xref: /openbmc/qemu/hw/usb/ccid-card-emulated.c (revision f1733749)
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 "hw/qdev-properties.h"
37 #include "qapi/error.h"
38 
39 #define DPRINTF(card, lvl, fmt, ...) \
40 do {\
41     if (lvl <= card->debug) {\
42         printf("ccid-card-emul: %s: " fmt , __func__, ## __VA_ARGS__);\
43     } \
44 } while (0)
45 
46 
47 #define TYPE_EMULATED_CCID "ccid-card-emulated"
48 #define EMULATED_CCID_CARD(obj) \
49     OBJECT_CHECK(EmulatedState, (obj), TYPE_EMULATED_CCID)
50 
51 #define BACKEND_NSS_EMULATED_NAME "nss-emulated"
52 #define BACKEND_CERTIFICATES_NAME "certificates"
53 
54 enum {
55     BACKEND_NSS_EMULATED = 1,
56     BACKEND_CERTIFICATES
57 };
58 
59 #define DEFAULT_BACKEND BACKEND_NSS_EMULATED
60 
61 typedef struct EmulatedState EmulatedState;
62 
63 enum {
64     EMUL_READER_INSERT = 0,
65     EMUL_READER_REMOVE,
66     EMUL_CARD_INSERT,
67     EMUL_CARD_REMOVE,
68     EMUL_GUEST_APDU,
69     EMUL_RESPONSE_APDU,
70     EMUL_ERROR,
71 };
72 
73 static const char *emul_event_to_string(uint32_t emul_event)
74 {
75     switch (emul_event) {
76     case EMUL_READER_INSERT:
77         return "EMUL_READER_INSERT";
78     case EMUL_READER_REMOVE:
79         return "EMUL_READER_REMOVE";
80     case EMUL_CARD_INSERT:
81         return "EMUL_CARD_INSERT";
82     case EMUL_CARD_REMOVE:
83         return "EMUL_CARD_REMOVE";
84     case EMUL_GUEST_APDU:
85         return "EMUL_GUEST_APDU";
86     case EMUL_RESPONSE_APDU:
87         return "EMUL_RESPONSE_APDU";
88     case EMUL_ERROR:
89         return "EMUL_ERROR";
90     }
91     return "UNKNOWN";
92 }
93 
94 typedef struct EmulEvent {
95     QSIMPLEQ_ENTRY(EmulEvent) entry;
96     union {
97         struct {
98             uint32_t type;
99         } gen;
100         struct {
101             uint32_t type;
102             uint64_t code;
103         } error;
104         struct {
105             uint32_t type;
106             uint32_t len;
107             uint8_t data[];
108         } data;
109     } p;
110 } EmulEvent;
111 
112 #define MAX_ATR_SIZE 40
113 struct EmulatedState {
114     CCIDCardState base;
115     uint8_t  debug;
116     char    *backend_str;
117     uint32_t backend;
118     char    *cert1;
119     char    *cert2;
120     char    *cert3;
121     char    *db;
122     uint8_t  atr[MAX_ATR_SIZE];
123     uint8_t  atr_length;
124     QSIMPLEQ_HEAD(, EmulEvent) event_list;
125     QemuMutex event_list_mutex;
126     QemuThread event_thread_id;
127     VReader *reader;
128     QSIMPLEQ_HEAD(, EmulEvent) guest_apdu_list;
129     QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
130     QemuMutex handle_apdu_mutex;
131     QemuCond handle_apdu_cond;
132     EventNotifier notifier;
133     int      quit_apdu_thread;
134     QemuThread apdu_thread_id;
135 };
136 
137 static void emulated_apdu_from_guest(CCIDCardState *base,
138     const uint8_t *apdu, uint32_t len)
139 {
140     EmulatedState *card = EMULATED_CCID_CARD(base);
141     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
142 
143     assert(event);
144     event->p.data.type = EMUL_GUEST_APDU;
145     event->p.data.len = len;
146     memcpy(event->p.data.data, apdu, len);
147     qemu_mutex_lock(&card->vreader_mutex);
148     QSIMPLEQ_INSERT_TAIL(&card->guest_apdu_list, event, entry);
149     qemu_mutex_unlock(&card->vreader_mutex);
150     qemu_mutex_lock(&card->handle_apdu_mutex);
151     qemu_cond_signal(&card->handle_apdu_cond);
152     qemu_mutex_unlock(&card->handle_apdu_mutex);
153 }
154 
155 static const uint8_t *emulated_get_atr(CCIDCardState *base, uint32_t *len)
156 {
157     EmulatedState *card = EMULATED_CCID_CARD(base);
158 
159     *len = card->atr_length;
160     return card->atr;
161 }
162 
163 static void emulated_push_event(EmulatedState *card, EmulEvent *event)
164 {
165     qemu_mutex_lock(&card->event_list_mutex);
166     QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
167     qemu_mutex_unlock(&card->event_list_mutex);
168     event_notifier_set(&card->notifier);
169 }
170 
171 static void emulated_push_type(EmulatedState *card, uint32_t type)
172 {
173     EmulEvent *event = g_new(EmulEvent, 1);
174 
175     assert(event);
176     event->p.gen.type = type;
177     emulated_push_event(card, event);
178 }
179 
180 static void emulated_push_error(EmulatedState *card, uint64_t code)
181 {
182     EmulEvent *event = g_new(EmulEvent, 1);
183 
184     assert(event);
185     event->p.error.type = EMUL_ERROR;
186     event->p.error.code = code;
187     emulated_push_event(card, event);
188 }
189 
190 static void emulated_push_data_type(EmulatedState *card, uint32_t type,
191     const uint8_t *data, uint32_t len)
192 {
193     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
194 
195     assert(event);
196     event->p.data.type = type;
197     event->p.data.len = len;
198     memcpy(event->p.data.data, data, len);
199     emulated_push_event(card, event);
200 }
201 
202 static void emulated_push_reader_insert(EmulatedState *card)
203 {
204     emulated_push_type(card, EMUL_READER_INSERT);
205 }
206 
207 static void emulated_push_reader_remove(EmulatedState *card)
208 {
209     emulated_push_type(card, EMUL_READER_REMOVE);
210 }
211 
212 static void emulated_push_card_insert(EmulatedState *card,
213     const uint8_t *atr, uint32_t len)
214 {
215     emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
216 }
217 
218 static void emulated_push_card_remove(EmulatedState *card)
219 {
220     emulated_push_type(card, EMUL_CARD_REMOVE);
221 }
222 
223 static void emulated_push_response_apdu(EmulatedState *card,
224     const uint8_t *apdu, uint32_t len)
225 {
226     emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
227 }
228 
229 #define APDU_BUF_SIZE 270
230 static void *handle_apdu_thread(void* arg)
231 {
232     EmulatedState *card = arg;
233     uint8_t recv_data[APDU_BUF_SIZE];
234     int recv_len;
235     VReaderStatus reader_status;
236     EmulEvent *event;
237 
238     while (1) {
239         qemu_mutex_lock(&card->handle_apdu_mutex);
240         qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
241         qemu_mutex_unlock(&card->handle_apdu_mutex);
242         if (card->quit_apdu_thread) {
243             card->quit_apdu_thread = 0; /* debugging */
244             break;
245         }
246         qemu_mutex_lock(&card->vreader_mutex);
247         while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
248             event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
249             assert((unsigned long)event > 1000);
250             QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
251             if (event->p.data.type != EMUL_GUEST_APDU) {
252                 DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
253                 g_free(event);
254                 continue;
255             }
256             if (card->reader == NULL) {
257                 DPRINTF(card, 1, "reader is NULL\n");
258                 g_free(event);
259                 continue;
260             }
261             recv_len = sizeof(recv_data);
262             reader_status = vreader_xfr_bytes(card->reader,
263                     event->p.data.data, event->p.data.len,
264                     recv_data, &recv_len);
265             DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
266             if (reader_status == VREADER_OK) {
267                 emulated_push_response_apdu(card, recv_data, recv_len);
268             } else {
269                 emulated_push_error(card, reader_status);
270             }
271             g_free(event);
272         }
273         qemu_mutex_unlock(&card->vreader_mutex);
274     }
275     return NULL;
276 }
277 
278 static void *event_thread(void *arg)
279 {
280     int atr_len = MAX_ATR_SIZE;
281     uint8_t atr[MAX_ATR_SIZE];
282     VEvent *event = NULL;
283     EmulatedState *card = arg;
284 
285     while (1) {
286         const char *reader_name;
287 
288         event = vevent_wait_next_vevent();
289         if (event == NULL || event->type == VEVENT_LAST) {
290             break;
291         }
292         if (event->type != VEVENT_READER_INSERT) {
293             if (card->reader == NULL && event->reader != NULL) {
294                 /* Happens after device_add followed by card remove or insert.
295                  * XXX: create synthetic add_reader events if vcard_emul_init
296                  * already called, which happens if device_del and device_add
297                  * are called */
298                 card->reader = vreader_reference(event->reader);
299             } else {
300                 if (event->reader != card->reader) {
301                     fprintf(stderr,
302                         "ERROR: wrong reader: quiting event_thread\n");
303                     break;
304                 }
305             }
306         }
307         switch (event->type) {
308         case VEVENT_READER_INSERT:
309             /* TODO: take a specific reader. i.e. track which reader
310              * we are seeing here, check it is the one we want (the first,
311              * or by a particular name), and ignore if we don't want it.
312              */
313             reader_name = vreader_get_name(event->reader);
314             if (card->reader != NULL) {
315                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
316                     vreader_get_name(card->reader), reader_name);
317                 qemu_mutex_lock(&card->vreader_mutex);
318                 vreader_free(card->reader);
319                 qemu_mutex_unlock(&card->vreader_mutex);
320                 emulated_push_reader_remove(card);
321             }
322             qemu_mutex_lock(&card->vreader_mutex);
323             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
324             card->reader = vreader_reference(event->reader);
325             qemu_mutex_unlock(&card->vreader_mutex);
326             emulated_push_reader_insert(card);
327             break;
328         case VEVENT_READER_REMOVE:
329             DPRINTF(card, 2, " READER REMOVE: %s\n",
330                     vreader_get_name(event->reader));
331             qemu_mutex_lock(&card->vreader_mutex);
332             vreader_free(card->reader);
333             card->reader = NULL;
334             qemu_mutex_unlock(&card->vreader_mutex);
335             emulated_push_reader_remove(card);
336             break;
337         case VEVENT_CARD_INSERT:
338             /* get the ATR (intended as a response to a power on from the
339              * reader */
340             atr_len = MAX_ATR_SIZE;
341             vreader_power_on(event->reader, atr, &atr_len);
342             card->atr_length = (uint8_t)atr_len;
343             DPRINTF(card, 2, " CARD INSERT\n");
344             emulated_push_card_insert(card, atr, atr_len);
345             break;
346         case VEVENT_CARD_REMOVE:
347             DPRINTF(card, 2, " CARD REMOVE\n");
348             emulated_push_card_remove(card);
349             break;
350         case VEVENT_LAST: /* quit */
351             vevent_delete(event);
352             return NULL;
353             break;
354         default:
355             break;
356         }
357         vevent_delete(event);
358     }
359     return NULL;
360 }
361 
362 static void card_event_handler(EventNotifier *notifier)
363 {
364     EmulatedState *card = container_of(notifier, EmulatedState, notifier);
365     EmulEvent *event, *next;
366 
367     event_notifier_test_and_clear(&card->notifier);
368     qemu_mutex_lock(&card->event_list_mutex);
369     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
370         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
371         switch (event->p.gen.type) {
372         case EMUL_RESPONSE_APDU:
373             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
374                 event->p.data.len);
375             break;
376         case EMUL_READER_INSERT:
377             ccid_card_ccid_attach(&card->base);
378             break;
379         case EMUL_READER_REMOVE:
380             ccid_card_ccid_detach(&card->base);
381             break;
382         case EMUL_CARD_INSERT:
383             assert(event->p.data.len <= MAX_ATR_SIZE);
384             card->atr_length = event->p.data.len;
385             memcpy(card->atr, event->p.data.data, card->atr_length);
386             ccid_card_card_inserted(&card->base);
387             break;
388         case EMUL_CARD_REMOVE:
389             ccid_card_card_removed(&card->base);
390             break;
391         case EMUL_ERROR:
392             ccid_card_card_error(&card->base, event->p.error.code);
393             break;
394         default:
395             DPRINTF(card, 2, "unexpected event\n");
396             break;
397         }
398         g_free(event);
399     }
400     QSIMPLEQ_INIT(&card->event_list);
401     qemu_mutex_unlock(&card->event_list_mutex);
402 }
403 
404 static int init_event_notifier(EmulatedState *card, Error **errp)
405 {
406     if (event_notifier_init(&card->notifier, false) < 0) {
407         error_setg(errp, "ccid-card-emul: event notifier creation failed");
408         return -1;
409     }
410     event_notifier_set_handler(&card->notifier, card_event_handler);
411     return 0;
412 }
413 
414 static void clean_event_notifier(EmulatedState *card)
415 {
416     event_notifier_set_handler(&card->notifier, NULL);
417     event_notifier_cleanup(&card->notifier);
418 }
419 
420 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
421 #define CERTIFICATES_ARGS_TEMPLATE\
422     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
423 
424 static int wrap_vcard_emul_init(VCardEmulOptions *options)
425 {
426     static int called;
427     static int options_was_null;
428 
429     if (called) {
430         if ((options == NULL) != options_was_null) {
431             printf("%s: warning: running emulated with certificates"
432                    " and emulated side by side is not supported\n",
433                    __func__);
434             return VCARD_EMUL_FAIL;
435         }
436         vcard_emul_replay_insertion_events();
437         return VCARD_EMUL_OK;
438     }
439     options_was_null = (options == NULL);
440     called = 1;
441     return vcard_emul_init(options);
442 }
443 
444 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
445 {
446     char emul_args[200];
447     VCardEmulOptions *options = NULL;
448 
449     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
450         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
451         card->cert1, card->cert2, card->cert3);
452     options = vcard_emul_options(emul_args);
453     if (options == NULL) {
454         printf("%s: warning: not using certificates due to"
455                " initialization error\n", __func__);
456     }
457     return wrap_vcard_emul_init(options);
458 }
459 
460 typedef struct EnumTable {
461     const char *name;
462     uint32_t value;
463 } EnumTable;
464 
465 static const EnumTable backend_enum_table[] = {
466     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
467     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
468     {NULL, 0},
469 };
470 
471 static uint32_t parse_enumeration(char *str,
472     const EnumTable *table, uint32_t not_found_value)
473 {
474     uint32_t ret = not_found_value;
475 
476     if (str == NULL)
477         return 0;
478 
479     while (table->name != NULL) {
480         if (strcmp(table->name, str) == 0) {
481             ret = table->value;
482             break;
483         }
484         table++;
485     }
486     return ret;
487 }
488 
489 static void emulated_realize(CCIDCardState *base, Error **errp)
490 {
491     EmulatedState *card = EMULATED_CCID_CARD(base);
492     VCardEmulError ret;
493     const EnumTable *ptable;
494 
495     QSIMPLEQ_INIT(&card->event_list);
496     QSIMPLEQ_INIT(&card->guest_apdu_list);
497     qemu_mutex_init(&card->event_list_mutex);
498     qemu_mutex_init(&card->vreader_mutex);
499     qemu_mutex_init(&card->handle_apdu_mutex);
500     qemu_cond_init(&card->handle_apdu_cond);
501     card->reader = NULL;
502     card->quit_apdu_thread = 0;
503     if (init_event_notifier(card, errp) < 0) {
504         goto out1;
505     }
506 
507     card->backend = 0;
508     if (card->backend_str) {
509         card->backend = parse_enumeration(card->backend_str,
510                                           backend_enum_table, 0);
511     }
512 
513     if (card->backend == 0) {
514         error_setg(errp, "backend must be one of:");
515         for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
516             error_append_hint(errp, "%s\n", ptable->name);
517         }
518         goto out2;
519     }
520 
521     /* TODO: a passthru backened that works on local machine. third card type?*/
522     if (card->backend == BACKEND_CERTIFICATES) {
523         if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
524             ret = emulated_initialize_vcard_from_certificates(card);
525         } else {
526             error_setg(errp, "%s: you must provide all three certs for"
527                        " certificates backend", TYPE_EMULATED_CCID);
528             goto out2;
529         }
530     } else {
531         if (card->backend != BACKEND_NSS_EMULATED) {
532             error_setg(errp, "%s: bad backend specified. The options are:%s"
533                        " (default), %s.", TYPE_EMULATED_CCID,
534                        BACKEND_NSS_EMULATED_NAME, BACKEND_CERTIFICATES_NAME);
535             goto out2;
536         }
537         if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
538             error_setg(errp, "%s: unexpected cert parameters to nss emulated "
539                        "backend", TYPE_EMULATED_CCID);
540             goto out2;
541         }
542         /* default to mirroring the local hardware readers */
543         ret = wrap_vcard_emul_init(NULL);
544     }
545     if (ret != VCARD_EMUL_OK) {
546         error_setg(errp, "%s: failed to initialize vcard", TYPE_EMULATED_CCID);
547         goto out2;
548     }
549     qemu_thread_create(&card->event_thread_id, "ccid/event", event_thread,
550                        card, QEMU_THREAD_JOINABLE);
551     qemu_thread_create(&card->apdu_thread_id, "ccid/apdu", handle_apdu_thread,
552                        card, QEMU_THREAD_JOINABLE);
553 
554     return;
555 
556 out2:
557     clean_event_notifier(card);
558 out1:
559     qemu_cond_destroy(&card->handle_apdu_cond);
560     qemu_mutex_destroy(&card->handle_apdu_mutex);
561     qemu_mutex_destroy(&card->vreader_mutex);
562     qemu_mutex_destroy(&card->event_list_mutex);
563 }
564 
565 static void emulated_unrealize(CCIDCardState *base, Error **errp)
566 {
567     EmulatedState *card = EMULATED_CCID_CARD(base);
568     VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
569 
570     vevent_queue_vevent(vevent); /* stop vevent thread */
571     qemu_thread_join(&card->event_thread_id);
572 
573     card->quit_apdu_thread = 1; /* stop handle_apdu thread */
574     qemu_cond_signal(&card->handle_apdu_cond);
575     qemu_thread_join(&card->apdu_thread_id);
576 
577     clean_event_notifier(card);
578     /* threads exited, can destroy all condvars/mutexes */
579     qemu_cond_destroy(&card->handle_apdu_cond);
580     qemu_mutex_destroy(&card->handle_apdu_mutex);
581     qemu_mutex_destroy(&card->vreader_mutex);
582     qemu_mutex_destroy(&card->event_list_mutex);
583 }
584 
585 static Property emulated_card_properties[] = {
586     DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
587     DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
588     DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
589     DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
590     DEFINE_PROP_STRING("db", EmulatedState, db),
591     DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
592     DEFINE_PROP_END_OF_LIST(),
593 };
594 
595 static void emulated_class_initfn(ObjectClass *klass, void *data)
596 {
597     DeviceClass *dc = DEVICE_CLASS(klass);
598     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
599 
600     cc->realize = emulated_realize;
601     cc->unrealize = emulated_unrealize;
602     cc->get_atr = emulated_get_atr;
603     cc->apdu_from_guest = emulated_apdu_from_guest;
604     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
605     dc->desc = "emulated smartcard";
606     dc->props = emulated_card_properties;
607 }
608 
609 static const TypeInfo emulated_card_info = {
610     .name          = TYPE_EMULATED_CCID,
611     .parent        = TYPE_CCID_CARD,
612     .instance_size = sizeof(EmulatedState),
613     .class_init    = emulated_class_initfn,
614 };
615 
616 static void ccid_card_emulated_register_types(void)
617 {
618     type_register_static(&emulated_card_info);
619 }
620 
621 type_init(ccid_card_emulated_register_types)
622