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 "monitor/monitor.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 = (EmulEvent *)g_malloc(sizeof(EmulEvent));
 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 = (EmulEvent *)g_malloc(sizeof(EmulEvent));
 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)