view miscutil/make-imeisv.c @ 1011:6d9b10633f10

etmsync Pirelli IMEI retrieval: fix poor use of printf() Bug reported by Vadim Yanitskiy <fixeria@osmocom.org>: the construct where a static-allocated string was passed to printf() without any format arguments causes newer compilers to report a security problem. Given that formatted output is not needed here, just fixed string output, change printf() to fputs(), and direct the error message to stderr while at it.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 23 May 2024 17:29:57 +0000
parents 2dcfad8a3ed0
children
line wrap: on
line source

/*
 * This utility constructs a 16-digit IMEISV from a 15-digit IMEI
 * (which must have a valid Luhn check digit) and a 2-digit SV field.
 * It is intended for use in shell scripts.
 */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>

parse_imei_arg(input, buf)
	char *input, *buf;
{
	char *cp;
	int i;

	cp = input;
	if (!isdigit(*cp)) {
inv:		fprintf(stderr,
			"error: IMEI argument must have 15 decimal digits\n");
		exit(1);
	}
	for (i = 0; i < 15; i++) {
		if (ispunct(*cp))
			cp++;
		if (!isdigit(*cp))
			goto inv;
		buf[i] = *cp++;
	}
	if (*cp)
		goto inv;
}

check_luhn(digits)
	char *digits;
{
	int i, dig, sum;

	sum = 0;
	for (i = 0; i < 14; i++) {
		dig = digits[i] - '0';
		if (i & 1) {
			dig *= 2;
			if (dig > 9)
				dig -= 9;
		}
		sum += dig;
	}
	dig = sum % 10;
	if (dig)
		dig = 10 - dig;
	if (digits[14] != dig + '0') {
		fprintf(stderr, "error: given IMEI fails Luhn check\n");
		exit(1);
	}
}

main(argc, argv)
	char **argv;
{
	char imeibuf[15];

	if (argc != 3) {
		fprintf(stderr, "usage: %s IMEI SV\n", argv[0]);
		exit(1);
	}
	parse_imei_arg(argv[1], imeibuf);
	check_luhn(imeibuf);
	if (!isdigit(argv[2][0]) || !isdigit(argv[2][1]) || argv[2][2]) {
		fprintf(stderr,
			"error: SV argument must have 2 decimal digits\n");
		exit(1);
	}
	printf("%.8s-%.6s-%s\n", imeibuf, imeibuf + 8, argv[2]);
	exit(0);
}