1 /* $OpenBSD: test_sshbuf_fuzz.c,v 1.4 2021/12/18 06:53:59 anton Exp $ */
2 /*
3 * Regress test for sshbuf.h buffer API
4 *
5 * Placed in the public domain
6 */
7
8 #include <sys/types.h>
9 #include <stdio.h>
10 #include <stdint.h>
11 #include <stdlib.h>
12 #include <string.h>
13
14 #include "test_helper.h"
15
16 #include "ssherr.h"
17 #include "sshbuf.h"
18
19 #define NUM_FUZZ_TESTS (1 << 18)
20
21 void sshbuf_fuzz_tests(void);
22
23 void
sshbuf_fuzz_tests(void)24 sshbuf_fuzz_tests(void)
25 {
26 struct sshbuf *p1;
27 u_char *dp;
28 size_t sz, sz2, i, ntests = NUM_FUZZ_TESTS;
29 u_int32_t r;
30 int ret;
31
32 if (test_is_fast())
33 ntests >>= 2;
34 if (test_is_slow())
35 ntests <<= 2;
36
37 /* NB. uses sshbuf internals */
38 TEST_START("fuzz alloc/dealloc");
39 p1 = sshbuf_new();
40 ASSERT_INT_EQ(sshbuf_set_max_size(p1, 16 * 1024), 0);
41 ASSERT_PTR_NE(p1, NULL);
42 ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
43 ASSERT_MEM_ZERO_NE(sshbuf_ptr(p1), sshbuf_len(p1));
44 for (i = 0; i < ntests; i++) {
45 r = arc4random_uniform(10);
46 if (r == 0) {
47 /* 10% chance: small reserve */
48 r = arc4random_uniform(10);
49 fuzz_reserve:
50 sz = sshbuf_avail(p1);
51 sz2 = sshbuf_len(p1);
52 ret = sshbuf_reserve(p1, r, &dp);
53 if (ret < 0) {
54 ASSERT_PTR_EQ(dp, NULL);
55 ASSERT_SIZE_T_LT(sz, r);
56 ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz);
57 ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2);
58 } else {
59 ASSERT_PTR_NE(dp, NULL);
60 ASSERT_SIZE_T_GE(sz, r);
61 ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz - r);
62 ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2 + r);
63 memset(dp, arc4random_uniform(255) + 1, r);
64 }
65 } else if (r < 3) {
66 /* 20% chance: big reserve */
67 r = arc4random_uniform(8 * 1024);
68 goto fuzz_reserve;
69 } else if (r == 3) {
70 /* 10% chance: small consume */
71 r = arc4random_uniform(10);
72 fuzz_consume:
73 sz = sshbuf_avail(p1);
74 sz2 = sshbuf_len(p1);
75 /* 50% change consume from end, otherwise start */
76 ret = ((arc4random() & 1) ?
77 sshbuf_consume : sshbuf_consume_end)(p1, r);
78 if (ret < 0) {
79 ASSERT_SIZE_T_LT(sz2, r);
80 ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz);
81 ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2);
82 } else {
83 ASSERT_SIZE_T_GE(sz2, r);
84 ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz + r);
85 ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2 - r);
86 }
87 } else if (r < 8) {
88 /* 40% chance: big consume */
89 r = arc4random_uniform(2 * 1024);
90 goto fuzz_consume;
91 } else if (r == 8) {
92 /* 10% chance: reset max size */
93 r = arc4random_uniform(16 * 1024);
94 sz = sshbuf_max_size(p1);
95 if (sshbuf_set_max_size(p1, r) < 0)
96 ASSERT_SIZE_T_EQ(sshbuf_max_size(p1), sz);
97 else
98 ASSERT_SIZE_T_EQ(sshbuf_max_size(p1), r);
99 } else {
100 if (arc4random_uniform(8192) == 0) {
101 /* tiny chance: new buffer */
102 ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
103 ASSERT_MEM_ZERO_NE(sshbuf_ptr(p1), sshbuf_len(p1));
104 sshbuf_free(p1);
105 p1 = sshbuf_new();
106 ASSERT_PTR_NE(p1, NULL);
107 ASSERT_INT_EQ(sshbuf_set_max_size(p1,
108 16 * 1024), 0);
109 } else {
110 /* Almost 10%: giant reserve */
111 /* use arc4random_buf for r > 2^32 on 64 bit */
112 arc4random_buf(&r, sizeof(r));
113 while (r < SSHBUF_SIZE_MAX / 2) {
114 r <<= 1;
115 r |= arc4random() & 1;
116 }
117 goto fuzz_reserve;
118 }
119 }
120 ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
121 ASSERT_SIZE_T_LE(sshbuf_max_size(p1), 16 * 1024);
122 }
123 ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
124 ASSERT_MEM_ZERO_NE(sshbuf_ptr(p1), sshbuf_len(p1));
125 sshbuf_free(p1);
126 TEST_DONE();
127 }
128