Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright (c) 2018 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 | | */ |
6 | | |
7 | | #include <openssl/sha.h> |
8 | | #include <openssl/x509.h> |
9 | | |
10 | | #include <string.h> |
11 | | #ifdef HAVE_UNISTD_H |
12 | | #include <unistd.h> |
13 | | #endif |
14 | | |
15 | | #include "fido.h" |
16 | | #include "fido/es256.h" |
17 | | |
18 | | #if defined(_MSC_VER) |
19 | | static int |
20 | | usleep(unsigned int usec) |
21 | | { |
22 | | Sleep(usec / 1000); |
23 | | |
24 | | return (0); |
25 | | } |
26 | | #endif |
27 | | |
28 | | static int |
29 | | sig_get(fido_blob_t *sig, const unsigned char **buf, size_t *len) |
30 | 1.31k | { |
31 | 1.31k | sig->len = *len; /* consume the whole buffer */ |
32 | 1.31k | if ((sig->ptr = calloc(1, sig->len)) == NULL || |
33 | 1.31k | fido_buf_read(buf, len, sig->ptr, sig->len) < 0) { |
34 | 2 | fido_log_debug("%s: fido_buf_read", __func__); |
35 | 2 | if (sig->ptr != NULL) { |
36 | 0 | explicit_bzero(sig->ptr, sig->len); |
37 | 0 | free(sig->ptr); |
38 | 0 | sig->ptr = NULL; |
39 | 0 | sig->len = 0; |
40 | 0 | return (-1); |
41 | 0 | } |
42 | 1.31k | } |
43 | 1.31k | |
44 | 1.31k | return (0); |
45 | 1.31k | } |
46 | | |
47 | | static int |
48 | | x5c_get(fido_blob_t *x5c, const unsigned char **buf, size_t *len) |
49 | 689 | { |
50 | 689 | X509 *cert = NULL; |
51 | 689 | int ok = -1; |
52 | 689 | |
53 | 689 | if (*len > LONG_MAX) { |
54 | 0 | fido_log_debug("%s: invalid len %zu", __func__, *len); |
55 | 0 | goto fail; |
56 | 0 | } |
57 | 689 | |
58 | 689 | /* find out the certificate's length */ |
59 | 689 | const unsigned char *end = *buf; |
60 | 689 | if ((cert = d2i_X509(NULL, &end, (long)*len)) == NULL || end <= *buf || |
61 | 689 | (x5c->len = (size_t)(end - *buf)) >= *len) { |
62 | 297 | fido_log_debug("%s: d2i_X509", __func__); |
63 | 297 | goto fail; |
64 | 297 | } |
65 | 392 | |
66 | 392 | /* read accordingly */ |
67 | 392 | if ((x5c->ptr = calloc(1, x5c->len)) == NULL || |
68 | 392 | fido_buf_read(buf, len, x5c->ptr, x5c->len) < 0) { |
69 | 0 | fido_log_debug("%s: fido_buf_read", __func__); |
70 | 0 | goto fail; |
71 | 0 | } |
72 | 392 | |
73 | 392 | ok = 0; |
74 | 689 | fail: |
75 | 689 | if (cert != NULL) |
76 | 689 | X509_free(cert); |
77 | 689 | |
78 | 689 | if (ok < 0) { |
79 | 297 | free(x5c->ptr); |
80 | 297 | x5c->ptr = NULL; |
81 | 297 | x5c->len = 0; |
82 | 297 | } |
83 | 689 | |
84 | 689 | return (ok); |
85 | 392 | } |
86 | | |
87 | | static int |
88 | | authdata_fake(const char *rp_id, uint8_t flags, uint32_t sigcount, |
89 | | fido_blob_t *fake_cbor_ad) |
90 | 925 | { |
91 | 925 | fido_authdata_t ad; |
92 | 925 | cbor_item_t *item = NULL; |
93 | 925 | size_t alloc_len; |
94 | 925 | |
95 | 925 | memset(&ad, 0, sizeof(ad)); |
96 | 925 | |
97 | 925 | if (SHA256((const void *)rp_id, strlen(rp_id), |
98 | 925 | ad.rp_id_hash) != ad.rp_id_hash) { |
99 | 1 | fido_log_debug("%s: sha256", __func__); |
100 | 1 | return (-1); |
101 | 1 | } |
102 | 924 | |
103 | 924 | ad.flags = flags; /* XXX translate? */ |
104 | 924 | ad.sigcount = sigcount; |
105 | 924 | |
106 | 924 | if ((item = cbor_build_bytestring((const unsigned char *)&ad, |
107 | 924 | sizeof(ad))) == NULL) { |
108 | 1 | fido_log_debug("%s: cbor_build_bytestring", __func__); |
109 | 1 | return (-1); |
110 | 1 | } |
111 | 923 | |
112 | 923 | if (fake_cbor_ad->ptr != NULL || |
113 | 923 | (fake_cbor_ad->len = cbor_serialize_alloc(item, &fake_cbor_ad->ptr, |
114 | 923 | &alloc_len)) == 0) { |
115 | 2 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
116 | 2 | cbor_decref(&item); |
117 | 2 | return (-1); |
118 | 2 | } |
119 | 921 | |
120 | 921 | cbor_decref(&item); |
121 | 921 | |
122 | 921 | return (0); |
123 | 921 | } |
124 | | |
125 | | static int |
126 | | send_dummy_register(fido_dev_t *dev, int ms) |
127 | 33 | { |
128 | 33 | iso7816_apdu_t *apdu = NULL; |
129 | 33 | unsigned char challenge[SHA256_DIGEST_LENGTH]; |
130 | 33 | unsigned char application[SHA256_DIGEST_LENGTH]; |
131 | 33 | unsigned char reply[FIDO_MAXMSG]; |
132 | 33 | int r; |
133 | 33 | |
134 | 33 | #ifdef FIDO_FUZZ |
135 | 33 | ms = 0; /* XXX */ |
136 | 33 | #endif |
137 | 33 | |
138 | 33 | /* dummy challenge & application */ |
139 | 33 | memset(&challenge, 0xff, sizeof(challenge)); |
140 | 33 | memset(&application, 0xff, sizeof(application)); |
141 | 33 | |
142 | 33 | if ((apdu = iso7816_new(U2F_CMD_REGISTER, 0, 2 * |
143 | 33 | SHA256_DIGEST_LENGTH)) == NULL || |
144 | 33 | iso7816_add(apdu, &challenge, sizeof(challenge)) < 0 || |
145 | 33 | iso7816_add(apdu, &application, sizeof(application)) < 0) { |
146 | 0 | fido_log_debug("%s: iso7816", __func__); |
147 | 0 | r = FIDO_ERR_INTERNAL; |
148 | 0 | goto fail; |
149 | 0 | } |
150 | 33 | |
151 | 138 | do { |
152 | 138 | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
153 | 138 | iso7816_len(apdu)) < 0) { |
154 | 3 | fido_log_debug("%s: fido_tx", __func__); |
155 | 3 | r = FIDO_ERR_TX; |
156 | 3 | goto fail; |
157 | 3 | } |
158 | 135 | if (fido_rx(dev, CTAP_CMD_MSG, &reply, sizeof(reply), ms) < 2) { |
159 | 22 | fido_log_debug("%s: fido_rx", __func__); |
160 | 22 | r = FIDO_ERR_RX; |
161 | 22 | goto fail; |
162 | 22 | } |
163 | 113 | if (usleep((ms == -1 ? 100 : ms) * 1000) < 0) { |
164 | 0 | fido_log_debug("%s: usleep", __func__); |
165 | 0 | r = FIDO_ERR_RX; |
166 | 0 | goto fail; |
167 | 0 | } |
168 | 113 | } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED); |
169 | 33 | |
170 | 33 | r = FIDO_OK; |
171 | 33 | fail: |
172 | 33 | iso7816_free(&apdu); |
173 | 33 | |
174 | 33 | return (r); |
175 | 8 | } |
176 | | |
177 | | static int |
178 | | key_lookup(fido_dev_t *dev, const char *rp_id, const fido_blob_t *key_id, |
179 | | int *found, int ms) |
180 | 2.16k | { |
181 | 2.16k | iso7816_apdu_t *apdu = NULL; |
182 | 2.16k | unsigned char challenge[SHA256_DIGEST_LENGTH]; |
183 | 2.16k | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
184 | 2.16k | unsigned char reply[FIDO_MAXMSG]; |
185 | 2.16k | uint8_t key_id_len; |
186 | 2.16k | int r; |
187 | 2.16k | |
188 | 2.16k | if (key_id->len > UINT8_MAX || rp_id == NULL) { |
189 | 13 | fido_log_debug("%s: key_id->len=%zu, rp_id=%p", __func__, |
190 | 13 | key_id->len, (const void *)rp_id); |
191 | 13 | r = FIDO_ERR_INVALID_ARGUMENT; |
192 | 13 | goto fail; |
193 | 13 | } |
194 | 2.14k | |
195 | 2.14k | memset(&challenge, 0xff, sizeof(challenge)); |
196 | 2.14k | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
197 | 2.14k | |
198 | 2.14k | if (SHA256((const void *)rp_id, strlen(rp_id), |
199 | 2.14k | rp_id_hash) != rp_id_hash) { |
200 | 1 | fido_log_debug("%s: sha256", __func__); |
201 | 1 | r = FIDO_ERR_INTERNAL; |
202 | 1 | goto fail; |
203 | 1 | } |
204 | 2.14k | |
205 | 2.14k | key_id_len = (uint8_t)key_id->len; |
206 | 2.14k | |
207 | 2.14k | if ((apdu = iso7816_new(U2F_CMD_AUTH, U2F_AUTH_CHECK, 2 * |
208 | 2.14k | SHA256_DIGEST_LENGTH + sizeof(key_id_len) + key_id_len)) == NULL || |
209 | 2.14k | iso7816_add(apdu, &challenge, sizeof(challenge)) < 0 || |
210 | 2.14k | iso7816_add(apdu, &rp_id_hash, sizeof(rp_id_hash)) < 0 || |
211 | 2.14k | iso7816_add(apdu, &key_id_len, sizeof(key_id_len)) < 0 || |
212 | 2.14k | iso7816_add(apdu, key_id->ptr, key_id_len) < 0) { |
213 | 3 | fido_log_debug("%s: iso7816", __func__); |
214 | 3 | r = FIDO_ERR_INTERNAL; |
215 | 3 | goto fail; |
216 | 3 | } |
217 | 2.14k | |
218 | 2.14k | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
219 | 2.14k | iso7816_len(apdu)) < 0) { |
220 | 17 | fido_log_debug("%s: fido_tx", __func__); |
221 | 17 | r = FIDO_ERR_TX; |
222 | 17 | goto fail; |
223 | 17 | } |
224 | 2.12k | if (fido_rx(dev, CTAP_CMD_MSG, &reply, sizeof(reply), ms) != 2) { |
225 | 952 | fido_log_debug("%s: fido_rx", __func__); |
226 | 952 | r = FIDO_ERR_RX; |
227 | 952 | goto fail; |
228 | 952 | } |
229 | 1.17k | |
230 | 1.17k | switch ((reply[0] << 8) | reply[1]) { |
231 | 1.17k | case SW_CONDITIONS_NOT_SATISFIED: |
232 | 1.03k | *found = 1; /* key exists */ |
233 | 1.03k | break; |
234 | 1.17k | case SW_WRONG_DATA: |
235 | 57 | *found = 0; /* key does not exist */ |
236 | 57 | break; |
237 | 1.17k | default: |
238 | 80 | /* unexpected sw */ |
239 | 80 | r = FIDO_ERR_INTERNAL; |
240 | 80 | goto fail; |
241 | 1.09k | } |
242 | 1.09k | |
243 | 1.09k | r = FIDO_OK; |
244 | 2.16k | fail: |
245 | 2.16k | iso7816_free(&apdu); |
246 | 2.16k | |
247 | 2.16k | return (r); |
248 | 1.09k | } |
249 | | |
250 | | static int |
251 | | parse_auth_reply(fido_blob_t *sig, fido_blob_t *ad, const char *rp_id, |
252 | | const unsigned char *reply, size_t len) |
253 | 952 | { |
254 | 952 | uint8_t flags; |
255 | 952 | uint32_t sigcount; |
256 | 952 | |
257 | 952 | if (len < 2 || ((reply[len - 2] << 8) | reply[len - 1]) != SW_NO_ERROR) { |
258 | 26 | fido_log_debug("%s: unexpected sw", __func__); |
259 | 26 | return (FIDO_ERR_RX); |
260 | 26 | } |
261 | 926 | |
262 | 926 | len -= 2; |
263 | 926 | |
264 | 926 | if (fido_buf_read(&reply, &len, &flags, sizeof(flags)) < 0 || |
265 | 926 | fido_buf_read(&reply, &len, &sigcount, sizeof(sigcount)) < 0) { |
266 | 1 | fido_log_debug("%s: fido_buf_read", __func__); |
267 | 1 | return (FIDO_ERR_RX); |
268 | 1 | } |
269 | 925 | |
270 | 925 | if (sig_get(sig, &reply, &len) < 0) { |
271 | 0 | fido_log_debug("%s: sig_get", __func__); |
272 | 0 | return (FIDO_ERR_RX); |
273 | 0 | } |
274 | 925 | |
275 | 925 | if (authdata_fake(rp_id, flags, sigcount, ad) < 0) { |
276 | 4 | fido_log_debug("%s; authdata_fake", __func__); |
277 | 4 | return (FIDO_ERR_RX); |
278 | 4 | } |
279 | 921 | |
280 | 921 | return (FIDO_OK); |
281 | 921 | } |
282 | | |
283 | | static int |
284 | | do_auth(fido_dev_t *dev, const fido_blob_t *cdh, const char *rp_id, |
285 | | const fido_blob_t *key_id, fido_blob_t *sig, fido_blob_t *ad, int ms) |
286 | 1.00k | { |
287 | 1.00k | iso7816_apdu_t *apdu = NULL; |
288 | 1.00k | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
289 | 1.00k | unsigned char reply[FIDO_MAXMSG]; |
290 | 1.00k | int reply_len; |
291 | 1.00k | uint8_t key_id_len; |
292 | 1.00k | int r; |
293 | 1.00k | |
294 | 1.00k | #ifdef FIDO_FUZZ |
295 | 1.00k | ms = 0; /* XXX */ |
296 | 1.00k | #endif |
297 | 1.00k | |
298 | 1.00k | if (cdh->len != SHA256_DIGEST_LENGTH || key_id->len > UINT8_MAX || |
299 | 1.00k | rp_id == NULL) { |
300 | 30 | r = FIDO_ERR_INVALID_ARGUMENT; |
301 | 30 | goto fail; |
302 | 30 | } |
303 | 975 | |
304 | 975 | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
305 | 975 | |
306 | 975 | if (SHA256((const void *)rp_id, strlen(rp_id), |
307 | 975 | rp_id_hash) != rp_id_hash) { |
308 | 1 | fido_log_debug("%s: sha256", __func__); |
309 | 1 | r = FIDO_ERR_INTERNAL; |
310 | 1 | goto fail; |
311 | 1 | } |
312 | 974 | |
313 | 974 | key_id_len = (uint8_t)key_id->len; |
314 | 974 | |
315 | 974 | if ((apdu = iso7816_new(U2F_CMD_AUTH, U2F_AUTH_SIGN, 2 * |
316 | 974 | SHA256_DIGEST_LENGTH + sizeof(key_id_len) + key_id_len)) == NULL || |
317 | 974 | iso7816_add(apdu, cdh->ptr, cdh->len) < 0 || |
318 | 974 | iso7816_add(apdu, &rp_id_hash, sizeof(rp_id_hash)) < 0 || |
319 | 974 | iso7816_add(apdu, &key_id_len, sizeof(key_id_len)) < 0 || |
320 | 974 | iso7816_add(apdu, key_id->ptr, key_id_len) < 0) { |
321 | 0 | fido_log_debug("%s: iso7816", __func__); |
322 | 0 | r = FIDO_ERR_INTERNAL; |
323 | 0 | goto fail; |
324 | 0 | } |
325 | 974 | |
326 | 2.82k | do { |
327 | 2.82k | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
328 | 2.82k | iso7816_len(apdu)) < 0) { |
329 | 2 | fido_log_debug("%s: fido_tx", __func__); |
330 | 2 | r = FIDO_ERR_TX; |
331 | 2 | goto fail; |
332 | 2 | } |
333 | 2.81k | if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, &reply, |
334 | 2.81k | sizeof(reply), ms)) < 2) { |
335 | 18 | fido_log_debug("%s: fido_rx", __func__); |
336 | 18 | r = FIDO_ERR_RX; |
337 | 18 | goto fail; |
338 | 18 | } |
339 | 2.80k | if (usleep((ms == -1 ? 100 : ms) * 1000) < 0) { |
340 | 2 | fido_log_debug("%s: usleep", __func__); |
341 | 2 | r = FIDO_ERR_RX; |
342 | 2 | goto fail; |
343 | 2 | } |
344 | 2.79k | } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED); |
345 | 974 | |
346 | 974 | if ((r = parse_auth_reply(sig, ad, rp_id, reply, |
347 | 952 | (size_t)reply_len)) != FIDO_OK) { |
348 | 31 | fido_log_debug("%s: parse_auth_reply", __func__); |
349 | 31 | goto fail; |
350 | 31 | } |
351 | 1.00k | |
352 | 1.00k | fail: |
353 | 1.00k | iso7816_free(&apdu); |
354 | 1.00k | |
355 | 1.00k | return (r); |
356 | 952 | } |
357 | | |
358 | | static int |
359 | | cbor_blob_from_ec_point(const uint8_t *ec_point, size_t ec_point_len, |
360 | | fido_blob_t *cbor_blob) |
361 | 392 | { |
362 | 392 | es256_pk_t *pk = NULL; |
363 | 392 | cbor_item_t *pk_cbor = NULL; |
364 | 392 | size_t alloc_len; |
365 | 392 | int ok = -1; |
366 | 392 | |
367 | 392 | /* only handle uncompressed points */ |
368 | 392 | if (ec_point_len != 65 || ec_point[0] != 0x04) { |
369 | 5 | fido_log_debug("%s: unexpected format", __func__); |
370 | 5 | goto fail; |
371 | 5 | } |
372 | 387 | |
373 | 387 | if ((pk = es256_pk_new()) == NULL || |
374 | 387 | es256_pk_set_x(pk, &ec_point[1]) < 0 || |
375 | 387 | es256_pk_set_y(pk, &ec_point[33]) < 0) { |
376 | 0 | fido_log_debug("%s: es256_pk_set", __func__); |
377 | 0 | goto fail; |
378 | 0 | } |
379 | 387 | |
380 | 387 | if ((pk_cbor = es256_pk_encode(pk, 0)) == NULL) { |
381 | 19 | fido_log_debug("%s: es256_pk_encode", __func__); |
382 | 19 | goto fail; |
383 | 19 | } |
384 | 368 | |
385 | 368 | if ((cbor_blob->len = cbor_serialize_alloc(pk_cbor, &cbor_blob->ptr, |
386 | 368 | &alloc_len)) != 77) { |
387 | 1 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
388 | 1 | goto fail; |
389 | 1 | } |
390 | 367 | |
391 | 367 | ok = 0; |
392 | 392 | fail: |
393 | 392 | es256_pk_free(&pk); |
394 | 392 | |
395 | 392 | if (pk_cbor) |
396 | 368 | cbor_decref(&pk_cbor); |
397 | 392 | |
398 | 392 | return (ok); |
399 | 367 | } |
400 | | |
401 | | static int |
402 | | encode_cred_authdata(const char *rp_id, const uint8_t *kh, uint8_t kh_len, |
403 | | const uint8_t *pubkey, size_t pubkey_len, fido_blob_t *out) |
404 | 392 | { |
405 | 392 | fido_authdata_t authdata; |
406 | 392 | fido_attcred_raw_t attcred_raw; |
407 | 392 | fido_blob_t pk_blob; |
408 | 392 | fido_blob_t authdata_blob; |
409 | 392 | cbor_item_t *authdata_cbor = NULL; |
410 | 392 | unsigned char *ptr; |
411 | 392 | size_t len; |
412 | 392 | size_t alloc_len; |
413 | 392 | int ok = -1; |
414 | 392 | |
415 | 392 | memset(&pk_blob, 0, sizeof(pk_blob)); |
416 | 392 | memset(&authdata, 0, sizeof(authdata)); |
417 | 392 | memset(&authdata_blob, 0, sizeof(authdata_blob)); |
418 | 392 | memset(out, 0, sizeof(*out)); |
419 | 392 | |
420 | 392 | if (rp_id == NULL) { |
421 | 0 | fido_log_debug("%s: NULL rp_id", __func__); |
422 | 0 | goto fail; |
423 | 0 | } |
424 | 392 | |
425 | 392 | if (cbor_blob_from_ec_point(pubkey, pubkey_len, &pk_blob) < 0) { |
426 | 25 | fido_log_debug("%s: cbor_blob_from_ec_point", __func__); |
427 | 25 | goto fail; |
428 | 25 | } |
429 | 367 | |
430 | 367 | if (SHA256((const void *)rp_id, strlen(rp_id), |
431 | 367 | authdata.rp_id_hash) != authdata.rp_id_hash) { |
432 | 2 | fido_log_debug("%s: sha256", __func__); |
433 | 2 | goto fail; |
434 | 2 | } |
435 | 365 | |
436 | 365 | authdata.flags = (CTAP_AUTHDATA_ATT_CRED | CTAP_AUTHDATA_USER_PRESENT); |
437 | 365 | authdata.sigcount = 0; |
438 | 365 | |
439 | 365 | memset(&attcred_raw.aaguid, 0, sizeof(attcred_raw.aaguid)); |
440 | 365 | attcred_raw.id_len = htobe16(kh_len); |
441 | 365 | |
442 | 365 | len = authdata_blob.len = sizeof(authdata) + sizeof(attcred_raw) + |
443 | 365 | kh_len + pk_blob.len; |
444 | 365 | ptr = authdata_blob.ptr = calloc(1, authdata_blob.len); |
445 | 365 | |
446 | 365 | fido_log_debug("%s: ptr=%p, len=%zu", __func__, (void *)ptr, len); |
447 | 365 | |
448 | 365 | if (authdata_blob.ptr == NULL) |
449 | 365 | goto fail; |
450 | 364 | |
451 | 364 | if (fido_buf_write(&ptr, &len, &authdata, sizeof(authdata)) < 0 || |
452 | 364 | fido_buf_write(&ptr, &len, &attcred_raw, sizeof(attcred_raw)) < 0 || |
453 | 364 | fido_buf_write(&ptr, &len, kh, kh_len) < 0 || |
454 | 364 | fido_buf_write(&ptr, &len, pk_blob.ptr, pk_blob.len) < 0) { |
455 | 0 | fido_log_debug("%s: fido_buf_write", __func__); |
456 | 0 | goto fail; |
457 | 0 | } |
458 | 364 | |
459 | 364 | if ((authdata_cbor = fido_blob_encode(&authdata_blob)) == NULL) { |
460 | 1 | fido_log_debug("%s: fido_blob_encode", __func__); |
461 | 1 | goto fail; |
462 | 1 | } |
463 | 363 | |
464 | 363 | if ((out->len = cbor_serialize_alloc(authdata_cbor, &out->ptr, |
465 | 363 | &alloc_len)) == 0) { |
466 | 0 | fido_log_debug("%s: cbor_serialize_alloc", __func__); |
467 | 0 | goto fail; |
468 | 0 | } |
469 | 363 | |
470 | 363 | ok = 0; |
471 | 392 | fail: |
472 | 392 | if (authdata_cbor) |
473 | 363 | cbor_decref(&authdata_cbor); |
474 | 392 | |
475 | 392 | if (pk_blob.ptr) { |
476 | 367 | explicit_bzero(pk_blob.ptr, pk_blob.len); |
477 | 367 | free(pk_blob.ptr); |
478 | 367 | } |
479 | 392 | if (authdata_blob.ptr) { |
480 | 364 | explicit_bzero(authdata_blob.ptr, authdata_blob.len); |
481 | 364 | free(authdata_blob.ptr); |
482 | 364 | } |
483 | 392 | |
484 | 392 | return (ok); |
485 | 363 | } |
486 | | |
487 | | static int |
488 | | parse_register_reply(fido_cred_t *cred, const unsigned char *reply, size_t len) |
489 | 718 | { |
490 | 718 | fido_blob_t x5c; |
491 | 718 | fido_blob_t sig; |
492 | 718 | fido_blob_t ad; |
493 | 718 | uint8_t dummy; |
494 | 718 | uint8_t pubkey[65]; |
495 | 718 | uint8_t kh_len = 0; |
496 | 718 | uint8_t *kh = NULL; |
497 | 718 | int r; |
498 | 718 | |
499 | 718 | memset(&x5c, 0, sizeof(x5c)); |
500 | 718 | memset(&sig, 0, sizeof(sig)); |
501 | 718 | memset(&ad, 0, sizeof(ad)); |
502 | 718 | r = FIDO_ERR_RX; |
503 | 718 | |
504 | 718 | /* status word */ |
505 | 718 | if (len < 2 || ((reply[len - 2] << 8) | reply[len - 1]) != SW_NO_ERROR) { |
506 | 22 | fido_log_debug("%s: unexpected sw", __func__); |
507 | 22 | goto fail; |
508 | 22 | } |
509 | 696 | |
510 | 696 | len -= 2; |
511 | 696 | |
512 | 696 | /* reserved byte */ |
513 | 696 | if (fido_buf_read(&reply, &len, &dummy, sizeof(dummy)) < 0 || |
514 | 696 | dummy != 0x05) { |
515 | 4 | fido_log_debug("%s: reserved byte", __func__); |
516 | 4 | goto fail; |
517 | 4 | } |
518 | 692 | |
519 | 692 | /* pubkey + key handle */ |
520 | 692 | if (fido_buf_read(&reply, &len, &pubkey, sizeof(pubkey)) < 0 || |
521 | 692 | fido_buf_read(&reply, &len, &kh_len, sizeof(kh_len)) < 0 || |
522 | 692 | (kh = calloc(1, kh_len)) == NULL || |
523 | 692 | fido_buf_read(&reply, &len, kh, kh_len) < 0) { |
524 | 3 | fido_log_debug("%s: fido_buf_read", __func__); |
525 | 3 | goto fail; |
526 | 3 | } |
527 | 689 | |
528 | 689 | /* x5c + sig */ |
529 | 689 | if (x5c_get(&x5c, &reply, &len) < 0 || |
530 | 689 | sig_get(&sig, &reply, &len) < 0) { |
531 | 297 | fido_log_debug("%s: x5c || sig", __func__); |
532 | 297 | goto fail; |
533 | 297 | } |
534 | 392 | |
535 | 392 | /* authdata */ |
536 | 392 | if (encode_cred_authdata(cred->rp.id, kh, kh_len, pubkey, |
537 | 392 | sizeof(pubkey), &ad) < 0) { |
538 | 29 | fido_log_debug("%s: encode_cred_authdata", __func__); |
539 | 29 | goto fail; |
540 | 29 | } |
541 | 363 | |
542 | 363 | if (fido_cred_set_fmt(cred, "fido-u2f") != FIDO_OK || |
543 | 363 | fido_cred_set_authdata(cred, ad.ptr, ad.len) != FIDO_OK || |
544 | 363 | fido_cred_set_x509(cred, x5c.ptr, x5c.len) != FIDO_OK || |
545 | 363 | fido_cred_set_sig(cred, sig.ptr, sig.len) != FIDO_OK) { |
546 | 11 | fido_log_debug("%s: fido_cred_set", __func__); |
547 | 11 | r = FIDO_ERR_INTERNAL; |
548 | 11 | goto fail; |
549 | 11 | } |
550 | 352 | |
551 | 352 | r = FIDO_OK; |
552 | 718 | fail: |
553 | 718 | if (kh) { |
554 | 689 | explicit_bzero(kh, kh_len); |
555 | 689 | free(kh); |
556 | 689 | } |
557 | 718 | if (x5c.ptr) { |
558 | 392 | explicit_bzero(x5c.ptr, x5c.len); |
559 | 392 | free(x5c.ptr); |
560 | 392 | } |
561 | 718 | if (sig.ptr) { |
562 | 392 | explicit_bzero(sig.ptr, sig.len); |
563 | 392 | free(sig.ptr); |
564 | 392 | } |
565 | 718 | if (ad.ptr) { |
566 | 363 | explicit_bzero(ad.ptr, ad.len); |
567 | 363 | free(ad.ptr); |
568 | 363 | } |
569 | 718 | |
570 | 718 | return (r); |
571 | 352 | } |
572 | | |
573 | | int |
574 | | u2f_register(fido_dev_t *dev, fido_cred_t *cred, int ms) |
575 | 877 | { |
576 | 877 | iso7816_apdu_t *apdu = NULL; |
577 | 877 | unsigned char rp_id_hash[SHA256_DIGEST_LENGTH]; |
578 | 877 | unsigned char reply[FIDO_MAXMSG]; |
579 | 877 | int reply_len; |
580 | 877 | int found; |
581 | 877 | int r; |
582 | 877 | |
583 | 877 | #ifdef FIDO_FUZZ |
584 | 877 | ms = 0; /* XXX */ |
585 | 877 | #endif |
586 | 877 | |
587 | 877 | if (cred->rk == FIDO_OPT_TRUE || cred->uv == FIDO_OPT_TRUE) { |
588 | 4 | fido_log_debug("%s: rk=%d, uv=%d", __func__, cred->rk, |
589 | 4 | cred->uv); |
590 | 4 | return (FIDO_ERR_UNSUPPORTED_OPTION); |
591 | 4 | } |
592 | 873 | |
593 | 873 | if (cred->type != COSE_ES256 || cred->cdh.ptr == NULL || |
594 | 873 | cred->rp.id == NULL || cred->cdh.len != SHA256_DIGEST_LENGTH) { |
595 | 29 | fido_log_debug("%s: type=%d, cdh=(%p,%zu)" , __func__, |
596 | 29 | cred->type, (void *)cred->cdh.ptr, cred->cdh.len); |
597 | 29 | return (FIDO_ERR_INVALID_ARGUMENT); |
598 | 29 | } |
599 | 844 | |
600 | 845 | for (size_t i = 0; i < cred->excl.len; i++) { |
601 | 100 | if ((r = key_lookup(dev, cred->rp.id, &cred->excl.ptr[i], |
602 | 100 | &found, ms)) != FIDO_OK) { |
603 | 66 | fido_log_debug("%s: key_lookup", __func__); |
604 | 66 | return (r); |
605 | 66 | } |
606 | 34 | if (found) { |
607 | 33 | if ((r = send_dummy_register(dev, ms)) != FIDO_OK) { |
608 | 25 | fido_log_debug("%s: send_dummy_register", |
609 | 25 | __func__); |
610 | 25 | return (r); |
611 | 25 | } |
612 | 8 | return (FIDO_ERR_CREDENTIAL_EXCLUDED); |
613 | 8 | } |
614 | 34 | } |
615 | 844 | |
616 | 844 | memset(&rp_id_hash, 0, sizeof(rp_id_hash)); |
617 | 745 | |
618 | 745 | if (SHA256((const void *)cred->rp.id, strlen(cred->rp.id), |
619 | 745 | rp_id_hash) != rp_id_hash) { |
620 | 0 | fido_log_debug("%s: sha256", __func__); |
621 | 0 | return (FIDO_ERR_INTERNAL); |
622 | 0 | } |
623 | 745 | |
624 | 745 | if ((apdu = iso7816_new(U2F_CMD_REGISTER, 0, 2 * |
625 | 745 | SHA256_DIGEST_LENGTH)) == NULL || |
626 | 745 | iso7816_add(apdu, cred->cdh.ptr, cred->cdh.len) < 0 || |
627 | 745 | iso7816_add(apdu, rp_id_hash, sizeof(rp_id_hash)) < 0) { |
628 | 0 | fido_log_debug("%s: iso7816", __func__); |
629 | 0 | r = FIDO_ERR_INTERNAL; |
630 | 0 | goto fail; |
631 | 0 | } |
632 | 745 | |
633 | 4.43k | do { |
634 | 4.43k | if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu), |
635 | 4.43k | iso7816_len(apdu)) < 0) { |
636 | 10 | fido_log_debug("%s: fido_tx", __func__); |
637 | 10 | r = FIDO_ERR_TX; |
638 | 10 | goto fail; |
639 | 10 | } |
640 | 4.42k | if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, &reply, |
641 | 4.42k | sizeof(reply), ms)) < 2) { |
642 | 15 | fido_log_debug("%s: fido_rx", __func__); |
643 | 15 | r = FIDO_ERR_RX; |
644 | 15 | goto fail; |
645 | 15 | } |
646 | 4.41k | if (usleep((ms == -1 ? 100 : ms) * 1000) < 0) { |
647 | 2 | fido_log_debug("%s: usleep", __func__); |
648 | 2 | r = FIDO_ERR_RX; |
649 | 2 | goto fail; |
650 | 2 | } |
651 | 4.40k | } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED); |
652 | 745 | |
653 | 745 | if ((r = parse_register_reply(cred, reply, |
654 | 718 | (size_t)reply_len)) != FIDO_OK) { |
655 | 366 | fido_log_debug("%s: parse_register_reply", __func__); |
656 | 366 | goto fail; |
657 | 366 | } |
658 | 745 | fail: |
659 | 745 | iso7816_free(&apdu); |
660 | 745 | |
661 | 745 | return (r); |
662 | 718 | } |
663 | | |
664 | | static int |
665 | | u2f_authenticate_single(fido_dev_t *dev, const fido_blob_t *key_id, |
666 | | fido_assert_t *fa, size_t idx, int ms) |
667 | 2.06k | { |
668 | 2.06k | fido_blob_t sig; |
669 | 2.06k | fido_blob_t ad; |
670 | 2.06k | int found; |
671 | 2.06k | int r; |
672 | 2.06k | |
673 | 2.06k | memset(&sig, 0, sizeof(sig)); |
674 | 2.06k | memset(&ad, 0, sizeof(ad)); |
675 | 2.06k | |
676 | 2.06k | if ((r = key_lookup(dev, fa->rp_id, key_id, &found, ms)) != FIDO_OK) { |
677 | 1.00k | fido_log_debug("%s: key_lookup", __func__); |
678 | 1.00k | goto fail; |
679 | 1.00k | } |
680 | 1.06k | |
681 | 1.06k | if (!found) { |
682 | 56 | fido_log_debug("%s: not found", __func__); |
683 | 56 | r = FIDO_ERR_CREDENTIAL_EXCLUDED; |
684 | 56 | goto fail; |
685 | 56 | } |
686 | 1.00k | |
687 | 1.00k | if (fido_blob_set(&fa->stmt[idx].id, key_id->ptr, key_id->len) < 0) { |
688 | 1 | fido_log_debug("%s: fido_blob_set", __func__); |
689 | 1 | r = FIDO_ERR_INTERNAL; |
690 | 1 | goto fail; |
691 | 1 | } |
692 | 1.00k | |
693 | 1.00k | if (fa->up == FIDO_OPT_FALSE) { |
694 | 0 | fido_log_debug("%s: checking for key existence only", __func__); |
695 | 0 | r = FIDO_ERR_USER_PRESENCE_REQUIRED; |
696 | 0 | goto fail; |
697 | 0 | } |
698 | 1.00k | |
699 | 1.00k | if ((r = do_auth(dev, &fa->cdh, fa->rp_id, key_id, &sig, &ad, |
700 | 1.00k | ms)) != FIDO_OK) { |
701 | 84 | fido_log_debug("%s: do_auth", __func__); |
702 | 84 | goto fail; |
703 | 84 | } |
704 | 921 | |
705 | 921 | if (fido_assert_set_authdata(fa, idx, ad.ptr, ad.len) != FIDO_OK || |
706 | 921 | fido_assert_set_sig(fa, idx, sig.ptr, sig.len) != FIDO_OK) { |
707 | 9 | fido_log_debug("%s: fido_assert_set", __func__); |
708 | 9 | r = FIDO_ERR_INTERNAL; |
709 | 9 | goto fail; |
710 | 9 | } |
711 | 912 | |
712 | 912 | r = FIDO_OK; |
713 | 2.06k | fail: |
714 | 2.06k | if (sig.ptr) { |
715 | 923 | explicit_bzero(sig.ptr, sig.len); |
716 | 923 | free(sig.ptr); |
717 | 923 | } |
718 | 2.06k | if (ad.ptr) { |
719 | 921 | explicit_bzero(ad.ptr, ad.len); |
720 | 921 | free(ad.ptr); |
721 | 921 | } |
722 | 2.06k | |
723 | 2.06k | return (r); |
724 | 912 | } |
725 | | |
726 | | int |
727 | | u2f_authenticate(fido_dev_t *dev, fido_assert_t *fa, int ms) |
728 | 1.16k | { |
729 | 1.16k | int nfound = 0; |
730 | 1.16k | int nauth_ok = 0; |
731 | 1.16k | int r; |
732 | 1.16k | |
733 | 1.16k | if (fa->uv == FIDO_OPT_TRUE || fa->allow_list.ptr == NULL) { |
734 | 46 | fido_log_debug("%s: uv=%d, allow_list=%p", __func__, fa->uv, |
735 | 46 | (void *)fa->allow_list.ptr); |
736 | 46 | return (FIDO_ERR_UNSUPPORTED_OPTION); |
737 | 46 | } |
738 | 1.11k | |
739 | 1.11k | if ((r = fido_assert_set_count(fa, fa->allow_list.len)) != FIDO_OK) { |
740 | 2 | fido_log_debug("%s: fido_assert_set_count", __func__); |
741 | 2 | return (r); |
742 | 2 | } |
743 | 1.11k | |
744 | 2.08k | for (size_t i = 0; i < fa->allow_list.len; i++) { |
745 | 2.06k | switch ((r = u2f_authenticate_single(dev, |
746 | 2.06k | &fa->allow_list.ptr[i], fa, nfound, ms))) { |
747 | 2.06k | case FIDO_OK: |
748 | 912 | nauth_ok++; |
749 | 912 | /* FALLTHROUGH */ |
750 | 912 | case FIDO_ERR_USER_PRESENCE_REQUIRED: |
751 | 912 | nfound++; |
752 | 912 | break; |
753 | 1.15k | default: |
754 | 1.15k | if (r != FIDO_ERR_CREDENTIAL_EXCLUDED) { |
755 | 1.09k | fido_log_debug("%s: u2f_authenticate_single", |
756 | 1.09k | __func__); |
757 | 1.09k | return (r); |
758 | 1.09k | } |
759 | 2.06k | /* ignore credentials that don't exist */ |
760 | 2.06k | } |
761 | 2.06k | } |
762 | 1.11k | |
763 | 1.11k | fa->stmt_len = nfound; |
764 | 19 | |
765 | 19 | if (nfound == 0) |
766 | 0 | return (FIDO_ERR_NO_CREDENTIALS); |
767 | 19 | if (nauth_ok == 0) |
768 | 0 | return (FIDO_ERR_USER_PRESENCE_REQUIRED); |
769 | 19 | |
770 | 19 | return (FIDO_OK); |
771 | 19 | } |