Mercurial > dropbear
annotate fuzzer-kexecdh.c @ 1629:258b57b208ae
Fix for issue successfull login of disabled user (#78)
This commit introduces fix for scenario:
1. Root login disabled on dropbear
2. PAM authentication model enabled
While login as root user, after prompt for password
user is being notified about login failrue, but
after second attempt of prompt for password within
same session, login becames succesfull.
Signed-off-by: Pawel Rapkiewicz <[email protected]>
| author | vincentto13 <33652988+vincentto13@users.noreply.github.com> |
|---|---|
| date | Wed, 20 Mar 2019 15:03:40 +0100 |
| parents | a57822db3eac |
| children |
| 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 */ |
|
1595
4fe7cc9e45eb
reduce number of dh parameters so fuzzer doesn't timeout
Matt Johnston <matt@ucc.asn.au>
parents:
1592
diff
changeset
|
14 #define NUM_PARAMS 80 |
| 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 | |
|
1606
98d2b125eb89
kexhashbuf was much to small in kex fuzzers
Matt Johnston <matt@ucc.asn.au>
parents:
1595
diff
changeset
|
63 ses.kexhashbuf = buf_new(KEXHASHBUF_MAX_INTS); |
| 1589 | 64 kexecdh_comb_key(ecdh_param, ecdh_qs, svr_opts.hostkey); |
| 65 | |
| 1609 | 66 mp_clear(ses.dh_K); |
| 1589 | 67 m_free(ses.dh_K); |
| 68 buf_free(ecdh_qs); | |
| 69 | |
| 1609 | 70 buf_free(ses.hash); |
| 71 buf_free(ses.session_id); | |
| 72 /* kexhashbuf is freed in kexdh_comb_key */ | |
| 73 | |
| 1589 | 74 m_malloc_free_epoch(1, 0); |
| 75 } else { | |
| 76 m_malloc_free_epoch(1, 1); | |
| 77 TRACE(("dropbear_exit longjmped")) | |
| 78 /* dropbear_exit jumped here */ | |
| 79 } | |
| 80 | |
| 81 return 0; | |
| 82 } |