xref: /openbmc/qemu/hw/usb/ccid-card-emulated.c (revision 9884abee)
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 "sysemu/char.h"
37 #include "ccid.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 #define EMULATED_DEV_NAME "ccid-card-emulated"
47 
48 #define BACKEND_NSS_EMULATED_NAME "nss-emulated"
49 #define BACKEND_CERTIFICATES_NAME "certificates"
50 
51 enum {
52     BACKEND_NSS_EMULATED = 1,
53     BACKEND_CERTIFICATES
54 };
55 
56 #define DEFAULT_BACKEND BACKEND_NSS_EMULATED
57 
58 typedef struct EmulatedState EmulatedState;
59 
60 enum {
61     EMUL_READER_INSERT = 0,
62     EMUL_READER_REMOVE,
63     EMUL_CARD_INSERT,
64     EMUL_CARD_REMOVE,
65     EMUL_GUEST_APDU,
66     EMUL_RESPONSE_APDU,
67     EMUL_ERROR,
68 };
69 
70 static const char *emul_event_to_string(uint32_t emul_event)
71 {
72     switch (emul_event) {
73     case EMUL_READER_INSERT:
74         return "EMUL_READER_INSERT";
75     case EMUL_READER_REMOVE:
76         return "EMUL_READER_REMOVE";
77     case EMUL_CARD_INSERT:
78         return "EMUL_CARD_INSERT";
79     case EMUL_CARD_REMOVE:
80         return "EMUL_CARD_REMOVE";
81     case EMUL_GUEST_APDU:
82         return "EMUL_GUEST_APDU";
83     case EMUL_RESPONSE_APDU:
84         return "EMUL_RESPONSE_APDU";
85     case EMUL_ERROR:
86         return "EMUL_ERROR";
87     }
88     return "UNKNOWN";
89 }
90 
91 typedef struct EmulEvent {
92     QSIMPLEQ_ENTRY(EmulEvent) entry;
93     union {
94         struct {
95             uint32_t type;
96         } gen;
97         struct {
98             uint32_t type;
99             uint64_t code;
100         } error;
101         struct {
102             uint32_t type;
103             uint32_t len;
104             uint8_t data[];
105         } data;
106     } p;
107 } EmulEvent;
108 
109 #define MAX_ATR_SIZE 40
110 struct EmulatedState {
111     CCIDCardState base;
112     uint8_t  debug;
113     char    *backend_str;
114     uint32_t backend;
115     char    *cert1;
116     char    *cert2;
117     char    *cert3;
118     char    *db;
119     uint8_t  atr[MAX_ATR_SIZE];
120     uint8_t  atr_length;
121     QSIMPLEQ_HEAD(event_list, EmulEvent) event_list;
122     QemuMutex event_list_mutex;
123     QemuThread event_thread_id;
124     VReader *reader;
125     QSIMPLEQ_HEAD(guest_apdu_list, EmulEvent) guest_apdu_list;
126     QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
127     QemuMutex handle_apdu_mutex;
128     QemuCond handle_apdu_cond;
129     EventNotifier notifier;
130     int      quit_apdu_thread;
131     QemuThread apdu_thread_id;
132 };
133 
134 static void emulated_apdu_from_guest(CCIDCardState *base,
135     const uint8_t *apdu, uint32_t len)
136 {
137     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
138     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
139 
140     assert(event);
141     event->p.data.type = EMUL_GUEST_APDU;
142     event->p.data.len = len;
143     memcpy(event->p.data.data, apdu, len);
144     qemu_mutex_lock(&card->vreader_mutex);
145     QSIMPLEQ_INSERT_TAIL(&card->guest_apdu_list, event, entry);
146     qemu_mutex_unlock(&card->vreader_mutex);
147     qemu_mutex_lock(&card->handle_apdu_mutex);
148     qemu_cond_signal(&card->handle_apdu_cond);
149     qemu_mutex_unlock(&card->handle_apdu_mutex);
150 }
151 
152 static const uint8_t *emulated_get_atr(CCIDCardState *base, uint32_t *len)
153 {
154     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
155 
156     *len = card->atr_length;
157     return card->atr;
158 }
159 
160 static void emulated_push_event(EmulatedState *card, EmulEvent *event)
161 {
162     qemu_mutex_lock(&card->event_list_mutex);
163     QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
164     qemu_mutex_unlock(&card->event_list_mutex);
165     event_notifier_set(&card->notifier);
166 }
167 
168 static void emulated_push_type(EmulatedState *card, uint32_t type)
169 {
170     EmulEvent *event = g_new(EmulEvent, 1);
171 
172     assert(event);
173     event->p.gen.type = type;
174     emulated_push_event(card, event);
175 }
176 
177 static void emulated_push_error(EmulatedState *card, uint64_t code)
178 {
179     EmulEvent *event = g_new(EmulEvent, 1);
180 
181     assert(event);
182     event->p.error.type = EMUL_ERROR;
183     event->p.error.code = code;
184     emulated_push_event(card, event);
185 }
186 
187 static void emulated_push_data_type(EmulatedState *card, uint32_t type,
188     const uint8_t *data, uint32_t len)
189 {
190     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
191 
192     assert(event);
193     event->p.data.type = type;
194     event->p.data.len = len;
195     memcpy(event->p.data.data, data, len);
196     emulated_push_event(card, event);
197 }
198 
199 static void emulated_push_reader_insert(EmulatedState *card)
200 {
201     emulated_push_type(card, EMUL_READER_INSERT);
202 }
203 
204 static void emulated_push_reader_remove(EmulatedState *card)
205 {
206     emulated_push_type(card, EMUL_READER_REMOVE);
207 }
208 
209 static void emulated_push_card_insert(EmulatedState *card,
210     const uint8_t *atr, uint32_t len)
211 {
212     emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
213 }
214 
215 static void emulated_push_card_remove(EmulatedState *card)
216 {
217     emulated_push_type(card, EMUL_CARD_REMOVE);
218 }
219 
220 static void emulated_push_response_apdu(EmulatedState *card,
221     const uint8_t *apdu, uint32_t len)
222 {
223     emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
224 }
225 
226 #define APDU_BUF_SIZE 270
227 static void *handle_apdu_thread(void* arg)
228 {
229     EmulatedState *card = arg;
230     uint8_t recv_data[APDU_BUF_SIZE];
231     int recv_len;
232     VReaderStatus reader_status;
233     EmulEvent *event;
234 
235     while (1) {
236         qemu_mutex_lock(&card->handle_apdu_mutex);
237         qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
238         qemu_mutex_unlock(&card->handle_apdu_mutex);
239         if (card->quit_apdu_thread) {
240             card->quit_apdu_thread = 0; /* debugging */
241             break;
242         }
243         qemu_mutex_lock(&card->vreader_mutex);
244         while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
245             event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
246             assert((unsigned long)event > 1000);
247             QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
248             if (event->p.data.type != EMUL_GUEST_APDU) {
249                 DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
250                 g_free(event);
251                 continue;
252             }
253             if (card->reader == NULL) {
254                 DPRINTF(card, 1, "reader is NULL\n");
255                 g_free(event);
256                 continue;
257             }
258             recv_len = sizeof(recv_data);
259             reader_status = vreader_xfr_bytes(card->reader,
260                     event->p.data.data, event->p.data.len,
261                     recv_data, &recv_len);
262             DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
263             if (reader_status == VREADER_OK) {
264                 emulated_push_response_apdu(card, recv_data, recv_len);
265             } else {
266                 emulated_push_error(card, reader_status);
267             }
268             g_free(event);
269         }
270         qemu_mutex_unlock(&card->vreader_mutex);
271     }
272     return NULL;
273 }
274 
275 static void *event_thread(void *arg)
276 {
277     int atr_len = MAX_ATR_SIZE;
278     uint8_t atr[MAX_ATR_SIZE];
279     VEvent *event = NULL;
280     EmulatedState *card = arg;
281 
282     while (1) {
283         const char *reader_name;
284 
285         event = vevent_wait_next_vevent();
286         if (event == NULL || event->type == VEVENT_LAST) {
287             break;
288         }
289         if (event->type != VEVENT_READER_INSERT) {
290             if (card->reader == NULL && event->reader != NULL) {
291                 /* Happens after device_add followed by card remove or insert.
292                  * XXX: create synthetic add_reader events if vcard_emul_init
293                  * already called, which happens if device_del and device_add
294                  * are called */
295                 card->reader = vreader_reference(event->reader);
296             } else {
297                 if (event->reader != card->reader) {
298                     fprintf(stderr,
299                         "ERROR: wrong reader: quiting event_thread\n");
300                     break;
301                 }
302             }
303         }
304         switch (event->type) {
305         case VEVENT_READER_INSERT:
306             /* TODO: take a specific reader. i.e. track which reader
307              * we are seeing here, check it is the one we want (the first,
308              * or by a particular name), and ignore if we don't want it.
309              */
310             reader_name = vreader_get_name(event->reader);
311             if (card->reader != NULL) {
312                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
313                     vreader_get_name(card->reader), reader_name);
314                 qemu_mutex_lock(&card->vreader_mutex);
315                 vreader_free(card->reader);
316                 qemu_mutex_unlock(&card->vreader_mutex);
317                 emulated_push_reader_remove(card);
318             }
319             qemu_mutex_lock(&card->vreader_mutex);
320             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
321             card->reader = vreader_reference(event->reader);
322             qemu_mutex_unlock(&card->vreader_mutex);
323             emulated_push_reader_insert(card);
324             break;
325         case VEVENT_READER_REMOVE:
326             DPRINTF(card, 2, " READER REMOVE: %s\n",
327                     vreader_get_name(event->reader));
328             qemu_mutex_lock(&card->vreader_mutex);
329             vreader_free(card->reader);
330             card->reader = NULL;
331             qemu_mutex_unlock(&card->vreader_mutex);
332             emulated_push_reader_remove(card);
333             break;
334         case VEVENT_CARD_INSERT:
335             /* get the ATR (intended as a response to a power on from the
336              * reader */
337             atr_len = MAX_ATR_SIZE;
338             vreader_power_on(event->reader, atr, &atr_len);
339             card->atr_length = (uint8_t)atr_len;
340             DPRINTF(card, 2, " CARD INSERT\n");
341             emulated_push_card_insert(card, atr, atr_len);
342             break;
343         case VEVENT_CARD_REMOVE:
344             DPRINTF(card, 2, " CARD REMOVE\n");
345             emulated_push_card_remove(card);
346             break;
347         case VEVENT_LAST: /* quit */
348             vevent_delete(event);
349             return NULL;
350             break;
351         default:
352             break;
353         }
354         vevent_delete(event);
355     }
356     return NULL;
357 }
358 
359 static void card_event_handler(EventNotifier *notifier)
360 {
361     EmulatedState *card = container_of(notifier, EmulatedState, notifier);
362     EmulEvent *event, *next;
363 
364     event_notifier_test_and_clear(&card->notifier);
365     qemu_mutex_lock(&card->event_list_mutex);
366     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
367         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
368         switch (event->p.gen.type) {
369         case EMUL_RESPONSE_APDU:
370             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
371                 event->p.data.len);
372             break;
373         case EMUL_READER_INSERT:
374             ccid_card_ccid_attach(&card->base);
375             break;
376         case EMUL_READER_REMOVE:
377             ccid_card_ccid_detach(&card->base);
378             break;
379         case EMUL_CARD_INSERT:
380             assert(event->p.data.len <= MAX_ATR_SIZE);
381             card->atr_length = event->p.data.len;
382             memcpy(card->atr, event->p.data.data, card->atr_length);
383             ccid_card_card_inserted(&card->base);
384             break;
385         case EMUL_CARD_REMOVE:
386             ccid_card_card_removed(&card->base);
387             break;
388         case EMUL_ERROR:
389             ccid_card_card_error(&card->base, event->p.error.code);
390             break;
391         default:
392             DPRINTF(card, 2, "unexpected event\n");
393             break;
394         }
395         g_free(event);
396     }
397     QSIMPLEQ_INIT(&card->event_list);
398     qemu_mutex_unlock(&card->event_list_mutex);
399 }
400 
401 static int init_event_notifier(EmulatedState *card)
402 {
403     if (event_notifier_init(&card->notifier, false) < 0) {
404         DPRINTF(card, 2, "event notifier creation failed\n");
405         return -1;
406     }
407     event_notifier_set_handler(&card->notifier, card_event_handler);
408     return 0;
409 }
410 
411 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
412 #define CERTIFICATES_ARGS_TEMPLATE\
413     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
414 
415 static int wrap_vcard_emul_init(VCardEmulOptions *options)
416 {
417     static int called;
418     static int options_was_null;
419 
420     if (called) {
421         if ((options == NULL) != options_was_null) {
422             printf("%s: warning: running emulated with certificates"
423                    " and emulated side by side is not supported\n",
424                    __func__);
425             return VCARD_EMUL_FAIL;
426         }
427         vcard_emul_replay_insertion_events();
428         return VCARD_EMUL_OK;
429     }
430     options_was_null = (options == NULL);
431     called = 1;
432     return vcard_emul_init(options);
433 }
434 
435 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
436 {
437     char emul_args[200];
438     VCardEmulOptions *options = NULL;
439 
440     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
441         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
442         card->cert1, card->cert2, card->cert3);
443     options = vcard_emul_options(emul_args);
444     if (options == NULL) {
445         printf("%s: warning: not using certificates due to"
446                " initialization error\n", __func__);
447     }
448     return wrap_vcard_emul_init(options);
449 }
450 
451 typedef struct EnumTable {
452     const char *name;
453     uint32_t value;
454 } EnumTable;
455 
456 static const EnumTable backend_enum_table[] = {
457     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
458     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
459     {NULL, 0},
460 };
461 
462 static uint32_t parse_enumeration(char *str,
463     const EnumTable *table, uint32_t not_found_value)
464 {
465     uint32_t ret = not_found_value;
466 
467     if (str == NULL)
468         return 0;
469 
470     while (table->name != NULL) {
471         if (strcmp(table->name, str) == 0) {
472             ret = table->value;
473             break;
474         }
475         table++;
476     }
477     return ret;
478 }
479 
480 static int emulated_initfn(CCIDCardState *base)
481 {
482     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
483     VCardEmulError ret;
484     const EnumTable *ptable;
485 
486     QSIMPLEQ_INIT(&card->event_list);
487     QSIMPLEQ_INIT(&card->guest_apdu_list);
488     qemu_mutex_init(&card->event_list_mutex);
489     qemu_mutex_init(&card->vreader_mutex);
490     qemu_mutex_init(&card->handle_apdu_mutex);
491     qemu_cond_init(&card->handle_apdu_cond);
492     card->reader = NULL;
493     card->quit_apdu_thread = 0;
494     if (init_event_notifier(card) < 0) {
495         return -1;
496     }
497 
498     card->backend = 0;
499     if (card->backend_str) {
500         card->backend = parse_enumeration(card->backend_str,
501                                           backend_enum_table, 0);
502     }
503 
504     if (card->backend == 0) {
505         printf("backend must be one of:\n");
506         for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
507             printf("%s\n", ptable->name);
508         }
509         return -1;
510     }
511 
512     /* TODO: a passthru backened that works on local machine. third card type?*/
513     if (card->backend == BACKEND_CERTIFICATES) {
514         if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
515             ret = emulated_initialize_vcard_from_certificates(card);
516         } else {
517             printf("%s: you must provide all three certs for"
518                    " certificates backend\n", EMULATED_DEV_NAME);
519             return -1;
520         }
521     } else {
522         if (card->backend != BACKEND_NSS_EMULATED) {
523             printf("%s: bad backend specified. The options are:\n%s (default),"
524                 " %s.\n", EMULATED_DEV_NAME, BACKEND_NSS_EMULATED_NAME,
525                 BACKEND_CERTIFICATES_NAME);
526             return -1;
527         }
528         if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
529             printf("%s: unexpected cert parameters to nss emulated backend\n",
530                    EMULATED_DEV_NAME);
531             return -1;
532         }
533         /* default to mirroring the local hardware readers */
534         ret = wrap_vcard_emul_init(NULL);
535     }
536     if (ret != VCARD_EMUL_OK) {
537         printf("%s: failed to initialize vcard\n", EMULATED_DEV_NAME);
538         return -1;
539     }
540     qemu_thread_create(&card->event_thread_id, "ccid/event", event_thread,
541                        card, QEMU_THREAD_JOINABLE);
542     qemu_thread_create(&card->apdu_thread_id, "ccid/apdu", handle_apdu_thread,
543                        card, QEMU_THREAD_JOINABLE);
544     return 0;
545 }
546 
547 static int emulated_exitfn(CCIDCardState *base)
548 {
549     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
550     VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
551 
552     vevent_queue_vevent(vevent); /* stop vevent thread */
553     qemu_thread_join(&card->event_thread_id);
554 
555     card->quit_apdu_thread = 1; /* stop handle_apdu thread */
556     qemu_cond_signal(&card->handle_apdu_cond);
557     qemu_thread_join(&card->apdu_thread_id);
558 
559     /* threads exited, can destroy all condvars/mutexes */
560     qemu_cond_destroy(&card->handle_apdu_cond);
561     qemu_mutex_destroy(&card->handle_apdu_mutex);
562     qemu_mutex_destroy(&card->vreader_mutex);
563     qemu_mutex_destroy(&card->event_list_mutex);
564     return 0;
565 }
566 
567 static Property emulated_card_properties[] = {
568     DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
569     DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
570     DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
571     DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
572     DEFINE_PROP_STRING("db", EmulatedState, db),
573     DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
574     DEFINE_PROP_END_OF_LIST(),
575 };
576 
577 static void emulated_class_initfn(ObjectClass *klass, void *data)
578 {
579     DeviceClass *dc = DEVICE_CLASS(klass);
580     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
581 
582     cc->initfn = emulated_initfn;
583     cc->exitfn = emulated_exitfn;
584     cc->get_atr = emulated_get_atr;
585     cc->apdu_from_guest = emulated_apdu_from_guest;
586     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
587     dc->desc = "emulated smartcard";
588     dc->props = emulated_card_properties;
589 }
590 
591 static const TypeInfo emulated_card_info = {
592     .name          = EMULATED_DEV_NAME,
593     .parent        = TYPE_CCID_CARD,
594     .instance_size = sizeof(EmulatedState),
595     .class_init    = emulated_class_initfn,
596 };
597 
598 static void ccid_card_emulated_register_types(void)
599 {
600     type_register_static(&emulated_card_info);
601 }
602 
603 type_init(ccid_card_emulated_register_types)
604