hw/usb/ccid-card-emulated.c

   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)