xref: /openbmc/qemu/hw/usb/ccid-card-emulated.c (revision 0a9516c2)
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 <eventt.h>
30 #include <vevent.h>
31 #include <vreader.h>
32 #include <vcard_emul.h>
33 
34 #include "qemu/thread.h"
35 #include "sysemu/char.h"
36 #include "ccid.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 #define EMULATED_DEV_NAME "ccid-card-emulated"
46 
47 #define BACKEND_NSS_EMULATED_NAME "nss-emulated"
48 #define BACKEND_CERTIFICATES_NAME "certificates"
49 
50 enum {
51     BACKEND_NSS_EMULATED = 1,
52     BACKEND_CERTIFICATES
53 };
54 
55 #define DEFAULT_BACKEND BACKEND_NSS_EMULATED
56 
57 typedef struct EmulatedState EmulatedState;
58 
59 enum {
60     EMUL_READER_INSERT = 0,
61     EMUL_READER_REMOVE,
62     EMUL_CARD_INSERT,
63     EMUL_CARD_REMOVE,
64     EMUL_GUEST_APDU,
65     EMUL_RESPONSE_APDU,
66     EMUL_ERROR,
67 };
68 
69 static const char *emul_event_to_string(uint32_t emul_event)
70 {
71     switch (emul_event) {
72     case EMUL_READER_INSERT:
73         return "EMUL_READER_INSERT";
74     case EMUL_READER_REMOVE:
75         return "EMUL_READER_REMOVE";
76     case EMUL_CARD_INSERT:
77         return "EMUL_CARD_INSERT";
78     case EMUL_CARD_REMOVE:
79         return "EMUL_CARD_REMOVE";
80     case EMUL_GUEST_APDU:
81         return "EMUL_GUEST_APDU";
82     case EMUL_RESPONSE_APDU:
83         return "EMUL_RESPONSE_APDU";
84     case EMUL_ERROR:
85         return "EMUL_ERROR";
86     }
87     return "UNKNOWN";
88 }
89 
90 typedef struct EmulEvent {
91     QSIMPLEQ_ENTRY(EmulEvent) entry;
92     union {
93         struct {
94             uint32_t type;
95         } gen;
96         struct {
97             uint32_t type;
98             uint64_t code;
99         } error;
100         struct {
101             uint32_t type;
102             uint32_t len;
103             uint8_t data[];
104         } data;
105     } p;
106 } EmulEvent;
107 
108 #define MAX_ATR_SIZE 40
109 struct EmulatedState {
110     CCIDCardState base;
111     uint8_t  debug;
112     char    *backend_str;
113     uint32_t backend;
114     char    *cert1;
115     char    *cert2;
116     char    *cert3;
117     char    *db;
118     uint8_t  atr[MAX_ATR_SIZE];
119     uint8_t  atr_length;
120     QSIMPLEQ_HEAD(event_list, EmulEvent) event_list;
121     QemuMutex event_list_mutex;
122     QemuThread event_thread_id;
123     VReader *reader;
124     QSIMPLEQ_HEAD(guest_apdu_list, EmulEvent) guest_apdu_list;
125     QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
126     QemuMutex handle_apdu_mutex;
127     QemuCond handle_apdu_cond;
128     EventNotifier notifier;
129     int      quit_apdu_thread;
130     QemuThread apdu_thread_id;
131 };
132 
133 static void emulated_apdu_from_guest(CCIDCardState *base,
134     const uint8_t *apdu, uint32_t len)
135 {
136     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
137     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
138 
139     assert(event);
140     event->p.data.type = EMUL_GUEST_APDU;
141     event->p.data.len = len;
142     memcpy(event->p.data.data, apdu, len);
143     qemu_mutex_lock(&card->vreader_mutex);
144     QSIMPLEQ_INSERT_TAIL(&card->guest_apdu_list, event, entry);
145     qemu_mutex_unlock(&card->vreader_mutex);
146     qemu_mutex_lock(&card->handle_apdu_mutex);
147     qemu_cond_signal(&card->handle_apdu_cond);
148     qemu_mutex_unlock(&card->handle_apdu_mutex);
149 }
150 
151 static const uint8_t *emulated_get_atr(CCIDCardState *base, uint32_t *len)
152 {
153     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
154 
155     *len = card->atr_length;
156     return card->atr;
157 }
158 
159 static void emulated_push_event(EmulatedState *card, EmulEvent *event)
160 {
161     qemu_mutex_lock(&card->event_list_mutex);
162     QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
163     qemu_mutex_unlock(&card->event_list_mutex);
164     event_notifier_set(&card->notifier);
165 }
166 
167 static void emulated_push_type(EmulatedState *card, uint32_t type)
168 {
169     EmulEvent *event = g_new(EmulEvent, 1);
170 
171     assert(event);
172     event->p.gen.type = type;
173     emulated_push_event(card, event);
174 }
175 
176 static void emulated_push_error(EmulatedState *card, uint64_t code)
177 {
178     EmulEvent *event = g_new(EmulEvent, 1);
179 
180     assert(event);
181     event->p.error.type = EMUL_ERROR;
182     event->p.error.code = code;
183     emulated_push_event(card, event);
184 }
185 
186 static void emulated_push_data_type(EmulatedState *card, uint32_t type,
187     const uint8_t *data, uint32_t len)
188 {
189     EmulEvent *event = (EmulEvent *)g_malloc(sizeof(EmulEvent) + len);
190 
191     assert(event);
192     event->p.data.type = type;
193     event->p.data.len = len;
194     memcpy(event->p.data.data, data, len);
195     emulated_push_event(card, event);
196 }
197 
198 static void emulated_push_reader_insert(EmulatedState *card)
199 {
200     emulated_push_type(card, EMUL_READER_INSERT);
201 }
202 
203 static void emulated_push_reader_remove(EmulatedState *card)
204 {
205     emulated_push_type(card, EMUL_READER_REMOVE);
206 }
207 
208 static void emulated_push_card_insert(EmulatedState *card,
209     const uint8_t *atr, uint32_t len)
210 {
211     emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
212 }
213 
214 static void emulated_push_card_remove(EmulatedState *card)
215 {
216     emulated_push_type(card, EMUL_CARD_REMOVE);
217 }
218 
219 static void emulated_push_response_apdu(EmulatedState *card,
220     const uint8_t *apdu, uint32_t len)
221 {
222     emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
223 }
224 
225 #define APDU_BUF_SIZE 270
226 static void *handle_apdu_thread(void* arg)
227 {
228     EmulatedState *card = arg;
229     uint8_t recv_data[APDU_BUF_SIZE];
230     int recv_len;
231     VReaderStatus reader_status;
232     EmulEvent *event;
233 
234     while (1) {
235         qemu_mutex_lock(&card->handle_apdu_mutex);
236         qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
237         qemu_mutex_unlock(&card->handle_apdu_mutex);
238         if (card->quit_apdu_thread) {
239             card->quit_apdu_thread = 0; /* debugging */
240             break;
241         }
242         qemu_mutex_lock(&card->vreader_mutex);
243         while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
244             event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
245             assert((unsigned long)event > 1000);
246             QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
247             if (event->p.data.type != EMUL_GUEST_APDU) {
248                 DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
249                 g_free(event);
250                 continue;
251             }
252             if (card->reader == NULL) {
253                 DPRINTF(card, 1, "reader is NULL\n");
254                 g_free(event);
255                 continue;
256             }
257             recv_len = sizeof(recv_data);
258             reader_status = vreader_xfr_bytes(card->reader,
259                     event->p.data.data, event->p.data.len,
260                     recv_data, &recv_len);
261             DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
262             if (reader_status == VREADER_OK) {
263                 emulated_push_response_apdu(card, recv_data, recv_len);
264             } else {
265                 emulated_push_error(card, reader_status);
266             }
267             g_free(event);
268         }
269         qemu_mutex_unlock(&card->vreader_mutex);
270     }
271     return NULL;
272 }
273 
274 static void *event_thread(void *arg)
275 {
276     int atr_len = MAX_ATR_SIZE;
277     uint8_t atr[MAX_ATR_SIZE];
278     VEvent *event = NULL;
279     EmulatedState *card = arg;
280 
281     while (1) {
282         const char *reader_name;
283 
284         event = vevent_wait_next_vevent();
285         if (event == NULL || event->type == VEVENT_LAST) {
286             break;
287         }
288         if (event->type != VEVENT_READER_INSERT) {
289             if (card->reader == NULL && event->reader != NULL) {
290                 /* Happens after device_add followed by card remove or insert.
291                  * XXX: create synthetic add_reader events if vcard_emul_init
292                  * already called, which happens if device_del and device_add
293                  * are called */
294                 card->reader = vreader_reference(event->reader);
295             } else {
296                 if (event->reader != card->reader) {
297                     fprintf(stderr,
298                         "ERROR: wrong reader: quiting event_thread\n");
299                     break;
300                 }
301             }
302         }
303         switch (event->type) {
304         case VEVENT_READER_INSERT:
305             /* TODO: take a specific reader. i.e. track which reader
306              * we are seeing here, check it is the one we want (the first,
307              * or by a particular name), and ignore if we don't want it.
308              */
309             reader_name = vreader_get_name(event->reader);
310             if (card->reader != NULL) {
311                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
312                     vreader_get_name(card->reader), reader_name);
313                 qemu_mutex_lock(&card->vreader_mutex);
314                 vreader_free(card->reader);
315                 qemu_mutex_unlock(&card->vreader_mutex);
316                 emulated_push_reader_remove(card);
317             }
318             qemu_mutex_lock(&card->vreader_mutex);
319             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
320             card->reader = vreader_reference(event->reader);
321             qemu_mutex_unlock(&card->vreader_mutex);
322             emulated_push_reader_insert(card);
323             break;
324         case VEVENT_READER_REMOVE:
325             DPRINTF(card, 2, " READER REMOVE: %s\n",
326                     vreader_get_name(event->reader));
327             qemu_mutex_lock(&card->vreader_mutex);
328             vreader_free(card->reader);
329             card->reader = NULL;
330             qemu_mutex_unlock(&card->vreader_mutex);
331             emulated_push_reader_remove(card);
332             break;
333         case VEVENT_CARD_INSERT:
334             /* get the ATR (intended as a response to a power on from the
335              * reader */
336             atr_len = MAX_ATR_SIZE;
337             vreader_power_on(event->reader, atr, &atr_len);
338             card->atr_length = (uint8_t)atr_len;
339             DPRINTF(card, 2, " CARD INSERT\n");
340             emulated_push_card_insert(card, atr, atr_len);
341             break;
342         case VEVENT_CARD_REMOVE:
343             DPRINTF(card, 2, " CARD REMOVE\n");
344             emulated_push_card_remove(card);
345             break;
346         case VEVENT_LAST: /* quit */
347             vevent_delete(event);
348             return NULL;
349             break;
350         default:
351             break;
352         }
353         vevent_delete(event);
354     }
355     return NULL;
356 }
357 
358 static void card_event_handler(EventNotifier *notifier)
359 {
360     EmulatedState *card = container_of(notifier, EmulatedState, notifier);
361     EmulEvent *event, *next;
362 
363     event_notifier_test_and_clear(&card->notifier);
364     qemu_mutex_lock(&card->event_list_mutex);
365     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
366         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
367         switch (event->p.gen.type) {
368         case EMUL_RESPONSE_APDU:
369             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
370                 event->p.data.len);
371             break;
372         case EMUL_READER_INSERT:
373             ccid_card_ccid_attach(&card->base);
374             break;
375         case EMUL_READER_REMOVE:
376             ccid_card_ccid_detach(&card->base);
377             break;
378         case EMUL_CARD_INSERT:
379             assert(event->p.data.len <= MAX_ATR_SIZE);
380             card->atr_length = event->p.data.len;
381             memcpy(card->atr, event->p.data.data, card->atr_length);
382             ccid_card_card_inserted(&card->base);
383             break;
384         case EMUL_CARD_REMOVE:
385             ccid_card_card_removed(&card->base);
386             break;
387         case EMUL_ERROR:
388             ccid_card_card_error(&card->base, event->p.error.code);
389             break;
390         default:
391             DPRINTF(card, 2, "unexpected event\n");
392             break;
393         }
394         g_free(event);
395     }
396     QSIMPLEQ_INIT(&card->event_list);
397     qemu_mutex_unlock(&card->event_list_mutex);
398 }
399 
400 static int init_event_notifier(EmulatedState *card)
401 {
402     if (event_notifier_init(&card->notifier, false) < 0) {
403         DPRINTF(card, 2, "event notifier creation failed\n");
404         return -1;
405     }
406     event_notifier_set_handler(&card->notifier, card_event_handler);
407     return 0;
408 }
409 
410 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
411 #define CERTIFICATES_ARGS_TEMPLATE\
412     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
413 
414 static int wrap_vcard_emul_init(VCardEmulOptions *options)
415 {
416     static int called;
417     static int options_was_null;
418 
419     if (called) {
420         if ((options == NULL) != options_was_null) {
421             printf("%s: warning: running emulated with certificates"
422                    " and emulated side by side is not supported\n",
423                    __func__);
424             return VCARD_EMUL_FAIL;
425         }
426         vcard_emul_replay_insertion_events();
427         return VCARD_EMUL_OK;
428     }
429     options_was_null = (options == NULL);
430     called = 1;
431     return vcard_emul_init(options);
432 }
433 
434 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
435 {
436     char emul_args[200];
437     VCardEmulOptions *options = NULL;
438 
439     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
440         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
441         card->cert1, card->cert2, card->cert3);
442     options = vcard_emul_options(emul_args);
443     if (options == NULL) {
444         printf("%s: warning: not using certificates due to"
445                " initialization error\n", __func__);
446     }
447     return wrap_vcard_emul_init(options);
448 }
449 
450 typedef struct EnumTable {
451     const char *name;
452     uint32_t value;
453 } EnumTable;
454 
455 static const EnumTable backend_enum_table[] = {
456     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
457     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
458     {NULL, 0},
459 };
460 
461 static uint32_t parse_enumeration(char *str,
462     const EnumTable *table, uint32_t not_found_value)
463 {
464     uint32_t ret = not_found_value;
465 
466     if (str == NULL)
467         return 0;
468 
469     while (table->name != NULL) {
470         if (strcmp(table->name, str) == 0) {
471             ret = table->value;
472             break;
473         }
474         table++;
475     }
476     return ret;
477 }
478 
479 static int emulated_initfn(CCIDCardState *base)
480 {
481     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
482     VCardEmulError ret;
483     const EnumTable *ptable;
484 
485     QSIMPLEQ_INIT(&card->event_list);
486     QSIMPLEQ_INIT(&card->guest_apdu_list);
487     qemu_mutex_init(&card->event_list_mutex);
488     qemu_mutex_init(&card->vreader_mutex);
489     qemu_mutex_init(&card->handle_apdu_mutex);
490     qemu_cond_init(&card->handle_apdu_cond);
491     card->reader = NULL;
492     card->quit_apdu_thread = 0;
493     if (init_event_notifier(card) < 0) {
494         return -1;
495     }
496 
497     card->backend = 0;
498     if (card->backend_str) {
499         card->backend = parse_enumeration(card->backend_str,
500                                           backend_enum_table, 0);
501     }
502 
503     if (card->backend == 0) {
504         printf("backend must be one of:\n");
505         for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
506             printf("%s\n", ptable->name);
507         }
508         return -1;
509     }
510 
511     /* TODO: a passthru backened that works on local machine. third card type?*/
512     if (card->backend == BACKEND_CERTIFICATES) {
513         if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
514             ret = emulated_initialize_vcard_from_certificates(card);
515         } else {
516             printf("%s: you must provide all three certs for"
517                    " certificates backend\n", EMULATED_DEV_NAME);
518             return -1;
519         }
520     } else {
521         if (card->backend != BACKEND_NSS_EMULATED) {
522             printf("%s: bad backend specified. The options are:\n%s (default),"
523                 " %s.\n", EMULATED_DEV_NAME, BACKEND_NSS_EMULATED_NAME,
524                 BACKEND_CERTIFICATES_NAME);
525             return -1;
526         }
527         if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
528             printf("%s: unexpected cert parameters to nss emulated backend\n",
529                    EMULATED_DEV_NAME);
530             return -1;
531         }
532         /* default to mirroring the local hardware readers */
533         ret = wrap_vcard_emul_init(NULL);
534     }
535     if (ret != VCARD_EMUL_OK) {
536         printf("%s: failed to initialize vcard\n", EMULATED_DEV_NAME);
537         return -1;
538     }
539     qemu_thread_create(&card->event_thread_id, "ccid/event", event_thread,
540                        card, QEMU_THREAD_JOINABLE);
541     qemu_thread_create(&card->apdu_thread_id, "ccid/apdu", handle_apdu_thread,
542                        card, QEMU_THREAD_JOINABLE);
543     return 0;
544 }
545 
546 static int emulated_exitfn(CCIDCardState *base)
547 {
548     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
549     VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
550 
551     vevent_queue_vevent(vevent); /* stop vevent thread */
552     qemu_thread_join(&card->event_thread_id);
553 
554     card->quit_apdu_thread = 1; /* stop handle_apdu thread */
555     qemu_cond_signal(&card->handle_apdu_cond);
556     qemu_thread_join(&card->apdu_thread_id);
557 
558     /* threads exited, can destroy all condvars/mutexes */
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     return 0;
564 }
565 
566 static Property emulated_card_properties[] = {
567     DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
568     DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
569     DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
570     DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
571     DEFINE_PROP_STRING("db", EmulatedState, db),
572     DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
573     DEFINE_PROP_END_OF_LIST(),
574 };
575 
576 static void emulated_class_initfn(ObjectClass *klass, void *data)
577 {
578     DeviceClass *dc = DEVICE_CLASS(klass);
579     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
580 
581     cc->initfn = emulated_initfn;
582     cc->exitfn = emulated_exitfn;
583     cc->get_atr = emulated_get_atr;
584     cc->apdu_from_guest = emulated_apdu_from_guest;
585     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
586     dc->desc = "emulated smartcard";
587     dc->props = emulated_card_properties;
588 }
589 
590 static const TypeInfo emulated_card_info = {
591     .name          = EMULATED_DEV_NAME,
592     .parent        = TYPE_CCID_CARD,
593     .instance_size = sizeof(EmulatedState),
594     .class_init    = emulated_class_initfn,
595 };
596 
597 static void ccid_card_emulated_register_types(void)
598 {
599     type_register_static(&emulated_card_info);
600 }
601 
602 type_init(ccid_card_emulated_register_types)
603