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comparison fuzzer-kexdh.c @ 1589:35af85194268

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Add kexdh and kexecdh fuzzers
author Matt Johnston <matt@ucc.asn.au>
date Mon, 05 Mar 2018 11:50:31 +0800
parents
children 46506b32650a
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1588:149a5329d83a 1589:35af85194268
1 #include "fuzz.h"
2 #include "session.h"
3 #include "fuzz-wrapfd.h"
4 #include "debug.h"
5 #include "runopts.h"
6 #include "algo.h"
7 #include "bignum.h"
8
9 int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
10 static int once = 0;
11 static struct key_context* keep_newkeys = NULL;
12 #define NUM_PARAMS 800
13 static struct kex_dh_param *dh_params[NUM_PARAMS];
14
15 if (!once) {
16 fuzz_common_setup();
17 fuzz_svr_setup();
18
19 keep_newkeys = (struct key_context*)m_malloc(sizeof(struct key_context));
20 keep_newkeys->algo_kex = fuzz_get_algo(sshkex, "diffie-hellman-group14-sha256");
21 keep_newkeys->algo_hostkey = DROPBEAR_SIGNKEY_ECDSA_NISTP256;
22 ses.newkeys = keep_newkeys;
23
24 /* Pre-generate parameters */
25 int i;
26 for (i = 0; i < NUM_PARAMS; i++) {
27 dh_params[i] = gen_kexdh_param();
28 }
29
30 once = 1;
31 }
32
33 if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
34 return 0;
35 }
36
37 m_malloc_set_epoch(1);
38
39 if (setjmp(fuzz.jmp) == 0) {
40 /* Based on recv_msg_kexdh_init()/send_msg_kexdh_reply()
41 with DROPBEAR_KEX_NORMAL_DH */
42 ses.newkeys = keep_newkeys;
43
44 /* Choose from the collection of ecdh params */
45 unsigned int e = buf_getint(fuzz.input);
46 struct kex_dh_param * dh_param = dh_params[e % NUM_PARAMS];
47
48 DEF_MP_INT(dh_e);
49 m_mp_init(&dh_e);
50 if (buf_getmpint(fuzz.input, &dh_e) != DROPBEAR_SUCCESS) {
51 dropbear_exit("Bad kex value");
52 }
53
54 ses.kexhashbuf = buf_new(4);
55 buf_putint(ses.kexhashbuf, 12345);
56 kexdh_comb_key(dh_param, &dh_e, svr_opts.hostkey);
57
58 /* kexhashbuf is freed in kexdh_comb_key */
59 m_free(ses.dh_K);
60 mp_clear(&dh_e);
61
62 m_malloc_free_epoch(1, 0);
63 } else {
64 m_malloc_free_epoch(1, 1);
65 TRACE(("dropbear_exit longjmped"))
66 /* dropbear_exit jumped here */
67 }
68
69 return 0;
70 }