Mercurial > dropbear
annotate fuzzer-kexecdh.c @ 1593:c8c20fb57a9a
Don't read uninitialised value.
From https://github.com/libtom/libtommath/commit/1d03522625f46214733e8e143a4765c01fc146f9
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Mon, 05 Mar 2018 16:50:24 +0800 |
| parents | 46506b32650a |
| children | 4fe7cc9e45eb |
| rev | line source |
|---|---|
| 1589 | 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 const struct dropbear_kex *ecdh[3]; /* 256, 384, 521 */ | |
| 12 static struct key_context* keep_newkeys = NULL; | |
|
1592
46506b32650a
reduce number of params so it doesn't hit a timeout
Matt Johnston <matt@ucc.asn.au>
parents:
1589
diff
changeset
|
13 /* number of generated parameters is limited by the timeout for the first run */ |
|
46506b32650a
reduce number of params so it doesn't hit a timeout
Matt Johnston <matt@ucc.asn.au>
parents:
1589
diff
changeset
|
14 #define NUM_PARAMS 300 |
| 1589 | 15 static struct kex_ecdh_param *ecdh_params[NUM_PARAMS]; |
| 16 | |
| 17 if (!once) { | |
| 18 fuzz_common_setup(); | |
| 19 fuzz_svr_setup(); | |
| 20 | |
| 21 /* ses gets zeroed by fuzz_set_input */ | |
| 22 keep_newkeys = (struct key_context*)m_malloc(sizeof(struct key_context)); | |
| 23 ecdh[0] = fuzz_get_algo(sshkex, "ecdh-sha2-nistp256"); | |
| 24 ecdh[1] = fuzz_get_algo(sshkex, "ecdh-sha2-nistp384"); | |
| 25 ecdh[2] = fuzz_get_algo(sshkex, "ecdh-sha2-nistp521"); | |
| 26 assert(ecdh[0]); | |
| 27 assert(ecdh[1]); | |
| 28 assert(ecdh[2]); | |
| 29 keep_newkeys->algo_hostkey = DROPBEAR_SIGNKEY_ECDSA_NISTP256; | |
| 30 ses.newkeys = keep_newkeys; | |
| 31 | |
| 32 /* Pre-generate parameters */ | |
| 33 int i; | |
| 34 for (i = 0; i < NUM_PARAMS; i++) { | |
| 35 ses.newkeys->algo_kex = ecdh[i % 3]; | |
| 36 ecdh_params[i] = gen_kexecdh_param(); | |
| 37 } | |
| 38 | |
| 39 once = 1; | |
| 40 } | |
| 41 | |
| 42 if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) { | |
| 43 return 0; | |
| 44 } | |
| 45 | |
| 46 m_malloc_set_epoch(1); | |
| 47 | |
| 48 if (setjmp(fuzz.jmp) == 0) { | |
| 49 /* Based on recv_msg_kexdh_init()/send_msg_kexdh_reply() | |
| 50 with DROPBEAR_KEX_ECDH */ | |
| 51 ses.newkeys = keep_newkeys; | |
| 52 | |
| 53 /* random choice of ecdh 256, 384, 521 */ | |
| 54 unsigned char b = buf_getbyte(fuzz.input); | |
| 55 ses.newkeys->algo_kex = ecdh[b % 3]; | |
| 56 | |
| 57 /* Choose from the collection of ecdh params */ | |
| 58 unsigned int e = buf_getint(fuzz.input); | |
| 59 struct kex_ecdh_param *ecdh_param = ecdh_params[e % NUM_PARAMS]; | |
| 60 | |
| 61 buffer * ecdh_qs = buf_getstringbuf(fuzz.input); | |
| 62 | |
| 63 ses.kexhashbuf = buf_new(4); | |
| 64 buf_putint(ses.kexhashbuf, 12345); | |
| 65 kexecdh_comb_key(ecdh_param, ecdh_qs, svr_opts.hostkey); | |
| 66 | |
| 67 /* kexhashbuf is freed in kexdh_comb_key */ | |
| 68 m_free(ses.dh_K); | |
| 69 buf_free(ecdh_qs); | |
| 70 | |
| 71 m_malloc_free_epoch(1, 0); | |
| 72 } else { | |
| 73 m_malloc_free_epoch(1, 1); | |
| 74 TRACE(("dropbear_exit longjmped")) | |
| 75 /* dropbear_exit jumped here */ | |
| 76 } | |
| 77 | |
| 78 return 0; | |
| 79 } |