_data(sc_card_t *card, unsigned int tag, u8 *buf, size_t len)
{
	int	r;

	sc_debug(card->ctx, "called, tag=%04x\n", tag);
	if (card->ops->get_data == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->get_data(card, tag, buf, len);
	SC_FUNC_RETURN(card->ctx, 1, r);
}

int sc_put_data(sc_card_t *card, unsigned int tag, const u8 *buf, size_t len)
{
	int	r;

	sc_debug(card->ctx, "called, tag=%04x\n", tag);
	if (card->ops->put_data == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->put_data(card, tag, buf, len);
	SC_FUNC_RETURN(card->ctx, 1, r);
}

int sc_get_challenge(sc_card_t *card, u8 *rnd, size_t len)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->get_challenge == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->get_challenge(card, rnd, len);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_read_record(sc_card_t *card, unsigned int rec_nr, u8 *buf,
		   size_t count, unsigned long flags)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->read_record == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->read_record(card, rec_nr, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_write_record(sc_card_t *card, unsigned int rec_nr, const u8 * buf,
		    size_t count, unsigned long flags)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->write_record == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->write_record(card, rec_nr, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_append_record(sc_card_t *card, const u8 * buf, size_t count,
		     unsigned long flags)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->append_record == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->append_record(card, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_update_record(sc_card_t *card, unsigned int rec_nr, const u8 * buf,
		     size_t count, unsigned long flags)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->update_record == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->update_record(card, rec_nr, buf, count, flags);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_delete_record(sc_card_t *card, unsigned int rec_nr)
{
	int r;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->delete_record == NULL)
		SC_FUNC_RETURN(card->ctx, 2, SC_ERROR_NOT_SUPPORTED);
	r = card->ops->delete_record(card, rec_nr);
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int sc_card_valid(const sc_card_t *card) {
#ifndef NDEBUG
	assert(card != NULL);
#endif
	return card->magic == SC_CARD_MAGIC;
}

int
sc_card_ctl(sc_card_t *card, unsigned long cmd, void *args)
{
	int r = SC_ERROR_NOT_SUPPORTED;

	assert(card != NULL);
	SC_FUNC_CALLED(card->ctx, 2);
	if (card->ops->card_ctl != NULL)
		r = card->ops->card_ctl(card, cmd, args);

	/* suppress "not supported" error messages */
	if (r == SC_ERROR_NOT_SUPPORTED) {
		sc_debug(card->ctx, "card_ctl(%lu) not supported\n",
			(unsigned long) cmd);
		return r;
	}
	SC_FUNC_RETURN(card->ctx, 2, r);
}

int _sc_card_add_algorithm(sc_card_t *card, const sc_algorithm_info_t *info)
{
	sc_algorithm_info_t *p;

	assert(sc_card_valid(card) && info != NULL);
	p = (sc_algorithm_info_t *) realloc(card->algorithms, (card->algorithm_count + 1) * sizeof(*info));
	if (!p) {
		if (card->algorithms)
			free(card->algorithms);
		card->algorithms = NULL;
		card->algorithm_count = 0;
		return SC_ERROR_OUT_OF_MEMORY;
	}
	card->algorithms = p;
	p += card->algorithm_count;
	card->algorithm_count++;
	*p = *info;
	return 0;
}

int _sc_card_add_rsa_alg(sc_card_t *card, unsigned int key_length,
			 unsigned long flags, unsigned long exponent)
{
	sc_algorithm_info_t info;

	memset(&info, 0, sizeof(info));
	info.algorithm = SC_ALGORITHM_RSA;
	info.key_length = key_length;
	info.flags = flags;
	info.u._rsa.exponent = exponent;

	return _sc_card_add_algorithm(card, &info);
}

sc_algorithm_info_t * _sc_card_find_rsa_alg(sc_card_t *card,
						 unsigned int key_length)
{
	int i;

	for (i = 0; i < card->algorithm_count; i++) {
		sc_algorithm_info_t *info = &card->algorithms[i];

		if (info->algorithm != SC_ALGORITHM_RSA)
			continue;
		if (info->key_length != key_length)
			continue;
		return info;
	}
	return NULL;
}

static int match_atr_table(sc_context_t *ctx, struct sc_atr_table *table, u8 *atr, size_t atr_len)
{
	u8 *card_atr_bin = atr;
	size_t card_atr_bin_len = atr_len;
	char card_atr_hex[3 * SC_MAX_ATR_SIZE];
	size_t card_atr_hex_len;
	unsigned int i = 0;

	if (ctx == NULL || table == NULL || atr == NULL)
		return -1;
	sc_bin_to_hex(card_atr_bin, card_atr_bin_len, card_atr_hex, sizeof(card_atr_hex), ':');
	card_atr_hex_len = strlen(card_atr_hex);

	if (ctx->debug >= 4)
		sc_debug(ctx, "ATR     : %s\n", card_atr_hex);

	for (i = 0; table[i].atr != NULL; i++) {
		const char *tatr = table[i].atr;
		const char *matr = table[i].atrmask;
		size_t tatr_len = strlen(tatr);
		u8 mbin[SC_MAX_ATR_SIZE], tbin[SC_MAX_ATR_SIZE];
		size_t mbin_len, tbin_len, s, matr_len;
		size_t fix_hex_len = card_atr_hex_len;
		size_t fix_bin_len = card_atr_bin_len;

		if (ctx->debug >= 4)
			sc_debug(ctx, "ATR try : %s\n", tatr);

		if (tatr_len != fix_hex_len) {
			if (ctx->debug >= 5)
				sc_debug(ctx, "ignored - wrong length\n", tatr);
			continue;
		}
		if (matr != NULL) {
			if (ctx->debug >= 4)
				sc_debug(ctx, "ATR mask: %s\n", matr);

			matr_len = strlen(matr);
			if (tatr_len != matr_len)
				continue;
			tbin_len = sizeof(tbin);
			sc_hex_to_bin(tatr, tbin, &tbin_len);
			mbin_len = sizeof(mbin);
			sc_hex_to_bin(matr, mbin, &mbin_len);
			if (mbin_len != fix_bin_len) {
				sc_debug(ctx,"length of atr and atr mask do not match - ignored: %s - %s", tatr, matr); 
				continue;
			}
			for (s = 0; s < tbin_len; s++) {
				/* reduce tatr with mask */
				tbin[s] = (tbin[s] & mbin[s]);
				/* create copy of card_atr_bin masked) */
				mbin[s] = (card_atr_bin[s] & mbin[s]);
			}
			if (memcmp(tbin, mbin, tbin_len) != 0)
				continue;
		} else {
			if (strncasecmp(tatr, card_atr_hex, tatr_len) != 0)
				continue;
		}
		return i;
	}
	return -1;
}

int _sc_match_atr(sc_card_t *card, struct sc_atr_table *table, int *type_out)
{
	int res;

	if (card == NULL)
		return -1;
	res = match_atr_table(card->ctx, table, card->atr, card->atr_len);
	if (res < 0)
		return res;
	if (type_out != NULL)
		*type_out = table[res].type;
	return res;
}

scconf_block *_sc_match_atr_block(sc_context_t *ctx, struct sc_card_driver *driver, u8 *atr, size_t atr_len)
{
	struct sc_card_driver *drv;
	struct sc_atr_table *table;
	int res;

	if (ctx == NULL)
		return NULL;
	if (driver) {
		drv = driver;
		table = drv->atr_map;
		res = match_atr_table(ctx, table, atr, atr_len);
		if (res < 0)
			return NULL;
		return table[res].card_atr;
	} else {
		unsigned int i;

		for (i = 0; ctx->card_drivers[i] != NULL; i++) {
			drv = ctx->card_drivers[i];
			table = drv->atr_map;
			res = match_atr_table(ctx, table, atr, atr_len);
			if (res < 0)
				continue;
			return table[res].card_atr;
		}
	}
	return NULL;
}

int _sc_add_atr(sc_context_t *ctx, struct sc_card_driver *driver, struct sc_atr_table *src)
{
	struct sc_atr_table *map, *dst;

	map = (struct sc_atr_table *) realloc(driver->atr_map,
			(driver->natrs + 2) * sizeof(struct sc_atr_table));
	if (!map)
		return SC_ERROR_OUT_OF_MEMORY;
	driver->atr_map = map;
	dst = &driver->atr_map[driver->natrs++];
	memset(dst, 0, sizeof(*dst));
	memset(&driver->atr_map[driver->natrs], 0, sizeof(struct sc_atr_table));
	dst->atr = strdup(src->atr);
	if (!dst->atr)
		return SC_ERROR_OUT_OF_MEMORY;
	if (src->atrmask) {
		dst->atrmask = strdup(src->atrmask);
		if (!dst->atrmask)
			return SC_ERROR_OUT_OF_MEMORY;
	} else {
		dst->atrmask = NULL;
	}
	if (src->name) {
		dst->name = strdup(src->name);
		if (!dst->name)
			return SC_ERROR_OUT_OF_MEMORY;
	} else {
		dst->name = NULL;
	}
	dst->type = src->type;
	dst->flags = src->flags;
	dst->card_atr = src->card_atr;
	return SC_SUCCESS;
}

int _sc_free_atr(sc_context_t *ctx, struct sc_card_driver *driver)
{
	unsigned int i;

	for (i = 0; i < driver->natrs; i++) {
		struct sc_atr_table *src = &driver->atr_map[i];

		if (src->atr)
			free(src->atr);
		if (src->atrmask)
			free(src->atrmask);
		if (src->name)
			free(src->name);
		src->card_atr = NULL;
		src = NULL;
	}
	if (driver->atr_map)
		free(driver->atr_map);
	driver->atr_map = NULL;
	driver->natrs = 0;

	return SC_SUCCESS;
}

int _sc_check_forced_protocol(sc_context_t *ctx, u8 *atr, size_t atr_len, unsigned int *protocol)
{
	scconf_block *atrblock = NULL;
	int ok = 0;

	if (!protocol)
		return 0;
	atrblock = _sc_match_atr_block(ctx, NULL, atr, atr_len);
	if (atrblock != NULL) {
		const char *forcestr;

		forcestr = scconf_get_str(atrblock, "force_protocol", "unknown");
		if (!strcmp(forcestr, "t0")) {
			*protocol = SC_PROTO_T0;
			ok = 1;
		} else if (!strcmp(forcestr, "t1")) {
			*protocol = SC_PROTO_T1;
			ok = 1;
		} else if (!strcmp(forcestr, "raw")) {
			*protocol = SC_PROTO_RAW;
			ok = 1;
		}
		if (ok)
			sc_debug(ctx, "force_protocol: %s\n", forcestr);
	}
	return ok;
}

scconf_block *sc_get_conf_block(sc_context_t *ctx, const char *name1, const char *name2, int priority)
{
	int i;
	scconf_block *conf_block = NULL;
	
	for (i = 0; ctx->conf_blocks[i] != NULL; i++) {
		scconf_block **blocks;
		
		blocks = scconf_find_blocks(ctx->conf, ctx->conf_blocks[i], name1, name2);
		if (blocks != NULL) {
			conf_block = blocks[0];
			free(blocks);
		}
		if (conf_block != NULL && priority)
			break;
	}
	return conf_block;
}