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 * 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 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 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 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 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 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 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 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 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 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