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 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 "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     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     int      pipe[2];
 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     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 *)g_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 *)g_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 *)g_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                 g_free(event);
 253                 continue;
 254             }
 255             if (card->reader == NULL) {
 256                 DPRINTF(card, 1, "reader is NULL\n");
 257                 g_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             g_free(event);
 271         }
 272         qemu_mutex_unlock(&card->vreader_mutex);
 273     }
 274     return NULL;
 275 }
 276
 277 static void *event_thread(void *arg)
 278 {
 279     int atr_len = MAX_ATR_SIZE;
 280     uint8_t atr[MAX_ATR_SIZE];
 281     VEvent *event = NULL;
 282     EmulatedState *card = arg;
 283
 284     while (1) {
 285         const char *reader_name;
 286
 287         event = vevent_wait_next_vevent();
 288         if (event == NULL || event->type == VEVENT_LAST) {
 289             break;
 290         }
 291         if (event->type != VEVENT_READER_INSERT) {
 292             if (card->reader == NULL && event->reader != NULL) {
 293                 /* Happens after device_add followed by card remove or insert.
 294                  * XXX: create synthetic add_reader events if vcard_emul_init
 295                  * already called, which happens if device_del and device_add
 296                  * are called */
 297                 card->reader = vreader_reference(event->reader);
 298             } else {
 299                 if (event->reader != card->reader) {
 300                     fprintf(stderr,
 301                         "ERROR: wrong reader: quiting event_thread\n");
 302                     break;
 303                 }
 304             }
 305         }
 306         switch (event->type) {
 307         case VEVENT_READER_INSERT:
 308             /* TODO: take a specific reader. i.e. track which reader
 309              * we are seeing here, check it is the one we want (the first,
 310              * or by a particular name), and ignore if we don't want it.
 311              */
 312             reader_name = vreader_get_name(event->reader);
 313             if (card->reader != NULL) {
 314                 DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
 315                     vreader_get_name(card->reader), reader_name);
 316                 qemu_mutex_lock(&card->vreader_mutex);
 317                 vreader_free(card->reader);
 318                 qemu_mutex_unlock(&card->vreader_mutex);
 319                 emulated_push_reader_remove(card);
 320             }
 321             qemu_mutex_lock(&card->vreader_mutex);
 322             DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
 323             card->reader = vreader_reference(event->reader);
 324             qemu_mutex_unlock(&card->vreader_mutex);
 325             emulated_push_reader_insert(card);
 326             break;
 327         case VEVENT_READER_REMOVE:
 328             DPRINTF(card, 2, " READER REMOVE: %s\n",
 329                     vreader_get_name(event->reader));
 330             qemu_mutex_lock(&card->vreader_mutex);
 331             vreader_free(card->reader);
 332             card->reader = NULL;
 333             qemu_mutex_unlock(&card->vreader_mutex);
 334             emulated_push_reader_remove(card);
 335             break;
 336         case VEVENT_CARD_INSERT:
 337             /* get the ATR (intended as a response to a power on from the
 338              * reader */
 339             atr_len = MAX_ATR_SIZE;
 340             vreader_power_on(event->reader, atr, &atr_len);
 341             card->atr_length = (uint8_t)atr_len;
 342             DPRINTF(card, 2, " CARD INSERT\n");
 343             emulated_push_card_insert(card, atr, atr_len);
 344             break;
 345         case VEVENT_CARD_REMOVE:
 346             DPRINTF(card, 2, " CARD REMOVE\n");
 347             emulated_push_card_remove(card);
 348             break;
 349         case VEVENT_LAST: /* quit */
 350             vevent_delete(event);
 351             return NULL;
 352             break;
 353         default:
 354             break;
 355         }
 356         vevent_delete(event);
 357     }
 358     return NULL;
 359 }
 360
 361 static void pipe_read(void *opaque)
 362 {
 363     EmulatedState *card = opaque;
 364     EmulEvent *event, *next;
 365     char dummy;
 366     int len;
 367
 368     do {
 369         len = read(card->pipe[0], &dummy, sizeof(dummy));
 370     } while (len == sizeof(dummy));
 371     qemu_mutex_lock(&card->event_list_mutex);
 372     QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
 373         DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
 374         switch (event->p.gen.type) {
 375         case EMUL_RESPONSE_APDU:
 376             ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
 377                 event->p.data.len);
 378             break;
 379         case EMUL_READER_INSERT:
 380             ccid_card_ccid_attach(&card->base);
 381             break;
 382         case EMUL_READER_REMOVE:
 383             ccid_card_ccid_detach(&card->base);
 384             break;
 385         case EMUL_CARD_INSERT:
 386             assert(event->p.data.len <= MAX_ATR_SIZE);
 387             card->atr_length = event->p.data.len;
 388             memcpy(card->atr, event->p.data.data, card->atr_length);
 389             ccid_card_card_inserted(&card->base);
 390             break;
 391         case EMUL_CARD_REMOVE:
 392             ccid_card_card_removed(&card->base);
 393             break;
 394         case EMUL_ERROR:
 395             ccid_card_card_error(&card->base, event->p.error.code);
 396             break;
 397         default:
 398             DPRINTF(card, 2, "unexpected event\n");
 399             break;
 400         }
 401         g_free(event);
 402     }
 403     QSIMPLEQ_INIT(&card->event_list);
 404     qemu_mutex_unlock(&card->event_list_mutex);
 405 }
 406
 407 static int init_pipe_signaling(EmulatedState *card)
 408 {
 409     if (pipe(card->pipe) < 0) {
 410         DPRINTF(card, 2, "pipe creation failed\n");
 411         return -1;
 412     }
 413     fcntl(card->pipe[0], F_SETFL, O_NONBLOCK);
 414     fcntl(card->pipe[1], F_SETFL, O_NONBLOCK);
 415     fcntl(card->pipe[0], F_SETOWN, getpid());
 416     qemu_set_fd_handler(card->pipe[0], pipe_read, NULL, card);
 417     return 0;
 418 }
 419
 420 #define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
 421 #define CERTIFICATES_ARGS_TEMPLATE\
 422     "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
 423
 424 static int wrap_vcard_emul_init(VCardEmulOptions *options)
 425 {
 426     static int called;
 427     static int options_was_null;
 428
 429     if (called) {
 430         if ((options == NULL) != options_was_null) {
 431             printf("%s: warning: running emulated with certificates"
 432                    " and emulated side by side is not supported\n",
 433                    __func__);
 434             return VCARD_EMUL_FAIL;
 435         }
 436         vcard_emul_replay_insertion_events();
 437         return VCARD_EMUL_OK;
 438     }
 439     options_was_null = (options == NULL);
 440     called = 1;
 441     return vcard_emul_init(options);
 442 }
 443
 444 static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
 445 {
 446     char emul_args[200];
 447     VCardEmulOptions *options = NULL;
 448
 449     snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
 450         card->db ? card->db : CERTIFICATES_DEFAULT_DB,
 451         card->cert1, card->cert2, card->cert3);
 452     options = vcard_emul_options(emul_args);
 453     if (options == NULL) {
 454         printf("%s: warning: not using certificates due to"
 455                " initialization error\n", __func__);
 456     }
 457     return wrap_vcard_emul_init(options);
 458 }
 459
 460 typedef struct EnumTable {
 461     const char *name;
 462     uint32_t value;
 463 } EnumTable;
 464
 465 EnumTable backend_enum_table[] = {
 466     {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
 467     {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
 468     {NULL, 0},
 469 };
 470
 471 static uint32_t parse_enumeration(char *str,
 472     EnumTable *table, uint32_t not_found_value)
 473 {
 474     uint32_t ret = not_found_value;
 475
 476     while (table->name != NULL) {
 477         if (strcmp(table->name, str) == 0) {
 478             ret = table->value;
 479             break;
 480         }
 481         table++;
 482     }
 483     return ret;
 484 }
 485
 486 static int emulated_initfn(CCIDCardState *base)
 487 {
 488     EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
 489     VCardEmulError ret;
 490     EnumTable *ptable;
 491
 492     QSIMPLEQ_INIT(&card->event_list);
 493     QSIMPLEQ_INIT(&card->guest_apdu_list);
 494     qemu_mutex_init(&card->event_list_mutex);
 495     qemu_mutex_init(&card->vreader_mutex);
 496     qemu_mutex_init(&card->handle_apdu_mutex);
 497     qemu_cond_init(&card->handle_apdu_cond);
 498     card->reader = NULL;
 499     card->quit_apdu_thread = 0;
 500     if (init_pipe_signaling(card) < 0) {
 501         return -1;
 502     }
 503     card->backend = parse_enumeration(card->backend_str, backend_enum_table, 0);
 504     if (card->backend == 0) {
 505         printf("unknown 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, event_thread, card,
 541                        QEMU_THREAD_JOINABLE);
 542     qemu_thread_create(&card->apdu_thread_id, handle_apdu_thread, card,
 543                        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 CCIDCardInfo emulated_card_info = {
 568     .qdev.name = EMULATED_DEV_NAME,
 569     .qdev.desc = "emulated smartcard",
 570     .qdev.size = sizeof(EmulatedState),
 571     .initfn = emulated_initfn,
 572     .exitfn = emulated_exitfn,
 573     .get_atr = emulated_get_atr,
 574     .apdu_from_guest = emulated_apdu_from_guest,
 575     .qdev.unplug    = qdev_simple_unplug_cb,
 576     .qdev.props     = (Property[]) {
 577         DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
 578         DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
 579         DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
 580         DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
 581         DEFINE_PROP_STRING("db", EmulatedState, db),
 582         DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
 583         DEFINE_PROP_END_OF_LIST(),
 584     },
 585 };
 586
 587 static void ccid_card_emulated_register_devices(void)
 588 {
 589     ccid_card_qdev_register(&emulated_card_info);
 590 }
 591
 592 device_init(ccid_card_emulated_register_devices)