Coverage Report

Created: 2025-10-04 18:33

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/libfido2/src/io.c
Line
Count
Source
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 "fido.h"
9
#include "packed.h"
10
11
PACKED_TYPE(frame_t,
12
struct frame {
13
        uint32_t cid; /* channel id */
14
        union {
15
                uint8_t type;
16
                struct {
17
                        uint8_t cmd;
18
                        uint8_t bcnth;
19
                        uint8_t bcntl;
20
                        uint8_t data[CTAP_MAX_REPORT_LEN - CTAP_INIT_HEADER_LEN];
21
                } init;
22
                struct {
23
                        uint8_t seq;
24
                        uint8_t data[CTAP_MAX_REPORT_LEN - CTAP_CONT_HEADER_LEN];
25
                } cont;
26
        } body;
27
})
28
29
#ifndef MIN
30
1.12M
#define MIN(x, y) ((x) > (y) ? (y) : (x))
31
#endif
32
33
static int
34
tx_pkt(fido_dev_t *d, const void *pkt, size_t len, int *ms)
35
1.14M
{
36
1.14M
        struct timespec ts;
37
1.14M
        int n;
38
39
1.14M
        if (fido_time_now(&ts) != 0)
40
2.54k
                return (-1);
41
42
1.14M
        n = d->io.write(d->io_handle, pkt, len);
43
44
1.14M
        if (fido_time_delta(&ts, ms) != 0)
45
5.00k
                return (-1);
46
47
1.14M
        return (n);
48
1.14M
}
49
50
static int
51
tx_empty(fido_dev_t *d, uint8_t cmd, int *ms)
52
25.1k
{
53
25.1k
        struct frame    *fp;
54
25.1k
        unsigned char    pkt[sizeof(*fp) + 1];
55
25.1k
        const size_t     len = d->tx_len + 1;
56
25.1k
        int              n;
57
58
25.1k
        memset(&pkt, 0, sizeof(pkt));
59
25.1k
        fp = (struct frame *)(pkt + 1);
60
25.1k
        fp->cid = d->cid;
61
25.1k
        fp->body.init.cmd = CTAP_FRAME_INIT | cmd;
62
63
25.1k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
64
25.1k
            (size_t)n != len)
65
375
                return (-1);
66
67
24.7k
        return (0);
68
25.1k
}
69
70
static size_t
71
tx_preamble(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
72
579k
{
73
579k
        struct frame    *fp;
74
579k
        unsigned char    pkt[sizeof(*fp) + 1];
75
579k
        const size_t     len = d->tx_len + 1;
76
579k
        int              n;
77
78
579k
        if (d->tx_len - CTAP_INIT_HEADER_LEN > sizeof(fp->body.init.data))
79
0
                return (0);
80
81
579k
        memset(&pkt, 0, sizeof(pkt));
82
579k
        fp = (struct frame *)(pkt + 1);
83
579k
        fp->cid = d->cid;
84
579k
        fp->body.init.cmd = CTAP_FRAME_INIT | cmd;
85
579k
        fp->body.init.bcnth = (count >> 8) & 0xff;
86
579k
        fp->body.init.bcntl = count & 0xff;
87
579k
        count = MIN(count, d->tx_len - CTAP_INIT_HEADER_LEN);
88
579k
        memcpy(&fp->body.init.data, buf, count);
89
90
579k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
91
579k
            (size_t)n != len)
92
5.80k
                return (0);
93
94
573k
        return (count);
95
579k
}
96
97
static size_t
98
tx_frame(fido_dev_t *d, uint8_t seq, const void *buf, size_t count, int *ms)
99
544k
{
100
544k
        struct frame    *fp;
101
544k
        unsigned char    pkt[sizeof(*fp) + 1];
102
544k
        const size_t     len = d->tx_len + 1;
103
544k
        int              n;
104
105
544k
        if (d->tx_len - CTAP_CONT_HEADER_LEN > sizeof(fp->body.cont.data))
106
0
                return (0);
107
108
544k
        memset(&pkt, 0, sizeof(pkt));
109
544k
        fp = (struct frame *)(pkt + 1);
110
544k
        fp->cid = d->cid;
111
544k
        fp->body.cont.seq = seq;
112
544k
        count = MIN(count, d->tx_len - CTAP_CONT_HEADER_LEN);
113
544k
        memcpy(&fp->body.cont.data, buf, count);
114
115
544k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
116
544k
            (size_t)n != len)
117
3.34k
                return (0);
118
119
541k
        return (count);
120
544k
}
121
122
static int
123
tx(fido_dev_t *d, uint8_t cmd, const unsigned char *buf, size_t count, int *ms)
124
579k
{
125
579k
        size_t n, sent;
126
127
579k
        if ((sent = tx_preamble(d, cmd, buf, count, ms)) == 0) {
128
5.80k
                fido_log_debug("%s: tx_preamble", __func__);
129
5.80k
                return (-1);
130
5.80k
        }
131
132
1.11M
        for (uint8_t seq = 0; sent < count; sent += n) {
133
545k
                if (seq & 0x80) {
134
411
                        fido_log_debug("%s: seq & 0x80", __func__);
135
411
                        return (-1);
136
411
                }
137
544k
                if ((n = tx_frame(d, seq++, buf + sent, count - sent,
138
544k
                    ms)) == 0) {
139
3.34k
                        fido_log_debug("%s: tx_frame", __func__);
140
3.34k
                        return (-1);
141
3.34k
                }
142
544k
        }
143
144
570k
        return (0);
145
573k
}
146
147
static int
148
transport_tx(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
149
22.6k
{
150
22.6k
        struct timespec ts;
151
22.6k
        int n;
152
153
22.6k
        if (fido_time_now(&ts) != 0)
154
274
                return (-1);
155
156
22.3k
        n = d->transport.tx(d, cmd, buf, count);
157
158
22.3k
        if (fido_time_delta(&ts, ms) != 0)
159
133
                return (-1);
160
161
22.2k
        return (n);
162
22.3k
}
163
164
int
165
fido_tx(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
166
627k
{
167
627k
        fido_log_debug("%s: dev=%p, cmd=0x%02x", __func__, (void *)d, cmd);
168
627k
        fido_log_xxd(buf, count, "%s", __func__);
169
170
627k
        if (d->transport.tx != NULL)
171
22.6k
                return (transport_tx(d, cmd, buf, count, ms));
172
605k
        if (d->io_handle == NULL || d->io.write == NULL || count > UINT16_MAX) {
173
341
                fido_log_debug("%s: invalid argument", __func__);
174
341
                return (-1);
175
341
        }
176
177
604k
        return (count == 0 ? tx_empty(d, cmd, ms) : tx(d, cmd, buf, count, ms));
178
605k
}
179
180
static int
181
rx_frame(fido_dev_t *d, struct frame *fp, int *ms)
182
1.25M
{
183
1.25M
        struct timespec ts;
184
1.25M
        int n;
185
186
1.25M
        memset(fp, 0, sizeof(*fp));
187
188
1.25M
        if (fido_time_now(&ts) != 0)
189
1.68k
                return (-1);
190
191
1.25M
        if (d->rx_len > sizeof(*fp) || (n = d->io.read(d->io_handle,
192
1.25M
            (unsigned char *)fp, d->rx_len, *ms)) < 0 || (size_t)n != d->rx_len)
193
202k
                return (-1);
194
195
1.05M
        return (fido_time_delta(&ts, ms));
196
1.25M
}
197
198
static int
199
rx_preamble(fido_dev_t *d, uint8_t cmd, struct frame *fp, int *ms)
200
580k
{
201
606k
        do {
202
606k
                if (rx_frame(d, fp, ms) < 0)
203
196k
                        return (-1);
204
409k
#ifdef FIDO_FUZZ
205
409k
                fp->cid = d->cid;
206
409k
#endif
207
409k
        } while (fp->cid != d->cid || (fp->cid == d->cid &&
208
409k
            fp->body.init.cmd == (CTAP_FRAME_INIT | CTAP_KEEPALIVE)));
209
210
384k
        if (d->rx_len > sizeof(*fp))
211
0
                return (-1);
212
213
384k
        fido_log_xxd(fp, d->rx_len, "%s", __func__);
214
384k
#ifdef FIDO_FUZZ
215
384k
        fp->body.init.cmd = (CTAP_FRAME_INIT | cmd);
216
384k
#endif
217
218
384k
        if (fp->cid != d->cid || fp->body.init.cmd != (CTAP_FRAME_INIT | cmd)) {
219
0
                fido_log_debug("%s: cid (0x%x, 0x%x), cmd (0x%02x, 0x%02x)",
220
0
                    __func__, fp->cid, d->cid, fp->body.init.cmd, cmd);
221
0
                return (-1);
222
0
        }
223
224
384k
        return (0);
225
384k
}
226
227
static int
228
rx(fido_dev_t *d, uint8_t cmd, unsigned char *buf, size_t count, int *ms)
229
580k
{
230
580k
        struct frame f;
231
580k
        size_t r, payload_len, init_data_len, cont_data_len;
232
233
580k
        if (d->rx_len <= CTAP_INIT_HEADER_LEN ||
234
580k
            d->rx_len <= CTAP_CONT_HEADER_LEN)
235
0
                return (-1);
236
237
580k
        init_data_len = d->rx_len - CTAP_INIT_HEADER_LEN;
238
580k
        cont_data_len = d->rx_len - CTAP_CONT_HEADER_LEN;
239
240
580k
        if (init_data_len > sizeof(f.body.init.data) ||
241
580k
            cont_data_len > sizeof(f.body.cont.data))
242
0
                return (-1);
243
244
580k
        if (rx_preamble(d, cmd, &f, ms) < 0) {
245
196k
                fido_log_debug("%s: rx_preamble", __func__);
246
196k
                return (-1);
247
196k
        }
248
249
384k
        payload_len = (size_t)((f.body.init.bcnth << 8) | f.body.init.bcntl);
250
384k
        fido_log_debug("%s: payload_len=%zu", __func__, payload_len);
251
252
384k
        if (count < payload_len) {
253
37.6k
                fido_log_debug("%s: count < payload_len", __func__);
254
37.6k
                return (-1);
255
37.6k
        }
256
257
346k
        if (payload_len < init_data_len) {
258
188k
                memcpy(buf, f.body.init.data, payload_len);
259
188k
                return ((int)payload_len);
260
188k
        }
261
262
157k
        memcpy(buf, f.body.init.data, init_data_len);
263
157k
        r = init_data_len;
264
265
797k
        for (int seq = 0; r < payload_len; seq++) {
266
650k
                if (rx_frame(d, &f, ms) < 0) {
267
9.67k
                        fido_log_debug("%s: rx_frame", __func__);
268
9.67k
                        return (-1);
269
9.67k
                }
270
271
640k
                fido_log_xxd(&f, d->rx_len, "%s", __func__);
272
640k
#ifdef FIDO_FUZZ
273
640k
                f.cid = d->cid;
274
640k
                f.body.cont.seq = (uint8_t)seq;
275
640k
#endif
276
277
640k
                if (f.cid != d->cid || f.body.cont.seq != seq) {
278
72
                        fido_log_debug("%s: cid (0x%x, 0x%x), seq (%d, %d)",
279
72
                            __func__, f.cid, d->cid, f.body.cont.seq, seq);
280
72
                        return (-1);
281
72
                }
282
283
640k
                if (payload_len - r > cont_data_len) {
284
503k
                        memcpy(buf + r, f.body.cont.data, cont_data_len);
285
503k
                        r += cont_data_len;
286
503k
                } else {
287
136k
                        memcpy(buf + r, f.body.cont.data, payload_len - r);
288
136k
                        r += payload_len - r; /* break */
289
136k
                }
290
640k
        }
291
292
147k
        return ((int)r);
293
157k
}
294
295
static int
296
transport_rx(fido_dev_t *d, uint8_t cmd, void *buf, size_t count, int *ms)
297
20.8k
{
298
20.8k
        struct timespec ts;
299
20.8k
        int n;
300
301
20.8k
        if (fido_time_now(&ts) != 0)
302
175
                return (-1);
303
304
20.7k
        n = d->transport.rx(d, cmd, buf, count, *ms);
305
306
20.7k
        if (fido_time_delta(&ts, ms) != 0)
307
472
                return (-1);
308
309
20.2k
        return (n);
310
20.7k
}
311
312
int
313
fido_rx(fido_dev_t *d, uint8_t cmd, void *buf, size_t count, int *ms)
314
601k
{
315
601k
        int n;
316
317
601k
        fido_log_debug("%s: dev=%p, cmd=0x%02x, ms=%d", __func__, (void *)d,
318
601k
            cmd, *ms);
319
320
601k
        if (d->transport.rx != NULL)
321
20.8k
                return (transport_rx(d, cmd, buf, count, ms));
322
580k
        if (d->io_handle == NULL || d->io.read == NULL || count > UINT16_MAX) {
323
0
                fido_log_debug("%s: invalid argument", __func__);
324
0
                return (-1);
325
0
        }
326
580k
        if ((n = rx(d, cmd, buf, count, ms)) >= 0)
327
336k
                fido_log_xxd(buf, (size_t)n, "%s", __func__);
328
329
580k
        return (n);
330
580k
}
331
332
int
333
fido_rx_cbor_status(fido_dev_t *d, int *ms)
334
12.4k
{
335
12.4k
        unsigned char   *msg;
336
12.4k
        int              msglen;
337
12.4k
        int              r;
338
339
12.4k
        if ((msg = malloc(FIDO_MAXMSG)) == NULL) {
340
81
                r = FIDO_ERR_INTERNAL;
341
81
                goto out;
342
81
        }
343
344
12.3k
        if ((msglen = fido_rx(d, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0 ||
345
12.3k
            (size_t)msglen < 1) {
346
7.65k
                fido_log_debug("%s: fido_rx", __func__);
347
7.65k
                r = FIDO_ERR_RX;
348
7.65k
                goto out;
349
7.65k
        }
350
351
4.73k
        r = msg[0];
352
12.4k
out:
353
12.4k
        freezero(msg, FIDO_MAXMSG);
354
355
12.4k
        return (r);
356
4.73k
}