/*	$OpenBSD: bn_unit.c,v 1.3 2023/02/14 15:08:15 tb Exp $ */

/*
 * Copyright (c) 2022 Theo Buehler <tb@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <err.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/bn.h>

static int
test_bn_print_wrapper(char *a, size_t size, const char *descr,
    int (*to_bn)(BIGNUM **, const char *))
{
	int ret;

	ret = to_bn(NULL, a);
	if (ret != 0 && (ret < 0 || (size_t)ret != size - 1)) {
		fprintf(stderr, "unexpected %s() return"
		    "want 0 or %zu, got %d\n", descr, size - 1, ret);
		return 1;
	}

	return 0;
}

static int
test_bn_print_null_derefs(void)
{
	size_t size = INT_MAX / 4 + 4;
	size_t datalimit = (size + 500 * 1024) / 1024;
	char *a;
	char digit;
	int failed = 0;

	if ((a = malloc(size)) == NULL) {
		warn("malloc(%zu) failed (make sure data limit is >= %zu KiB)",
		    size, datalimit);
		return 0;
	}

	/* Fill with a random digit since coverity doesn't like us using '0'. */
	digit = '0' + arc4random_uniform(10);

	memset(a, digit, size - 1);
	a[size - 1] = '\0';

	failed |= test_bn_print_wrapper(a, size, "BN_dec2bn", BN_dec2bn);
	failed |= test_bn_print_wrapper(a, size, "BN_hex2bn", BN_hex2bn);

	free(a);

	return failed;
}

static int
test_bn_num_bits_word(void)
{
	BN_ULONG w = 1;
	int i, num_bits;
	int failed = 0;

	if ((num_bits = BN_num_bits_word(0)) != 0) {
		warnx("BN_num_bits_word(0): want 0, got %d", num_bits);
		failed |= 1;
	}

	for (i = 0; i < BN_BITS2; i++) {
		if ((num_bits = BN_num_bits_word(w << i)) != i + 1) {
			warnx("BN_num_bits_word(0x%llx): want %d, got %d",
			    (unsigned long long)(w << i), i + 1, num_bits);
			failed |= 1;
		}
	}

	return failed;
}

int
main(void)
{
	int failed = 0;

	failed |= test_bn_print_null_derefs();
	failed |= test_bn_num_bits_word();

	return failed;
}