/*
 * This module implements the a38 command for exercising
 * the SIM's RUN GSM ALGORITHM operation.
 */

#include <sys/types.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <pcsclite.h>
#include <winscard.h>
#include "globals.h"

static
hexarg_16bytes(arg, databuf)
	char *arg;
	u_char *databuf;
{
	unsigned count;

	for (count = 0; ; count++) {
		while (isspace(*arg))
			arg++;
		if (!*arg)
			break;
		if (!isxdigit(arg[0]) || !isxdigit(arg[1])) {
			fprintf(stderr, "error: invalid hex string input\n");
			return(-1);
		}
		if (count >= 16) {
			fprintf(stderr,
			"error: hex string is longer than required 16 bytes\n");
			return(-1);
		}
		databuf[count] = (decode_hex_digit(arg[0]) << 4) |
				 decode_hex_digit(arg[1]);
		arg += 2;
	}
	if (count < 16) {
		fprintf(stderr,
		"error: hex string is shorter than required 16 bytes\n");
		return(-1);
	}
	return(0);
}

cmd_a38(argc, argv)
	char **argv;
{
	u_char cmd[21];
	int rc;

	/* RUN GSM ALGORITHM command APDU */
	cmd[0] = 0xA0;
	cmd[1] = 0x88;
	cmd[2] = 0;
	cmd[3] = 0;
	cmd[4] = 16;
	rc = hexarg_16bytes(argv[1], cmd + 5);
	if (rc < 0)
		return(rc);
	rc = apdu_exchange(cmd, 21);
	if (rc < 0)
		return(rc);
	if (sim_resp_sw != 0x9F0C) {
		fprintf(stderr,
		"error or unexpected SW response to RUN GSM ALGO: %04X\n",
			sim_resp_sw);
		return(-1);
	}
	/* GET RESPONSE follow-up */
	cmd[1] = 0xC0;
	cmd[4] = 12;
	rc = apdu_exchange(cmd, 5);
	if (rc < 0)
		return(rc);
	if (sim_resp_sw != 0x9000) {
		fprintf(stderr, "bad SW resp to GET RESPONSE: %04X\n",
			sim_resp_sw);
		return(-1);
	}
	if (sim_resp_data_len != 12) {
		fprintf(stderr,
			"error: GET RESPONSE returned %u bytes, expected 12\n",
			sim_resp_data_len);
		return(-1);
	}
	printf("SRES: %02X %02X %02X %02X\n", sim_resp_data[0],
		sim_resp_data[1], sim_resp_data[2], sim_resp_data[3]);
	printf("Kc: %02X %02X %02X %02X %02X %02X %02X %02X\n",
		sim_resp_data[4], sim_resp_data[5], sim_resp_data[6],
		sim_resp_data[7], sim_resp_data[8], sim_resp_data[9],
		sim_resp_data[10], sim_resp_data[11]);
	return(0);
}