xref: /freebsd/contrib/libfido2/fuzz/fuzz_netlink.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*
2  * Copyright (c) 2020 Yubico AB. All rights reserved.
3  * Use of this source code is governed by a BSD-style
4  * license that can be found in the LICENSE file.
5  */
6 
7 #include <assert.h>
8 #include <stdint.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <stdio.h>
12 
13 #include "../openbsd-compat/openbsd-compat.h"
14 #include "mutator_aux.h"
15 #include "dummy.h"
16 
17 struct param {
18 	int seed;
19 	int dev;
20 	struct blob wiredata;
21 };
22 
23 struct param *
24 unpack(const uint8_t *ptr, size_t len)
25 {
26 	cbor_item_t *item = NULL, **v;
27 	struct cbor_load_result cbor;
28 	struct param *p;
29 	int ok = -1;
30 
31 	if ((p = calloc(1, sizeof(*p))) == NULL ||
32 	    (item = cbor_load(ptr, len, &cbor)) == NULL ||
33 	    cbor.read != len ||
34 	    cbor_isa_array(item) == false ||
35 	    cbor_array_is_definite(item) == false ||
36 	    cbor_array_size(item) != 3 ||
37 	    (v = cbor_array_handle(item)) == NULL)
38 		goto fail;
39 
40 	if (unpack_int(v[0], &p->seed) < 0 ||
41 	    unpack_int(v[1], &p->dev) < 0 ||
42 	    unpack_blob(v[2], &p->wiredata) < 0)
43 		goto fail;
44 
45 	ok = 0;
46 fail:
47 	if (ok < 0) {
48 		free(p);
49 		p = NULL;
50 	}
51 
52 	if (item)
53 		cbor_decref(&item);
54 
55 	return p;
56 }
57 
58 size_t
59 pack(uint8_t *ptr, size_t len, const struct param *p)
60 {
61 	cbor_item_t *argv[3], *array = NULL;
62 	size_t cbor_alloc_len, cbor_len = 0;
63 	unsigned char *cbor = NULL;
64 
65 	memset(argv, 0, sizeof(argv));
66 
67 	if ((array = cbor_new_definite_array(3)) == NULL ||
68 	    (argv[0] = pack_int(p->seed)) == NULL ||
69 	    (argv[1] = pack_int(p->dev)) == NULL ||
70 	    (argv[2] = pack_blob(&p->wiredata)) == NULL)
71 		goto fail;
72 
73 	for (size_t i = 0; i < 3; i++)
74 		if (cbor_array_push(array, argv[i]) == false)
75 			goto fail;
76 
77 	if ((cbor_len = cbor_serialize_alloc(array, &cbor,
78 	    &cbor_alloc_len)) > len) {
79 		cbor_len = 0;
80 		goto fail;
81 	}
82 
83 	memcpy(ptr, cbor, cbor_len);
84 fail:
85 	for (size_t i = 0; i < 3; i++)
86 		if (argv[i])
87 			cbor_decref(&argv[i]);
88 
89 	if (array)
90 		cbor_decref(&array);
91 
92 	free(cbor);
93 
94 	return cbor_len;
95 }
96 
97 size_t
98 pack_dummy(uint8_t *ptr, size_t len)
99 {
100 	struct param dummy;
101 	uint8_t	blob[4096];
102 	size_t blob_len;
103 
104 	memset(&dummy, 0, sizeof(dummy));
105 
106 	dummy.wiredata.len = sizeof(dummy_netlink_wiredata);
107 	memcpy(&dummy.wiredata.body, &dummy_netlink_wiredata,
108 	    dummy.wiredata.len);
109 
110 	assert((blob_len = pack(blob, sizeof(blob), &dummy)) != 0);
111 
112 	if (blob_len > len) {
113 		memcpy(ptr, blob, len);
114 		return len;
115 	}
116 
117 	memcpy(ptr, blob, blob_len);
118 
119 	return blob_len;
120 }
121 
122 void
123 test(const struct param *p)
124 {
125 	fido_nl_t *nl;
126 	uint32_t target;
127 
128 	prng_init((unsigned int)p->seed);
129 	fuzz_clock_reset();
130 	fido_init(FIDO_DEBUG);
131 	fido_set_log_handler(consume_str);
132 
133 	set_netlink_io_functions(fd_read, fd_write);
134 	set_wire_data(p->wiredata.body, p->wiredata.len);
135 
136 	if ((nl = fido_nl_new()) == NULL)
137 		return;
138 
139 	consume(&nl->fd, sizeof(nl->fd));
140 	consume(&nl->nfc_type, sizeof(nl->nfc_type));
141 	consume(&nl->nfc_mcastgrp, sizeof(nl->nfc_mcastgrp));
142 	consume(&nl->saddr, sizeof(nl->saddr));
143 
144 	fido_nl_power_nfc(nl, (uint32_t)p->dev);
145 
146 	if (fido_nl_get_nfc_target(nl, (uint32_t)p->dev, &target) == 0)
147 		consume(&target, sizeof(target));
148 
149 	fido_nl_free(&nl);
150 }
151 
152 void
153 mutate(struct param *p, unsigned int seed, unsigned int flags) NO_MSAN
154 {
155 	if (flags & MUTATE_SEED)
156 		p->seed = (int)seed;
157 
158 	if (flags & MUTATE_PARAM)
159 		mutate_int(&p->dev);
160 
161 	if (flags & MUTATE_WIREDATA)
162 		mutate_blob(&p->wiredata);
163 }
164