1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/*
* Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL licenses, (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* https://www.openssl.org/source/license.html
* or in the file LICENSE in the source distribution.
*/
/*
* Confirm that if (d, r) = a / b, then b * d + r == a, and that sign(d) ==
* sign(a), and 0 <= r <= b
*/
#include <stdio.h>
#include <openssl/bn.h>
#include "fuzzer.h"
int FuzzerInitialize(int *argc, char ***argv) {
return 1;
}
int FuzzerTestOneInput(const uint8_t *buf, size_t len) {
static BN_CTX *ctx;
static BIGNUM *b1;
static BIGNUM *b2;
static BIGNUM *b3;
static BIGNUM *b4;
static BIGNUM *b5;
int success = 0;
size_t l1 = 0, l2 = 0;
/* s1 and s2 will be the signs for b1 and b2. */
int s1 = 0, s2 = 0;
if (ctx == NULL) {
b1 = BN_new();
b2 = BN_new();
b3 = BN_new();
b4 = BN_new();
b5 = BN_new();
ctx = BN_CTX_new();
}
/* We are going to split the buffer in two, sizes l1 and l2, giving b1 and
* b2.
*/
if (len > 0) {
--len;
/* Use first byte to divide the remaining buffer into 3Fths. I admit
* this disallows some number sizes. If it matters, better ideas are
* welcome (Ben).
*/
l1 = ((buf[0] & 0x3f) * len) / 0x3f;
s1 = buf[0] & 0x40;
s2 = buf[0] & 0x80;
++buf;
l2 = len - l1;
}
OPENSSL_assert(BN_bin2bn(buf, l1, b1) == b1);
BN_set_negative(b1, s1);
OPENSSL_assert(BN_bin2bn(buf + l1, l2, b2) == b2);
BN_set_negative(b2, s2);
/* divide by 0 is an error */
if (BN_is_zero(b2)) {
success = 1;
goto done;
}
OPENSSL_assert(BN_div(b3, b4, b1, b2, ctx));
if (BN_is_zero(b1))
success = BN_is_zero(b3) && BN_is_zero(b4);
else if (BN_is_negative(b1))
success = (BN_is_negative(b3) != BN_is_negative(b2) || BN_is_zero(b3))
&& (BN_is_negative(b4) || BN_is_zero(b4));
else
success = (BN_is_negative(b3) == BN_is_negative(b2) || BN_is_zero(b3))
&& (!BN_is_negative(b4) || BN_is_zero(b4));
OPENSSL_assert(BN_mul(b5, b3, b2, ctx));
OPENSSL_assert(BN_add(b5, b5, b4));
success = success && BN_cmp(b5, b1) == 0;
if (!success) {
BN_print_fp(stdout, b1);
putchar('\n');
BN_print_fp(stdout, b2);
putchar('\n');
BN_print_fp(stdout, b3);
putchar('\n');
BN_print_fp(stdout, b4);
putchar('\n');
BN_print_fp(stdout, b5);
putchar('\n');
printf("%d %d %d %d %d %d %d\n", BN_is_negative(b1),
BN_is_negative(b2),
BN_is_negative(b3), BN_is_negative(b4), BN_is_zero(b4),
BN_is_negative(b3) != BN_is_negative(b2)
&& (BN_is_negative(b4) || BN_is_zero(b4)),
BN_cmp(b5, b1));
puts("----\n");
}
done:
OPENSSL_assert(success);
return 0;
}
|
