1 /*
2 * Copyright (c) 2019-2022 Yubico AB. All rights reserved.
3 * Use of this source code is governed by a BSD-style
4 * license that can be found in the LICENSE file.
5 * SPDX-License-Identifier: BSD-2-Clause
6 */
7
8 #include <assert.h>
9 #include <stdint.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13
14 #include "mutator_aux.h"
15 #include "wiredata_fido2.h"
16 #include "wiredata_u2f.h"
17 #include "dummy.h"
18
19 #include "../openbsd-compat/openbsd-compat.h"
20
21 /* Parameter set defining a FIDO2 make credential operation. */
22 struct param {
23 char pin[MAXSTR];
24 char rp_id[MAXSTR];
25 char rp_name[MAXSTR];
26 char user_icon[MAXSTR];
27 char user_name[MAXSTR];
28 char user_nick[MAXSTR];
29 int ext;
30 int seed;
31 struct blob cdh;
32 struct blob excl_cred;
33 struct blob user_id;
34 struct blob wire_data;
35 uint8_t excl_count;
36 uint8_t rk;
37 uint8_t type;
38 uint8_t opt;
39 uint8_t uv;
40 };
41
42 /*
43 * Collection of HID reports from an authenticator issued with a FIDO2
44 * make credential using the example parameters above.
45 */
46 static const uint8_t dummy_wire_data_fido[] = {
47 WIREDATA_CTAP_INIT,
48 WIREDATA_CTAP_CBOR_INFO,
49 WIREDATA_CTAP_CBOR_AUTHKEY,
50 WIREDATA_CTAP_CBOR_PINTOKEN,
51 WIREDATA_CTAP_KEEPALIVE,
52 WIREDATA_CTAP_KEEPALIVE,
53 WIREDATA_CTAP_KEEPALIVE,
54 WIREDATA_CTAP_CBOR_CRED,
55 };
56
57 /*
58 * Collection of HID reports from an authenticator issued with a U2F
59 * registration using the example parameters above.
60 */
61 static const uint8_t dummy_wire_data_u2f[] = {
62 WIREDATA_CTAP_INIT,
63 WIREDATA_CTAP_U2F_6985,
64 WIREDATA_CTAP_U2F_6985,
65 WIREDATA_CTAP_U2F_6985,
66 WIREDATA_CTAP_U2F_6985,
67 WIREDATA_CTAP_U2F_6985,
68 WIREDATA_CTAP_U2F_REGISTER,
69 };
70
71 struct param *
unpack(const uint8_t * ptr,size_t len)72 unpack(const uint8_t *ptr, size_t len)
73 {
74 cbor_item_t *item = NULL, **v;
75 struct cbor_load_result cbor;
76 struct param *p;
77 int ok = -1;
78
79 if ((p = calloc(1, sizeof(*p))) == NULL ||
80 (item = cbor_load(ptr, len, &cbor)) == NULL ||
81 cbor.read != len ||
82 cbor_isa_array(item) == false ||
83 cbor_array_is_definite(item) == false ||
84 cbor_array_size(item) != 17 ||
85 (v = cbor_array_handle(item)) == NULL)
86 goto fail;
87
88 if (unpack_byte(v[0], &p->rk) < 0 ||
89 unpack_byte(v[1], &p->type) < 0 ||
90 unpack_byte(v[2], &p->opt) < 0 ||
91 unpack_byte(v[3], &p->uv) < 0 ||
92 unpack_byte(v[4], &p->excl_count) < 0 ||
93 unpack_int(v[5], &p->ext) < 0 ||
94 unpack_int(v[6], &p->seed) < 0 ||
95 unpack_string(v[7], p->pin) < 0 ||
96 unpack_string(v[8], p->rp_id) < 0 ||
97 unpack_string(v[9], p->rp_name) < 0 ||
98 unpack_string(v[10], p->user_icon) < 0 ||
99 unpack_string(v[11], p->user_name) < 0 ||
100 unpack_string(v[12], p->user_nick) < 0 ||
101 unpack_blob(v[13], &p->cdh) < 0 ||
102 unpack_blob(v[14], &p->user_id) < 0 ||
103 unpack_blob(v[15], &p->wire_data) < 0 ||
104 unpack_blob(v[16], &p->excl_cred) < 0)
105 goto fail;
106
107 ok = 0;
108 fail:
109 if (ok < 0) {
110 free(p);
111 p = NULL;
112 }
113
114 if (item)
115 cbor_decref(&item);
116
117 return p;
118 }
119
120 size_t
pack(uint8_t * ptr,size_t len,const struct param * p)121 pack(uint8_t *ptr, size_t len, const struct param *p)
122 {
123 cbor_item_t *argv[17], *array = NULL;
124 size_t cbor_alloc_len, cbor_len = 0;
125 unsigned char *cbor = NULL;
126
127 memset(argv, 0, sizeof(argv));
128
129 if ((array = cbor_new_definite_array(17)) == NULL ||
130 (argv[0] = pack_byte(p->rk)) == NULL ||
131 (argv[1] = pack_byte(p->type)) == NULL ||
132 (argv[2] = pack_byte(p->opt)) == NULL ||
133 (argv[3] = pack_byte(p->uv)) == NULL ||
134 (argv[4] = pack_byte(p->excl_count)) == NULL ||
135 (argv[5] = pack_int(p->ext)) == NULL ||
136 (argv[6] = pack_int(p->seed)) == NULL ||
137 (argv[7] = pack_string(p->pin)) == NULL ||
138 (argv[8] = pack_string(p->rp_id)) == NULL ||
139 (argv[9] = pack_string(p->rp_name)) == NULL ||
140 (argv[10] = pack_string(p->user_icon)) == NULL ||
141 (argv[11] = pack_string(p->user_name)) == NULL ||
142 (argv[12] = pack_string(p->user_nick)) == NULL ||
143 (argv[13] = pack_blob(&p->cdh)) == NULL ||
144 (argv[14] = pack_blob(&p->user_id)) == NULL ||
145 (argv[15] = pack_blob(&p->wire_data)) == NULL ||
146 (argv[16] = pack_blob(&p->excl_cred)) == NULL)
147 goto fail;
148
149 for (size_t i = 0; i < 17; i++)
150 if (cbor_array_push(array, argv[i]) == false)
151 goto fail;
152
153 if ((cbor_len = cbor_serialize_alloc(array, &cbor,
154 &cbor_alloc_len)) == 0 || cbor_len > len) {
155 cbor_len = 0;
156 goto fail;
157 }
158
159 memcpy(ptr, cbor, cbor_len);
160 fail:
161 for (size_t i = 0; i < 17; i++)
162 if (argv[i])
163 cbor_decref(&argv[i]);
164
165 if (array)
166 cbor_decref(&array);
167
168 free(cbor);
169
170 return cbor_len;
171 }
172
173 size_t
pack_dummy(uint8_t * ptr,size_t len)174 pack_dummy(uint8_t *ptr, size_t len)
175 {
176 struct param dummy;
177 uint8_t blob[MAXCORPUS];
178 size_t blob_len;
179
180 memset(&dummy, 0, sizeof(dummy));
181
182 dummy.type = 1;
183 dummy.ext = FIDO_EXT_HMAC_SECRET;
184
185 strlcpy(dummy.pin, dummy_pin, sizeof(dummy.pin));
186 strlcpy(dummy.rp_id, dummy_rp_id, sizeof(dummy.rp_id));
187 strlcpy(dummy.rp_name, dummy_rp_name, sizeof(dummy.rp_name));
188 strlcpy(dummy.user_icon, dummy_user_icon, sizeof(dummy.user_icon));
189 strlcpy(dummy.user_name, dummy_user_name, sizeof(dummy.user_name));
190 strlcpy(dummy.user_nick, dummy_user_nick, sizeof(dummy.user_nick));
191
192 dummy.cdh.len = sizeof(dummy_cdh);
193 dummy.user_id.len = sizeof(dummy_user_id);
194 dummy.wire_data.len = sizeof(dummy_wire_data_fido);
195
196 memcpy(&dummy.cdh.body, &dummy_cdh, dummy.cdh.len);
197 memcpy(&dummy.user_id.body, &dummy_user_id, dummy.user_id.len);
198 memcpy(&dummy.wire_data.body, &dummy_wire_data_fido,
199 dummy.wire_data.len);
200
201 assert((blob_len = pack(blob, sizeof(blob), &dummy)) != 0);
202
203 if (blob_len > len) {
204 memcpy(ptr, blob, len);
205 return len;
206 }
207
208 memcpy(ptr, blob, blob_len);
209
210 return blob_len;
211 }
212
213 static void
make_cred(fido_cred_t * cred,uint8_t opt,int type,const struct blob * cdh,const char * rp_id,const char * rp_name,const struct blob * user_id,const char * user_name,const char * user_nick,const char * user_icon,int ext,uint8_t rk,uint8_t uv,const char * pin,uint8_t excl_count,const struct blob * excl_cred)214 make_cred(fido_cred_t *cred, uint8_t opt, int type, const struct blob *cdh,
215 const char *rp_id, const char *rp_name, const struct blob *user_id,
216 const char *user_name, const char *user_nick, const char *user_icon,
217 int ext, uint8_t rk, uint8_t uv, const char *pin, uint8_t excl_count,
218 const struct blob *excl_cred)
219 {
220 fido_dev_t *dev;
221
222 if ((dev = open_dev(opt & 2)) == NULL)
223 return;
224 if (opt & 1)
225 fido_dev_force_u2f(dev);
226
227 for (uint8_t i = 0; i < excl_count; i++)
228 fido_cred_exclude(cred, excl_cred->body, excl_cred->len);
229
230 fido_cred_set_type(cred, type);
231 fido_cred_set_clientdata_hash(cred, cdh->body, cdh->len);
232 fido_cred_set_rp(cred, rp_id, rp_name);
233 fido_cred_set_user(cred, user_id->body, user_id->len, user_name,
234 user_nick, user_icon);
235
236 if (ext & FIDO_EXT_HMAC_SECRET)
237 fido_cred_set_extensions(cred, FIDO_EXT_HMAC_SECRET);
238 if (ext & FIDO_EXT_CRED_BLOB)
239 fido_cred_set_blob(cred, user_id->body, user_id->len);
240 if (ext & FIDO_EXT_LARGEBLOB_KEY)
241 fido_cred_set_extensions(cred, FIDO_EXT_LARGEBLOB_KEY);
242 if (ext & FIDO_EXT_MINPINLEN)
243 fido_cred_set_pin_minlen(cred, strlen(pin));
244
245 if (rk & 1)
246 fido_cred_set_rk(cred, FIDO_OPT_TRUE);
247 if (uv & 1)
248 fido_cred_set_uv(cred, FIDO_OPT_TRUE);
249 if (user_id->len)
250 fido_cred_set_prot(cred, user_id->body[0] & 0x03);
251
252 /* repeat memory operations to trigger reallocation paths */
253 fido_cred_set_type(cred, type);
254 fido_cred_set_clientdata_hash(cred, cdh->body, cdh->len);
255 fido_cred_set_rp(cred, rp_id, rp_name);
256 fido_cred_set_user(cred, user_id->body, user_id->len, user_name,
257 user_nick, user_icon);
258
259 if (strlen(pin) == 0)
260 pin = NULL;
261
262 fido_dev_make_cred(dev, cred, (opt & 1) ? NULL : pin);
263
264 fido_dev_cancel(dev);
265 fido_dev_close(dev);
266 fido_dev_free(&dev);
267 }
268
269 static void
verify_cred(int type,const unsigned char * cdh_ptr,size_t cdh_len,const char * rp_id,const char * rp_name,const unsigned char * authdata_ptr,size_t authdata_len,const unsigned char * authdata_raw_ptr,size_t authdata_raw_len,int ext,uint8_t rk,uint8_t uv,const unsigned char * x5c_ptr,size_t x5c_len,const unsigned char * sig_ptr,size_t sig_len,const unsigned char * attstmt_ptr,size_t attstmt_len,const char * fmt,int prot,size_t minpinlen)270 verify_cred(int type, const unsigned char *cdh_ptr, size_t cdh_len,
271 const char *rp_id, const char *rp_name, const unsigned char *authdata_ptr,
272 size_t authdata_len, const unsigned char *authdata_raw_ptr,
273 size_t authdata_raw_len, int ext, uint8_t rk, uint8_t uv,
274 const unsigned char *x5c_ptr, size_t x5c_len, const unsigned char *sig_ptr,
275 size_t sig_len, const unsigned char *attstmt_ptr, size_t attstmt_len,
276 const char *fmt, int prot, size_t minpinlen)
277 {
278 fido_cred_t *cred;
279 uint8_t flags;
280 uint32_t sigcount;
281 int r;
282
283 if ((cred = fido_cred_new()) == NULL)
284 return;
285
286 fido_cred_set_type(cred, type);
287 fido_cred_set_clientdata_hash(cred, cdh_ptr, cdh_len);
288 fido_cred_set_rp(cred, rp_id, rp_name);
289 consume(authdata_ptr, authdata_len);
290 consume(authdata_raw_ptr, authdata_raw_len);
291 consume(x5c_ptr, x5c_len);
292 consume(sig_ptr, sig_len);
293 consume(attstmt_ptr, attstmt_len);
294 if (fido_cred_set_authdata(cred, authdata_ptr, authdata_len) != FIDO_OK)
295 fido_cred_set_authdata_raw(cred, authdata_raw_ptr,
296 authdata_raw_len);
297 fido_cred_set_extensions(cred, ext);
298 if (fido_cred_set_attstmt(cred, attstmt_ptr, attstmt_len) != FIDO_OK) {
299 fido_cred_set_x509(cred, x5c_ptr, x5c_len);
300 fido_cred_set_sig(cred, sig_ptr, sig_len);
301 }
302 fido_cred_set_prot(cred, prot);
303 fido_cred_set_pin_minlen(cred, minpinlen);
304
305 if (rk & 1)
306 fido_cred_set_rk(cred, FIDO_OPT_TRUE);
307 if (uv & 1)
308 fido_cred_set_uv(cred, FIDO_OPT_TRUE);
309 if (fmt)
310 fido_cred_set_fmt(cred, fmt);
311
312 /* repeat memory operations to trigger reallocation paths */
313 if (fido_cred_set_authdata(cred, authdata_ptr, authdata_len) != FIDO_OK)
314 fido_cred_set_authdata_raw(cred, authdata_raw_ptr,
315 authdata_raw_len);
316 if (fido_cred_set_attstmt(cred, attstmt_ptr, attstmt_len) != FIDO_OK) {
317 fido_cred_set_x509(cred, x5c_ptr, x5c_len);
318 fido_cred_set_sig(cred, sig_ptr, sig_len);
319 }
320 fido_cred_set_x509(cred, x5c_ptr, x5c_len);
321 fido_cred_set_sig(cred, sig_ptr, sig_len);
322
323 r = fido_cred_verify(cred);
324 consume(&r, sizeof(r));
325 r = fido_cred_verify_self(cred);
326 consume(&r, sizeof(r));
327
328 consume(fido_cred_pubkey_ptr(cred), fido_cred_pubkey_len(cred));
329 consume(fido_cred_id_ptr(cred), fido_cred_id_len(cred));
330 consume(fido_cred_aaguid_ptr(cred), fido_cred_aaguid_len(cred));
331 consume(fido_cred_user_id_ptr(cred), fido_cred_user_id_len(cred));
332 consume_str(fido_cred_user_name(cred));
333 consume_str(fido_cred_display_name(cred));
334 consume(fido_cred_largeblob_key_ptr(cred),
335 fido_cred_largeblob_key_len(cred));
336
337 flags = fido_cred_flags(cred);
338 consume(&flags, sizeof(flags));
339 sigcount = fido_cred_sigcount(cred);
340 consume(&sigcount, sizeof(sigcount));
341 type = fido_cred_type(cred);
342 consume(&type, sizeof(type));
343 minpinlen = fido_cred_pin_minlen(cred);
344 consume(&minpinlen, sizeof(minpinlen));
345
346 fido_cred_free(&cred);
347 }
348
349 static void
test_cred(const struct param * p)350 test_cred(const struct param *p)
351 {
352 fido_cred_t *cred = NULL;
353 int cose_alg = 0;
354
355 if ((cred = fido_cred_new()) == NULL)
356 return;
357
358 switch (p->type & 3) {
359 case 0:
360 cose_alg = COSE_ES256;
361 break;
362 case 1:
363 cose_alg = COSE_RS256;
364 break;
365 case 2:
366 cose_alg = COSE_ES384;
367 break;
368 default:
369 cose_alg = COSE_EDDSA;
370 break;
371 }
372
373 set_wire_data(p->wire_data.body, p->wire_data.len);
374
375 make_cred(cred, p->opt, cose_alg, &p->cdh, p->rp_id, p->rp_name,
376 &p->user_id, p->user_name, p->user_nick, p->user_icon, p->ext,
377 p->rk, p->uv, p->pin, p->excl_count, &p->excl_cred);
378
379 verify_cred(cose_alg,
380 fido_cred_clientdata_hash_ptr(cred),
381 fido_cred_clientdata_hash_len(cred), fido_cred_rp_id(cred),
382 fido_cred_rp_name(cred), fido_cred_authdata_ptr(cred),
383 fido_cred_authdata_len(cred), fido_cred_authdata_raw_ptr(cred),
384 fido_cred_authdata_raw_len(cred), p->ext, p->rk, p->uv,
385 fido_cred_x5c_ptr(cred), fido_cred_x5c_len(cred),
386 fido_cred_sig_ptr(cred), fido_cred_sig_len(cred),
387 fido_cred_attstmt_ptr(cred), fido_cred_attstmt_len(cred),
388 fido_cred_fmt(cred), fido_cred_prot(cred),
389 fido_cred_pin_minlen(cred));
390
391 fido_cred_free(&cred);
392 }
393
394 static void
test_touch(const struct param * p)395 test_touch(const struct param *p)
396 {
397 fido_dev_t *dev;
398 int r;
399 int touched;
400
401 set_wire_data(p->wire_data.body, p->wire_data.len);
402
403 if ((dev = open_dev(p->opt & 2)) == NULL)
404 return;
405 if (p->opt & 1)
406 fido_dev_force_u2f(dev);
407
408 r = fido_dev_get_touch_begin(dev);
409 consume_str(fido_strerr(r));
410 r = fido_dev_get_touch_status(dev, &touched, -1);
411 consume_str(fido_strerr(r));
412 consume(&touched, sizeof(touched));
413
414 fido_dev_cancel(dev);
415 fido_dev_close(dev);
416 fido_dev_free(&dev);
417 }
418
419 static void
test_misc(const struct param * p)420 test_misc(const struct param *p)
421 {
422 fido_cred_t *cred = NULL;
423
424 if ((cred = fido_cred_new()) == NULL)
425 return;
426
427 /* reuse user id as credential id */
428 fido_cred_set_id(cred, p->user_id.body, p->user_id.len);
429 consume(fido_cred_id_ptr(cred), fido_cred_id_len(cred));
430 fido_cred_free(&cred);
431 }
432
433 void
test(const struct param * p)434 test(const struct param *p)
435 {
436 prng_init((unsigned int)p->seed);
437 fuzz_clock_reset();
438 fido_init(FIDO_DEBUG);
439 fido_set_log_handler(consume_str);
440
441 test_cred(p);
442 test_touch(p);
443 test_misc(p);
444 }
445
446 void
mutate(struct param * p,unsigned int seed,unsigned int flags)447 mutate(struct param *p, unsigned int seed, unsigned int flags) NO_MSAN
448 {
449 if (flags & MUTATE_SEED)
450 p->seed = (int)seed;
451
452 if (flags & MUTATE_PARAM) {
453 mutate_byte(&p->rk);
454 mutate_byte(&p->type);
455 mutate_byte(&p->opt);
456 mutate_byte(&p->uv);
457 mutate_byte(&p->excl_count);
458 mutate_int(&p->ext);
459 mutate_blob(&p->cdh);
460 mutate_blob(&p->user_id);
461 mutate_blob(&p->excl_cred);
462 mutate_string(p->pin);
463 mutate_string(p->user_icon);
464 mutate_string(p->user_name);
465 mutate_string(p->user_nick);
466 mutate_string(p->rp_id);
467 mutate_string(p->rp_name);
468 }
469
470 if (flags & MUTATE_WIREDATA) {
471 if (p->opt & 1) {
472 p->wire_data.len = sizeof(dummy_wire_data_u2f);
473 memcpy(&p->wire_data.body, &dummy_wire_data_u2f,
474 p->wire_data.len);
475 } else {
476 p->wire_data.len = sizeof(dummy_wire_data_fido);
477 memcpy(&p->wire_data.body, &dummy_wire_data_fido,
478 p->wire_data.len);
479 }
480 mutate_blob(&p->wire_data);
481 }
482 }
483