Coverage Report

Created: 2023-09-23 17:42

/libfido2/src/io.c
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 "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
184k
#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
187k
{
36
187k
        struct timespec ts;
37
187k
        int n;
38
39
187k
        if (fido_time_now(&ts) != 0)
40
447
                return (-1);
41
42
187k
        n = d->io.write(d->io_handle, pkt, len);
43
44
187k
        if (fido_time_delta(&ts, ms) != 0)
45
956
                return (-1);
46
47
186k
        return (n);
48
187k
}
49
50
static int
51
tx_empty(fido_dev_t *d, uint8_t cmd, int *ms)
52
2.85k
{
53
2.85k
        struct frame    *fp;
54
2.85k
        unsigned char    pkt[sizeof(*fp) + 1];
55
2.85k
        const size_t     len = d->tx_len + 1;
56
2.85k
        int              n;
57
58
2.85k
        memset(&pkt, 0, sizeof(pkt));
59
2.85k
        fp = (struct frame *)(pkt + 1);
60
2.85k
        fp->cid = d->cid;
61
2.85k
        fp->body.init.cmd = CTAP_FRAME_INIT | cmd;
62
63
2.85k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
64
2.85k
            (size_t)n != len)
65
45
                return (-1);
66
67
2.81k
        return (0);
68
2.85k
}
69
70
static size_t
71
tx_preamble(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
72
103k
{
73
103k
        struct frame    *fp;
74
103k
        unsigned char    pkt[sizeof(*fp) + 1];
75
103k
        const size_t     len = d->tx_len + 1;
76
103k
        int              n;
77
78
103k
        if (d->tx_len - CTAP_INIT_HEADER_LEN > sizeof(fp->body.init.data))
79
0
                return (0);
80
81
103k
        memset(&pkt, 0, sizeof(pkt));
82
103k
        fp = (struct frame *)(pkt + 1);
83
103k
        fp->cid = d->cid;
84
103k
        fp->body.init.cmd = CTAP_FRAME_INIT | cmd;
85
103k
        fp->body.init.bcnth = (count >> 8) & 0xff;
86
103k
        fp->body.init.bcntl = count & 0xff;
87
103k
        count = MIN(count, d->tx_len - CTAP_INIT_HEADER_LEN);
88
103k
        memcpy(&fp->body.init.data, buf, count);
89
90
103k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
91
103k
            (size_t)n != len)
92
1.14k
                return (0);
93
94
102k
        return (count);
95
103k
}
96
97
static size_t
98
tx_frame(fido_dev_t *d, uint8_t seq, const void *buf, size_t count, int *ms)
99
81.0k
{
100
81.0k
        struct frame    *fp;
101
81.0k
        unsigned char    pkt[sizeof(*fp) + 1];
102
81.0k
        const size_t     len = d->tx_len + 1;
103
81.0k
        int              n;
104
105
81.0k
        if (d->tx_len - CTAP_CONT_HEADER_LEN > sizeof(fp->body.cont.data))
106
0
                return (0);
107
108
81.0k
        memset(&pkt, 0, sizeof(pkt));
109
81.0k
        fp = (struct frame *)(pkt + 1);
110
81.0k
        fp->cid = d->cid;
111
81.0k
        fp->body.cont.seq = seq;
112
81.0k
        count = MIN(count, d->tx_len - CTAP_CONT_HEADER_LEN);
113
81.0k
        memcpy(&fp->body.cont.data, buf, count);
114
115
81.0k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
116
81.0k
            (size_t)n != len)
117
540
                return (0);
118
119
80.5k
        return (count);
120
81.0k
}
121
122
static int
123
tx(fido_dev_t *d, uint8_t cmd, const unsigned char *buf, size_t count, int *ms)
124
103k
{
125
103k
        size_t n, sent;
126
127
103k
        if ((sent = tx_preamble(d, cmd, buf, count, ms)) == 0) {
128
1.14k
                fido_log_debug("%s: tx_preamble", __func__);
129
1.14k
                return (-1);
130
1.14k
        }
131
132
183k
        for (uint8_t seq = 0; sent < count; sent += n) {
133
81.1k
                if (seq & 0x80) {
134
68
                        fido_log_debug("%s: seq & 0x80", __func__);
135
68
                        return (-1);
136
68
                }
137
81.0k
                if ((n = tx_frame(d, seq++, buf + sent, count - sent,
138
81.0k
                    ms)) == 0) {
139
540
                        fido_log_debug("%s: tx_frame", __func__);
140
540
                        return (-1);
141
540
                }
142
81.0k
        }
143
144
101k
        return (0);
145
102k
}
146
147
static int
148
transport_tx(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
149
3.83k
{
150
3.83k
        struct timespec ts;
151
3.83k
        int n;
152
153
3.83k
        if (fido_time_now(&ts) != 0)
154
37
                return (-1);
155
156
3.80k
        n = d->transport.tx(d, cmd, buf, count);
157
158
3.80k
        if (fido_time_delta(&ts, ms) != 0)
159
45
                return (-1);
160
161
3.75k
        return (n);
162
3.80k
}
163
164
int
165
fido_tx(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
166
110k
{
167
110k
        fido_log_debug("%s: dev=%p, cmd=0x%02x", __func__, (void *)d, cmd);
168
110k
        fido_log_xxd(buf, count, "%s", __func__);
169
170
110k
        if (d->transport.tx != NULL)
171
3.83k
                return (transport_tx(d, cmd, buf, count, ms));
172
106k
        if (d->io_handle == NULL || d->io.write == NULL || count > UINT16_MAX) {
173
18
                fido_log_debug("%s: invalid argument", __func__);
174
18
                return (-1);
175
18
        }
176
177
106k
        return (count == 0 ? tx_empty(d, cmd, ms) : tx(d, cmd, buf, count, ms));
178
106k
}
179
180
static int
181
rx_frame(fido_dev_t *d, struct frame *fp, int *ms)
182
221k
{
183
221k
        struct timespec ts;
184
221k
        int n;
185
186
221k
        memset(fp, 0, sizeof(*fp));
187
188
221k
        if (fido_time_now(&ts) != 0)
189
299
                return (-1);
190
191
221k
        if (d->rx_len > sizeof(*fp) || (n = d->io.read(d->io_handle,
192
221k
            (unsigned char *)fp, d->rx_len, *ms)) < 0 || (size_t)n != d->rx_len)
193
44.5k
                return (-1);
194
195
177k
        return (fido_time_delta(&ts, ms));
196
221k
}
197
198
static int
199
rx_preamble(fido_dev_t *d, uint8_t cmd, struct frame *fp, int *ms)
200
103k
{
201
106k
        do {
202
106k
                if (rx_frame(d, fp, ms) < 0)
203
43.2k
                        return (-1);
204
63.0k
#ifdef FIDO_FUZZ
205
63.0k
                fp->cid = d->cid;
206
63.0k
#endif
207
63.0k
        } while (fp->cid != d->cid || (fp->cid == d->cid &&
208
63.0k
            fp->body.init.cmd == (CTAP_FRAME_INIT | CTAP_KEEPALIVE)));
209
210
59.8k
        if (d->rx_len > sizeof(*fp))
211
0
                return (-1);
212
213
59.8k
        fido_log_xxd(fp, d->rx_len, "%s", __func__);
214
59.8k
#ifdef FIDO_FUZZ
215
59.8k
        fp->body.init.cmd = (CTAP_FRAME_INIT | cmd);
216
59.8k
#endif
217
218
59.8k
        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
59.8k
        return (0);
225
59.8k
}
226
227
static int
228
rx(fido_dev_t *d, uint8_t cmd, unsigned char *buf, size_t count, int *ms)
229
103k
{
230
103k
        struct frame f;
231
103k
        size_t r, payload_len, init_data_len, cont_data_len;
232
233
103k
        if (d->rx_len <= CTAP_INIT_HEADER_LEN ||
234
103k
            d->rx_len <= CTAP_CONT_HEADER_LEN)
235
0
                return (-1);
236
237
103k
        init_data_len = d->rx_len - CTAP_INIT_HEADER_LEN;
238
103k
        cont_data_len = d->rx_len - CTAP_CONT_HEADER_LEN;
239
240
103k
        if (init_data_len > sizeof(f.body.init.data) ||
241
103k
            cont_data_len > sizeof(f.body.cont.data))
242
0
                return (-1);
243
244
103k
        if (rx_preamble(d, cmd, &f, ms) < 0) {
245
43.2k
                fido_log_debug("%s: rx_preamble", __func__);
246
43.2k
                return (-1);
247
43.2k
        }
248
249
59.8k
        payload_len = (size_t)((f.body.init.bcnth << 8) | f.body.init.bcntl);
250
59.8k
        fido_log_debug("%s: payload_len=%zu", __func__, payload_len);
251
252
59.8k
        if (count < payload_len) {
253
4.72k
                fido_log_debug("%s: count < payload_len", __func__);
254
4.72k
                return (-1);
255
4.72k
        }
256
257
55.0k
        if (payload_len < init_data_len) {
258
28.9k
                memcpy(buf, f.body.init.data, payload_len);
259
28.9k
                return ((int)payload_len);
260
28.9k
        }
261
262
26.1k
        memcpy(buf, f.body.init.data, init_data_len);
263
26.1k
        r = init_data_len;
264
265
139k
        for (int seq = 0; r < payload_len; seq++) {
266
115k
                if (rx_frame(d, &f, ms) < 0) {
267
1.95k
                        fido_log_debug("%s: rx_frame", __func__);
268
1.95k
                        return (-1);
269
1.95k
                }
270
271
113k
                fido_log_xxd(&f, d->rx_len, "%s", __func__);
272
113k
#ifdef FIDO_FUZZ
273
113k
                f.cid = d->cid;
274
113k
                f.body.cont.seq = (uint8_t)seq;
275
113k
#endif
276
277
113k
                if (f.cid != d->cid || f.body.cont.seq != seq) {
278
20
                        fido_log_debug("%s: cid (0x%x, 0x%x), seq (%d, %d)",
279
20
                            __func__, f.cid, d->cid, f.body.cont.seq, seq);
280
20
                        return (-1);
281
20
                }
282
283
113k
                if (payload_len - r > cont_data_len) {
284
91.1k
                        memcpy(buf + r, f.body.cont.data, cont_data_len);
285
91.1k
                        r += cont_data_len;
286
91.1k
                } else {
287
22.5k
                        memcpy(buf + r, f.body.cont.data, payload_len - r);
288
22.5k
                        r += payload_len - r; /* break */
289
22.5k
                }
290
113k
        }
291
292
24.1k
        return ((int)r);
293
26.1k
}
294
295
static int
296
transport_rx(fido_dev_t *d, uint8_t cmd, void *buf, size_t count, int *ms)
297
3.44k
{
298
3.44k
        struct timespec ts;
299
3.44k
        int n;
300
301
3.44k
        if (fido_time_now(&ts) != 0)
302
44
                return (-1);
303
304
3.40k
        n = d->transport.rx(d, cmd, buf, count, *ms);
305
306
3.40k
        if (fido_time_delta(&ts, ms) != 0)
307
61
                return (-1);
308
309
3.34k
        return (n);
310
3.40k
}
311
312
int
313
fido_rx(fido_dev_t *d, uint8_t cmd, void *buf, size_t count, int *ms)
314
106k
{
315
106k
        int n;
316
317
106k
        fido_log_debug("%s: dev=%p, cmd=0x%02x, ms=%d", __func__, (void *)d,
318
106k
            cmd, *ms);
319
320
106k
        if (d->transport.rx != NULL)
321
3.44k
                return (transport_rx(d, cmd, buf, count, ms));
322
103k
        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
103k
        if ((n = rx(d, cmd, buf, count, ms)) >= 0)
327
53.1k
                fido_log_xxd(buf, (size_t)n, "%s", __func__);
328
329
103k
        return (n);
330
103k
}
331
332
int
333
fido_rx_cbor_status(fido_dev_t *d, int *ms)
334
2.81k
{
335
2.81k
        unsigned char   *msg;
336
2.81k
        int              msglen;
337
2.81k
        int              r;
338
339
2.81k
        if ((msg = malloc(FIDO_MAXMSG)) == NULL) {
340
18
                r = FIDO_ERR_INTERNAL;
341
18
                goto out;
342
18
        }
343
344
2.79k
        if ((msglen = fido_rx(d, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0 ||
345
2.79k
            (size_t)msglen < 1) {
346
1.84k
                fido_log_debug("%s: fido_rx", __func__);
347
1.84k
                r = FIDO_ERR_RX;
348
1.84k
                goto out;
349
1.84k
        }
350
351
949
        r = msg[0];
352
2.81k
out:
353
2.81k
        freezero(msg, FIDO_MAXMSG);
354
355
2.81k
        return (r);
356
949
}