xref: /freebsd/crypto/openssh/regress/unittests/sshbuf/test_sshbuf_fuzz.c (revision 3332f1b444d4a73238e9f59cca27bfc95fe936bd)
1 /* 	$OpenBSD: test_sshbuf_fuzz.c,v 1.2 2018/10/17 23:28:05 djm Exp $ */
2 /*
3  * Regress test for sshbuf.h buffer API
4  *
5  * Placed in the public domain
6  */
7 
8 #include "includes.h"
9 
10 #include <sys/types.h>
11 #include <sys/param.h>
12 #include <stdio.h>
13 #ifdef HAVE_STDINT_H
14 # include <stdint.h>
15 #endif
16 #include <stdlib.h>
17 #include <string.h>
18 
19 #include "../test_helper/test_helper.h"
20 
21 #include "ssherr.h"
22 #include "sshbuf.h"
23 
24 #define NUM_FUZZ_TESTS (1 << 18)
25 
26 void sshbuf_fuzz_tests(void);
27 
28 void
29 sshbuf_fuzz_tests(void)
30 {
31 	struct sshbuf *p1;
32 	u_char *dp;
33 	size_t sz, sz2, i, ntests = NUM_FUZZ_TESTS;
34 	u_int32_t r;
35 	int ret;
36 
37 	if (test_is_fast())
38 		ntests >>= 2;
39 	if (test_is_slow())
40 		ntests <<= 2;
41 
42 	/* NB. uses sshbuf internals */
43 	TEST_START("fuzz alloc/dealloc");
44 	p1 = sshbuf_new();
45 	ASSERT_INT_EQ(sshbuf_set_max_size(p1, 16 * 1024), 0);
46 	ASSERT_PTR_NE(p1, NULL);
47 	ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
48 	ASSERT_MEM_ZERO_NE(sshbuf_ptr(p1), sshbuf_len(p1));
49 	for (i = 0; i < NUM_FUZZ_TESTS; i++) {
50 		r = arc4random_uniform(10);
51 		if (r == 0) {
52 			/* 10% chance: small reserve */
53 			r = arc4random_uniform(10);
54  fuzz_reserve:
55 			sz = sshbuf_avail(p1);
56 			sz2 = sshbuf_len(p1);
57 			ret = sshbuf_reserve(p1, r, &dp);
58 			if (ret < 0) {
59 				ASSERT_PTR_EQ(dp, NULL);
60 				ASSERT_SIZE_T_LT(sz, r);
61 				ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz);
62 				ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2);
63 			} else {
64 				ASSERT_PTR_NE(dp, NULL);
65 				ASSERT_SIZE_T_GE(sz, r);
66 				ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz - r);
67 				ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2 + r);
68 				memset(dp, arc4random_uniform(255) + 1, r);
69 			}
70 		} else if (r < 3) {
71 			/* 20% chance: big reserve */
72 			r = arc4random_uniform(8 * 1024);
73 			goto fuzz_reserve;
74 		} else if (r == 3) {
75 			/* 10% chance: small consume */
76 			r = arc4random_uniform(10);
77  fuzz_consume:
78 			sz = sshbuf_avail(p1);
79 			sz2 = sshbuf_len(p1);
80 			/* 50% change consume from end, otherwise start */
81 			ret = ((arc4random() & 1) ?
82 			    sshbuf_consume : sshbuf_consume_end)(p1, r);
83 			if (ret < 0) {
84 				ASSERT_SIZE_T_LT(sz2, r);
85 				ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz);
86 				ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2);
87 			} else {
88 				ASSERT_SIZE_T_GE(sz2, r);
89 				ASSERT_SIZE_T_EQ(sshbuf_avail(p1), sz + r);
90 				ASSERT_SIZE_T_EQ(sshbuf_len(p1), sz2 - r);
91 			}
92 		} else if (r < 8) {
93 			/* 40% chance: big consume */
94 			r = arc4random_uniform(2 * 1024);
95 			goto fuzz_consume;
96 		} else if (r == 8) {
97 			/* 10% chance: reset max size */
98 			r = arc4random_uniform(16 * 1024);
99 			sz = sshbuf_max_size(p1);
100 			if (sshbuf_set_max_size(p1, r) < 0)
101 				ASSERT_SIZE_T_EQ(sshbuf_max_size(p1), sz);
102 			else
103 				ASSERT_SIZE_T_EQ(sshbuf_max_size(p1), r);
104 		} else {
105 			if (arc4random_uniform(8192) == 0) {
106 				/* tiny chance: new buffer */
107 				ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
108 				ASSERT_MEM_ZERO_NE(sshbuf_ptr(p1), sshbuf_len(p1));
109 				sshbuf_free(p1);
110 				p1 = sshbuf_new();
111 				ASSERT_PTR_NE(p1, NULL);
112 				ASSERT_INT_EQ(sshbuf_set_max_size(p1,
113 				    16 * 1024), 0);
114 			} else {
115 				/* Almost 10%: giant reserve */
116 				/* use arc4random_buf for r > 2^32 on 64 bit */
117 				arc4random_buf(&r, sizeof(r));
118 				while (r < SSHBUF_SIZE_MAX / 2) {
119 					r <<= 1;
120 					r |= arc4random() & 1;
121 				}
122 				goto fuzz_reserve;
123 			}
124 		}
125 		ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
126 		ASSERT_SIZE_T_LE(sshbuf_max_size(p1), 16 * 1024);
127 	}
128 	ASSERT_PTR_NE(sshbuf_ptr(p1), NULL);
129 	ASSERT_MEM_ZERO_NE(sshbuf_ptr(p1), sshbuf_len(p1));
130 	sshbuf_free(p1);
131 	TEST_DONE();
132 }
133