xref: /openbmc/qemu/hw/usb/ccid-card-emulated.c (revision dc5bd18f)
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 <eventt.h>
31 #include <vevent.h>
32 #include <vreader.h>
33 #include <vcard_emul.h>
34 
35 #include "qemu/thread.h"
36 #include "qemu/main-loop.h"
37 #include "ccid.h"
38 #include "qapi/error.h"
39 
40 #define DPRINTF(card, lvl, fmt, ...) \
41 do {\
42     if (lvl <= card->debug) {\
43         printf("ccid-card-emul: %s: " fmt , __func__, ## __VA_ARGS__);\
44     } \
45 } while (0)
46 
47 
48 #define TYPE_EMULATED_CCID "ccid-card-emulated"
49 #define EMULATED_CCID_CARD(obj) \
50     OBJECT_CHECK(EmulatedState, (obj), TYPE_EMULATED_CCID)
51 
52 #define BACKEND_NSS_EMULATED_NAME "nss-emulated"
53 #define BACKEND_CERTIFICATES_NAME "certificates"
54 
55 enum {
56     BACKEND_NSS_EMULATED = 1,
57     BACKEND_CERTIFICATES
58 };
59 
60 #define DEFAULT_BACKEND BACKEND_NSS_EMULATED
61 
62 typedef struct EmulatedState EmulatedState;
63 
64 enum {
65     EMUL_READER_INSERT = 0,
66     EMUL_READER_REMOVE,
67     EMUL_CARD_INSERT,
68     EMUL_CARD_REMOVE,
69     EMUL_GUEST_APDU,
70     EMUL_RESPONSE_APDU,
71     EMUL_ERROR,
72 };
73 
74 static const char *emul_event_to_string(uint32_t emul_event)
75 {
76     switch (emul_event) {
77     case EMUL_READER_INSERT:
78         return "EMUL_READER_INSERT";
79     case EMUL_READER_REMOVE:
80         return "EMUL_READER_REMOVE";
81     case EMUL_CARD_INSERT:
82         return "EMUL_CARD_INSERT";
83     case EMUL_CARD_REMOVE:
84         return "EMUL_CARD_REMOVE";
85     case EMUL_GUEST_APDU:
86         return "EMUL_GUEST_APDU";
87     case EMUL_RESPONSE_APDU:
88         return "EMUL_RESPONSE_APDU";
89     case EMUL_ERROR:
90         return "EMUL_ERROR";
91     }
92     return "UNKNOWN";
93 }
94 
95 typedef struct EmulEvent {
96     QSIMPLEQ_ENTRY(EmulEvent) entry;
97     union {
98         struct {
99             uint32_t type;
100         } gen;
101         struct {
102             uint32_t type;
103             uint64_t code;
104         } error;
105         struct {
106             uint32_t type;
107             uint32_t len;
108             uint8_t data[];
109         } data;
110     } p;
111 } EmulEvent;
112 
113 #define MAX_ATR_SIZE 40
114 struct EmulatedState {
115     CCIDCardState base;
116     uint8_t  debug;
117     char    *backend_str;
118     uint32_t backend;
119     char    *cert1;
120     char    *cert2;
121     char    *cert3;
122     char    *db;
123     uint8_t  atr[MAX_ATR_SIZE];
124     uint8_t  atr_length;
125     QSIMPLEQ_HEAD(event_list, EmulEvent) event_list;
126     QemuMutex event_list_mutex;
127     QemuThread event_thread_id;
128     VReader *reader;
129     QSIMPLEQ_HEAD(guest_apdu_list, EmulEvent) guest_apdu_list;
130     QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
131     QemuMutex handle_apdu_mutex;
132     QemuCond handle_apdu_cond;
133     EventNotifier notifier;
134     int      quit_apdu_thread;
135     QemuThread apdu_thread_id;
136 };
137 
138 static void emulated_apdu_from_guest(CCIDCardState *base,
139     const uint8_t *apdu, uint32_t len)
140 {
141     EmulatedState *card = EMULATED_CCID_CARD(base);
142     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
143 
144     assert(event);
145     event->p.data.type = EMUL_GUEST_APDU;
146     event->p.data.len = len;
147     memcpy(event->p.data.data, apdu, len);
148     qemu_mutex_lock(&card->vreader_mutex);
149     QSIMPLEQ_INSERT_TAIL(&card->guest_apdu_list, event, entry);
150     qemu_mutex_unlock(&card->vreader_mutex);
151     qemu_mutex_lock(&card->handle_apdu_mutex);
152     qemu_cond_signal(&card->handle_apdu_cond);
153     qemu_mutex_unlock(&card->handle_apdu_mutex);
154 }
155 
156 static const uint8_t *emulated_get_atr(CCIDCardState *base, uint32_t *len)
157 {
158     EmulatedState *card = EMULATED_CCID_CARD(base);
159 
160     *len = card->atr_length;
161     return card->atr;
162 }
163 
164 static void emulated_push_event(EmulatedState *card, EmulEvent *event)
165 {
166     qemu_mutex_lock(&card->event_list_mutex);
167     QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
168     qemu_mutex_unlock(&card->event_list_mutex);
169     event_notifier_set(&card->notifier);
170 }
171 
172 static void emulated_push_type(EmulatedState *card, uint32_t type)
173 {
174     EmulEvent *event = g_new(EmulEvent, 1);
175 
176     assert(event);
177     event->p.gen.type = type;
178     emulated_push_event(card, event);
179 }
180 
181 static void emulated_push_error(EmulatedState *card, uint64_t code)
182 {
183     EmulEvent *event = g_new(EmulEvent, 1);
184 
185     assert(event);
186     event->p.error.type = EMUL_ERROR;
187     event->p.error.code = code;
188     emulated_push_event(card, event);
189 }
190 
191 static void emulated_push_data_type(EmulatedState *card, uint32_t type,
192     const uint8_t *data, uint32_t len)
193 {
194     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
195 
196     assert(event);
197     event->p.data.type = type;
198     event->p.data.len = len;
199     memcpy(event->p.data.data, data, len);
200     emulated_push_event(card, event);
201 }
202 
203 static void emulated_push_reader_insert(EmulatedState *card)
204 {
205     emulated_push_type(card, EMUL_READER_INSERT);
206 }
207 
208 static void emulated_push_reader_remove(EmulatedState *card)
209 {
210     emulated_push_type(card, EMUL_READER_REMOVE);
211 }
212 
213 static void emulated_push_card_insert(EmulatedState *card,
214     const uint8_t *atr, uint32_t len)
215 {
216     emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
217 }
218 
219 static void emulated_push_card_remove(EmulatedState *card)
220 {
221     emulated_push_type(card, EMUL_CARD_REMOVE);
222 }
223 
224 static void emulated_push_response_apdu(EmulatedState *card,
225     const uint8_t *apdu, uint32_t len)
226 {
227     emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
228 }
229 
230 #define APDU_BUF_SIZE 270
231 static void *handle_apdu_thread(void* arg)
232 {
233     EmulatedState *card = arg;
234     uint8_t recv_data[APDU_BUF_SIZE];
235     int recv_len;
236     VReaderStatus reader_status;
237     EmulEvent *event;
238 
239     while (1) {
240         qemu_mutex_lock(&card->handle_apdu_mutex);
241         qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
242         qemu_mutex_unlock(&card->handle_apdu_mutex);
243         if (card->quit_apdu_thread) {
244             card->quit_apdu_thread = 0; /* debugging */
245             break;
246         }
247         qemu_mutex_lock(&card->vreader_mutex);
248         while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
249             event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
250             assert((unsigned long)event > 1000);
251             QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
252             if (event->p.data.type != EMUL_GUEST_APDU) {
253                 DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
254                 g_free(event);
255                 continue;
256             }
257             if (card->reader == NULL) {
258                 DPRINTF(card, 1, "reader is NULL\n");
259                 g_free(event);
260                 continue;
261             }
262             recv_len = sizeof(recv_data);
263             reader_status = vreader_xfr_bytes(card->reader,
264                     event->p.data.data, event->p.data.len,
265                     recv_data, &recv_len);
266             DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
267             if (reader_status == VREADER_OK) {
268                 emulated_push_response_apdu(card, recv_data, recv_len);
269             } else {
270                 emulated_push_error(card, reader_status);
271             }
272             g_free(event);
273         }
274         qemu_mutex_unlock(&card->vreader_mutex);
275     }
276     return NULL;
277 }
278 
279 static void *event_thread(void *arg)
280 {
281     int atr_len = MAX_ATR_SIZE;
282     uint8_t atr[MAX_ATR_SIZE];
283     VEvent *event = NULL;
284     EmulatedState *card = arg;
285 
286     while (1) {
287         const char *reader_name;
288 
289         event = vevent_wait_next_vevent();
290         if (event == NULL || event->type == VEVENT_LAST) {
291             break;
292         }
293         if (event->type != VEVENT_READER_INSERT) {
294             if (card->reader == NULL && event->reader != NULL) {
295                 /* Happens after device_add followed by card remove or insert.
296                  * XXX: create synthetic add_reader events if vcard_emul_init
297                  * already called, which happens if device_del and device_add
298                  * are called */
299                 card->reader = vreader_reference(event->reader);
300             } else {
301                 if (event->reader != card->reader) {
302                     fprintf(stderr,
303                         "ERROR: wrong reader: quiting event_thread\n");
304                     break;
305                 }
306             }
307         }
308         switch (event->type) {
309         case VEVENT_READER_INSERT:
310             /* TODO: take a specific reader. i.e. track which reader
311              * we are seeing here, check it is the one we want (the first,
312              * or by a particular name), and ignore if we don't want it.
313              */
314             reader_name = vreader_get_name(event->reader);
315             if (card->reader != NULL) {
316                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
317                     vreader_get_name(card->reader), reader_name);
318                 qemu_mutex_lock(&card->vreader_mutex);
319                 vreader_free(card->reader);
320                 qemu_mutex_unlock(&card->vreader_mutex);
321                 emulated_push_reader_remove(card);
322             }
323             qemu_mutex_lock(&card->vreader_mutex);
324             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
325             card->reader = vreader_reference(event->reader);
326             qemu_mutex_unlock(&card->vreader_mutex);
327             emulated_push_reader_insert(card);
328             break;
329         case VEVENT_READER_REMOVE:
330             DPRINTF(card, 2, " READER REMOVE: %s\n",
331                     vreader_get_name(event->reader));
332             qemu_mutex_lock(&card->vreader_mutex);
333             vreader_free(card->reader);
334             card->reader = NULL;
335             qemu_mutex_unlock(&card->vreader_mutex);
336             emulated_push_reader_remove(card);
337             break;
338         case VEVENT_CARD_INSERT:
339             /* get the ATR (intended as a response to a power on from the
340              * reader */
341             atr_len = MAX_ATR_SIZE;
342             vreader_power_on(event->reader, atr, &atr_len);
343             card->atr_length = (uint8_t)atr_len;
344             DPRINTF(card, 2, " CARD INSERT\n");
345             emulated_push_card_insert(card, atr, atr_len);
346             break;
347         case VEVENT_CARD_REMOVE:
348             DPRINTF(card, 2, " CARD REMOVE\n");
349             emulated_push_card_remove(card);
350             break;
351         case VEVENT_LAST: /* quit */
352             vevent_delete(event);
353             return NULL;
354             break;
355         default:
356             break;
357         }
358         vevent_delete(event);
359     }
360     return NULL;
361 }
362 
363 static void card_event_handler(EventNotifier *notifier)
364 {
365     EmulatedState *card = container_of(notifier, EmulatedState, notifier);
366     EmulEvent *event, *next;
367 
368     event_notifier_test_and_clear(&card->notifier);
369     qemu_mutex_lock(&card->event_list_mutex);
370     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
371         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
372         switch (event->p.gen.type) {
373         case EMUL_RESPONSE_APDU:
374             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
375                 event->p.data.len);
376             break;
377         case EMUL_READER_INSERT:
378             ccid_card_ccid_attach(&card->base);
379             break;
380         case EMUL_READER_REMOVE:
381             ccid_card_ccid_detach(&card->base);
382             break;
383         case EMUL_CARD_INSERT:
384             assert(event->p.data.len <= MAX_ATR_SIZE);
385             card->atr_length = event->p.data.len;
386             memcpy(card->atr, event->p.data.data, card->atr_length);
387             ccid_card_card_inserted(&card->base);
388             break;
389         case EMUL_CARD_REMOVE:
390             ccid_card_card_removed(&card->base);
391             break;
392         case EMUL_ERROR:
393             ccid_card_card_error(&card->base, event->p.error.code);
394             break;
395         default:
396             DPRINTF(card, 2, "unexpected event\n");
397             break;
398         }
399         g_free(event);
400     }
401     QSIMPLEQ_INIT(&card->event_list);
402     qemu_mutex_unlock(&card->event_list_mutex);
403 }
404 
405 static int init_event_notifier(EmulatedState *card, Error **errp)
406 {
407     if (event_notifier_init(&card->notifier, false) < 0) {
408         error_setg(errp, "ccid-card-emul: event notifier creation failed");
409         return -1;
410     }
411     event_notifier_set_handler(&card->notifier, card_event_handler);
412     return 0;
413 }
414 
415 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
416 #define CERTIFICATES_ARGS_TEMPLATE\
417     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
418 
419 static int wrap_vcard_emul_init(VCardEmulOptions *options)
420 {
421     static int called;
422     static int options_was_null;
423 
424     if (called) {
425         if ((options == NULL) != options_was_null) {
426             printf("%s: warning: running emulated with certificates"
427                    " and emulated side by side is not supported\n",
428                    __func__);
429             return VCARD_EMUL_FAIL;
430         }
431         vcard_emul_replay_insertion_events();
432         return VCARD_EMUL_OK;
433     }
434     options_was_null = (options == NULL);
435     called = 1;
436     return vcard_emul_init(options);
437 }
438 
439 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
440 {
441     char emul_args[200];
442     VCardEmulOptions *options = NULL;
443 
444     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
445         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
446         card->cert1, card->cert2, card->cert3);
447     options = vcard_emul_options(emul_args);
448     if (options == NULL) {
449         printf("%s: warning: not using certificates due to"
450                " initialization error\n", __func__);
451     }
452     return wrap_vcard_emul_init(options);
453 }
454 
455 typedef struct EnumTable {
456     const char *name;
457     uint32_t value;
458 } EnumTable;
459 
460 static const EnumTable backend_enum_table[] = {
461     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
462     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
463     {NULL, 0},
464 };
465 
466 static uint32_t parse_enumeration(char *str,
467     const EnumTable *table, uint32_t not_found_value)
468 {
469     uint32_t ret = not_found_value;
470 
471     if (str == NULL)
472         return 0;
473 
474     while (table->name != NULL) {
475         if (strcmp(table->name, str) == 0) {
476             ret = table->value;
477             break;
478         }
479         table++;
480     }
481     return ret;
482 }
483 
484 static void emulated_realize(CCIDCardState *base, Error **errp)
485 {
486     EmulatedState *card = EMULATED_CCID_CARD(base);
487     VCardEmulError ret;
488     const EnumTable *ptable;
489 
490     QSIMPLEQ_INIT(&card->event_list);
491     QSIMPLEQ_INIT(&card->guest_apdu_list);
492     qemu_mutex_init(&card->event_list_mutex);
493     qemu_mutex_init(&card->vreader_mutex);
494     qemu_mutex_init(&card->handle_apdu_mutex);
495     qemu_cond_init(&card->handle_apdu_cond);
496     card->reader = NULL;
497     card->quit_apdu_thread = 0;
498     if (init_event_notifier(card, errp) < 0) {
499         return;
500     }
501 
502     card->backend = 0;
503     if (card->backend_str) {
504         card->backend = parse_enumeration(card->backend_str,
505                                           backend_enum_table, 0);
506     }
507 
508     if (card->backend == 0) {
509         error_setg(errp, "backend must be one of:");
510         for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
511             error_append_hint(errp, "%s\n", ptable->name);
512         }
513         return;
514     }
515 
516     /* TODO: a passthru backened that works on local machine. third card type?*/
517     if (card->backend == BACKEND_CERTIFICATES) {
518         if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
519             ret = emulated_initialize_vcard_from_certificates(card);
520         } else {
521             error_setg(errp, "%s: you must provide all three certs for"
522                        " certificates backend", TYPE_EMULATED_CCID);
523             return;
524         }
525     } else {
526         if (card->backend != BACKEND_NSS_EMULATED) {
527             error_setg(errp, "%s: bad backend specified. The options are:%s"
528                        " (default), %s.", TYPE_EMULATED_CCID,
529                        BACKEND_NSS_EMULATED_NAME, BACKEND_CERTIFICATES_NAME);
530             return;
531         }
532         if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
533             error_setg(errp, "%s: unexpected cert parameters to nss emulated "
534                        "backend", TYPE_EMULATED_CCID);
535             return;
536         }
537         /* default to mirroring the local hardware readers */
538         ret = wrap_vcard_emul_init(NULL);
539     }
540     if (ret != VCARD_EMUL_OK) {
541         error_setg(errp, "%s: failed to initialize vcard", TYPE_EMULATED_CCID);
542         return;
543     }
544     qemu_thread_create(&card->event_thread_id, "ccid/event", event_thread,
545                        card, QEMU_THREAD_JOINABLE);
546     qemu_thread_create(&card->apdu_thread_id, "ccid/apdu", handle_apdu_thread,
547                        card, QEMU_THREAD_JOINABLE);
548 }
549 
550 static void emulated_unrealize(CCIDCardState *base, Error **errp)
551 {
552     EmulatedState *card = EMULATED_CCID_CARD(base);
553     VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
554 
555     vevent_queue_vevent(vevent); /* stop vevent thread */
556     qemu_thread_join(&card->event_thread_id);
557 
558     card->quit_apdu_thread = 1; /* stop handle_apdu thread */
559     qemu_cond_signal(&card->handle_apdu_cond);
560     qemu_thread_join(&card->apdu_thread_id);
561 
562     /* threads exited, can destroy all condvars/mutexes */
563     qemu_cond_destroy(&card->handle_apdu_cond);
564     qemu_mutex_destroy(&card->handle_apdu_mutex);
565     qemu_mutex_destroy(&card->vreader_mutex);
566     qemu_mutex_destroy(&card->event_list_mutex);
567 }
568 
569 static Property emulated_card_properties[] = {
570     DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
571     DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
572     DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
573     DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
574     DEFINE_PROP_STRING("db", EmulatedState, db),
575     DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
576     DEFINE_PROP_END_OF_LIST(),
577 };
578 
579 static void emulated_class_initfn(ObjectClass *klass, void *data)
580 {
581     DeviceClass *dc = DEVICE_CLASS(klass);
582     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
583 
584     cc->realize = emulated_realize;
585     cc->unrealize = emulated_unrealize;
586     cc->get_atr = emulated_get_atr;
587     cc->apdu_from_guest = emulated_apdu_from_guest;
588     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
589     dc->desc = "emulated smartcard";
590     dc->props = emulated_card_properties;
591 }
592 
593 static const TypeInfo emulated_card_info = {
594     .name          = TYPE_EMULATED_CCID,
595     .parent        = TYPE_CCID_CARD,
596     .instance_size = sizeof(EmulatedState),
597     .class_init    = emulated_class_initfn,
598 };
599 
600 static void ccid_card_emulated_register_types(void)
601 {
602     type_register_static(&emulated_card_info);
603 }
604 
605 type_init(ccid_card_emulated_register_types)
606