xref: /openbmc/qemu/hw/usb/ccid-card-emulated.c (revision 500eb6db)
1 /*
2  * CCID Card Device. Emulated card.
3  *
4  * Copyright (c) 2011 Red Hat.
5  * Written by Alon Levy.
6  *
7  * This code is licensed under the GNU LGPL, version 2 or later.
8  */
9 
10 /*
11  * It can be used to provide access to the local hardware in a non exclusive
12  * way, or it can use certificates. It requires the usb-ccid bus.
13  *
14  * Usage 1: standard, mirror hardware reader+card:
15  * qemu .. -usb -device usb-ccid -device ccid-card-emulated
16  *
17  * Usage 2: use certificates, no hardware required
18  * one time: create the certificates:
19  *  for i in 1 2 3; do
20  *      certutil -d /etc/pki/nssdb -x -t "CT,CT,CT" -S -s "CN=user$i" -n user$i
21  *  done
22  * qemu .. -usb -device usb-ccid \
23  *  -device ccid-card-emulated,cert1=user1,cert2=user2,cert3=user3
24  *
25  * If you use a non default db for the certificates you can specify it using
26  * the db parameter.
27  */
28 
29 #include "qemu/osdep.h"
30 #include <libcacard.h>
31 
32 #include "qemu/thread.h"
33 #include "qemu/main-loop.h"
34 #include "qemu/module.h"
35 #include "ccid.h"
36 #include "qapi/error.h"
37 
38 #define DPRINTF(card, lvl, fmt, ...) \
39 do {\
40     if (lvl <= card->debug) {\
41         printf("ccid-card-emul: %s: " fmt , __func__, ## __VA_ARGS__);\
42     } \
43 } while (0)
44 
45 
46 #define TYPE_EMULATED_CCID "ccid-card-emulated"
47 #define EMULATED_CCID_CARD(obj) \
48     OBJECT_CHECK(EmulatedState, (obj), TYPE_EMULATED_CCID)
49 
50 #define BACKEND_NSS_EMULATED_NAME "nss-emulated"
51 #define BACKEND_CERTIFICATES_NAME "certificates"
52 
53 enum {
54     BACKEND_NSS_EMULATED = 1,
55     BACKEND_CERTIFICATES
56 };
57 
58 #define DEFAULT_BACKEND BACKEND_NSS_EMULATED
59 
60 typedef struct EmulatedState EmulatedState;
61 
62 enum {
63     EMUL_READER_INSERT = 0,
64     EMUL_READER_REMOVE,
65     EMUL_CARD_INSERT,
66     EMUL_CARD_REMOVE,
67     EMUL_GUEST_APDU,
68     EMUL_RESPONSE_APDU,
69     EMUL_ERROR,
70 };
71 
72 static const char *emul_event_to_string(uint32_t emul_event)
73 {
74     switch (emul_event) {
75     case EMUL_READER_INSERT:
76         return "EMUL_READER_INSERT";
77     case EMUL_READER_REMOVE:
78         return "EMUL_READER_REMOVE";
79     case EMUL_CARD_INSERT:
80         return "EMUL_CARD_INSERT";
81     case EMUL_CARD_REMOVE:
82         return "EMUL_CARD_REMOVE";
83     case EMUL_GUEST_APDU:
84         return "EMUL_GUEST_APDU";
85     case EMUL_RESPONSE_APDU:
86         return "EMUL_RESPONSE_APDU";
87     case EMUL_ERROR:
88         return "EMUL_ERROR";
89     }
90     return "UNKNOWN";
91 }
92 
93 typedef struct EmulEvent {
94     QSIMPLEQ_ENTRY(EmulEvent) entry;
95     union {
96         struct {
97             uint32_t type;
98         } gen;
99         struct {
100             uint32_t type;
101             uint64_t code;
102         } error;
103         struct {
104             uint32_t type;
105             uint32_t len;
106             uint8_t data[];
107         } data;
108     } p;
109 } EmulEvent;
110 
111 #define MAX_ATR_SIZE 40
112 struct EmulatedState {
113     CCIDCardState base;
114     uint8_t  debug;
115     char    *backend_str;
116     uint32_t backend;
117     char    *cert1;
118     char    *cert2;
119     char    *cert3;
120     char    *db;
121     uint8_t  atr[MAX_ATR_SIZE];
122     uint8_t  atr_length;
123     QSIMPLEQ_HEAD(, EmulEvent) event_list;
124     QemuMutex event_list_mutex;
125     QemuThread event_thread_id;
126     VReader *reader;
127     QSIMPLEQ_HEAD(, EmulEvent) guest_apdu_list;
128     QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
129     QemuMutex handle_apdu_mutex;
130     QemuCond handle_apdu_cond;
131     EventNotifier notifier;
132     int      quit_apdu_thread;
133     QemuThread apdu_thread_id;
134 };
135 
136 static void emulated_apdu_from_guest(CCIDCardState *base,
137     const uint8_t *apdu, uint32_t len)
138 {
139     EmulatedState *card = EMULATED_CCID_CARD(base);
140     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
141 
142     assert(event);
143     event->p.data.type = EMUL_GUEST_APDU;
144     event->p.data.len = len;
145     memcpy(event->p.data.data, apdu, len);
146     qemu_mutex_lock(&card->vreader_mutex);
147     QSIMPLEQ_INSERT_TAIL(&card->guest_apdu_list, event, entry);
148     qemu_mutex_unlock(&card->vreader_mutex);
149     qemu_mutex_lock(&card->handle_apdu_mutex);
150     qemu_cond_signal(&card->handle_apdu_cond);
151     qemu_mutex_unlock(&card->handle_apdu_mutex);
152 }
153 
154 static const uint8_t *emulated_get_atr(CCIDCardState *base, uint32_t *len)
155 {
156     EmulatedState *card = EMULATED_CCID_CARD(base);
157 
158     *len = card->atr_length;
159     return card->atr;
160 }
161 
162 static void emulated_push_event(EmulatedState *card, EmulEvent *event)
163 {
164     qemu_mutex_lock(&card->event_list_mutex);
165     QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
166     qemu_mutex_unlock(&card->event_list_mutex);
167     event_notifier_set(&card->notifier);
168 }
169 
170 static void emulated_push_type(EmulatedState *card, uint32_t type)
171 {
172     EmulEvent *event = g_new(EmulEvent, 1);
173 
174     assert(event);
175     event->p.gen.type = type;
176     emulated_push_event(card, event);
177 }
178 
179 static void emulated_push_error(EmulatedState *card, uint64_t code)
180 {
181     EmulEvent *event = g_new(EmulEvent, 1);
182 
183     assert(event);
184     event->p.error.type = EMUL_ERROR;
185     event->p.error.code = code;
186     emulated_push_event(card, event);
187 }
188 
189 static void emulated_push_data_type(EmulatedState *card, uint32_t type,
190     const uint8_t *data, uint32_t len)
191 {
192     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
193 
194     assert(event);
195     event->p.data.type = type;
196     event->p.data.len = len;
197     memcpy(event->p.data.data, data, len);
198     emulated_push_event(card, event);
199 }
200 
201 static void emulated_push_reader_insert(EmulatedState *card)
202 {
203     emulated_push_type(card, EMUL_READER_INSERT);
204 }
205 
206 static void emulated_push_reader_remove(EmulatedState *card)
207 {
208     emulated_push_type(card, EMUL_READER_REMOVE);
209 }
210 
211 static void emulated_push_card_insert(EmulatedState *card,
212     const uint8_t *atr, uint32_t len)
213 {
214     emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
215 }
216 
217 static void emulated_push_card_remove(EmulatedState *card)
218 {
219     emulated_push_type(card, EMUL_CARD_REMOVE);
220 }
221 
222 static void emulated_push_response_apdu(EmulatedState *card,
223     const uint8_t *apdu, uint32_t len)
224 {
225     emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
226 }
227 
228 #define APDU_BUF_SIZE 270
229 static void *handle_apdu_thread(void* arg)
230 {
231     EmulatedState *card = arg;
232     uint8_t recv_data[APDU_BUF_SIZE];
233     int recv_len;
234     VReaderStatus reader_status;
235     EmulEvent *event;
236 
237     while (1) {
238         qemu_mutex_lock(&card->handle_apdu_mutex);
239         qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
240         qemu_mutex_unlock(&card->handle_apdu_mutex);
241         if (card->quit_apdu_thread) {
242             card->quit_apdu_thread = 0; /* debugging */
243             break;
244         }
245         qemu_mutex_lock(&card->vreader_mutex);
246         while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
247             event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
248             assert((unsigned long)event > 1000);
249             QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
250             if (event->p.data.type != EMUL_GUEST_APDU) {
251                 DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
252                 g_free(event);
253                 continue;
254             }
255             if (card->reader == NULL) {
256                 DPRINTF(card, 1, "reader is NULL\n");
257                 g_free(event);
258                 continue;
259             }
260             recv_len = sizeof(recv_data);
261             reader_status = vreader_xfr_bytes(card->reader,
262                     event->p.data.data, event->p.data.len,
263                     recv_data, &recv_len);
264             DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
265             if (reader_status == VREADER_OK) {
266                 emulated_push_response_apdu(card, recv_data, recv_len);
267             } else {
268                 emulated_push_error(card, reader_status);
269             }
270             g_free(event);
271         }
272         qemu_mutex_unlock(&card->vreader_mutex);
273     }
274     return NULL;
275 }
276 
277 static void *event_thread(void *arg)
278 {
279     int atr_len = MAX_ATR_SIZE;
280     uint8_t atr[MAX_ATR_SIZE];
281     VEvent *event = NULL;
282     EmulatedState *card = arg;
283 
284     while (1) {
285         const char *reader_name;
286 
287         event = vevent_wait_next_vevent();
288         if (event == NULL || event->type == VEVENT_LAST) {
289             break;
290         }
291         if (event->type != VEVENT_READER_INSERT) {
292             if (card->reader == NULL && event->reader != NULL) {
293                 /* Happens after device_add followed by card remove or insert.
294                  * XXX: create synthetic add_reader events if vcard_emul_init
295                  * already called, which happens if device_del and device_add
296                  * are called */
297                 card->reader = vreader_reference(event->reader);
298             } else {
299                 if (event->reader != card->reader) {
300                     fprintf(stderr,
301                         "ERROR: wrong reader: quiting event_thread\n");
302                     break;
303                 }
304             }
305         }
306         switch (event->type) {
307         case VEVENT_READER_INSERT:
308             /* TODO: take a specific reader. i.e. track which reader
309              * we are seeing here, check it is the one we want (the first,
310              * or by a particular name), and ignore if we don't want it.
311              */
312             reader_name = vreader_get_name(event->reader);
313             if (card->reader != NULL) {
314                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
315                     vreader_get_name(card->reader), reader_name);
316                 qemu_mutex_lock(&card->vreader_mutex);
317                 vreader_free(card->reader);
318                 qemu_mutex_unlock(&card->vreader_mutex);
319                 emulated_push_reader_remove(card);
320             }
321             qemu_mutex_lock(&card->vreader_mutex);
322             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
323             card->reader = vreader_reference(event->reader);
324             qemu_mutex_unlock(&card->vreader_mutex);
325             emulated_push_reader_insert(card);
326             break;
327         case VEVENT_READER_REMOVE:
328             DPRINTF(card, 2, " READER REMOVE: %s\n",
329                     vreader_get_name(event->reader));
330             qemu_mutex_lock(&card->vreader_mutex);
331             vreader_free(card->reader);
332             card->reader = NULL;
333             qemu_mutex_unlock(&card->vreader_mutex);
334             emulated_push_reader_remove(card);
335             break;
336         case VEVENT_CARD_INSERT:
337             /* get the ATR (intended as a response to a power on from the
338              * reader */
339             atr_len = MAX_ATR_SIZE;
340             vreader_power_on(event->reader, atr, &atr_len);
341             card->atr_length = (uint8_t)atr_len;
342             DPRINTF(card, 2, " CARD INSERT\n");
343             emulated_push_card_insert(card, atr, atr_len);
344             break;
345         case VEVENT_CARD_REMOVE:
346             DPRINTF(card, 2, " CARD REMOVE\n");
347             emulated_push_card_remove(card);
348             break;
349         case VEVENT_LAST: /* quit */
350             vevent_delete(event);
351             return NULL;
352             break;
353         default:
354             break;
355         }
356         vevent_delete(event);
357     }
358     return NULL;
359 }
360 
361 static void card_event_handler(EventNotifier *notifier)
362 {
363     EmulatedState *card = container_of(notifier, EmulatedState, notifier);
364     EmulEvent *event, *next;
365 
366     event_notifier_test_and_clear(&card->notifier);
367     qemu_mutex_lock(&card->event_list_mutex);
368     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
369         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
370         switch (event->p.gen.type) {
371         case EMUL_RESPONSE_APDU:
372             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
373                 event->p.data.len);
374             break;
375         case EMUL_READER_INSERT:
376             ccid_card_ccid_attach(&card->base);
377             break;
378         case EMUL_READER_REMOVE:
379             ccid_card_ccid_detach(&card->base);
380             break;
381         case EMUL_CARD_INSERT:
382             assert(event->p.data.len <= MAX_ATR_SIZE);
383             card->atr_length = event->p.data.len;
384             memcpy(card->atr, event->p.data.data, card->atr_length);
385             ccid_card_card_inserted(&card->base);
386             break;
387         case EMUL_CARD_REMOVE:
388             ccid_card_card_removed(&card->base);
389             break;
390         case EMUL_ERROR:
391             ccid_card_card_error(&card->base, event->p.error.code);
392             break;
393         default:
394             DPRINTF(card, 2, "unexpected event\n");
395             break;
396         }
397         g_free(event);
398     }
399     QSIMPLEQ_INIT(&card->event_list);
400     qemu_mutex_unlock(&card->event_list_mutex);
401 }
402 
403 static int init_event_notifier(EmulatedState *card, Error **errp)
404 {
405     if (event_notifier_init(&card->notifier, false) < 0) {
406         error_setg(errp, "ccid-card-emul: event notifier creation failed");
407         return -1;
408     }
409     event_notifier_set_handler(&card->notifier, card_event_handler);
410     return 0;
411 }
412 
413 static void clean_event_notifier(EmulatedState *card)
414 {
415     event_notifier_set_handler(&card->notifier, NULL);
416     event_notifier_cleanup(&card->notifier);
417 }
418 
419 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
420 #define CERTIFICATES_ARGS_TEMPLATE\
421     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
422 
423 static int wrap_vcard_emul_init(VCardEmulOptions *options)
424 {
425     static int called;
426     static int options_was_null;
427 
428     if (called) {
429         if ((options == NULL) != options_was_null) {
430             printf("%s: warning: running emulated with certificates"
431                    " and emulated side by side is not supported\n",
432                    __func__);
433             return VCARD_EMUL_FAIL;
434         }
435         vcard_emul_replay_insertion_events();
436         return VCARD_EMUL_OK;
437     }
438     options_was_null = (options == NULL);
439     called = 1;
440     return vcard_emul_init(options);
441 }
442 
443 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
444 {
445     char emul_args[200];
446     VCardEmulOptions *options = NULL;
447 
448     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
449         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
450         card->cert1, card->cert2, card->cert3);
451     options = vcard_emul_options(emul_args);
452     if (options == NULL) {
453         printf("%s: warning: not using certificates due to"
454                " initialization error\n", __func__);
455     }
456     return wrap_vcard_emul_init(options);
457 }
458 
459 typedef struct EnumTable {
460     const char *name;
461     uint32_t value;
462 } EnumTable;
463 
464 static const EnumTable backend_enum_table[] = {
465     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
466     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
467     {NULL, 0},
468 };
469 
470 static uint32_t parse_enumeration(char *str,
471     const EnumTable *table, uint32_t not_found_value)
472 {
473     uint32_t ret = not_found_value;
474 
475     if (str == NULL)
476         return 0;
477 
478     while (table->name != NULL) {
479         if (strcmp(table->name, str) == 0) {
480             ret = table->value;
481             break;
482         }
483         table++;
484     }
485     return ret;
486 }
487 
488 static void emulated_realize(CCIDCardState *base, Error **errp)
489 {
490     EmulatedState *card = EMULATED_CCID_CARD(base);
491     VCardEmulError ret;
492     const EnumTable *ptable;
493 
494     QSIMPLEQ_INIT(&card->event_list);
495     QSIMPLEQ_INIT(&card->guest_apdu_list);
496     qemu_mutex_init(&card->event_list_mutex);
497     qemu_mutex_init(&card->vreader_mutex);
498     qemu_mutex_init(&card->handle_apdu_mutex);
499     qemu_cond_init(&card->handle_apdu_cond);
500     card->reader = NULL;
501     card->quit_apdu_thread = 0;
502     if (init_event_notifier(card, errp) < 0) {
503         goto out1;
504     }
505 
506     card->backend = 0;
507     if (card->backend_str) {
508         card->backend = parse_enumeration(card->backend_str,
509                                           backend_enum_table, 0);
510     }
511 
512     if (card->backend == 0) {
513         error_setg(errp, "backend must be one of:");
514         for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
515             error_append_hint(errp, "%s\n", ptable->name);
516         }
517         goto out2;
518     }
519 
520     /* TODO: a passthru backened that works on local machine. third card type?*/
521     if (card->backend == BACKEND_CERTIFICATES) {
522         if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
523             ret = emulated_initialize_vcard_from_certificates(card);
524         } else {
525             error_setg(errp, "%s: you must provide all three certs for"
526                        " certificates backend", TYPE_EMULATED_CCID);
527             goto out2;
528         }
529     } else {
530         if (card->backend != BACKEND_NSS_EMULATED) {
531             error_setg(errp, "%s: bad backend specified. The options are:%s"
532                        " (default), %s.", TYPE_EMULATED_CCID,
533                        BACKEND_NSS_EMULATED_NAME, BACKEND_CERTIFICATES_NAME);
534             goto out2;
535         }
536         if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
537             error_setg(errp, "%s: unexpected cert parameters to nss emulated "
538                        "backend", TYPE_EMULATED_CCID);
539             goto out2;
540         }
541         /* default to mirroring the local hardware readers */
542         ret = wrap_vcard_emul_init(NULL);
543     }
544     if (ret != VCARD_EMUL_OK) {
545         error_setg(errp, "%s: failed to initialize vcard", TYPE_EMULATED_CCID);
546         goto out2;
547     }
548     qemu_thread_create(&card->event_thread_id, "ccid/event", event_thread,
549                        card, QEMU_THREAD_JOINABLE);
550     qemu_thread_create(&card->apdu_thread_id, "ccid/apdu", handle_apdu_thread,
551                        card, QEMU_THREAD_JOINABLE);
552 
553     return;
554 
555 out2:
556     clean_event_notifier(card);
557 out1:
558     qemu_cond_destroy(&card->handle_apdu_cond);
559     qemu_mutex_destroy(&card->handle_apdu_mutex);
560     qemu_mutex_destroy(&card->vreader_mutex);
561     qemu_mutex_destroy(&card->event_list_mutex);
562 }
563 
564 static void emulated_unrealize(CCIDCardState *base, Error **errp)
565 {
566     EmulatedState *card = EMULATED_CCID_CARD(base);
567     VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
568 
569     vevent_queue_vevent(vevent); /* stop vevent thread */
570     qemu_thread_join(&card->event_thread_id);
571 
572     card->quit_apdu_thread = 1; /* stop handle_apdu thread */
573     qemu_cond_signal(&card->handle_apdu_cond);
574     qemu_thread_join(&card->apdu_thread_id);
575 
576     clean_event_notifier(card);
577     /* threads exited, can destroy all condvars/mutexes */
578     qemu_cond_destroy(&card->handle_apdu_cond);
579     qemu_mutex_destroy(&card->handle_apdu_mutex);
580     qemu_mutex_destroy(&card->vreader_mutex);
581     qemu_mutex_destroy(&card->event_list_mutex);
582 }
583 
584 static Property emulated_card_properties[] = {
585     DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
586     DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
587     DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
588     DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
589     DEFINE_PROP_STRING("db", EmulatedState, db),
590     DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
591     DEFINE_PROP_END_OF_LIST(),
592 };
593 
594 static void emulated_class_initfn(ObjectClass *klass, void *data)
595 {
596     DeviceClass *dc = DEVICE_CLASS(klass);
597     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
598 
599     cc->realize = emulated_realize;
600     cc->unrealize = emulated_unrealize;
601     cc->get_atr = emulated_get_atr;
602     cc->apdu_from_guest = emulated_apdu_from_guest;
603     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
604     dc->desc = "emulated smartcard";
605     dc->props = emulated_card_properties;
606 }
607 
608 static const TypeInfo emulated_card_info = {
609     .name          = TYPE_EMULATED_CCID,
610     .parent        = TYPE_CCID_CARD,
611     .instance_size = sizeof(EmulatedState),
612     .class_init    = emulated_class_initfn,
613 };
614 
615 static void ccid_card_emulated_register_types(void)
616 {
617     type_register_static(&emulated_card_info);
618 }
619 
620 type_init(ccid_card_emulated_register_types)
621