Mercurial > dropbear
annotate fuzzer-kexdh.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 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
|
12 /* 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
|
13 #define NUM_PARAMS 300 |
| 1589 | 14 static struct kex_dh_param *dh_params[NUM_PARAMS]; |
| 15 | |
| 16 if (!once) { | |
| 17 fuzz_common_setup(); | |
| 18 fuzz_svr_setup(); | |
| 19 | |
| 20 keep_newkeys = (struct key_context*)m_malloc(sizeof(struct key_context)); | |
| 21 keep_newkeys->algo_kex = fuzz_get_algo(sshkex, "diffie-hellman-group14-sha256"); | |
| 22 keep_newkeys->algo_hostkey = DROPBEAR_SIGNKEY_ECDSA_NISTP256; | |
| 23 ses.newkeys = keep_newkeys; | |
| 24 | |
| 25 /* Pre-generate parameters */ | |
| 26 int i; | |
| 27 for (i = 0; i < NUM_PARAMS; i++) { | |
| 28 dh_params[i] = gen_kexdh_param(); | |
| 29 } | |
| 30 | |
| 31 once = 1; | |
| 32 } | |
| 33 | |
| 34 if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) { | |
| 35 return 0; | |
| 36 } | |
| 37 | |
| 38 m_malloc_set_epoch(1); | |
| 39 | |
| 40 if (setjmp(fuzz.jmp) == 0) { | |
| 41 /* Based on recv_msg_kexdh_init()/send_msg_kexdh_reply() | |
| 42 with DROPBEAR_KEX_NORMAL_DH */ | |
| 43 ses.newkeys = keep_newkeys; | |
| 44 | |
| 45 /* Choose from the collection of ecdh params */ | |
| 46 unsigned int e = buf_getint(fuzz.input); | |
| 47 struct kex_dh_param * dh_param = dh_params[e % NUM_PARAMS]; | |
| 48 | |
| 49 DEF_MP_INT(dh_e); | |
| 50 m_mp_init(&dh_e); | |
| 51 if (buf_getmpint(fuzz.input, &dh_e) != DROPBEAR_SUCCESS) { | |
| 52 dropbear_exit("Bad kex value"); | |
| 53 } | |
| 54 | |
| 55 ses.kexhashbuf = buf_new(4); | |
| 56 buf_putint(ses.kexhashbuf, 12345); | |
| 57 kexdh_comb_key(dh_param, &dh_e, svr_opts.hostkey); | |
| 58 | |
| 59 /* kexhashbuf is freed in kexdh_comb_key */ | |
| 60 m_free(ses.dh_K); | |
| 61 mp_clear(&dh_e); | |
| 62 | |
| 63 m_malloc_free_epoch(1, 0); | |
| 64 } else { | |
| 65 m_malloc_free_epoch(1, 1); | |
| 66 TRACE(("dropbear_exit longjmped")) | |
| 67 /* dropbear_exit jumped here */ | |
| 68 } | |
| 69 | |
| 70 return 0; | |
| 71 } |