Coverage Report

Created: 2024-06-03 09:43

/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
314k
#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
319k
{
36
319k
        struct timespec ts;
37
319k
        int n;
38
39
319k
        if (fido_time_now(&ts) != 0)
40
780
                return (-1);
41
42
318k
        n = d->io.write(d->io_handle, pkt, len);
43
44
318k
        if (fido_time_delta(&ts, ms) != 0)
45
1.50k
                return (-1);
46
47
317k
        return (n);
48
318k
}
49
50
static int
51
tx_empty(fido_dev_t *d, uint8_t cmd, int *ms)
52
4.83k
{
53
4.83k
        struct frame    *fp;
54
4.83k
        unsigned char    pkt[sizeof(*fp) + 1];
55
4.83k
        const size_t     len = d->tx_len + 1;
56
4.83k
        int              n;
57
58
4.83k
        memset(&pkt, 0, sizeof(pkt));
59
4.83k
        fp = (struct frame *)(pkt + 1);
60
4.83k
        fp->cid = d->cid;
61
4.83k
        fp->body.init.cmd = CTAP_FRAME_INIT | cmd;
62
63
4.83k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
64
4.83k
            (size_t)n != len)
65
81
                return (-1);
66
67
4.75k
        return (0);
68
4.83k
}
69
70
static size_t
71
tx_preamble(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
72
181k
{
73
181k
        struct frame    *fp;
74
181k
        unsigned char    pkt[sizeof(*fp) + 1];
75
181k
        const size_t     len = d->tx_len + 1;
76
181k
        int              n;
77
78
181k
        if (d->tx_len - CTAP_INIT_HEADER_LEN > sizeof(fp->body.init.data))
79
0
                return (0);
80
81
181k
        memset(&pkt, 0, sizeof(pkt));
82
181k
        fp = (struct frame *)(pkt + 1);
83
181k
        fp->cid = d->cid;
84
181k
        fp->body.init.cmd = CTAP_FRAME_INIT | cmd;
85
181k
        fp->body.init.bcnth = (count >> 8) & 0xff;
86
181k
        fp->body.init.bcntl = count & 0xff;
87
181k
        count = MIN(count, d->tx_len - CTAP_INIT_HEADER_LEN);
88
181k
        memcpy(&fp->body.init.data, buf, count);
89
90
181k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
91
181k
            (size_t)n != len)
92
1.82k
                return (0);
93
94
179k
        return (count);
95
181k
}
96
97
static size_t
98
tx_frame(fido_dev_t *d, uint8_t seq, const void *buf, size_t count, int *ms)
99
133k
{
100
133k
        struct frame    *fp;
101
133k
        unsigned char    pkt[sizeof(*fp) + 1];
102
133k
        const size_t     len = d->tx_len + 1;
103
133k
        int              n;
104
105
133k
        if (d->tx_len - CTAP_CONT_HEADER_LEN > sizeof(fp->body.cont.data))
106
0
                return (0);
107
108
133k
        memset(&pkt, 0, sizeof(pkt));
109
133k
        fp = (struct frame *)(pkt + 1);
110
133k
        fp->cid = d->cid;
111
133k
        fp->body.cont.seq = seq;
112
133k
        count = MIN(count, d->tx_len - CTAP_CONT_HEADER_LEN);
113
133k
        memcpy(&fp->body.cont.data, buf, count);
114
115
133k
        if (len > sizeof(pkt) || (n = tx_pkt(d, pkt, len, ms)) < 0 ||
116
133k
            (size_t)n != len)
117
912
                return (0);
118
119
132k
        return (count);
120
133k
}
121
122
static int
123
tx(fido_dev_t *d, uint8_t cmd, const unsigned char *buf, size_t count, int *ms)
124
181k
{
125
181k
        size_t n, sent;
126
127
181k
        if ((sent = tx_preamble(d, cmd, buf, count, ms)) == 0) {
128
1.82k
                fido_log_debug("%s: tx_preamble", __func__);
129
1.82k
                return (-1);
130
1.82k
        }
131
132
312k
        for (uint8_t seq = 0; sent < count; sent += n) {
133
133k
                if (seq & 0x80) {
134
90
                        fido_log_debug("%s: seq & 0x80", __func__);
135
90
                        return (-1);
136
90
                }
137
133k
                if ((n = tx_frame(d, seq++, buf + sent, count - sent,
138
133k
                    ms)) == 0) {
139
912
                        fido_log_debug("%s: tx_frame", __func__);
140
912
                        return (-1);
141
912
                }
142
133k
        }
143
144
178k
        return (0);
145
179k
}
146
147
static int
148
transport_tx(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
149
4.89k
{
150
4.89k
        struct timespec ts;
151
4.89k
        int n;
152
153
4.89k
        if (fido_time_now(&ts) != 0)
154
43
                return (-1);
155
156
4.85k
        n = d->transport.tx(d, cmd, buf, count);
157
158
4.85k
        if (fido_time_delta(&ts, ms) != 0)
159
57
                return (-1);
160
161
4.79k
        return (n);
162
4.85k
}
163
164
int
165
fido_tx(fido_dev_t *d, uint8_t cmd, const void *buf, size_t count, int *ms)
166
191k
{
167
191k
        fido_log_debug("%s: dev=%p, cmd=0x%02x", __func__, (void *)d, cmd);
168
191k
        fido_log_xxd(buf, count, "%s", __func__);
169
170
191k
        if (d->transport.tx != NULL)
171
4.89k
                return (transport_tx(d, cmd, buf, count, ms));
172
186k
        if (d->io_handle == NULL || d->io.write == NULL || count > UINT16_MAX) {
173
42
                fido_log_debug("%s: invalid argument", __func__);
174
42
                return (-1);
175
42
        }
176
177
186k
        return (count == 0 ? tx_empty(d, cmd, ms) : tx(d, cmd, buf, count, ms));
178
186k
}
179
180
static int
181
rx_frame(fido_dev_t *d, struct frame *fp, int *ms)
182
372k
{
183
372k
        struct timespec ts;
184
372k
        int n;
185
186
372k
        memset(fp, 0, sizeof(*fp));
187
188
372k
        if (fido_time_now(&ts) != 0)
189
512
                return (-1);
190
191
372k
        if (d->rx_len > sizeof(*fp) || (n = d->io.read(d->io_handle,
192
372k
            (unsigned char *)fp, d->rx_len, *ms)) < 0 || (size_t)n != d->rx_len)
193
68.9k
                return (-1);
194
195
303k
        return (fido_time_delta(&ts, ms));
196
372k
}
197
198
static int
199
rx_preamble(fido_dev_t *d, uint8_t cmd, struct frame *fp, int *ms)
200
180k
{
201
186k
        do {
202
186k
                if (rx_frame(d, fp, ms) < 0)
203
66.6k
                        return (-1);
204
119k
#ifdef FIDO_FUZZ
205
119k
                fp->cid = d->cid;
206
119k
#endif
207
119k
        } while (fp->cid != d->cid || (fp->cid == d->cid &&
208
119k
            fp->body.init.cmd == (CTAP_FRAME_INIT | CTAP_KEEPALIVE)));
209
210
114k
        if (d->rx_len > sizeof(*fp))
211
0
                return (-1);
212
213
114k
        fido_log_xxd(fp, d->rx_len, "%s", __func__);
214
114k
#ifdef FIDO_FUZZ
215
114k
        fp->body.init.cmd = (CTAP_FRAME_INIT | cmd);
216
114k
#endif
217
218
114k
        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
114k
        return (0);
225
114k
}
226
227
static int
228
rx(fido_dev_t *d, uint8_t cmd, unsigned char *buf, size_t count, int *ms)
229
180k
{
230
180k
        struct frame f;
231
180k
        size_t r, payload_len, init_data_len, cont_data_len;
232
233
180k
        if (d->rx_len <= CTAP_INIT_HEADER_LEN ||
234
180k
            d->rx_len <= CTAP_CONT_HEADER_LEN)
235
0
                return (-1);
236
237
180k
        init_data_len = d->rx_len - CTAP_INIT_HEADER_LEN;
238
180k
        cont_data_len = d->rx_len - CTAP_CONT_HEADER_LEN;
239
240
180k
        if (init_data_len > sizeof(f.body.init.data) ||
241
180k
            cont_data_len > sizeof(f.body.cont.data))
242
0
                return (-1);
243
244
180k
        if (rx_preamble(d, cmd, &f, ms) < 0) {
245
66.6k
                fido_log_debug("%s: rx_preamble", __func__);
246
66.6k
                return (-1);
247
66.6k
        }
248
249
114k
        payload_len = (size_t)((f.body.init.bcnth << 8) | f.body.init.bcntl);
250
114k
        fido_log_debug("%s: payload_len=%zu", __func__, payload_len);
251
252
114k
        if (count < payload_len) {
253
11.2k
                fido_log_debug("%s: count < payload_len", __func__);
254
11.2k
                return (-1);
255
11.2k
        }
256
257
102k
        if (payload_len < init_data_len) {
258
55.7k
                memcpy(buf, f.body.init.data, payload_len);
259
55.7k
                return ((int)payload_len);
260
55.7k
        }
261
262
47.0k
        memcpy(buf, f.body.init.data, init_data_len);
263
47.0k
        r = init_data_len;
264
265
230k
        for (int seq = 0; r < payload_len; seq++) {
266
186k
                if (rx_frame(d, &f, ms) < 0) {
267
3.34k
                        fido_log_debug("%s: rx_frame", __func__);
268
3.34k
                        return (-1);
269
3.34k
                }
270
271
183k
                fido_log_xxd(&f, d->rx_len, "%s", __func__);
272
183k
#ifdef FIDO_FUZZ
273
183k
                f.cid = d->cid;
274
183k
                f.body.cont.seq = (uint8_t)seq;
275
183k
#endif
276
277
183k
                if (f.cid != d->cid || f.body.cont.seq != seq) {
278
21
                        fido_log_debug("%s: cid (0x%x, 0x%x), seq (%d, %d)",
279
21
                            __func__, f.cid, d->cid, f.body.cont.seq, seq);
280
21
                        return (-1);
281
21
                }
282
283
183k
                if (payload_len - r > cont_data_len) {
284
143k
                        memcpy(buf + r, f.body.cont.data, cont_data_len);
285
143k
                        r += cont_data_len;
286
143k
                } else {
287
39.9k
                        memcpy(buf + r, f.body.cont.data, payload_len - r);
288
39.9k
                        r += payload_len - r; /* break */
289
39.9k
                }
290
183k
        }
291
292
43.7k
        return ((int)r);
293
47.0k
}
294
295
static int
296
transport_rx(fido_dev_t *d, uint8_t cmd, void *buf, size_t count, int *ms)
297
4.35k
{
298
4.35k
        struct timespec ts;
299
4.35k
        int n;
300
301
4.35k
        if (fido_time_now(&ts) != 0)
302
47
                return (-1);
303
304
4.30k
        n = d->transport.rx(d, cmd, buf, count, *ms);
305
306
4.30k
        if (fido_time_delta(&ts, ms) != 0)
307
65
                return (-1);
308
309
4.23k
        return (n);
310
4.30k
}
311
312
int
313
fido_rx(fido_dev_t *d, uint8_t cmd, void *buf, size_t count, int *ms)
314
185k
{
315
185k
        int n;
316
317
185k
        fido_log_debug("%s: dev=%p, cmd=0x%02x, ms=%d", __func__, (void *)d,
318
185k
            cmd, *ms);
319
320
185k
        if (d->transport.rx != NULL)
321
4.35k
                return (transport_rx(d, cmd, buf, count, ms));
322
180k
        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
180k
        if ((n = rx(d, cmd, buf, count, ms)) >= 0)
327
99.4k
                fido_log_xxd(buf, (size_t)n, "%s", __func__);
328
329
180k
        return (n);
330
180k
}
331
332
int
333
fido_rx_cbor_status(fido_dev_t *d, int *ms)
334
3.95k
{
335
3.95k
        unsigned char   *msg;
336
3.95k
        int              msglen;
337
3.95k
        int              r;
338
339
3.95k
        if ((msg = malloc(FIDO_MAXMSG)) == NULL) {
340
25
                r = FIDO_ERR_INTERNAL;
341
25
                goto out;
342
25
        }
343
344
3.93k
        if ((msglen = fido_rx(d, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0 ||
345
3.93k
            (size_t)msglen < 1) {
346
2.61k
                fido_log_debug("%s: fido_rx", __func__);
347
2.61k
                r = FIDO_ERR_RX;
348
2.61k
                goto out;
349
2.61k
        }
350
351
1.32k
        r = msg[0];
352
3.95k
out:
353
3.95k
        freezero(msg, FIDO_MAXMSG);
354
355
3.95k
        return (r);
356
1.32k
}