2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL licenses, (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 * https://www.openssl.org/source/license.html
8 * or in the file LICENSE in the source distribution.
12 * Confirm that if (d, r) = a / b, then b * d + r == a, and that sign(d) ==
13 * sign(a), and 0 <= r <= b
17 #include <openssl/bn.h>
20 int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) {
37 // We are going to split the buffer in two, sizes l1 and l2, giving b1 and
39 size_t l1 = 0, l2 = 0;
40 // s1 and s2 will be the signs for b1 and b2.
44 // Use first byte to divide the remaining buffer into 3Fths. I admit
45 // this disallows some number sizes. If it matters, better ideas are
47 l1 = ((buf[0] & 0x3f) * len) / 0x3f;
53 OPENSSL_assert(BN_bin2bn(buf, l1, b1) == b1);
54 BN_set_negative(b1, s1);
55 OPENSSL_assert(BN_bin2bn(buf + l1, l2, b2) == b2);
56 BN_set_negative(b2, s2);
58 // divide by 0 is an error
64 OPENSSL_assert(BN_div(b3, b4, b1, b2, ctx));
66 success = BN_is_zero(b3) && BN_is_zero(b4);
67 else if (BN_is_negative(b1))
68 success = (BN_is_negative(b3) != BN_is_negative(b2) || BN_is_zero(b3))
69 && (BN_is_negative(b4) || BN_is_zero(b4));
71 success = (BN_is_negative(b3) == BN_is_negative(b2) || BN_is_zero(b3))
72 && (!BN_is_negative(b4) || BN_is_zero(b4));
73 OPENSSL_assert(BN_mul(b5, b3, b2, ctx));
74 OPENSSL_assert(BN_add(b5, b5, b4));
76 success = success && BN_cmp(b5, b1) == 0;
78 BN_print_fp(stdout, b1);
80 BN_print_fp(stdout, b2);
82 BN_print_fp(stdout, b3);
84 BN_print_fp(stdout, b4);
86 BN_print_fp(stdout, b5);
88 printf("%d %d %d %d %d %d %d\n", BN_is_negative(b1),
90 BN_is_negative(b3), BN_is_negative(b4), BN_is_zero(b4),
91 BN_is_negative(b3) != BN_is_negative(b2)
92 && (BN_is_negative(b4) || BN_is_zero(b4)),
98 OPENSSL_assert(success);