hw/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 licenced 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 "qemu-char.h"
  36 #include "monitor.h"
  37 #include "hw/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     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     int      pipe[2];
 129     int      quit_apdu_thread;
 130     QemuMutex apdu_thread_quit_mutex;
 131     QemuCond apdu_thread_quit_cond;
 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 *)qemu_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     if (write(card->pipe[1], card, 1) != 1) {
 166         DPRINTF(card, 1, "write to pipe failed\n");
 167     }
 168 }
 169
 170 static void emulated_push_type(EmulatedState *card, uint32_t type)
 171 {
 172     EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent));
 173
 174     assert(event);
 175     event->p.gen.type = type;
 176     emulated_push_event(card, event);
 177 }
 178
 179 static void emulated_push_error(EmulatedState *card, uint64_t code)
 180 {
 181     EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent));
 182
 183     assert(event);
 184     event->p.error.type = EMUL_ERROR;
 185     event->p.error.code = code;
 186     emulated_push_event(card, event);
 187 }
 188
 189 static void emulated_push_data_type(EmulatedState *card, uint32_t type,
 190     const uint8_t *data, uint32_t len)
 191 {
 192     EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent) + len);
 193
 194     assert(event);
 195     event->p.data.type = type;
 196     event->p.data.len = len;
 197     memcpy(event->p.data.data, data, len);
 198     emulated_push_event(card, event);
 199 }
 200
 201 static void emulated_push_reader_insert(EmulatedState *card)
 202 {
 203     emulated_push_type(card, EMUL_READER_INSERT);
 204 }
 205
 206 static void emulated_push_reader_remove(EmulatedState *card)
 207 {
 208     emulated_push_type(card, EMUL_READER_REMOVE);
 209 }
 210
 211 static void emulated_push_card_insert(EmulatedState *card,
 212     const uint8_t *atr, uint32_t len)
 213 {
 214     emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
 215 }
 216
 217 static void emulated_push_card_remove(EmulatedState *card)
 218 {
 219     emulated_push_type(card, EMUL_CARD_REMOVE);
 220 }
 221
 222 static void emulated_push_response_apdu(EmulatedState *card,
 223     const uint8_t *apdu, uint32_t len)
 224 {
 225     emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
 226 }
 227
 228 #define APDU_BUF_SIZE 270
 229 static void *handle_apdu_thread(void* arg)
 230 {
 231     EmulatedState *card = arg;
 232     uint8_t recv_data[APDU_BUF_SIZE];
 233     int recv_len;
 234     VReaderStatus reader_status;
 235     EmulEvent *event;
 236
 237     while (1) {
 238         qemu_mutex_lock(&card->handle_apdu_mutex);
 239         qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
 240         qemu_mutex_unlock(&card->handle_apdu_mutex);
 241         if (card->quit_apdu_thread) {
 242             card->quit_apdu_thread = 0; /* debugging */
 243             break;
 244         }
 245         qemu_mutex_lock(&card->vreader_mutex);
 246         while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
 247             event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
 248             assert((unsigned long)event > 1000);
 249             QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
 250             if (event->p.data.type != EMUL_GUEST_APDU) {
 251                 DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
 252                 qemu_free(event);
 253                 continue;
 254             }
 255             if (card->reader == NULL) {
 256                 DPRINTF(card, 1, "reader is NULL\n");
 257                 qemu_free(event);
 258                 continue;
 259             }
 260             recv_len = sizeof(recv_data);
 261             reader_status = vreader_xfr_bytes(card->reader,
 262                     event->p.data.data, event->p.data.len,
 263                     recv_data, &recv_len);
 264             DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
 265             if (reader_status == VREADER_OK) {
 266                 emulated_push_response_apdu(card, recv_data, recv_len);
 267             } else {
 268                 emulated_push_error(card, reader_status);
 269             }
 270             qemu_free(event);
 271         }
 272         qemu_mutex_unlock(&card->vreader_mutex);
 273     }
 274     qemu_mutex_lock(&card->apdu_thread_quit_mutex);
 275     qemu_cond_signal(&card->apdu_thread_quit_cond);
 276     qemu_mutex_unlock(&card->apdu_thread_quit_mutex);
 277     return NULL;
 278 }
 279
 280 static void *event_thread(void *arg)
 281 {
 282     int atr_len = MAX_ATR_SIZE;
 283     uint8_t atr[MAX_ATR_SIZE];
 284     VEvent *event = NULL;
 285     EmulatedState *card = arg;
 286
 287     while (1) {
 288         const char *reader_name;
 289
 290         event = vevent_wait_next_vevent();
 291         if (event == NULL || event->type == VEVENT_LAST) {
 292             break;
 293         }
 294         if (event->type != VEVENT_READER_INSERT) {
 295             if (card->reader == NULL && event->reader != NULL) {
 296                 /* Happens after device_add followed by card remove or insert.
 297                  * XXX: create synthetic add_reader events if vcard_emul_init
 298                  * already called, which happens if device_del and device_add
 299                  * are called */
 300                 card->reader = vreader_reference(event->reader);
 301             } else {
 302                 if (event->reader != card->reader) {
 303                     fprintf(stderr,
 304                         "ERROR: wrong reader: quiting event_thread\n");
 305                     break;
 306                 }
 307             }
 308         }
 309         switch (event->type) {
 310         case VEVENT_READER_INSERT:
 311             /* TODO: take a specific reader. i.e. track which reader
 312              * we are seeing here, check it is the one we want (the first,
 313              * or by a particular name), and ignore if we don't want it.
 314              */
 315             reader_name = vreader_get_name(event->reader);
 316             if (card->reader != NULL) {
 317                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
 318                     vreader_get_name(card->reader), reader_name);
 319                 qemu_mutex_lock(&card->vreader_mutex);
 320                 vreader_free(card->reader);
 321                 qemu_mutex_unlock(&card->vreader_mutex);
 322                 emulated_push_reader_remove(card);
 323             }
 324             qemu_mutex_lock(&card->vreader_mutex);
 325             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
 326             card->reader = vreader_reference(event->reader);
 327             qemu_mutex_unlock(&card->vreader_mutex);
 328             emulated_push_reader_insert(card);
 329             break;
 330         case VEVENT_READER_REMOVE:
 331             DPRINTF(card, 2, " READER REMOVE: %s\n",
 332                     vreader_get_name(event->reader));
 333             qemu_mutex_lock(&card->vreader_mutex);
 334             vreader_free(card->reader);
 335             card->reader = NULL;
 336             qemu_mutex_unlock(&card->vreader_mutex);
 337             emulated_push_reader_remove(card);
 338             break;
 339         case VEVENT_CARD_INSERT:
 340             /* get the ATR (intended as a response to a power on from the
 341              * reader */
 342             atr_len = MAX_ATR_SIZE;
 343             vreader_power_on(event->reader, atr, &atr_len);
 344             card->atr_length = (uint8_t)atr_len;
 345             DPRINTF(card, 2, " CARD INSERT\n");
 346             emulated_push_card_insert(card, atr, atr_len);
 347             break;
 348         case VEVENT_CARD_REMOVE:
 349             DPRINTF(card, 2, " CARD REMOVE\n");
 350             emulated_push_card_remove(card);
 351             break;
 352         case VEVENT_LAST: /* quit */
 353             vevent_delete(event);
 354             return NULL;
 355             break;
 356         default:
 357             break;
 358         }
 359         vevent_delete(event);
 360     }
 361     return NULL;
 362 }
 363
 364 static void pipe_read(void *opaque)
 365 {
 366     EmulatedState *card = opaque;
 367     EmulEvent *event, *next;
 368     char dummy;
 369     int len;
 370
 371     do {
 372         len = read(card->pipe[0], &dummy, sizeof(dummy));
 373     } while (len == sizeof(dummy));
 374     qemu_mutex_lock(&card->event_list_mutex);
 375     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
 376         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
 377         switch (event->p.gen.type) {
 378         case EMUL_RESPONSE_APDU:
 379             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
 380                 event->p.data.len);
 381             break;
 382         case EMUL_READER_INSERT:
 383             ccid_card_ccid_attach(&card->base);
 384             break;
 385         case EMUL_READER_REMOVE:
 386             ccid_card_ccid_detach(&card->base);
 387             break;
 388         case EMUL_CARD_INSERT:
 389             assert(event->p.data.len <= MAX_ATR_SIZE);
 390             card->atr_length = event->p.data.len;
 391             memcpy(card->atr, event->p.data.data, card->atr_length);
 392             ccid_card_card_inserted(&card->base);
 393             break;
 394         case EMUL_CARD_REMOVE:
 395             ccid_card_card_removed(&card->base);
 396             break;
 397         case EMUL_ERROR:
 398             ccid_card_card_error(&card->base, event->p.error.code);
 399             break;
 400         default:
 401             DPRINTF(card, 2, "unexpected event\n");
 402             break;
 403         }
 404         qemu_free(event);
 405     }
 406     QSIMPLEQ_INIT(&card->event_list);
 407     qemu_mutex_unlock(&card->event_list_mutex);
 408 }
 409
 410 static int init_pipe_signaling(EmulatedState *card)
 411 {
 412     if (pipe(card->pipe) < 0) {
 413         DPRINTF(card, 2, "pipe creation failed\n");
 414         return -1;
 415     }
 416     fcntl(card->pipe[0], F_SETFL, O_NONBLOCK);
 417     fcntl(card->pipe[1], F_SETFL, O_NONBLOCK);
 418     fcntl(card->pipe[0], F_SETOWN, getpid());
 419     qemu_set_fd_handler(card->pipe[0], pipe_read, NULL, card);
 420     return 0;
 421 }
 422
 423 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
 424 #define CERTIFICATES_ARGS_TEMPLATE\
 425     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
 426
 427 static int wrap_vcard_emul_init(VCardEmulOptions *options)
 428 {
 429     static int called;
 430     static int options_was_null;
 431
 432     if (called) {
 433         if ((options == NULL) != options_was_null) {
 434             printf("%s: warning: running emulated with certificates"
 435                    " and emulated side by side is not supported\n",
 436                    __func__);
 437             return VCARD_EMUL_FAIL;
 438         }
 439         vcard_emul_replay_insertion_events();
 440         return VCARD_EMUL_OK;
 441     }
 442     options_was_null = (options == NULL);
 443     called = 1;
 444     return vcard_emul_init(options);
 445 }
 446
 447 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
 448 {
 449     char emul_args[200];
 450     VCardEmulOptions *options = NULL;
 451
 452     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
 453         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
 454         card->cert1, card->cert2, card->cert3);
 455     options = vcard_emul_options(emul_args);
 456     if (options == NULL) {
 457         printf("%s: warning: not using certificates due to"
 458                " initialization error\n", __func__);
 459     }
 460     return wrap_vcard_emul_init(options);
 461 }
 462
 463 typedef struct EnumTable {
 464     const char *name;
 465     uint32_t value;
 466 } EnumTable;
 467
 468 EnumTable backend_enum_table[] = {
 469     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
 470     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
 471     {NULL, 0},
 472 };
 473
 474 static uint32_t parse_enumeration(char *str,
 475     EnumTable *table, uint32_t not_found_value)
 476 {
 477     uint32_t ret = not_found_value;
 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 int emulated_initfn(CCIDCardState *base)
 490 {
 491     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
 492     QemuThread thread_id;
 493     VCardEmulError ret;
 494     EnumTable *ptable;
 495
 496     QSIMPLEQ_INIT(&card->event_list);
 497     QSIMPLEQ_INIT(&card->guest_apdu_list);
 498     qemu_mutex_init(&card->event_list_mutex);
 499     qemu_mutex_init(&card->vreader_mutex);
 500     qemu_mutex_init(&card->handle_apdu_mutex);
 501     qemu_cond_init(&card->handle_apdu_cond);
 502     card->reader = NULL;
 503     card->quit_apdu_thread = 0;
 504     if (init_pipe_signaling(card) < 0) {
 505         return -1;
 506     }
 507     card->backend = parse_enumeration(card->backend_str, backend_enum_table, 0);
 508     if (card->backend == 0) {
 509         printf("unknown backend, must be one of:\n");
 510         for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
 511             printf("%s\n", ptable->name);
 512         }
 513         return -1;
 514     }
 515
 516     /* TODO: a passthru backened that works on local machine. third card type?*/
 517     if (card->backend == BACKEND_CERTIFICATES) {
 518         if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
 519             ret = emulated_initialize_vcard_from_certificates(card);
 520         } else {
 521             printf("%s: you must provide all three certs for"
 522                    " certificates backend\n", EMULATED_DEV_NAME);
 523             return -1;
 524         }
 525     } else {
 526         if (card->backend != BACKEND_NSS_EMULATED) {
 527             printf("%s: bad backend specified. The options are:\n%s (default),"
 528                 " %s.\n", EMULATED_DEV_NAME, BACKEND_NSS_EMULATED_NAME,
 529                 BACKEND_CERTIFICATES_NAME);
 530             return -1;
 531         }
 532         if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
 533             printf("%s: unexpected cert parameters to nss emulated backend\n",
 534                    EMULATED_DEV_NAME);
 535             return -1;
 536         }
 537         /* default to mirroring the local hardware readers */
 538         ret = wrap_vcard_emul_init(NULL);
 539     }
 540     if (ret != VCARD_EMUL_OK) {
 541         printf("%s: failed to initialize vcard\n", EMULATED_DEV_NAME);
 542         return -1;
 543     }
 544     qemu_thread_create(&thread_id, event_thread, card);
 545     qemu_thread_create(&thread_id, handle_apdu_thread, card);
 546     return 0;
 547 }
 548
 549 static int emulated_exitfn(CCIDCardState *base)
 550 {
 551     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
 552     VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
 553
 554     vevent_queue_vevent(vevent); /* stop vevent thread */
 555     qemu_mutex_lock(&card->apdu_thread_quit_mutex);
 556     card->quit_apdu_thread = 1; /* stop handle_apdu thread */
 557     qemu_cond_signal(&card->handle_apdu_cond);
 558     qemu_cond_wait(&card->apdu_thread_quit_cond,
 559                       &card->apdu_thread_quit_mutex);
 560     /* handle_apdu thread stopped, can destroy all of it's mutexes */
 561     qemu_cond_destroy(&card->handle_apdu_cond);
 562     qemu_cond_destroy(&card->apdu_thread_quit_cond);
 563     qemu_mutex_destroy(&card->apdu_thread_quit_mutex);
 564     qemu_mutex_destroy(&card->handle_apdu_mutex);
 565     qemu_mutex_destroy(&card->vreader_mutex);
 566     qemu_mutex_destroy(&card->event_list_mutex);
 567     return 0;
 568 }
 569
 570 static CCIDCardInfo emulated_card_info = {
 571     .qdev.name = EMULATED_DEV_NAME,
 572     .qdev.desc = "emulated smartcard",
 573     .qdev.size = sizeof(EmulatedState),
 574     .initfn = emulated_initfn,
 575     .exitfn = emulated_exitfn,
 576     .get_atr = emulated_get_atr,
 577     .apdu_from_guest = emulated_apdu_from_guest,
 578     .qdev.unplug    = qdev_simple_unplug_cb,
 579     .qdev.props     = (Property[]) {
 580         DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
 581         DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
 582         DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
 583         DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
 584         DEFINE_PROP_STRING("db", EmulatedState, db),
 585         DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
 586         DEFINE_PROP_END_OF_LIST(),
 587     },
 588 };
 589
 590 static void ccid_card_emulated_register_devices(void)
 591 {
 592     ccid_card_qdev_register(&emulated_card_info);
 593 }
 594
 595 device_init(ccid_card_emulated_register_devices)