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#include "includes.h"
#include "includes.h"
#include "fuzz.h"
#include "dbutil.h"
#include "runopts.h"
#include "crypto_desc.h"
#include "session.h"
#include "dbrandom.h"
#include "bignum.h"
#include "fuzz-wrapfd.h"
struct dropbear_fuzz_options fuzz;
static void fuzz_dropbear_log(int UNUSED(priority), const char* format, va_list param);
static void load_fixed_hostkeys(void);
void fuzz_common_setup(void) {
fuzz.fuzzing = 1;
fuzz.wrapfds = 1;
fuzz.do_jmp = 1;
fuzz.input = m_malloc(sizeof(buffer));
_dropbear_log = fuzz_dropbear_log;
crypto_init();
fuzz_seed();
/* let any messages get flushed */
setlinebuf(stdout);
}
int fuzz_set_input(const uint8_t *Data, size_t Size) {
fuzz.input->data = (unsigned char*)Data;
fuzz.input->size = Size;
fuzz.input->len = Size;
fuzz.input->pos = 0;
memset(&ses, 0x0, sizeof(ses));
memset(&svr_ses, 0x0, sizeof(svr_ses));
wrapfd_setup();
fuzz_seed();
return DROPBEAR_SUCCESS;
}
#if DEBUG_TRACE
static void fuzz_dropbear_log(int UNUSED(priority), const char* format, va_list param) {
if (debug_trace) {
char printbuf[1024];
vsnprintf(printbuf, sizeof(printbuf), format, param);
fprintf(stderr, "%s\n", printbuf);
}
}
#else
static void fuzz_dropbear_log(int UNUSED(priority), const char* UNUSED(format), va_list UNUSED(param)) {
/* No print */
}
#endif /* DEBUG_TRACE */
void fuzz_svr_setup(void) {
fuzz_common_setup();
_dropbear_exit = svr_dropbear_exit;
char *argv[] = {
"-E",
};
int argc = sizeof(argv) / sizeof(*argv);
svr_getopts(argc, argv);
/* user lookups might be slow, cache it */
fuzz.pw_name = m_strdup("person");
fuzz.pw_dir = m_strdup("/tmp");
fuzz.pw_shell = m_strdup("/bin/zsh");
fuzz.pw_passwd = m_strdup("!!zzznope");
load_fixed_hostkeys();
}
static void load_fixed_hostkeys(void) {
#include "fuzz-hostkeys.c"
buffer *b = buf_new(3000);
enum signkey_type type;
TRACE(("load fixed hostkeys"))
svr_opts.hostkey = new_sign_key();
buf_setlen(b, 0);
buf_putbytes(b, keyr, keyr_len);
buf_setpos(b, 0);
type = DROPBEAR_SIGNKEY_RSA;
if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
dropbear_exit("failed fixed rsa hostkey");
}
buf_setlen(b, 0);
buf_putbytes(b, keyd, keyd_len);
buf_setpos(b, 0);
type = DROPBEAR_SIGNKEY_DSS;
if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
dropbear_exit("failed fixed dss hostkey");
}
buf_setlen(b, 0);
buf_putbytes(b, keye, keye_len);
buf_setpos(b, 0);
type = DROPBEAR_SIGNKEY_ECDSA_NISTP256;
if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
dropbear_exit("failed fixed ecdsa hostkey");
}
buf_free(b);
}
void fuzz_kex_fakealgos(void) {
ses.newkeys->recv.crypt_mode = &dropbear_mode_none;
}
void fuzz_get_socket_address(int UNUSED(fd), char **local_host, char **local_port,
char **remote_host, char **remote_port, int UNUSED(host_lookup)) {
if (local_host) {
*local_host = m_strdup("fuzzlocalhost");
}
if (local_port) {
*local_port = m_strdup("1234");
}
if (remote_host) {
*remote_host = m_strdup("fuzzremotehost");
}
if (remote_port) {
*remote_port = m_strdup("9876");
}
}
/* cut down version of svr_send_msg_kexdh_reply() that skips slow maths. Still populates structures */
void fuzz_fake_send_kexdh_reply(void) {
assert(!ses.dh_K);
m_mp_alloc_init_multi(&ses.dh_K, NULL);
mp_set_int(ses.dh_K, 12345678);
finish_kexhashbuf();
}
int fuzz_run_preauth(const uint8_t *Data, size_t Size, int skip_kexmaths) {
static int once = 0;
if (!once) {
fuzz_svr_setup();
fuzz.skip_kexmaths = skip_kexmaths;
once = 1;
}
if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
return 0;
}
/*
get prefix. input format is
string prefix
uint32 wrapfd seed
... to be extended later
[bytes] ssh input stream
*/
/* be careful to avoid triggering buffer.c assertions */
if (fuzz.input->len < 8) {
return 0;
}
size_t prefix_size = buf_getint(fuzz.input);
if (prefix_size != 4) {
return 0;
}
uint32_t wrapseed = buf_getint(fuzz.input);
wrapfd_setseed(wrapseed);
int fakesock = 20;
wrapfd_add(fakesock, fuzz.input, PLAIN);
m_malloc_set_epoch(1);
if (setjmp(fuzz.jmp) == 0) {
svr_session(fakesock, fakesock);
m_malloc_free_epoch(1, 0);
} else {
m_malloc_free_epoch(1, 1);
TRACE(("dropbear_exit longjmped"))
/* dropbear_exit jumped here */
}
return 0;
}
const void* fuzz_get_algo(const algo_type *algos, const char* name) {
const algo_type *t;
for (t = algos; t->name; t++) {
if (strcmp(t->name, name) == 0) {
return t->data;
}
}
assert(0);
}
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