Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright (c) 2020-2022 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 | | */ |
6 | | |
7 | | #include <stdio.h> |
8 | | #include <string.h> |
9 | | |
10 | | #include "fido.h" |
11 | | #include "fido/param.h" |
12 | | #include "iso7816.h" |
13 | | |
14 | 2.80k | #define TX_CHUNK_SIZE 240 |
15 | | |
16 | | static const uint8_t aid[] = { 0xa0, 0x00, 0x00, 0x06, 0x47, 0x2f, 0x00, 0x01 }; |
17 | | static const uint8_t v_u2f[] = { 'U', '2', 'F', '_', 'V', '2' }; |
18 | | static const uint8_t v_fido[] = { 'F', 'I', 'D', 'O', '_', '2', '_', '0' }; |
19 | | |
20 | | static int |
21 | | tx_short_apdu(fido_dev_t *d, const iso7816_header_t *h, const uint8_t *payload, |
22 | | uint8_t payload_len, uint8_t cla_flags) |
23 | 2.62k | { |
24 | 2.62k | uint8_t apdu[5 + UINT8_MAX + 1]; |
25 | 2.62k | uint8_t sw[2]; |
26 | 2.62k | size_t apdu_len; |
27 | 2.62k | int ok = -1; |
28 | | |
29 | 2.62k | memset(&apdu, 0, sizeof(apdu)); |
30 | 2.62k | apdu[0] = h->cla | cla_flags; |
31 | 2.62k | apdu[1] = h->ins; |
32 | 2.62k | apdu[2] = h->p1; |
33 | 2.62k | apdu[3] = h->p2; |
34 | 2.62k | apdu[4] = payload_len; |
35 | 2.62k | memcpy(&apdu[5], payload, payload_len); |
36 | 2.62k | apdu_len = (size_t)(5 + payload_len + 1); |
37 | | |
38 | 2.62k | if (d->io.write(d->io_handle, apdu, apdu_len) < 0) { |
39 | 25 | fido_log_debug("%s: write", __func__); |
40 | 25 | goto fail; |
41 | 25 | } |
42 | | |
43 | 2.60k | if (cla_flags & 0x10) { |
44 | 156 | if (d->io.read(d->io_handle, sw, sizeof(sw), -1) != 2) { |
45 | 62 | fido_log_debug("%s: read", __func__); |
46 | 62 | goto fail; |
47 | 62 | } |
48 | 94 | if ((sw[0] << 8 | sw[1]) != SW_NO_ERROR) { |
49 | 84 | fido_log_debug("%s: unexpected sw", __func__); |
50 | 84 | goto fail; |
51 | 84 | } |
52 | 94 | } |
53 | | |
54 | 2.45k | ok = 0; |
55 | 2.62k | fail: |
56 | 2.62k | explicit_bzero(apdu, sizeof(apdu)); |
57 | | |
58 | 2.62k | return ok; |
59 | 2.45k | } |
60 | | |
61 | | static int |
62 | | nfc_do_tx(fido_dev_t *d, const uint8_t *apdu_ptr, size_t apdu_len) |
63 | 2.87k | { |
64 | 2.87k | iso7816_header_t h; |
65 | | |
66 | 2.87k | if (fido_buf_read(&apdu_ptr, &apdu_len, &h, sizeof(h)) < 0) { |
67 | 253 | fido_log_debug("%s: header", __func__); |
68 | 253 | return -1; |
69 | 253 | } |
70 | 2.62k | if (apdu_len < 2) { |
71 | 5 | fido_log_debug("%s: apdu_len %zu", __func__, apdu_len); |
72 | 5 | return -1; |
73 | 5 | } |
74 | | |
75 | 2.61k | apdu_len -= 2; /* trim le1 le2 */ |
76 | | |
77 | 2.62k | while (apdu_len > TX_CHUNK_SIZE) { |
78 | 156 | if (tx_short_apdu(d, &h, apdu_ptr, TX_CHUNK_SIZE, 0x10) < 0) { |
79 | 146 | fido_log_debug("%s: chain", __func__); |
80 | 146 | return -1; |
81 | 146 | } |
82 | 10 | apdu_ptr += TX_CHUNK_SIZE; |
83 | 10 | apdu_len -= TX_CHUNK_SIZE; |
84 | 10 | } |
85 | | |
86 | 2.47k | if (tx_short_apdu(d, &h, apdu_ptr, (uint8_t)apdu_len, 0) < 0) { |
87 | 25 | fido_log_debug("%s: tx_short_apdu", __func__); |
88 | 25 | return -1; |
89 | 25 | } |
90 | | |
91 | 2.44k | return 0; |
92 | 2.47k | } |
93 | | |
94 | | int |
95 | | fido_nfc_tx(fido_dev_t *d, uint8_t cmd, const unsigned char *buf, size_t count) |
96 | 3.36k | { |
97 | 3.36k | iso7816_apdu_t *apdu = NULL; |
98 | 3.36k | const uint8_t *ptr; |
99 | 3.36k | size_t len; |
100 | 3.36k | int ok = -1; |
101 | | |
102 | 3.36k | switch (cmd) { |
103 | 1.21k | case CTAP_CMD_INIT: /* select */ |
104 | 1.21k | if ((apdu = iso7816_new(0, 0xa4, 0x04, sizeof(aid))) == NULL || |
105 | 1.21k | iso7816_add(apdu, aid, sizeof(aid)) < 0) { |
106 | 14 | fido_log_debug("%s: iso7816", __func__); |
107 | 14 | goto fail; |
108 | 14 | } |
109 | 1.20k | break; |
110 | 1.20k | case CTAP_CMD_CBOR: /* wrap cbor */ |
111 | 957 | if (count > UINT16_MAX || (apdu = iso7816_new(0x80, 0x10, 0x00, |
112 | 954 | (uint16_t)count)) == NULL || |
113 | 957 | iso7816_add(apdu, buf, count) < 0) { |
114 | 17 | fido_log_debug("%s: iso7816", __func__); |
115 | 17 | goto fail; |
116 | 17 | } |
117 | 940 | break; |
118 | 940 | case CTAP_CMD_MSG: /* already an apdu */ |
119 | 731 | break; |
120 | 455 | default: |
121 | 455 | fido_log_debug("%s: cmd=%02x", __func__, cmd); |
122 | 455 | goto fail; |
123 | 3.36k | } |
124 | | |
125 | 2.87k | if (apdu != NULL) { |
126 | 2.14k | ptr = iso7816_ptr(apdu); |
127 | 2.14k | len = iso7816_len(apdu); |
128 | 2.14k | } else { |
129 | 731 | ptr = buf; |
130 | 731 | len = count; |
131 | 731 | } |
132 | | |
133 | 2.87k | if (nfc_do_tx(d, ptr, len) < 0) { |
134 | 429 | fido_log_debug("%s: nfc_do_tx", __func__); |
135 | 429 | goto fail; |
136 | 429 | } |
137 | | |
138 | 2.44k | ok = 0; |
139 | 3.36k | fail: |
140 | 3.36k | iso7816_free(&apdu); |
141 | | |
142 | 3.36k | return ok; |
143 | 2.44k | } |
144 | | |
145 | | static int |
146 | | rx_init(fido_dev_t *d, unsigned char *buf, size_t count, int ms) |
147 | 1.18k | { |
148 | 1.18k | fido_ctap_info_t *attr = (fido_ctap_info_t *)buf; |
149 | 1.18k | uint8_t f[64]; |
150 | 1.18k | int n; |
151 | | |
152 | 1.18k | if (count != sizeof(*attr)) { |
153 | 246 | fido_log_debug("%s: count=%zu", __func__, count); |
154 | 246 | return -1; |
155 | 246 | } |
156 | | |
157 | 936 | memset(attr, 0, sizeof(*attr)); |
158 | | |
159 | 936 | if ((n = d->io.read(d->io_handle, f, sizeof(f), ms)) < 2 || |
160 | 936 | (f[n - 2] << 8 | f[n - 1]) != SW_NO_ERROR) { |
161 | 323 | fido_log_debug("%s: read", __func__); |
162 | 323 | return -1; |
163 | 323 | } |
164 | | |
165 | 613 | n -= 2; |
166 | | |
167 | 613 | if (n == sizeof(v_u2f) && memcmp(f, v_u2f, sizeof(v_u2f)) == 0) |
168 | 1 | attr->flags = FIDO_CAP_CBOR; |
169 | 612 | else if (n == sizeof(v_fido) && memcmp(f, v_fido, sizeof(v_fido)) == 0) |
170 | 1 | attr->flags = FIDO_CAP_CBOR | FIDO_CAP_NMSG; |
171 | 611 | else { |
172 | 611 | fido_log_debug("%s: unknown version string", __func__); |
173 | 611 | #ifdef FIDO_FUZZ |
174 | 611 | attr->flags = FIDO_CAP_CBOR | FIDO_CAP_NMSG; |
175 | | #else |
176 | | return -1; |
177 | | #endif |
178 | 611 | } |
179 | | |
180 | 613 | memcpy(&attr->nonce, &d->nonce, sizeof(attr->nonce)); /* XXX */ |
181 | | |
182 | 613 | return (int)count; |
183 | 936 | } |
184 | | |
185 | | static int |
186 | | tx_get_response(fido_dev_t *d, uint8_t count) |
187 | 96 | { |
188 | 96 | uint8_t apdu[5]; |
189 | | |
190 | 96 | memset(apdu, 0, sizeof(apdu)); |
191 | 96 | apdu[1] = 0xc0; /* GET_RESPONSE */ |
192 | 96 | apdu[4] = count; |
193 | | |
194 | 96 | if (d->io.write(d->io_handle, apdu, sizeof(apdu)) < 0) { |
195 | 10 | fido_log_debug("%s: write", __func__); |
196 | 10 | return -1; |
197 | 10 | } |
198 | | |
199 | 86 | return 0; |
200 | 96 | } |
201 | | |
202 | | static int |
203 | | rx_apdu(fido_dev_t *d, uint8_t sw[2], unsigned char **buf, size_t *count, int *ms) |
204 | 1.65k | { |
205 | 1.65k | uint8_t f[256 + 2]; |
206 | 1.65k | struct timespec ts; |
207 | 1.65k | int n, ok = -1; |
208 | | |
209 | 1.65k | if (fido_time_now(&ts) != 0) |
210 | 23 | goto fail; |
211 | | |
212 | 1.63k | if ((n = d->io.read(d->io_handle, f, sizeof(f), *ms)) < 2) { |
213 | 1.10k | fido_log_debug("%s: read", __func__); |
214 | 1.10k | goto fail; |
215 | 1.10k | } |
216 | | |
217 | 527 | if (fido_time_delta(&ts, ms) != 0) |
218 | 15 | goto fail; |
219 | | |
220 | 512 | if (fido_buf_write(buf, count, f, (size_t)(n - 2)) < 0) { |
221 | 0 | fido_log_debug("%s: fido_buf_write", __func__); |
222 | 0 | goto fail; |
223 | 0 | } |
224 | | |
225 | 512 | memcpy(sw, f + n - 2, 2); |
226 | | |
227 | 512 | ok = 0; |
228 | 1.65k | fail: |
229 | 1.65k | explicit_bzero(f, sizeof(f)); |
230 | | |
231 | 1.65k | return ok; |
232 | 512 | } |
233 | | |
234 | | static int |
235 | | rx_msg(fido_dev_t *d, unsigned char *buf, size_t count, int ms) |
236 | 1.57k | { |
237 | 1.57k | uint8_t sw[2]; |
238 | 1.57k | const size_t bufsiz = count; |
239 | | |
240 | 1.57k | if (rx_apdu(d, sw, &buf, &count, &ms) < 0) { |
241 | 1.08k | fido_log_debug("%s: preamble", __func__); |
242 | 1.08k | return -1; |
243 | 1.08k | } |
244 | | |
245 | 512 | while (sw[0] == SW1_MORE_DATA) |
246 | 96 | if (tx_get_response(d, sw[1]) < 0 || |
247 | 96 | rx_apdu(d, sw, &buf, &count, &ms) < 0) { |
248 | 75 | fido_log_debug("%s: chain", __func__); |
249 | 75 | return -1; |
250 | 75 | } |
251 | | |
252 | 416 | if (fido_buf_write(&buf, &count, sw, sizeof(sw)) < 0) { |
253 | 0 | fido_log_debug("%s: sw", __func__); |
254 | 0 | return -1; |
255 | 0 | } |
256 | | |
257 | 416 | if (bufsiz - count > INT_MAX) { |
258 | 0 | fido_log_debug("%s: bufsiz", __func__); |
259 | 0 | return -1; |
260 | 0 | } |
261 | | |
262 | 416 | return (int)(bufsiz - count); |
263 | 416 | } |
264 | | |
265 | | static int |
266 | | rx_cbor(fido_dev_t *d, unsigned char *buf, size_t count, int ms) |
267 | 870 | { |
268 | 870 | int r; |
269 | | |
270 | 870 | if ((r = rx_msg(d, buf, count, ms)) < 2) |
271 | 577 | return -1; |
272 | | |
273 | 293 | return r - 2; |
274 | 870 | } |
275 | | |
276 | | int |
277 | | fido_nfc_rx(fido_dev_t *d, uint8_t cmd, unsigned char *buf, size_t count, int ms) |
278 | 3.16k | { |
279 | 3.16k | switch (cmd) { |
280 | 1.18k | case CTAP_CMD_INIT: |
281 | 1.18k | return rx_init(d, buf, count, ms); |
282 | 870 | case CTAP_CMD_CBOR: |
283 | 870 | return rx_cbor(d, buf, count, ms); |
284 | 701 | case CTAP_CMD_MSG: |
285 | 701 | return rx_msg(d, buf, count, ms); |
286 | 414 | default: |
287 | 414 | fido_log_debug("%s: cmd=%02x", __func__, cmd); |
288 | 414 | return -1; |
289 | 3.16k | } |
290 | 3.16k | } |
291 | | |
292 | | #ifdef USE_NFC |
293 | | bool |
294 | | fido_is_nfc(const char *path) |
295 | 69.4k | { |
296 | 69.4k | return strncmp(path, FIDO_NFC_PREFIX, strlen(FIDO_NFC_PREFIX)) == 0; |
297 | 69.4k | } |
298 | | |
299 | | int |
300 | | fido_dev_set_nfc(fido_dev_t *d) |
301 | 0 | { |
302 | 0 | if (d->io_handle != NULL) { |
303 | 0 | fido_log_debug("%s: device open", __func__); |
304 | 0 | return -1; |
305 | 0 | } |
306 | 0 | d->io_own = true; |
307 | 0 | d->io = (fido_dev_io_t) { |
308 | 0 | fido_nfc_open, |
309 | 0 | fido_nfc_close, |
310 | 0 | fido_nfc_read, |
311 | 0 | fido_nfc_write, |
312 | 0 | }; |
313 | 0 | d->transport = (fido_dev_transport_t) { |
314 | 0 | fido_nfc_rx, |
315 | 0 | fido_nfc_tx, |
316 | 0 | }; |
317 | |
|
318 | 0 | return 0; |
319 | 0 | } |
320 | | #endif /* USE_NFC */ |