Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright (c) 2018-2022 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 <openssl/sha.h> |
9 | | #include <openssl/x509.h> |
10 | | |
11 | | #ifdef HAVE_UNISTD_H |
12 | | #include <unistd.h> |
13 | | #endif |
14 | | #include <errno.h> |
15 | | |
16 | | #include "fido.h" |
17 | | #include "fido/es256.h" |
18 | | #include "fallthrough.h" |
19 | | |
20 | 735 | #define U2F_PACE_MS (100) |
21 | | |
22 | | #if defined(_MSC_VER) |
23 | | static int |
24 | | usleep(unsigned int usec) |
25 | | { |
26 | | Sleep(usec / 1000); |
27 | | |
28 | | return (0); |
29 | | } |
30 | | #endif |
31 | | |
32 | | static int |
33 | | delay_ms(unsigned int ms, int *ms_remain) |
34 | 735 | { |
35 | 735 | if (*ms_remain > -1 && (unsigned int)*ms_remain < ms) |
36 | 489 | ms = (unsigned int)*ms_remain; |
37 | | |
38 | 735 | if (ms > UINT_MAX / 1000) { |
39 | 0 | fido_log_debug("%s: ms=%u", __func__, ms); |
40 | 0 | return (-1); |
41 | 0 | } |
42 | | |
43 | 735 | if (usleep(ms * 1000) < 0) { |
44 | 3 | fido_log_error(errno, "%s: usleep", __func__); |
45 | 3 | return (-1); |
46 | 3 | } |
47 | | |
48 | 732 | if (*ms_remain > -1) |
49 | 732 | *ms_remain -= (int)ms; |
50 | | |
51 | 732 | return (0); |
52 | 735 | } |
53 | | |
54 | | static int |
55 | | sig_get(fido_blob_t *sig, const unsigned char **buf, size_t *len) |
56 | 235 | { |
57 | 235 | sig->len = *len; /* consume the whole buffer */ |
58 | 235 | if ((sig->ptr = calloc(1, sig->len)) == NULL || |
59 | 235 | fido_buf_read(buf, len, sig->ptr, sig->len) < 0) { |
60 | 2 | fido_log_debug("%s: fido_buf_read", __func__); |
61 | 2 | fido_blob_reset(sig); |
62 | 2 | return (-1); |
63 | 2 | } |
64 | | |
65 | 233 | return (0); |
66 | 235 | } |
67 | | |
68 | | static int |
69 | | x5c_get(fido_blob_t *x5c, const unsigned char **buf, size_t *len) |
70 | 94 | { |
71 | 94 | X509 *cert = NULL; |
72 | 94 | int ok = -1; |
73 | | |
74 | 94 | if (*len > LONG_MAX) { |
75 | 0 | fido_log_debug("%s: invalid len %zu", __func__, *len); |
76 | 0 | goto fail; |
77 | 0 | } |
78 | | |
79 | | /* find out the certificate's length */ |
80 | 94 | const unsigned char *end = *buf; |
81 | 94 | if ((cert = d2i_X509(NULL, &end, (long)*len)) == NULL || end <= *buf || |
82 | 94 | (x5c->len = (size_t)(end - *buf)) >= *len) { |
83 | 9 | fido_log_debug("%s: d2i_X509", __func__); |
84 | 9 | goto fail; |
85 | 9 | } |
86 | | |
87 | | /* read accordingly */ |
88 | 85 | if ((x5c->ptr = calloc(1, x5c->len)) == NULL || |
89 | 85 | fido_buf_read(buf, len, x5c->ptr, x5c->len) < 0) { |
90 | 1 | fido_log_debug("%s: fido_buf_read", __func__); |
91 | 1 | goto fail; |
92 | 1 | } |
93 | | |
94 | 84 | ok = 0; |
95 | 94 | fail: |
96 | 94 | if (cert != NULL) |
97 | 85 | X509_free(cert); |
98 | | |
99 | 94 | if (ok < 0) |
100 | 10 | fido_blob_reset(x5c); |
101 | | |
102 | 94 | return (ok); |
103 | 84 | } |
104 | | |
105 | | static int |
106 | | authdata_fake(const char *rp_id, uint8_t flags, uint32_t sigcount, |
107 | | fido_blob_t *fake_cbor_ad) |
108 | 150 | { |
109 | 150 | fido_authdata_t ad; |
110 | 150 | cbor_item_t *item = NULL; |
111 | 150 | size_t alloc_len; |
112 | | |
113 | 150 | memset(&ad, 0, sizeof(ad)); |
114 | | |
115 | 150 | if (SHA256((const void *)rp_id, strlen(rp_id), |
116 | 150 | ad.rp_id_hash) != ad.rp_id_hash) { |
117 | 2 | fido_log_debug("%s: sha256", __func__); |
118 | 2 | return (-1); |
119 | 2 | } |
120 | | |
121 | 148 | ad.flags = flags; /* XXX translate? */ |
122 | 148 | ad.sigcount = sigcount; |
123 | | |
124 | 148 | if ((item = cbor_build_bytestring((const unsigned char *)&ad, |
125 | 148 | sizeof(ad))) == NULL) { |
126 | 1 | fido_log_debug("%s: cbor_build_bytestring", __func__); |
127 | 1 | return (-1); |
128 | 1 | } |
129 | | |
130 | 147 | if (fake_cbor_ad->ptr != NULL || |
131 | 147 | (fake_cbor_ad->len = cbor_serialize_alloc(item, &fake_cbor_ad->ptr, |
132 | 147 | &alloc_len)) == 0) { |
133 | 1 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
134 | 1 | cbor_decref(&item); |
135 | 1 | return (-1); |
136 | 1 | } |
137 | | |
138 | 146 | cbor_decref(&item); |
139 | | |
140 | 146 | return (0); |
141 | 147 | } |
142 | | |
143 | | /* TODO: use u2f_get_touch_begin & u2f_get_touch_status instead */ |
144 | | static int |
145 | | send_dummy_register(fido_dev_t *dev, int *ms) |
146 | 34 | { |
147 | 34 | iso7816_apdu_t *apdu = NULL; |
148 | 34 | unsigned char *reply = NULL; |
149 | 34 | unsigned char challenge[SHA256_DIGEST_LENGTH]; |
150 | 34 | unsigned char application[SHA256_DIGEST_LENGTH]; |
151 | 34 | int r; |
152 | | |
153 | | /* dummy challenge & application */ |
154 | 34 | memset(&challenge, 0xff, sizeof(challenge)); |
155 | 34 | memset(&application, 0xff, sizeof(application)); |
156 | | |
157 | 34 | if ((apdu = iso7816_new(0, U2F_CMD_REGISTER, 0, 2 * |
158 | 34 | SHA256_DIGEST_LENGTH)) == NULL || |
159 | 34 | iso7816_add(apdu, &challenge, sizeof(challenge)) < 0 || |
160 | 34 | iso7816_add(apdu, &application, sizeof(application)) < 0) { |
161 | 1 | fido_log_debug("%s: iso7816", __func__); |
162 | 1 | r = FIDO_ERR_INTERNAL; |
163 | 1 | goto fail; |
164 | 1 | } |
165 | | |
166 | 33 | if ((reply = malloc(FIDO_MAXMSG)) == NULL) { |
167 | 1 | fido_log_debug("%s: malloc", __func__); |
168 | 1 | r = FIDO_ERR_INTERNAL; |
169 | 1 | goto fail; |
170 | 1 | } |
171 | | |
172 | 76 | do { |
173 | 76 | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
174 | 76 | iso7816_len(apdu), ms) < 0) { |
175 | 4 | fido_log_debug("%s: fido_tx", __func__); |
176 | 4 | r = FIDO_ERR_TX; |
177 | 4 | goto fail; |
178 | 4 | } |
179 | 72 | if (fido_rx(dev, CTAP_CMD_MSG, reply, FIDO_MAXMSG, ms) < 2) { |
180 | 12 | fido_log_debug("%s: fido_rx", __func__); |
181 | 12 | r = FIDO_ERR_RX; |
182 | 12 | goto fail; |
183 | 12 | } |
184 | 60 | if (delay_ms(U2F_PACE_MS, ms) != 0) { |
185 | 1 | fido_log_debug("%s: delay_ms", __func__); |
186 | 1 | r = FIDO_ERR_RX; |
187 | 1 | goto fail; |
188 | 1 | } |
189 | 60 | } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED); |
190 | | |
191 | 15 | r = FIDO_OK; |
192 | 34 | fail: |
193 | 34 | iso7816_free(&apdu); |
194 | 34 | freezero(reply, FIDO_MAXMSG); |
195 | | |
196 | 34 | return (r); |
197 | 15 | } |
198 | | |
199 | | static int |
200 | | key_lookup(fido_dev_t *dev, const char *rp_id, const fido_blob_t *key_id, |
201 | | int *found, int *ms) |
202 | 1.04k | { |
203 | 1.04k | iso7816_apdu_t *apdu = NULL; |
204 | 1.04k | unsigned char *reply = NULL; |
205 | 1.04k | unsigned char challenge[SHA256_DIGEST_LENGTH]; |
206 | 1.04k | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
207 | 1.04k | uint8_t key_id_len; |
208 | 1.04k | int r; |
209 | | |
210 | 1.04k | if (key_id->len > UINT8_MAX || rp_id == NULL) { |
211 | 9 | fido_log_debug("%s: key_id->len=%zu, rp_id=%p", __func__, |
212 | 9 | key_id->len, (const void *)rp_id); |
213 | 9 | r = FIDO_ERR_INVALID_ARGUMENT; |
214 | 9 | goto fail; |
215 | 9 | } |
216 | | |
217 | 1.04k | memset(&challenge, 0xff, sizeof(challenge)); |
218 | 1.04k | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
219 | | |
220 | 1.04k | if (SHA256((const void *)rp_id, strlen(rp_id), |
221 | 1.04k | rp_id_hash) != rp_id_hash) { |
222 | 3 | fido_log_debug("%s: sha256", __func__); |
223 | 3 | r = FIDO_ERR_INTERNAL; |
224 | 3 | goto fail; |
225 | 3 | } |
226 | | |
227 | 1.03k | key_id_len = (uint8_t)key_id->len; |
228 | | |
229 | 1.03k | if ((apdu = iso7816_new(0, U2F_CMD_AUTH, U2F_AUTH_CHECK, (uint16_t)(2 * |
230 | 1.03k | SHA256_DIGEST_LENGTH + sizeof(key_id_len) + key_id_len))) == NULL || |
231 | 1.03k | iso7816_add(apdu, &challenge, sizeof(challenge)) < 0 || |
232 | 1.03k | iso7816_add(apdu, &rp_id_hash, sizeof(rp_id_hash)) < 0 || |
233 | 1.03k | iso7816_add(apdu, &key_id_len, sizeof(key_id_len)) < 0 || |
234 | 1.03k | iso7816_add(apdu, key_id->ptr, key_id_len) < 0) { |
235 | 3 | fido_log_debug("%s: iso7816", __func__); |
236 | 3 | r = FIDO_ERR_INTERNAL; |
237 | 3 | goto fail; |
238 | 3 | } |
239 | | |
240 | 1.03k | if ((reply = malloc(FIDO_MAXMSG)) == NULL) { |
241 | 2 | fido_log_debug("%s: malloc", __func__); |
242 | 2 | r = FIDO_ERR_INTERNAL; |
243 | 2 | goto fail; |
244 | 2 | } |
245 | | |
246 | 1.03k | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
247 | 1.03k | iso7816_len(apdu), ms) < 0) { |
248 | 77 | fido_log_debug("%s: fido_tx", __func__); |
249 | 77 | r = FIDO_ERR_TX; |
250 | 77 | goto fail; |
251 | 77 | } |
252 | 955 | if (fido_rx(dev, CTAP_CMD_MSG, reply, FIDO_MAXMSG, ms) != 2) { |
253 | 472 | fido_log_debug("%s: fido_rx", __func__); |
254 | 472 | r = FIDO_ERR_RX; |
255 | 472 | goto fail; |
256 | 472 | } |
257 | | |
258 | 483 | switch ((reply[0] << 8) | reply[1]) { |
259 | 344 | case SW_CONDITIONS_NOT_SATISFIED: |
260 | 344 | *found = 1; /* key exists */ |
261 | 344 | break; |
262 | 18 | case SW_WRONG_DATA: |
263 | 18 | *found = 0; /* key does not exist */ |
264 | 18 | break; |
265 | 121 | default: |
266 | | /* unexpected sw */ |
267 | 121 | r = FIDO_ERR_INTERNAL; |
268 | 121 | goto fail; |
269 | 483 | } |
270 | | |
271 | 362 | r = FIDO_OK; |
272 | 1.04k | fail: |
273 | 1.04k | iso7816_free(&apdu); |
274 | 1.04k | freezero(reply, FIDO_MAXMSG); |
275 | | |
276 | 1.04k | return (r); |
277 | 362 | } |
278 | | |
279 | | static int |
280 | | parse_auth_reply(fido_blob_t *sig, fido_blob_t *ad, const char *rp_id, |
281 | | const unsigned char *reply, size_t len) |
282 | 190 | { |
283 | 190 | uint8_t flags; |
284 | 190 | uint32_t sigcount; |
285 | | |
286 | 190 | if (len < 2 || ((reply[len - 2] << 8) | reply[len - 1]) != SW_NO_ERROR) { |
287 | 37 | fido_log_debug("%s: unexpected sw", __func__); |
288 | 37 | return (FIDO_ERR_RX); |
289 | 37 | } |
290 | | |
291 | 153 | len -= 2; |
292 | | |
293 | 153 | if (fido_buf_read(&reply, &len, &flags, sizeof(flags)) < 0 || |
294 | 153 | fido_buf_read(&reply, &len, &sigcount, sizeof(sigcount)) < 0) { |
295 | 2 | fido_log_debug("%s: fido_buf_read", __func__); |
296 | 2 | return (FIDO_ERR_RX); |
297 | 2 | } |
298 | | |
299 | 151 | if (sig_get(sig, &reply, &len) < 0) { |
300 | 1 | fido_log_debug("%s: sig_get", __func__); |
301 | 1 | return (FIDO_ERR_RX); |
302 | 1 | } |
303 | | |
304 | 150 | if (authdata_fake(rp_id, flags, sigcount, ad) < 0) { |
305 | 4 | fido_log_debug("%s; authdata_fake", __func__); |
306 | 4 | return (FIDO_ERR_RX); |
307 | 4 | } |
308 | | |
309 | 146 | return (FIDO_OK); |
310 | 150 | } |
311 | | |
312 | | static int |
313 | | do_auth(fido_dev_t *dev, const fido_blob_t *cdh, const char *rp_id, |
314 | | const fido_blob_t *key_id, fido_blob_t *sig, fido_blob_t *ad, int *ms) |
315 | 226 | { |
316 | 226 | iso7816_apdu_t *apdu = NULL; |
317 | 226 | unsigned char *reply = NULL; |
318 | 226 | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
319 | 226 | int reply_len; |
320 | 226 | uint8_t key_id_len; |
321 | 226 | int r; |
322 | | |
323 | 226 | #ifdef FIDO_FUZZ |
324 | 226 | *ms = 0; /* XXX */ |
325 | 226 | #endif |
326 | | |
327 | 226 | if (cdh->len != SHA256_DIGEST_LENGTH || key_id->len > UINT8_MAX || |
328 | 226 | rp_id == NULL) { |
329 | 13 | r = FIDO_ERR_INVALID_ARGUMENT; |
330 | 13 | goto fail; |
331 | 13 | } |
332 | | |
333 | 213 | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
334 | | |
335 | 213 | if (SHA256((const void *)rp_id, strlen(rp_id), |
336 | 213 | rp_id_hash) != rp_id_hash) { |
337 | 1 | fido_log_debug("%s: sha256", __func__); |
338 | 1 | r = FIDO_ERR_INTERNAL; |
339 | 1 | goto fail; |
340 | 1 | } |
341 | | |
342 | 212 | key_id_len = (uint8_t)key_id->len; |
343 | | |
344 | 212 | if ((apdu = iso7816_new(0, U2F_CMD_AUTH, U2F_AUTH_SIGN, (uint16_t)(2 * |
345 | 212 | SHA256_DIGEST_LENGTH + sizeof(key_id_len) + key_id_len))) == NULL || |
346 | 212 | iso7816_add(apdu, cdh->ptr, cdh->len) < 0 || |
347 | 212 | iso7816_add(apdu, &rp_id_hash, sizeof(rp_id_hash)) < 0 || |
348 | 212 | iso7816_add(apdu, &key_id_len, sizeof(key_id_len)) < 0 || |
349 | 212 | iso7816_add(apdu, key_id->ptr, key_id_len) < 0) { |
350 | 1 | fido_log_debug("%s: iso7816", __func__); |
351 | 1 | r = FIDO_ERR_INTERNAL; |
352 | 1 | goto fail; |
353 | 1 | } |
354 | | |
355 | 211 | if ((reply = malloc(FIDO_MAXMSG)) == NULL) { |
356 | 1 | fido_log_debug("%s: malloc", __func__); |
357 | 1 | r = FIDO_ERR_INTERNAL; |
358 | 1 | goto fail; |
359 | 1 | } |
360 | | |
361 | 331 | do { |
362 | 331 | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
363 | 331 | iso7816_len(apdu), ms) < 0) { |
364 | 3 | fido_log_debug("%s: fido_tx", __func__); |
365 | 3 | r = FIDO_ERR_TX; |
366 | 3 | goto fail; |
367 | 3 | } |
368 | 328 | if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, reply, |
369 | 328 | FIDO_MAXMSG, ms)) < 2) { |
370 | 16 | fido_log_debug("%s: fido_rx", __func__); |
371 | 16 | r = FIDO_ERR_RX; |
372 | 16 | goto fail; |
373 | 16 | } |
374 | 312 | if (delay_ms(U2F_PACE_MS, ms) != 0) { |
375 | 1 | fido_log_debug("%s: delay_ms", __func__); |
376 | 1 | r = FIDO_ERR_RX; |
377 | 1 | goto fail; |
378 | 1 | } |
379 | 312 | } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED); |
380 | | |
381 | 190 | if ((r = parse_auth_reply(sig, ad, rp_id, reply, |
382 | 190 | (size_t)reply_len)) != FIDO_OK) { |
383 | 44 | fido_log_debug("%s: parse_auth_reply", __func__); |
384 | 44 | goto fail; |
385 | 44 | } |
386 | | |
387 | 226 | fail: |
388 | 226 | iso7816_free(&apdu); |
389 | 226 | freezero(reply, FIDO_MAXMSG); |
390 | | |
391 | 226 | return (r); |
392 | 190 | } |
393 | | |
394 | | static int |
395 | | cbor_blob_from_ec_point(const uint8_t *ec_point, size_t ec_point_len, |
396 | | fido_blob_t *cbor_blob) |
397 | 70 | { |
398 | 70 | es256_pk_t *pk = NULL; |
399 | 70 | cbor_item_t *pk_cbor = NULL; |
400 | 70 | size_t alloc_len; |
401 | 70 | int ok = -1; |
402 | | |
403 | | /* only handle uncompressed points */ |
404 | 70 | if (ec_point_len != 65 || ec_point[0] != 0x04) { |
405 | 8 | fido_log_debug("%s: unexpected format", __func__); |
406 | 8 | goto fail; |
407 | 8 | } |
408 | | |
409 | 62 | if ((pk = es256_pk_new()) == NULL || |
410 | 62 | es256_pk_set_x(pk, &ec_point[1]) < 0 || |
411 | 62 | es256_pk_set_y(pk, &ec_point[33]) < 0) { |
412 | 1 | fido_log_debug("%s: es256_pk_set", __func__); |
413 | 1 | goto fail; |
414 | 1 | } |
415 | | |
416 | 61 | if ((pk_cbor = es256_pk_encode(pk, 0)) == NULL) { |
417 | 1 | fido_log_debug("%s: es256_pk_encode", __func__); |
418 | 1 | goto fail; |
419 | 1 | } |
420 | | |
421 | 60 | if ((cbor_blob->len = cbor_serialize_alloc(pk_cbor, &cbor_blob->ptr, |
422 | 60 | &alloc_len)) != 77) { |
423 | 1 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
424 | 1 | goto fail; |
425 | 1 | } |
426 | | |
427 | 59 | ok = 0; |
428 | 70 | fail: |
429 | 70 | es256_pk_free(&pk); |
430 | | |
431 | 70 | if (pk_cbor) |
432 | 60 | cbor_decref(&pk_cbor); |
433 | | |
434 | 70 | return (ok); |
435 | 59 | } |
436 | | |
437 | | static int |
438 | | encode_cred_attstmt(int cose_alg, const fido_blob_t *x5c, |
439 | | const fido_blob_t *sig, fido_blob_t *out) |
440 | 83 | { |
441 | 83 | cbor_item_t *item = NULL; |
442 | 83 | cbor_item_t *x5c_cbor = NULL; |
443 | 83 | const uint8_t alg_cbor = (uint8_t)(-cose_alg - 1); |
444 | 83 | struct cbor_pair kv[3]; |
445 | 83 | size_t alloc_len; |
446 | 83 | int ok = -1; |
447 | | |
448 | 83 | memset(&kv, 0, sizeof(kv)); |
449 | 83 | memset(out, 0, sizeof(*out)); |
450 | | |
451 | 83 | if ((item = cbor_new_definite_map(3)) == NULL) { |
452 | 1 | fido_log_debug("%s: cbor_new_definite_map", __func__); |
453 | 1 | goto fail; |
454 | 1 | } |
455 | | |
456 | 82 | if ((kv[0].key = cbor_build_string("alg")) == NULL || |
457 | 82 | (kv[0].value = cbor_build_negint8(alg_cbor)) == NULL || |
458 | 82 | !cbor_map_add(item, kv[0])) { |
459 | 3 | fido_log_debug("%s: alg", __func__); |
460 | 3 | goto fail; |
461 | 3 | } |
462 | | |
463 | 79 | if ((kv[1].key = cbor_build_string("sig")) == NULL || |
464 | 79 | (kv[1].value = fido_blob_encode(sig)) == NULL || |
465 | 79 | !cbor_map_add(item, kv[1])) { |
466 | 3 | fido_log_debug("%s: sig", __func__); |
467 | 3 | goto fail; |
468 | 3 | } |
469 | | |
470 | 76 | if ((kv[2].key = cbor_build_string("x5c")) == NULL || |
471 | 76 | (kv[2].value = cbor_new_definite_array(1)) == NULL || |
472 | 76 | (x5c_cbor = fido_blob_encode(x5c)) == NULL || |
473 | 76 | !cbor_array_push(kv[2].value, x5c_cbor) || |
474 | 76 | !cbor_map_add(item, kv[2])) { |
475 | 5 | fido_log_debug("%s: x5c", __func__); |
476 | 5 | goto fail; |
477 | 5 | } |
478 | | |
479 | 71 | if ((out->len = cbor_serialize_alloc(item, &out->ptr, |
480 | 71 | &alloc_len)) == 0) { |
481 | 1 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
482 | 1 | goto fail; |
483 | 1 | } |
484 | | |
485 | 70 | ok = 0; |
486 | 83 | fail: |
487 | 83 | if (item != NULL) |
488 | 82 | cbor_decref(&item); |
489 | 83 | if (x5c_cbor != NULL) |
490 | 73 | cbor_decref(&x5c_cbor); |
491 | | |
492 | 332 | for (size_t i = 0; i < nitems(kv); i++) { |
493 | 249 | if (kv[i].key) |
494 | 234 | cbor_decref(&kv[i].key); |
495 | 249 | if (kv[i].value) |
496 | 231 | cbor_decref(&kv[i].value); |
497 | 249 | } |
498 | | |
499 | 83 | return (ok); |
500 | 70 | } |
501 | | |
502 | | static int |
503 | | encode_cred_authdata(const char *rp_id, const uint8_t *kh, uint8_t kh_len, |
504 | | const uint8_t *pubkey, size_t pubkey_len, fido_blob_t *out) |
505 | 70 | { |
506 | 70 | fido_authdata_t authdata; |
507 | 70 | fido_attcred_raw_t attcred_raw; |
508 | 70 | fido_blob_t pk_blob; |
509 | 70 | fido_blob_t authdata_blob; |
510 | 70 | cbor_item_t *authdata_cbor = NULL; |
511 | 70 | unsigned char *ptr; |
512 | 70 | size_t len; |
513 | 70 | size_t alloc_len; |
514 | 70 | int ok = -1; |
515 | | |
516 | 70 | memset(&pk_blob, 0, sizeof(pk_blob)); |
517 | 70 | memset(&authdata, 0, sizeof(authdata)); |
518 | 70 | memset(&authdata_blob, 0, sizeof(authdata_blob)); |
519 | 70 | memset(out, 0, sizeof(*out)); |
520 | | |
521 | 70 | if (rp_id == NULL) { |
522 | 0 | fido_log_debug("%s: NULL rp_id", __func__); |
523 | 0 | goto fail; |
524 | 0 | } |
525 | | |
526 | 70 | if (cbor_blob_from_ec_point(pubkey, pubkey_len, &pk_blob) < 0) { |
527 | 11 | fido_log_debug("%s: cbor_blob_from_ec_point", __func__); |
528 | 11 | goto fail; |
529 | 11 | } |
530 | | |
531 | 59 | if (SHA256((const void *)rp_id, strlen(rp_id), |
532 | 59 | authdata.rp_id_hash) != authdata.rp_id_hash) { |
533 | 1 | fido_log_debug("%s: sha256", __func__); |
534 | 1 | goto fail; |
535 | 1 | } |
536 | | |
537 | 58 | authdata.flags = (CTAP_AUTHDATA_ATT_CRED | CTAP_AUTHDATA_USER_PRESENT); |
538 | 58 | authdata.sigcount = 0; |
539 | | |
540 | 58 | memset(&attcred_raw.aaguid, 0, sizeof(attcred_raw.aaguid)); |
541 | 58 | attcred_raw.id_len = htobe16(kh_len); |
542 | | |
543 | 58 | len = authdata_blob.len = sizeof(authdata) + sizeof(attcred_raw) + |
544 | 58 | kh_len + pk_blob.len; |
545 | 58 | ptr = authdata_blob.ptr = calloc(1, authdata_blob.len); |
546 | | |
547 | 58 | fido_log_debug("%s: ptr=%p, len=%zu", __func__, (void *)ptr, len); |
548 | | |
549 | 58 | if (authdata_blob.ptr == NULL) |
550 | 1 | goto fail; |
551 | | |
552 | 57 | if (fido_buf_write(&ptr, &len, &authdata, sizeof(authdata)) < 0 || |
553 | 57 | fido_buf_write(&ptr, &len, &attcred_raw, sizeof(attcred_raw)) < 0 || |
554 | 57 | fido_buf_write(&ptr, &len, kh, kh_len) < 0 || |
555 | 57 | fido_buf_write(&ptr, &len, pk_blob.ptr, pk_blob.len) < 0) { |
556 | 0 | fido_log_debug("%s: fido_buf_write", __func__); |
557 | 0 | goto fail; |
558 | 0 | } |
559 | | |
560 | 57 | if ((authdata_cbor = fido_blob_encode(&authdata_blob)) == NULL) { |
561 | 1 | fido_log_debug("%s: fido_blob_encode", __func__); |
562 | 1 | goto fail; |
563 | 1 | } |
564 | | |
565 | 56 | if ((out->len = cbor_serialize_alloc(authdata_cbor, &out->ptr, |
566 | 56 | &alloc_len)) == 0) { |
567 | 1 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
568 | 1 | goto fail; |
569 | 1 | } |
570 | | |
571 | 55 | ok = 0; |
572 | 70 | fail: |
573 | 70 | if (authdata_cbor) |
574 | 56 | cbor_decref(&authdata_cbor); |
575 | | |
576 | 70 | fido_blob_reset(&pk_blob); |
577 | 70 | fido_blob_reset(&authdata_blob); |
578 | | |
579 | 70 | return (ok); |
580 | 55 | } |
581 | | |
582 | | static int |
583 | | parse_register_reply(fido_cred_t *cred, const unsigned char *reply, size_t len) |
584 | 152 | { |
585 | 152 | fido_blob_t x5c; |
586 | 152 | fido_blob_t sig; |
587 | 152 | fido_blob_t ad; |
588 | 152 | fido_blob_t stmt; |
589 | 152 | uint8_t dummy; |
590 | 152 | uint8_t pubkey[65]; |
591 | 152 | uint8_t kh_len = 0; |
592 | 152 | uint8_t *kh = NULL; |
593 | 152 | int r; |
594 | | |
595 | 152 | memset(&x5c, 0, sizeof(x5c)); |
596 | 152 | memset(&sig, 0, sizeof(sig)); |
597 | 152 | memset(&ad, 0, sizeof(ad)); |
598 | 152 | memset(&stmt, 0, sizeof(stmt)); |
599 | 152 | r = FIDO_ERR_RX; |
600 | | |
601 | | /* status word */ |
602 | 152 | if (len < 2 || ((reply[len - 2] << 8) | reply[len - 1]) != SW_NO_ERROR) { |
603 | 46 | fido_log_debug("%s: unexpected sw", __func__); |
604 | 46 | goto fail; |
605 | 46 | } |
606 | | |
607 | 106 | len -= 2; |
608 | | |
609 | | /* reserved byte */ |
610 | 106 | if (fido_buf_read(&reply, &len, &dummy, sizeof(dummy)) < 0 || |
611 | 106 | dummy != 0x05) { |
612 | 10 | fido_log_debug("%s: reserved byte", __func__); |
613 | 10 | goto fail; |
614 | 10 | } |
615 | | |
616 | | /* pubkey + key handle */ |
617 | 96 | if (fido_buf_read(&reply, &len, &pubkey, sizeof(pubkey)) < 0 || |
618 | 96 | fido_buf_read(&reply, &len, &kh_len, sizeof(kh_len)) < 0 || |
619 | 96 | (kh = calloc(1, kh_len)) == NULL || |
620 | 96 | fido_buf_read(&reply, &len, kh, kh_len) < 0) { |
621 | 2 | fido_log_debug("%s: fido_buf_read", __func__); |
622 | 2 | goto fail; |
623 | 2 | } |
624 | | |
625 | | /* x5c + sig */ |
626 | 94 | if (x5c_get(&x5c, &reply, &len) < 0 || |
627 | 94 | sig_get(&sig, &reply, &len) < 0) { |
628 | 11 | fido_log_debug("%s: x5c || sig", __func__); |
629 | 11 | goto fail; |
630 | 11 | } |
631 | | |
632 | | /* attstmt */ |
633 | 83 | if (encode_cred_attstmt(COSE_ES256, &x5c, &sig, &stmt) < 0) { |
634 | 13 | fido_log_debug("%s: encode_cred_attstmt", __func__); |
635 | 13 | goto fail; |
636 | 13 | } |
637 | | |
638 | | /* authdata */ |
639 | 70 | if (encode_cred_authdata(cred->rp.id, kh, kh_len, pubkey, |
640 | 70 | sizeof(pubkey), &ad) < 0) { |
641 | 15 | fido_log_debug("%s: encode_cred_authdata", __func__); |
642 | 15 | goto fail; |
643 | 15 | } |
644 | | |
645 | 55 | if (fido_cred_set_fmt(cred, "fido-u2f") != FIDO_OK || |
646 | 55 | fido_cred_set_authdata(cred, ad.ptr, ad.len) != FIDO_OK || |
647 | 55 | fido_cred_set_attstmt(cred, stmt.ptr, stmt.len) != FIDO_OK) { |
648 | 8 | fido_log_debug("%s: fido_cred_set", __func__); |
649 | 8 | r = FIDO_ERR_INTERNAL; |
650 | 8 | goto fail; |
651 | 8 | } |
652 | | |
653 | 47 | r = FIDO_OK; |
654 | 152 | fail: |
655 | 152 | freezero(kh, kh_len); |
656 | 152 | fido_blob_reset(&x5c); |
657 | 152 | fido_blob_reset(&sig); |
658 | 152 | fido_blob_reset(&ad); |
659 | 152 | fido_blob_reset(&stmt); |
660 | | |
661 | 152 | return (r); |
662 | 47 | } |
663 | | |
664 | | int |
665 | | u2f_register(fido_dev_t *dev, fido_cred_t *cred, int *ms) |
666 | 407 | { |
667 | 407 | iso7816_apdu_t *apdu = NULL; |
668 | 407 | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
669 | 407 | unsigned char *reply = NULL; |
670 | 407 | int reply_len; |
671 | 407 | int found; |
672 | 407 | int r; |
673 | | |
674 | 407 | if (cred->rk == FIDO_OPT_TRUE || cred->uv == FIDO_OPT_TRUE) { |
675 | 7 | fido_log_debug("%s: rk=%d, uv=%d", __func__, cred->rk, |
676 | 7 | cred->uv); |
677 | 7 | return (FIDO_ERR_UNSUPPORTED_OPTION); |
678 | 7 | } |
679 | | |
680 | 400 | if (cred->type != COSE_ES256 || cred->cdh.ptr == NULL || |
681 | 400 | cred->rp.id == NULL || cred->cdh.len != SHA256_DIGEST_LENGTH) { |
682 | 35 | fido_log_debug("%s: type=%d, cdh=(%p,%zu)" , __func__, |
683 | 35 | cred->type, (void *)cred->cdh.ptr, cred->cdh.len); |
684 | 35 | return (FIDO_ERR_INVALID_ARGUMENT); |
685 | 35 | } |
686 | | |
687 | 373 | for (size_t i = 0; i < cred->excl.len; i++) { |
688 | 195 | if ((r = key_lookup(dev, cred->rp.id, &cred->excl.ptr[i], |
689 | 195 | &found, ms)) != FIDO_OK) { |
690 | 153 | fido_log_debug("%s: key_lookup", __func__); |
691 | 153 | return (r); |
692 | 153 | } |
693 | 42 | if (found) { |
694 | 34 | if ((r = send_dummy_register(dev, ms)) != FIDO_OK) { |
695 | 19 | fido_log_debug("%s: send_dummy_register", |
696 | 19 | __func__); |
697 | 19 | return (r); |
698 | 19 | } |
699 | 15 | return (FIDO_ERR_CREDENTIAL_EXCLUDED); |
700 | 34 | } |
701 | 42 | } |
702 | | |
703 | 178 | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
704 | | |
705 | 178 | if (SHA256((const void *)cred->rp.id, strlen(cred->rp.id), |
706 | 178 | rp_id_hash) != rp_id_hash) { |
707 | 1 | fido_log_debug("%s: sha256", __func__); |
708 | 1 | return (FIDO_ERR_INTERNAL); |
709 | 1 | } |
710 | | |
711 | 177 | if ((apdu = iso7816_new(0, U2F_CMD_REGISTER, 0, 2 * |
712 | 177 | SHA256_DIGEST_LENGTH)) == NULL || |
713 | 177 | iso7816_add(apdu, cred->cdh.ptr, cred->cdh.len) < 0 || |
714 | 177 | iso7816_add(apdu, rp_id_hash, sizeof(rp_id_hash)) < 0) { |
715 | 1 | fido_log_debug("%s: iso7816", __func__); |
716 | 1 | r = FIDO_ERR_INTERNAL; |
717 | 1 | goto fail; |
718 | 1 | } |
719 | | |
720 | 176 | if ((reply = malloc(FIDO_MAXMSG)) == NULL) { |
721 | 1 | fido_log_debug("%s: malloc", __func__); |
722 | 1 | r = FIDO_ERR_INTERNAL; |
723 | 1 | goto fail; |
724 | 1 | } |
725 | | |
726 | 385 | do { |
727 | 385 | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
728 | 385 | iso7816_len(apdu), ms) < 0) { |
729 | 2 | fido_log_debug("%s: fido_tx", __func__); |
730 | 2 | r = FIDO_ERR_TX; |
731 | 2 | goto fail; |
732 | 2 | } |
733 | 383 | if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, reply, |
734 | 383 | FIDO_MAXMSG, ms)) < 2) { |
735 | 20 | fido_log_debug("%s: fido_rx", __func__); |
736 | 20 | r = FIDO_ERR_RX; |
737 | 20 | goto fail; |
738 | 20 | } |
739 | 363 | if (delay_ms(U2F_PACE_MS, ms) != 0) { |
740 | 1 | fido_log_debug("%s: delay_ms", __func__); |
741 | 1 | r = FIDO_ERR_RX; |
742 | 1 | goto fail; |
743 | 1 | } |
744 | 363 | } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED); |
745 | | |
746 | 152 | if ((r = parse_register_reply(cred, reply, |
747 | 152 | (size_t)reply_len)) != FIDO_OK) { |
748 | 105 | fido_log_debug("%s: parse_register_reply", __func__); |
749 | 105 | goto fail; |
750 | 105 | } |
751 | 177 | fail: |
752 | 177 | iso7816_free(&apdu); |
753 | 177 | freezero(reply, FIDO_MAXMSG); |
754 | | |
755 | 177 | return (r); |
756 | 152 | } |
757 | | |
758 | | static int |
759 | | u2f_authenticate_single(fido_dev_t *dev, const fido_blob_t *key_id, |
760 | | fido_assert_t *fa, size_t idx, int *ms) |
761 | 854 | { |
762 | 854 | fido_blob_t sig; |
763 | 854 | fido_blob_t ad; |
764 | 854 | int found; |
765 | 854 | int r; |
766 | | |
767 | 854 | memset(&sig, 0, sizeof(sig)); |
768 | 854 | memset(&ad, 0, sizeof(ad)); |
769 | | |
770 | 854 | if ((r = key_lookup(dev, fa->rp_id, key_id, &found, ms)) != FIDO_OK) { |
771 | 534 | fido_log_debug("%s: key_lookup", __func__); |
772 | 534 | goto fail; |
773 | 534 | } |
774 | | |
775 | 320 | if (!found) { |
776 | 10 | fido_log_debug("%s: not found", __func__); |
777 | 10 | r = FIDO_ERR_CREDENTIAL_EXCLUDED; |
778 | 10 | goto fail; |
779 | 10 | } |
780 | | |
781 | 310 | if (fido_blob_set(&fa->stmt[idx].id, key_id->ptr, key_id->len) < 0) { |
782 | 1 | fido_log_debug("%s: fido_blob_set", __func__); |
783 | 1 | r = FIDO_ERR_INTERNAL; |
784 | 1 | goto fail; |
785 | 1 | } |
786 | | |
787 | 309 | if (fa->up == FIDO_OPT_FALSE) { |
788 | 83 | fido_log_debug("%s: checking for key existence only", __func__); |
789 | 83 | r = FIDO_ERR_USER_PRESENCE_REQUIRED; |
790 | 83 | goto fail; |
791 | 83 | } |
792 | | |
793 | 226 | if ((r = do_auth(dev, &fa->cdh, fa->rp_id, key_id, &sig, &ad, |
794 | 226 | ms)) != FIDO_OK) { |
795 | 80 | fido_log_debug("%s: do_auth", __func__); |
796 | 80 | goto fail; |
797 | 80 | } |
798 | | |
799 | 146 | if (fido_assert_set_authdata(fa, idx, ad.ptr, ad.len) != FIDO_OK || |
800 | 146 | fido_assert_set_sig(fa, idx, sig.ptr, sig.len) != FIDO_OK) { |
801 | 5 | fido_log_debug("%s: fido_assert_set", __func__); |
802 | 5 | r = FIDO_ERR_INTERNAL; |
803 | 5 | goto fail; |
804 | 5 | } |
805 | | |
806 | 141 | r = FIDO_OK; |
807 | 854 | fail: |
808 | 854 | fido_blob_reset(&sig); |
809 | 854 | fido_blob_reset(&ad); |
810 | | |
811 | 854 | return (r); |
812 | 141 | } |
813 | | |
814 | | int |
815 | | u2f_authenticate(fido_dev_t *dev, fido_assert_t *fa, int *ms) |
816 | 702 | { |
817 | 702 | size_t nfound = 0; |
818 | 702 | size_t nauth_ok = 0; |
819 | 702 | int r; |
820 | | |
821 | 702 | if (fa->uv == FIDO_OPT_TRUE || fa->allow_list.ptr == NULL) { |
822 | 72 | fido_log_debug("%s: uv=%d, allow_list=%p", __func__, fa->uv, |
823 | 72 | (void *)fa->allow_list.ptr); |
824 | 72 | return (FIDO_ERR_UNSUPPORTED_OPTION); |
825 | 72 | } |
826 | | |
827 | 630 | if ((r = fido_assert_set_count(fa, fa->allow_list.len)) != FIDO_OK) { |
828 | 1 | fido_log_debug("%s: fido_assert_set_count", __func__); |
829 | 1 | return (r); |
830 | 1 | } |
831 | | |
832 | 863 | for (size_t i = 0; i < fa->allow_list.len; i++) { |
833 | 854 | switch ((r = u2f_authenticate_single(dev, |
834 | 854 | &fa->allow_list.ptr[i], fa, nfound, ms))) { |
835 | 141 | case FIDO_OK: |
836 | 141 | nauth_ok++; |
837 | 141 | FALLTHROUGH |
838 | 224 | case FIDO_ERR_USER_PRESENCE_REQUIRED: |
839 | 224 | nfound++; |
840 | 224 | break; |
841 | 630 | default: |
842 | 630 | if (r != FIDO_ERR_CREDENTIAL_EXCLUDED) { |
843 | 620 | fido_log_debug("%s: u2f_authenticate_single", |
844 | 620 | __func__); |
845 | 620 | return (r); |
846 | 620 | } |
847 | | /* ignore credentials that don't exist */ |
848 | 854 | } |
849 | 854 | } |
850 | | |
851 | 9 | fa->stmt_len = nfound; |
852 | | |
853 | 9 | if (nfound == 0) |
854 | 2 | return (FIDO_ERR_NO_CREDENTIALS); |
855 | 7 | if (nauth_ok == 0) |
856 | 1 | return (FIDO_ERR_USER_PRESENCE_REQUIRED); |
857 | | |
858 | 6 | return (FIDO_OK); |
859 | 7 | } |
860 | | |
861 | | int |
862 | | u2f_get_touch_begin(fido_dev_t *dev, int *ms) |
863 | 1.79k | { |
864 | 1.79k | iso7816_apdu_t *apdu = NULL; |
865 | 1.79k | const char *clientdata = FIDO_DUMMY_CLIENTDATA; |
866 | 1.79k | const char *rp_id = FIDO_DUMMY_RP_ID; |
867 | 1.79k | unsigned char *reply = NULL; |
868 | 1.79k | unsigned char clientdata_hash[SHA256_DIGEST_LENGTH]; |
869 | 1.79k | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
870 | 1.79k | int r; |
871 | | |
872 | 1.79k | memset(&clientdata_hash, 0, sizeof(clientdata_hash)); |
873 | 1.79k | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
874 | | |
875 | 1.79k | if (SHA256((const void *)clientdata, strlen(clientdata), |
876 | 1.79k | clientdata_hash) != clientdata_hash || SHA256((const void *)rp_id, |
877 | 1.78k | strlen(rp_id), rp_id_hash) != rp_id_hash) { |
878 | 13 | fido_log_debug("%s: sha256", __func__); |
879 | 13 | return (FIDO_ERR_INTERNAL); |
880 | 13 | } |
881 | | |
882 | 1.78k | if ((apdu = iso7816_new(0, U2F_CMD_REGISTER, 0, 2 * |
883 | 1.78k | SHA256_DIGEST_LENGTH)) == NULL || |
884 | 1.78k | iso7816_add(apdu, clientdata_hash, sizeof(clientdata_hash)) < 0 || |
885 | 1.78k | iso7816_add(apdu, rp_id_hash, sizeof(rp_id_hash)) < 0) { |
886 | 9 | fido_log_debug("%s: iso7816", __func__); |
887 | 9 | r = FIDO_ERR_INTERNAL; |
888 | 9 | goto fail; |
889 | 9 | } |
890 | | |
891 | 1.77k | if ((reply = malloc(FIDO_MAXMSG)) == NULL) { |
892 | 10 | fido_log_debug("%s: malloc", __func__); |
893 | 10 | r = FIDO_ERR_INTERNAL; |
894 | 10 | goto fail; |
895 | 10 | } |
896 | | |
897 | 1.76k | if (dev->attr.flags & FIDO_CAP_WINK) { |
898 | 1.04k | fido_tx(dev, CTAP_CMD_WINK, NULL, 0, ms); |
899 | 1.04k | fido_rx(dev, CTAP_CMD_WINK, reply, FIDO_MAXMSG, ms); |
900 | 1.04k | } |
901 | | |
902 | 1.76k | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
903 | 1.76k | iso7816_len(apdu), ms) < 0) { |
904 | 111 | fido_log_debug("%s: fido_tx", __func__); |
905 | 111 | r = FIDO_ERR_TX; |
906 | 111 | goto fail; |
907 | 111 | } |
908 | | |
909 | 1.65k | r = FIDO_OK; |
910 | 1.78k | fail: |
911 | 1.78k | iso7816_free(&apdu); |
912 | 1.78k | freezero(reply, FIDO_MAXMSG); |
913 | | |
914 | 1.78k | return (r); |
915 | 1.65k | } |
916 | | |
917 | | int |
918 | | u2f_get_touch_status(fido_dev_t *dev, int *touched, int *ms) |
919 | 1.77k | { |
920 | 1.77k | unsigned char *reply; |
921 | 1.77k | int reply_len; |
922 | 1.77k | int r; |
923 | | |
924 | 1.77k | if ((reply = malloc(FIDO_MAXMSG)) == NULL) { |
925 | 6 | fido_log_debug("%s: malloc", __func__); |
926 | 6 | r = FIDO_ERR_INTERNAL; |
927 | 6 | goto out; |
928 | 6 | } |
929 | | |
930 | 1.76k | if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, reply, FIDO_MAXMSG, |
931 | 1.76k | ms)) < 2) { |
932 | 1.59k | fido_log_debug("%s: fido_rx", __func__); |
933 | 1.59k | r = FIDO_OK; /* ignore */ |
934 | 1.59k | goto out; |
935 | 1.59k | } |
936 | | |
937 | 173 | switch ((reply[reply_len - 2] << 8) | reply[reply_len - 1]) { |
938 | 21 | case SW_CONDITIONS_NOT_SATISFIED: |
939 | 21 | if ((r = u2f_get_touch_begin(dev, ms)) != FIDO_OK) { |
940 | 6 | fido_log_debug("%s: u2f_get_touch_begin", __func__); |
941 | 6 | goto out; |
942 | 6 | } |
943 | 15 | *touched = 0; |
944 | 15 | break; |
945 | 2 | case SW_NO_ERROR: |
946 | 2 | *touched = 1; |
947 | 2 | break; |
948 | 150 | default: |
949 | 150 | fido_log_debug("%s: unexpected sw", __func__); |
950 | 150 | r = FIDO_ERR_RX; |
951 | 150 | goto out; |
952 | 173 | } |
953 | | |
954 | 17 | r = FIDO_OK; |
955 | 1.77k | out: |
956 | 1.77k | freezero(reply, FIDO_MAXMSG); |
957 | | |
958 | 1.77k | return (r); |
959 | 17 | } |