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26#include "qemu/osdep.h"
27#include "qemu/module.h"
28#include "qemu/thread.h"
29#include "qemu/main-loop.h"
30#include "qapi/error.h"
31#include "hw/usb.h"
32#include "hw/qdev-properties.h"
33
34#include <u2f-emu/u2f-emu.h>
35
36#include "u2f.h"
37
38
39struct synced_counter {
40
41 struct u2f_emu_vdev_counter vdev_counter;
42
43
44 uint32_t value;
45 FILE *fp;
46};
47
48static void counter_increment(struct u2f_emu_vdev_counter *vdev_counter)
49{
50 struct synced_counter *counter = (struct synced_counter *)vdev_counter;
51 ++counter->value;
52
53
54 if (fseek(counter->fp, 0, SEEK_SET) == -1) {
55 return;
56 }
57 fprintf(counter->fp, "%u\n", counter->value);
58}
59
60static uint32_t counter_read(struct u2f_emu_vdev_counter *vdev_counter)
61{
62 struct synced_counter *counter = (struct synced_counter *)vdev_counter;
63 return counter->value;
64}
65
66typedef struct U2FEmulatedState U2FEmulatedState;
67
68#define PENDING_OUT_NUM 32
69
70struct U2FEmulatedState {
71 U2FKeyState base;
72
73
74 u2f_emu_vdev *vdev;
75 QemuMutex vdev_mutex;
76
77
78 char *dir;
79 char *cert;
80 char *privkey;
81 char *entropy;
82 char *counter;
83 struct synced_counter synced_counter;
84
85
86 uint8_t pending_out[PENDING_OUT_NUM][U2FHID_PACKET_SIZE];
87 uint8_t pending_out_start;
88 uint8_t pending_out_end;
89 uint8_t pending_out_num;
90 QemuMutex pending_out_mutex;
91
92
93 QemuCond key_cond;
94 QemuMutex key_mutex;
95 QemuThread key_thread;
96 bool stop_thread;
97 EventNotifier notifier;
98};
99
100#define TYPE_U2F_EMULATED "u2f-emulated"
101#define EMULATED_U2F_KEY(obj) \
102 OBJECT_CHECK(U2FEmulatedState, (obj), TYPE_U2F_EMULATED)
103
104static void u2f_emulated_reset(U2FEmulatedState *key)
105{
106 key->pending_out_start = 0;
107 key->pending_out_end = 0;
108 key->pending_out_num = 0;
109}
110
111static void u2f_pending_out_add(U2FEmulatedState *key,
112 const uint8_t packet[U2FHID_PACKET_SIZE])
113{
114 int index;
115
116 if (key->pending_out_num >= PENDING_OUT_NUM) {
117 return;
118 }
119
120 index = key->pending_out_end;
121 key->pending_out_end = (index + 1) % PENDING_OUT_NUM;
122 ++key->pending_out_num;
123
124 memcpy(&key->pending_out[index], packet, U2FHID_PACKET_SIZE);
125}
126
127static uint8_t *u2f_pending_out_get(U2FEmulatedState *key)
128{
129 int index;
130
131 if (key->pending_out_num == 0) {
132 return NULL;
133 }
134
135 index = key->pending_out_start;
136 key->pending_out_start = (index + 1) % PENDING_OUT_NUM;
137 --key->pending_out_num;
138
139 return key->pending_out[index];
140}
141
142static void u2f_emulated_recv_from_guest(U2FKeyState *base,
143 const uint8_t packet[U2FHID_PACKET_SIZE])
144{
145 U2FEmulatedState *key = EMULATED_U2F_KEY(base);
146
147 qemu_mutex_lock(&key->pending_out_mutex);
148 u2f_pending_out_add(key, packet);
149 qemu_mutex_unlock(&key->pending_out_mutex);
150
151 qemu_mutex_lock(&key->key_mutex);
152 qemu_cond_signal(&key->key_cond);
153 qemu_mutex_unlock(&key->key_mutex);
154}
155
156static void *u2f_emulated_thread(void* arg)
157{
158 U2FEmulatedState *key = arg;
159 uint8_t packet[U2FHID_PACKET_SIZE];
160 uint8_t *packet_out = NULL;
161
162
163 while (true) {
164
165 qemu_mutex_lock(&key->key_mutex);
166 qemu_cond_wait(&key->key_cond, &key->key_mutex);
167 qemu_mutex_unlock(&key->key_mutex);
168
169
170 if (key->stop_thread) {
171 key->stop_thread = false;
172 break;
173 }
174
175 qemu_mutex_lock(&key->pending_out_mutex);
176 packet_out = u2f_pending_out_get(key);
177 if (packet_out == NULL) {
178 qemu_mutex_unlock(&key->pending_out_mutex);
179 continue;
180 }
181 memcpy(packet, packet_out, U2FHID_PACKET_SIZE);
182 qemu_mutex_unlock(&key->pending_out_mutex);
183
184 qemu_mutex_lock(&key->vdev_mutex);
185 u2f_emu_vdev_send(key->vdev, U2F_EMU_USB, packet,
186 U2FHID_PACKET_SIZE);
187
188
189 if (u2f_emu_vdev_has_response(key->vdev, U2F_EMU_USB)) {
190 event_notifier_set(&key->notifier);
191 }
192 qemu_mutex_unlock(&key->vdev_mutex);
193 }
194 return NULL;
195}
196
197static ssize_t u2f_emulated_read(const char *path, char *buffer,
198 size_t buffer_len)
199{
200 int fd;
201 ssize_t ret;
202
203 fd = qemu_open_old(path, O_RDONLY);
204 if (fd < 0) {
205 return -1;
206 }
207
208 ret = read(fd, buffer, buffer_len);
209 close(fd);
210
211 return ret;
212}
213
214static bool u2f_emulated_setup_counter(const char *path,
215 struct synced_counter *counter)
216{
217 int fd, ret;
218 FILE *fp;
219
220 fd = qemu_open_old(path, O_RDWR);
221 if (fd < 0) {
222 return false;
223 }
224 fp = fdopen(fd, "r+");
225 if (fp == NULL) {
226 close(fd);
227 return false;
228 }
229 ret = fscanf(fp, "%u", &counter->value);
230 if (ret == EOF) {
231 fclose(fp);
232 return false;
233 }
234 counter->fp = fp;
235 counter->vdev_counter.counter_increment = counter_increment;
236 counter->vdev_counter.counter_read = counter_read;
237
238 return true;
239}
240
241static u2f_emu_rc u2f_emulated_setup_vdev_manualy(U2FEmulatedState *key)
242{
243 ssize_t ret;
244 char cert_pem[4096], privkey_pem[2048];
245 struct u2f_emu_vdev_setup setup_info;
246
247
248 ret = u2f_emulated_read(key->cert, cert_pem, sizeof(cert_pem));
249 if (ret < 0) {
250 return -1;
251 }
252
253
254 ret = u2f_emulated_read(key->privkey, privkey_pem, sizeof(privkey_pem));
255 if (ret < 0) {
256 return -1;
257 }
258
259
260 ret = u2f_emulated_read(key->entropy, (char *)&setup_info.entropy,
261 sizeof(setup_info.entropy));
262 if (ret < 0) {
263 return -1;
264 }
265
266
267 if (!u2f_emulated_setup_counter(key->counter, &key->synced_counter)) {
268 return -1;
269 }
270
271
272 setup_info.certificate = cert_pem;
273 setup_info.private_key = privkey_pem;
274 setup_info.counter = (struct u2f_emu_vdev_counter *)&key->synced_counter;
275
276 return u2f_emu_vdev_new(&key->vdev, &setup_info);
277}
278
279static void u2f_emulated_event_handler(EventNotifier *notifier)
280{
281 U2FEmulatedState *key = container_of(notifier, U2FEmulatedState, notifier);
282 size_t packet_size;
283 uint8_t *packet_in = NULL;
284
285 event_notifier_test_and_clear(&key->notifier);
286 qemu_mutex_lock(&key->vdev_mutex);
287 while (u2f_emu_vdev_has_response(key->vdev, U2F_EMU_USB)) {
288 packet_size = u2f_emu_vdev_get_response(key->vdev, U2F_EMU_USB,
289 &packet_in);
290 if (packet_size == U2FHID_PACKET_SIZE) {
291 u2f_send_to_guest(&key->base, packet_in);
292 }
293 u2f_emu_vdev_free_response(packet_in);
294 }
295 qemu_mutex_unlock(&key->vdev_mutex);
296}
297
298static void u2f_emulated_realize(U2FKeyState *base, Error **errp)
299{
300 U2FEmulatedState *key = EMULATED_U2F_KEY(base);
301 u2f_emu_rc rc;
302
303 if (key->cert != NULL || key->privkey != NULL || key->entropy != NULL
304 || key->counter != NULL) {
305 if (key->cert != NULL && key->privkey != NULL
306 && key->entropy != NULL && key->counter != NULL) {
307 rc = u2f_emulated_setup_vdev_manualy(key);
308 } else {
309 error_setg(errp, "%s: cert, priv, entropy and counter "
310 "parameters must be provided to manualy configure "
311 "the emulated device", TYPE_U2F_EMULATED);
312 return;
313 }
314 } else if (key->dir != NULL) {
315 rc = u2f_emu_vdev_new_from_dir(&key->vdev, key->dir);
316 } else {
317 rc = u2f_emu_vdev_new_ephemeral(&key->vdev);
318 }
319
320 if (rc != U2F_EMU_OK) {
321 error_setg(errp, "%s: Failed to setup the key", TYPE_U2F_EMULATED);
322 return;
323 }
324
325 if (event_notifier_init(&key->notifier, false) < 0) {
326 error_setg(errp, "%s: Failed to initialize notifier",
327 TYPE_U2F_EMULATED);
328 return;
329 }
330
331 event_notifier_set_handler(&key->notifier, u2f_emulated_event_handler);
332
333
334 qemu_cond_init(&key->key_cond);
335 qemu_mutex_init(&key->vdev_mutex);
336 qemu_mutex_init(&key->pending_out_mutex);
337 qemu_mutex_init(&key->key_mutex);
338 u2f_emulated_reset(key);
339
340
341 key->stop_thread = false;
342 qemu_thread_create(&key->key_thread, "u2f-key", u2f_emulated_thread,
343 key, QEMU_THREAD_JOINABLE);
344}
345
346static void u2f_emulated_unrealize(U2FKeyState *base)
347{
348 U2FEmulatedState *key = EMULATED_U2F_KEY(base);
349
350
351 key->stop_thread = true;
352 qemu_cond_signal(&key->key_cond);
353 qemu_thread_join(&key->key_thread);
354
355
356 event_notifier_set_handler(&key->notifier, NULL);
357 event_notifier_cleanup(&key->notifier);
358
359
360 qemu_cond_destroy(&key->key_cond);
361 qemu_mutex_destroy(&key->vdev_mutex);
362 qemu_mutex_destroy(&key->key_mutex);
363 qemu_mutex_destroy(&key->pending_out_mutex);
364
365
366 u2f_emu_vdev_free(key->vdev);
367 if (key->synced_counter.fp != NULL) {
368 fclose(key->synced_counter.fp);
369 }
370}
371
372static Property u2f_emulated_properties[] = {
373 DEFINE_PROP_STRING("dir", U2FEmulatedState, dir),
374 DEFINE_PROP_STRING("cert", U2FEmulatedState, cert),
375 DEFINE_PROP_STRING("privkey", U2FEmulatedState, privkey),
376 DEFINE_PROP_STRING("entropy", U2FEmulatedState, entropy),
377 DEFINE_PROP_STRING("counter", U2FEmulatedState, counter),
378 DEFINE_PROP_END_OF_LIST(),
379};
380
381static void u2f_emulated_class_init(ObjectClass *klass, void *data)
382{
383 DeviceClass *dc = DEVICE_CLASS(klass);
384 U2FKeyClass *kc = U2F_KEY_CLASS(klass);
385
386 kc->realize = u2f_emulated_realize;
387 kc->unrealize = u2f_emulated_unrealize;
388 kc->recv_from_guest = u2f_emulated_recv_from_guest;
389 dc->desc = "QEMU U2F emulated key";
390 device_class_set_props(dc, u2f_emulated_properties);
391}
392
393static const TypeInfo u2f_key_emulated_info = {
394 .name = TYPE_U2F_EMULATED,
395 .parent = TYPE_U2F_KEY,
396 .instance_size = sizeof(U2FEmulatedState),
397 .class_init = u2f_emulated_class_init
398};
399
400static void u2f_key_emulated_register_types(void)
401{
402 type_register_static(&u2f_key_emulated_info);
403}
404
405type_init(u2f_key_emulated_register_types)
406
