/src/hpn-ssh/regress/misc/fuzz-harness/kex_fuzz.cc

Source (jump to first uncovered line)
// libfuzzer driver for key exchange fuzzing.


#include <sys/types.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

extern "C" {

#include "includes.h"
#include "ssherr.h"
#include "ssh_api.h"
#include "sshbuf.h"
#include "packet.h"
#include "myproposal.h"
#include "xmalloc.h"
#include "authfile.h"
#include "log.h"

#include "fixed-keys.h"

// Define if you want to generate traces.
/* #define STANDALONE 1 */

static int prepare_key(struct shared_state *st, int keytype, int bits);

struct shared_state {
  size_t nkeys;
  struct sshkey **privkeys, **pubkeys;
};

struct test_state {
  struct sshbuf *smsgs, *cmsgs; /* output, for standalone mode */
  struct sshbuf *sin, *cin; /* input; setup per-test in do_kex_with_key */
  struct sshbuf *s_template, *c_template; /* main copy of input */
};

static int
do_send_and_receive(struct ssh *from, struct ssh *to,
    struct sshbuf *store, int clobber, size_t *n)
{
  u_char type;
  size_t len;
  const u_char *buf;
  int r;

  for (*n = 0;; (*n)++) {
    if ((r = ssh_packet_next(from, &type)) != 0) {
      debug_fr(r, "ssh_packet_next");
      return r;
    }
    if (type != 0)
      return 0;
    buf = ssh_output_ptr(from, &len);
    debug_f("%zu%s", len, clobber ? " ignore" : "");
    if (len == 0)
      return 0;
    if ((r = ssh_output_consume(from, len)) != 0) {
      debug_fr(r, "ssh_output_consume");
      return r;
    }
    if (store != NULL && (r = sshbuf_put(store, buf, len)) != 0) {
      debug_fr(r, "sshbuf_put");
      return r;
    }
    if (!clobber && (r = ssh_input_append(to, buf, len)) != 0) {
      debug_fr(r, "ssh_input_append");
      return r;
    }
  }
}

static int
run_kex(struct test_state *ts, struct ssh *client, struct ssh *server)
{
  int r = 0;
  size_t cn, sn;

  /* If fuzzing, replace server/client input */
  if (ts->sin != NULL) {
    if ((r = ssh_input_append(server, sshbuf_ptr(ts->sin),
        sshbuf_len(ts->sin))) != 0) {
      error_fr(r, "ssh_input_append");
      return r;
    }
    sshbuf_reset(ts->sin);
  }
  if (ts->cin != NULL) {
    if ((r = ssh_input_append(client, sshbuf_ptr(ts->cin),
        sshbuf_len(ts->cin))) != 0) {
      error_fr(r, "ssh_input_append");
      return r;
    }
    sshbuf_reset(ts->cin);
  }
  while (!server->kex->done || !client->kex->done) {
    cn = sn = 0;
    debug_f("S:");
    if ((r = do_send_and_receive(server, client,
        ts->smsgs, ts->cin != NULL, &sn)) != 0) {
      debug_fr(r, "S->C");
      break;
    }
    debug_f("C:");
    if ((r = do_send_and_receive(client, server,
        ts->cmsgs, ts->sin != NULL, &cn)) != 0) {
      debug_fr(r, "C->S");
      break;
    }
    if (cn == 0 && sn == 0) {
      debug_f("kex stalled");
      r = SSH_ERR_PROTOCOL_ERROR;
      break;
    }
  }
  debug_fr(r, "done");
  return r;
}

static void
store_key(struct shared_state *st, struct sshkey *pubkey,
    struct sshkey *privkey)
{
  if (st == NULL || pubkey->type < 0 || pubkey->type > INT_MAX ||
      privkey->type != pubkey->type ||
      ((size_t)pubkey->type < st->nkeys &&
       st->pubkeys[pubkey->type] != NULL))
    abort();
  if ((size_t)pubkey->type >= st->nkeys) {
    st->pubkeys = (struct sshkey **)xrecallocarray(st->pubkeys,
        st->nkeys, pubkey->type + 1, sizeof(*st->pubkeys));
    st->privkeys = (struct sshkey **)xrecallocarray(st->privkeys,
        st->nkeys, privkey->type + 1, sizeof(*st->privkeys));
    st->nkeys = privkey->type + 1;
  }
  debug_f("store %s at %d", sshkey_ssh_name(pubkey), pubkey->type);
  st->pubkeys[pubkey->type] = pubkey;
  st->privkeys[privkey->type] = privkey;
}

static int
prepare_keys(struct shared_state *st)
{
  if (prepare_key(st, KEY_RSA, 2048) != 0 ||
      prepare_key(st, KEY_ECDSA, 256) != 0 ||
      prepare_key(st, KEY_ED25519, 256) != 0) {
    error_f("key prepare failed");
    return -1;
  }
  return 0;
}

static struct sshkey *
get_pubkey(struct shared_state *st, int keytype)
{
  if (st == NULL || keytype < 0 || (size_t)keytype >= st->nkeys ||
      st->pubkeys == NULL || st->pubkeys[keytype] == NULL)
    abort();
  return st->pubkeys[keytype];
}

static struct sshkey *
get_privkey(struct shared_state *st, int keytype)
{
  if (st == NULL || keytype < 0 || (size_t)keytype >= st->nkeys ||
      st->privkeys == NULL || st->privkeys[keytype] == NULL)
    abort();
  return st->privkeys[keytype];
}

static int
do_kex_with_key(struct shared_state *st, struct test_state *ts,
    const char *kex, int keytype)
{
  struct ssh *client = NULL, *server = NULL;
  struct sshkey *privkey = NULL, *pubkey = NULL;
  struct sshbuf *state = NULL;
  struct kex_params kex_params;
  const char *ccp, *proposal[PROPOSAL_MAX] = { KEX_CLIENT };
  char *myproposal[PROPOSAL_MAX] = {0}, *keyname = NULL;
  int i, r;

  ts->cin = ts->sin = NULL;
  if (ts->c_template != NULL &&
      (ts->cin = sshbuf_fromb(ts->c_template)) == NULL)
    abort();
  if (ts->s_template != NULL &&
      (ts->sin = sshbuf_fromb(ts->s_template)) == NULL)
    abort();

  pubkey = get_pubkey(st, keytype);
  privkey = get_privkey(st, keytype);
  keyname = xstrdup(sshkey_ssh_name(privkey));
  if (ts->cin != NULL) {
    debug_f("%s %s clobber client %zu", kex, keyname,
        sshbuf_len(ts->cin));
  } else if (ts->sin != NULL) {
    debug_f("%s %s clobber server %zu", kex, keyname,
        sshbuf_len(ts->sin));
  } else
    debug_f("%s %s noclobber", kex, keyname);

  for (i = 0; i < PROPOSAL_MAX; i++) {
    ccp = proposal[i];
#ifdef CIPHER_NONE_AVAIL
    if (i == PROPOSAL_ENC_ALGS_CTOS || i == PROPOSAL_ENC_ALGS_STOC)
      ccp = "none";
#endif
    if (i == PROPOSAL_SERVER_HOST_KEY_ALGS)
      ccp = keyname;
    else if (i == PROPOSAL_KEX_ALGS && kex != NULL)
      ccp = kex;
    if ((myproposal[i] = strdup(ccp)) == NULL) {
      error_f("strdup prop %d", i);
      goto fail;
    }
  }
  memcpy(kex_params.proposal, myproposal, sizeof(myproposal));
  if ((r = ssh_init(&client, 0, &kex_params)) != 0) {
    error_fr(r, "init client");
    goto fail;
  }
  if ((r = ssh_init(&server, 1, &kex_params)) != 0) {
    error_fr(r, "init server");
    goto fail;
  }
  if ((r = ssh_add_hostkey(server, privkey)) != 0 ||
      (r = ssh_add_hostkey(client, pubkey)) != 0) {
    error_fr(r, "add hostkeys");
    goto fail;
  }
  if ((r = run_kex(ts, client, server)) != 0) {
    error_fr(r, "kex");
    goto fail;
  }
  /* XXX rekex, set_state, etc */
 fail:
  for (i = 0; i < PROPOSAL_MAX; i++)
    free(myproposal[i]);
  sshbuf_free(ts->sin);
  sshbuf_free(ts->cin);
  sshbuf_free(state);
  ssh_free(client);
  ssh_free(server);
  free(keyname);
  return r;
}

static int
prepare_key(struct shared_state *st, int kt, int bits)
{
  const char *pubstr = NULL;
  const char *privstr = NULL;
  char *tmp, *cp;
  struct sshkey *privkey = NULL, *pubkey = NULL;
  struct sshbuf *b = NULL;
  int r;

  switch (kt) {
  case KEY_RSA:
    pubstr = PUB_RSA;
    privstr = PRIV_RSA;
    break;
  case KEY_ECDSA:
    pubstr = PUB_ECDSA;
    privstr = PRIV_ECDSA;
    break;
  case KEY_ED25519:
    pubstr = PUB_ED25519;
    privstr = PRIV_ED25519;
    break;
  default:
    abort();
  }
  if ((b = sshbuf_from(privstr, strlen(privstr))) == NULL)
    abort();
  if ((r = sshkey_parse_private_fileblob(b, "", &privkey, NULL)) != 0) {
    error_fr(r, "priv %d", kt);
    abort();
  }
  sshbuf_free(b);
  tmp = cp = xstrdup(pubstr);
  if ((pubkey = sshkey_new(KEY_UNSPEC)) == NULL)
    abort();
  if ((r = sshkey_read(pubkey, &cp)) != 0) {
    error_fr(r, "pub %d", kt);
    abort();
  }
  free(tmp);

  store_key(st, pubkey, privkey);
  return 0;
}

#if defined(STANDALONE)

#if 0 /* use this if generating new keys to embed above */
static int
prepare_key(struct shared_state *st, int keytype, int bits)
{
  struct sshkey *privkey = NULL, *pubkey = NULL;
  int r;

  if ((r = sshkey_generate(keytype, bits, &privkey)) != 0) {
    error_fr(r, "generate");
    abort();
  }
  if ((r = sshkey_from_private(privkey, &pubkey)) != 0) {
    error_fr(r, "make pubkey");
    abort();
  }
  store_key(st, pubkey, privkey);
  return 0;
}
#endif

int main(void)
{
  static struct shared_state *st;
  struct test_state *ts;
  const int keytypes[] = { KEY_RSA, KEY_ECDSA, KEY_ED25519, -1 };
  static const char * const kextypes[] = {
    "sntrup761x25519-sha512@openssh.com",
    "curve25519-sha256@libssh.org",
    "ecdh-sha2-nistp256",
    "diffie-hellman-group1-sha1",
    "diffie-hellman-group-exchange-sha1",
    NULL,
  };
  int i, j;
  char *path;
  FILE *f;

  log_init("kex_fuzz", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 1);

  if (st == NULL) {
    st = (struct shared_state *)xcalloc(1, sizeof(*st));
    prepare_keys(st);
  }
  /* Run each kex method for each key and save client/server packets */
  for (i = 0; keytypes[i] != -1; i++) {
    for (j = 0; kextypes[j] != NULL; j++) {
      ts = (struct test_state *)xcalloc(1, sizeof(*ts));
      ts->smsgs = sshbuf_new();
      ts->cmsgs = sshbuf_new();
      do_kex_with_key(st, ts, kextypes[j], keytypes[i]);
      xasprintf(&path, "S2C-%s-%s",
          kextypes[j], sshkey_type(st->pubkeys[keytypes[i]]));
      debug_f("%s", path);
      if ((f = fopen(path, "wb+")) == NULL)
        abort();
      if (fwrite(sshbuf_ptr(ts->smsgs), 1,
          sshbuf_len(ts->smsgs), f) != sshbuf_len(ts->smsgs))
        abort();
      fclose(f);
      free(path);
      //sshbuf_dump(ts->smsgs, stderr);
      xasprintf(&path, "C2S-%s-%s",
          kextypes[j], sshkey_type(st->pubkeys[keytypes[i]]));
      debug_f("%s", path);
      if ((f = fopen(path, "wb+")) == NULL)
        abort();
      if (fwrite(sshbuf_ptr(ts->cmsgs), 1,
          sshbuf_len(ts->cmsgs), f) != sshbuf_len(ts->cmsgs))
        abort();
      fclose(f);
      free(path);
      //sshbuf_dump(ts->cmsgs, stderr);
      sshbuf_free(ts->smsgs);
      sshbuf_free(ts->cmsgs);
      free(ts);
    }
  }
  for (i = 0; keytypes[i] != -1; i++) {
    xasprintf(&path, "%s.priv",
        sshkey_type(st->privkeys[keytypes[i]]));
    debug_f("%s", path);
    if (sshkey_save_private(st->privkeys[keytypes[i]], path,
        "", "", SSHKEY_PRIVATE_OPENSSH, NULL, 0) != 0)
      abort();
    free(path);
    xasprintf(&path, "%s.pub",
        sshkey_type(st->pubkeys[keytypes[i]]));
    debug_f("%s", path);
    if (sshkey_save_public(st->pubkeys[keytypes[i]], path, "") != 0)
      abort();
    free(path);
  }
}
#else /* !STANDALONE */
static void
do_kex(struct shared_state *st, struct test_state *ts, const char *kex)
{
  do_kex_with_key(st, ts, kex, KEY_RSA);
  do_kex_with_key(st, ts, kex, KEY_ECDSA);
  do_kex_with_key(st, ts, kex, KEY_ED25519);
}

static void
kex_tests(struct shared_state *st, struct test_state *ts)
{
  do_kex(st, ts, "sntrup761x25519-sha512@openssh.com");
  do_kex(st, ts, "curve25519-sha256@libssh.org");
  do_kex(st, ts, "ecdh-sha2-nistp256");
  do_kex(st, ts, "diffie-hellman-group1-sha1");
  do_kex(st, ts, "diffie-hellman-group-exchange-sha1");
}

int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
{
  static struct shared_state *st;
  struct test_state *ts;
  u_char crbuf[SSH_MAX_PRE_BANNER_LINES * 4];
  u_char zbuf[4096] = {0};
  static LogLevel loglevel = SYSLOG_LEVEL_INFO;

  if (st == NULL) {
    if (getenv("DEBUG") != NULL || getenv("KEX_FUZZ_DEBUG") != NULL)
      loglevel = SYSLOG_LEVEL_DEBUG3;
    log_init("kex_fuzz",
        loglevel, SYSLOG_FACILITY_AUTH, 1);
    st = (struct shared_state *)xcalloc(1, sizeof(*st));
    prepare_keys(st);
  }

  /* Ensure that we can complete (fail) banner exchange at least */
  memset(crbuf, '\n', sizeof(crbuf));

  ts = (struct test_state *)xcalloc(1, sizeof(*ts));
  if ((ts->s_template = sshbuf_new()) == NULL ||
      sshbuf_put(ts->s_template, data, size) != 0 ||
      sshbuf_put(ts->s_template, crbuf, sizeof(crbuf)) != 0 ||
      sshbuf_put(ts->s_template, zbuf, sizeof(zbuf)) != 0)
    abort();
  kex_tests(st, ts);
  sshbuf_free(ts->s_template);
  free(ts);

  ts = (struct test_state *)xcalloc(1, sizeof(*ts));
  if ((ts->c_template = sshbuf_new()) == NULL ||
      sshbuf_put(ts->c_template, data, size) != 0 ||
      sshbuf_put(ts->c_template, crbuf, sizeof(crbuf)) != 0 ||
      sshbuf_put(ts->c_template, zbuf, sizeof(zbuf)) != 0)
    abort();
  kex_tests(st, ts);
  sshbuf_free(ts->c_template);
  free(ts);

  return 0;
}
#endif /* STANDALONE */
} /* extern "C" */

Coverage Report

Created: 2025-07-11 06:19

Line	Count	Source (jump to first uncovered line)
1		// libfuzzer driver for key exchange fuzzing.
2
3
4		#include <sys/types.h>
5		#include <stdio.h>
6		#include <stdint.h>
7		#include <stdlib.h>
8		#include <string.h>
9
10		extern "C" {
11
12		#include "includes.h"
13		#include "ssherr.h"
14		#include "ssh_api.h"
15		#include "sshbuf.h"
16		#include "packet.h"
17		#include "myproposal.h"
18		#include "xmalloc.h"
19		#include "authfile.h"
20		#include "log.h"
21
22		#include "fixed-keys.h"
23
24		// Define if you want to generate traces.
25		/* #define STANDALONE 1 */
26
27		static int prepare_key(struct shared_state *st, int keytype, int bits);
28
29		struct shared_state {
30		size_t nkeys;
31		struct sshkey privkeys, pubkeys;
32		};
33
34		struct test_state {
35		struct sshbuf smsgs, cmsgs; /* output, for standalone mode */
36		struct sshbuf sin, cin; /* input; setup per-test in do_kex_with_key */
37		struct sshbuf s_template, c_template; /* main copy of input */
38		};
39
40		static int
41		do_send_and_receive(struct ssh from, struct ssh to,
42		struct sshbuf store, int clobber, size_t n)
43	22.5k	{
44	22.5k	u_char type;
45	22.5k	size_t len;
46	22.5k	const u_char *buf;
47	22.5k	int r;
48
49	38.0k	for (n = 0;; (n)++) {
50	38.0k	if ((r = ssh_packet_next(from, &type)) != 0) {
51	15.0k	debug_fr(r, "ssh_packet_next");
52	15.0k	return r;
53	15.0k	}
54	23.0k	if (type != 0)
55	0	return 0;
56	23.0k	buf = ssh_output_ptr(from, &len);
57	23.0k	debug_f("%zu%s", len, clobber ? " ignore" : "");
58	23.0k	if (len == 0)
59	7.50k	return 0;
60	15.5k	if ((r = ssh_output_consume(from, len)) != 0) {
61	0	debug_fr(r, "ssh_output_consume");
62	0	return r;
63	0	}
64	15.5k	if (store != NULL && (r = sshbuf_put(store, buf, len)) != 0) {
65	0	debug_fr(r, "sshbuf_put");
66	0	return r;
67	0	}
68	15.5k	if (!clobber && (r = ssh_input_append(to, buf, len)) != 0) {
69	0	debug_fr(r, "ssh_input_append");
70	0	return r;
71	0	}
72	15.5k	}
73	22.5k	}
74
75		static int
76		run_kex(struct test_state ts, struct ssh client, struct ssh *server)
77	15.0k	{
78	15.0k	int r = 0;
79	15.0k	size_t cn, sn;
80
81		/* If fuzzing, replace server/client input */
82	15.0k	if (ts->sin != NULL) {
83	7.50k	if ((r = ssh_input_append(server, sshbuf_ptr(ts->sin),
84	7.50k	sshbuf_len(ts->sin))) != 0) {
85	0	error_fr(r, "ssh_input_append");
86	0	return r;
87	0	}
88	7.50k	sshbuf_reset(ts->sin);
89	7.50k	}
90	15.0k	if (ts->cin != NULL) {
91	7.50k	if ((r = ssh_input_append(client, sshbuf_ptr(ts->cin),
92	7.50k	sshbuf_len(ts->cin))) != 0) {
93	0	error_fr(r, "ssh_input_append");
94	0	return r;
95	0	}
96	7.50k	sshbuf_reset(ts->cin);
97	7.50k	}
98	15.0k	while (!server->kex->done \|\| !client->kex->done) {
99	15.0k	cn = sn = 0;
100	15.0k	debug_f("S:");
101	15.0k	if ((r = do_send_and_receive(server, client,
102	15.0k	ts->smsgs, ts->cin != NULL, &sn)) != 0) {
103	7.50k	debug_fr(r, "S->C");
104	7.50k	break;
105	7.50k	}
106	7.50k	debug_f("C:");
107	7.50k	if ((r = do_send_and_receive(client, server,
108	7.50k	ts->cmsgs, ts->sin != NULL, &cn)) != 0) {
109	7.50k	debug_fr(r, "C->S");
110	7.50k	break;
111	7.50k	}
112	0	if (cn == 0 && sn == 0) {
113	0	debug_f("kex stalled");
114	0	r = SSH_ERR_PROTOCOL_ERROR;
115	0	break;
116	0	}
117	0	}
118	15.0k	debug_fr(r, "done");
119	15.0k	return r;
120	15.0k	}
121
122		static void
123		store_key(struct shared_state st, struct sshkey pubkey,
124		struct sshkey *privkey)
125	3	{
126	3	if (st == NULL \|\| pubkey->type < 0 \|\| pubkey->type > INT_MAX \|\|
127	3	privkey->type != pubkey->type \|\|
128	3	((size_t)pubkey->type < st->nkeys &&
129	3	st->pubkeys[pubkey->type] != NULL))
130	0	abort();
131	3	if ((size_t)pubkey->type >= st->nkeys) {
132	3	st->pubkeys = (struct sshkey **)xrecallocarray(st->pubkeys,
133	3	st->nkeys, pubkey->type + 1, sizeof(*st->pubkeys));
134	3	st->privkeys = (struct sshkey **)xrecallocarray(st->privkeys,
135	3	st->nkeys, privkey->type + 1, sizeof(*st->privkeys));
136	3	st->nkeys = privkey->type + 1;
137	3	}
138	3	debug_f("store %s at %d", sshkey_ssh_name(pubkey), pubkey->type);
139	3	st->pubkeys[pubkey->type] = pubkey;
140	3	st->privkeys[privkey->type] = privkey;
141	3	}
142
143		static int
144		prepare_keys(struct shared_state *st)
145	1	{
146	1	if (prepare_key(st, KEY_RSA, 2048) != 0 \|\|
147	1	prepare_key(st, KEY_ECDSA, 256) != 0 \|\|
148	1	prepare_key(st, KEY_ED25519, 256) != 0) {
149	0	error_f("key prepare failed");
150	0	return -1;
151	0	}
152	1	return 0;
153	1	}
154
155		static struct sshkey *
156		get_pubkey(struct shared_state *st, int keytype)
157	15.0k	{
158	15.0k	if (st == NULL \|\| keytype < 0 \|\| (size_t)keytype >= st->nkeys \|\|
159	15.0k	st->pubkeys == NULL \|\| st->pubkeys[keytype] == NULL)
160	0	abort();
161	15.0k	return st->pubkeys[keytype];
162	15.0k	}
163
164		static struct sshkey *
165		get_privkey(struct shared_state *st, int keytype)
166	15.0k	{
167	15.0k	if (st == NULL \|\| keytype < 0 \|\| (size_t)keytype >= st->nkeys \|\|
168	15.0k	st->privkeys == NULL \|\| st->privkeys[keytype] == NULL)
169	0	abort();
170	15.0k	return st->privkeys[keytype];
171	15.0k	}
172
173		static int
174		do_kex_with_key(struct shared_state st, struct test_state ts,
175		const char *kex, int keytype)
176	15.0k	{
177	15.0k	struct ssh client = NULL, server = NULL;
178	15.0k	struct sshkey privkey = NULL, pubkey = NULL;
179	15.0k	struct sshbuf *state = NULL;
180	15.0k	struct kex_params kex_params;
181	15.0k	const char ccp, proposal[PROPOSAL_MAX] = { KEX_CLIENT };
182	15.0k	char myproposal[PROPOSAL_MAX] = {0}, keyname = NULL;
183	15.0k	int i, r;
184
185	15.0k	ts->cin = ts->sin = NULL;
186	15.0k	if (ts->c_template != NULL &&
187	15.0k	(ts->cin = sshbuf_fromb(ts->c_template)) == NULL)
188	0	abort();
189	15.0k	if (ts->s_template != NULL &&
190	15.0k	(ts->sin = sshbuf_fromb(ts->s_template)) == NULL)
191	0	abort();
192
193	15.0k	pubkey = get_pubkey(st, keytype);
194	15.0k	privkey = get_privkey(st, keytype);
195	15.0k	keyname = xstrdup(sshkey_ssh_name(privkey));
196	15.0k	if (ts->cin != NULL) {
197	7.50k	debug_f("%s %s clobber client %zu", kex, keyname,
198	7.50k	sshbuf_len(ts->cin));
199	7.50k	} else if (ts->sin != NULL) {
200	7.50k	debug_f("%s %s clobber server %zu", kex, keyname,
201	7.50k	sshbuf_len(ts->sin));
202	7.50k	} else
203	0	debug_f("%s %s noclobber", kex, keyname);
204
205	165k	for (i = 0; i < PROPOSAL_MAX; i++) {
206	150k	ccp = proposal[i];
207	150k	#ifdef CIPHER_NONE_AVAIL
208	150k	if (i == PROPOSAL_ENC_ALGS_CTOS \|\| i == PROPOSAL_ENC_ALGS_STOC)
209	30.0k	ccp = "none";
210	150k	#endif
211	150k	if (i == PROPOSAL_SERVER_HOST_KEY_ALGS)
212	15.0k	ccp = keyname;
213	135k	else if (i == PROPOSAL_KEX_ALGS && kex != NULL)
214	15.0k	ccp = kex;
215	150k	if ((myproposal[i] = strdup(ccp)) == NULL) {
216	0	error_f("strdup prop %d", i);
217	0	goto fail;
218	0	}
219	150k	}
220	15.0k	memcpy(kex_params.proposal, myproposal, sizeof(myproposal));
221	15.0k	if ((r = ssh_init(&client, 0, &kex_params)) != 0) {
222	0	error_fr(r, "init client");
223	0	goto fail;
224	0	}
225	15.0k	if ((r = ssh_init(&server, 1, &kex_params)) != 0) {
226	0	error_fr(r, "init server");
227	0	goto fail;
228	0	}
229	15.0k	if ((r = ssh_add_hostkey(server, privkey)) != 0 \|\|
230	15.0k	(r = ssh_add_hostkey(client, pubkey)) != 0) {
231	0	error_fr(r, "add hostkeys");
232	0	goto fail;
233	0	}
234	15.0k	if ((r = run_kex(ts, client, server)) != 0) {
235	15.0k	error_fr(r, "kex");
236	15.0k	goto fail;
237	15.0k	}
238		/* XXX rekex, set_state, etc */
239	15.0k	fail:
240	165k	for (i = 0; i < PROPOSAL_MAX; i++)
241	150k	free(myproposal[i]);
242	15.0k	sshbuf_free(ts->sin);
243	15.0k	sshbuf_free(ts->cin);
244	15.0k	sshbuf_free(state);
245	15.0k	ssh_free(client);
246	15.0k	ssh_free(server);
247	15.0k	free(keyname);
248	15.0k	return r;
249	15.0k	}
250
251		static int
252		prepare_key(struct shared_state *st, int kt, int bits)
253	3	{
254	3	const char *pubstr = NULL;
255	3	const char *privstr = NULL;
256	3	char tmp, cp;
257	3	struct sshkey privkey = NULL, pubkey = NULL;
258	3	struct sshbuf *b = NULL;
259	3	int r;
260
261	3	switch (kt) {
262	1	case KEY_RSA:
263	1	pubstr = PUB_RSA;
264	1	privstr = PRIV_RSA;
265	1	break;
266	1	case KEY_ECDSA:
267	1	pubstr = PUB_ECDSA;
268	1	privstr = PRIV_ECDSA;
269	1	break;
270	1	case KEY_ED25519:
271	1	pubstr = PUB_ED25519;
272	1	privstr = PRIV_ED25519;
273	1	break;
274	0	default:
275	0	abort();
276	3	}
277	3	if ((b = sshbuf_from(privstr, strlen(privstr))) == NULL)
278	0	abort();
279	3	if ((r = sshkey_parse_private_fileblob(b, "", &privkey, NULL)) != 0) {
280	0	error_fr(r, "priv %d", kt);
281	0	abort();
282	0	}
283	3	sshbuf_free(b);
284	3	tmp = cp = xstrdup(pubstr);
285	3	if ((pubkey = sshkey_new(KEY_UNSPEC)) == NULL)
286	0	abort();
287	3	if ((r = sshkey_read(pubkey, &cp)) != 0) {
288	0	error_fr(r, "pub %d", kt);
289	0	abort();
290	0	}
291	3	free(tmp);
292
293	3	store_key(st, pubkey, privkey);
294	3	return 0;
295	3	}
296
297		#if defined(STANDALONE)
298
299		#if 0 /* use this if generating new keys to embed above */
300		static int
301		prepare_key(struct shared_state *st, int keytype, int bits)
302		{
303		struct sshkey privkey = NULL, pubkey = NULL;
304		int r;
305
306		if ((r = sshkey_generate(keytype, bits, &privkey)) != 0) {
307		error_fr(r, "generate");
308		abort();
309		}
310		if ((r = sshkey_from_private(privkey, &pubkey)) != 0) {
311		error_fr(r, "make pubkey");
312		abort();
313		}
314		store_key(st, pubkey, privkey);
315		return 0;
316		}
317		#endif
318
319		int main(void)
320		{
321		static struct shared_state *st;
322		struct test_state *ts;
323		const int keytypes[] = { KEY_RSA, KEY_ECDSA, KEY_ED25519, -1 };
324		static const char * const kextypes[] = {
325		"sntrup761x25519-sha512@openssh.com",
326		"curve25519-sha256@libssh.org",
327		"ecdh-sha2-nistp256",
328		"diffie-hellman-group1-sha1",
329		"diffie-hellman-group-exchange-sha1",
330		NULL,
331		};
332		int i, j;
333		char *path;
334		FILE *f;
335
336		log_init("kex_fuzz", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 1);
337
338		if (st == NULL) {
339		st = (struct shared_state )xcalloc(1, sizeof(st));
340		prepare_keys(st);
341		}
342		/* Run each kex method for each key and save client/server packets */
343		for (i = 0; keytypes[i] != -1; i++) {
344		for (j = 0; kextypes[j] != NULL; j++) {
345		ts = (struct test_state )xcalloc(1, sizeof(ts));
346		ts->smsgs = sshbuf_new();
347		ts->cmsgs = sshbuf_new();
348		do_kex_with_key(st, ts, kextypes[j], keytypes[i]);
349		xasprintf(&path, "S2C-%s-%s",
350		kextypes[j], sshkey_type(st->pubkeys[keytypes[i]]));
351		debug_f("%s", path);
352		if ((f = fopen(path, "wb+")) == NULL)
353		abort();
354		if (fwrite(sshbuf_ptr(ts->smsgs), 1,
355		sshbuf_len(ts->smsgs), f) != sshbuf_len(ts->smsgs))
356		abort();
357		fclose(f);
358		free(path);
359		//sshbuf_dump(ts->smsgs, stderr);
360		xasprintf(&path, "C2S-%s-%s",
361		kextypes[j], sshkey_type(st->pubkeys[keytypes[i]]));
362		debug_f("%s", path);
363		if ((f = fopen(path, "wb+")) == NULL)
364		abort();
365		if (fwrite(sshbuf_ptr(ts->cmsgs), 1,
366		sshbuf_len(ts->cmsgs), f) != sshbuf_len(ts->cmsgs))
367		abort();
368		fclose(f);
369		free(path);
370		//sshbuf_dump(ts->cmsgs, stderr);
371		sshbuf_free(ts->smsgs);
372		sshbuf_free(ts->cmsgs);
373		free(ts);
374		}
375		}
376		for (i = 0; keytypes[i] != -1; i++) {
377		xasprintf(&path, "%s.priv",
378		sshkey_type(st->privkeys[keytypes[i]]));
379		debug_f("%s", path);
380		if (sshkey_save_private(st->privkeys[keytypes[i]], path,
381		"", "", SSHKEY_PRIVATE_OPENSSH, NULL, 0) != 0)
382		abort();
383		free(path);
384		xasprintf(&path, "%s.pub",
385		sshkey_type(st->pubkeys[keytypes[i]]));
386		debug_f("%s", path);
387		if (sshkey_save_public(st->pubkeys[keytypes[i]], path, "") != 0)
388		abort();
389		free(path);
390		}
391		}
392		#else /* !STANDALONE */
393		static void
394		do_kex(struct shared_state st, struct test_state ts, const char *kex)
395	5.00k	{
396	5.00k	do_kex_with_key(st, ts, kex, KEY_RSA);
397	5.00k	do_kex_with_key(st, ts, kex, KEY_ECDSA);
398	5.00k	do_kex_with_key(st, ts, kex, KEY_ED25519);
399	5.00k	}
400
401		static void
402		kex_tests(struct shared_state st, struct test_state ts)
403	1.00k	{
404	1.00k	do_kex(st, ts, "sntrup761x25519-sha512@openssh.com");
405	1.00k	do_kex(st, ts, "curve25519-sha256@libssh.org");
406	1.00k	do_kex(st, ts, "ecdh-sha2-nistp256");
407	1.00k	do_kex(st, ts, "diffie-hellman-group1-sha1");
408	1.00k	do_kex(st, ts, "diffie-hellman-group-exchange-sha1");
409	1.00k	}
410
411		int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
412	500	{
413	500	static struct shared_state *st;
414	500	struct test_state *ts;
415	500	u_char crbuf[SSH_MAX_PRE_BANNER_LINES * 4];
416	500	u_char zbuf[4096] = {0};
417	500	static LogLevel loglevel = SYSLOG_LEVEL_INFO;
418
419	500	if (st == NULL) {
420	1	if (getenv("DEBUG") != NULL \|\| getenv("KEX_FUZZ_DEBUG") != NULL)
421	0	loglevel = SYSLOG_LEVEL_DEBUG3;
422	1	log_init("kex_fuzz",
423	1	loglevel, SYSLOG_FACILITY_AUTH, 1);
424	1	st = (struct shared_state )xcalloc(1, sizeof(st));
425	1	prepare_keys(st);
426	1	}
427
428		/* Ensure that we can complete (fail) banner exchange at least */
429	500	memset(crbuf, '\n', sizeof(crbuf));
430
431	500	ts = (struct test_state )xcalloc(1, sizeof(ts));
432	500	if ((ts->s_template = sshbuf_new()) == NULL \|\|
433	500	sshbuf_put(ts->s_template, data, size) != 0 \|\|
434	500	sshbuf_put(ts->s_template, crbuf, sizeof(crbuf)) != 0 \|\|
435	500	sshbuf_put(ts->s_template, zbuf, sizeof(zbuf)) != 0)
436	0	abort();
437	500	kex_tests(st, ts);
438	500	sshbuf_free(ts->s_template);
439	500	free(ts);
440
441	500	ts = (struct test_state )xcalloc(1, sizeof(ts));
442	500	if ((ts->c_template = sshbuf_new()) == NULL \|\|
443	500	sshbuf_put(ts->c_template, data, size) != 0 \|\|
444	500	sshbuf_put(ts->c_template, crbuf, sizeof(crbuf)) != 0 \|\|
445	500	sshbuf_put(ts->c_template, zbuf, sizeof(zbuf)) != 0)
446	0	abort();
447	500	kex_tests(st, ts);
448	500	sshbuf_free(ts->c_template);
449	500	free(ts);
450
451	500	return 0;
452	500	}
453		#endif /* STANDALONE */
454		} /* extern "C" */