qemu/hw/usb/ccid-card-emulated.c
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   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, ...) \
  40do {\
  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
  51enum {
  52    BACKEND_NSS_EMULATED = 1,
  53    BACKEND_CERTIFICATES
  54};
  55
  56#define DEFAULT_BACKEND BACKEND_NSS_EMULATED
  57
  58typedef struct EmulatedState EmulatedState;
  59
  60enum {
  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
  70static 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
  91typedef 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
 110struct 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
 134static 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
 152static 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
 160static 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
 170static 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
 179static 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
 189static 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
 201static void emulated_push_reader_insert(EmulatedState *card)
 202{
 203    emulated_push_type(card, EMUL_READER_INSERT);
 204}
 205
 206static void emulated_push_reader_remove(EmulatedState *card)
 207{
 208    emulated_push_type(card, EMUL_READER_REMOVE);
 209}
 210
 211static 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
 217static void emulated_push_card_remove(EmulatedState *card)
 218{
 219    emulated_push_type(card, EMUL_CARD_REMOVE);
 220}
 221
 222static 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
 229static 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
 277static 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
 361static 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
 407static 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
 424static 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
 444static 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
 460typedef struct EnumTable {
 461    const char *name;
 462    uint32_t value;
 463} EnumTable;
 464
 465static const EnumTable backend_enum_table[] = {
 466    {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
 467    {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
 468    {NULL, 0},
 469};
 470
 471static uint32_t parse_enumeration(char *str,
 472    const EnumTable *table, uint32_t not_found_value)
 473{
 474    uint32_t ret = not_found_value;
 475
 476    if (str == NULL)
 477        return 0;
 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
 489static int emulated_initfn(CCIDCardState *base)
 490{
 491    EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
 492    VCardEmulError ret;
 493    const EnumTable *ptable;
 494
 495    QSIMPLEQ_INIT(&card->event_list);
 496    QSIMPLEQ_INIT(&card->guest_apdu_list);
 497    qemu_mutex_init(&card->event_list_mutex);
 498    qemu_mutex_init(&card->vreader_mutex);
 499    qemu_mutex_init(&card->handle_apdu_mutex);
 500    qemu_cond_init(&card->handle_apdu_cond);
 501    card->reader = NULL;
 502    card->quit_apdu_thread = 0;
 503    if (init_pipe_signaling(card) < 0) {
 504        return -1;
 505    }
 506
 507    card->backend = 0;
 508    if (card->backend_str) {
 509        card->backend = parse_enumeration(card->backend_str,
 510                                          backend_enum_table, 0);
 511    }
 512
 513    if (card->backend == 0) {
 514        printf("backend must be one of:\n");
 515        for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
 516            printf("%s\n", ptable->name);
 517        }
 518        return -1;
 519    }
 520
 521    /* TODO: a passthru backened that works on local machine. third card type?*/
 522    if (card->backend == BACKEND_CERTIFICATES) {
 523        if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
 524            ret = emulated_initialize_vcard_from_certificates(card);
 525        } else {
 526            printf("%s: you must provide all three certs for"
 527                   " certificates backend\n", EMULATED_DEV_NAME);
 528            return -1;
 529        }
 530    } else {
 531        if (card->backend != BACKEND_NSS_EMULATED) {
 532            printf("%s: bad backend specified. The options are:\n%s (default),"
 533                " %s.\n", EMULATED_DEV_NAME, BACKEND_NSS_EMULATED_NAME,
 534                BACKEND_CERTIFICATES_NAME);
 535            return -1;
 536        }
 537        if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
 538            printf("%s: unexpected cert parameters to nss emulated backend\n",
 539                   EMULATED_DEV_NAME);
 540            return -1;
 541        }
 542        /* default to mirroring the local hardware readers */
 543        ret = wrap_vcard_emul_init(NULL);
 544    }
 545    if (ret != VCARD_EMUL_OK) {
 546        printf("%s: failed to initialize vcard\n", EMULATED_DEV_NAME);
 547        return -1;
 548    }
 549    qemu_thread_create(&card->event_thread_id, event_thread, card,
 550                       QEMU_THREAD_JOINABLE);
 551    qemu_thread_create(&card->apdu_thread_id, handle_apdu_thread, card,
 552                       QEMU_THREAD_JOINABLE);
 553    return 0;
 554}
 555
 556static int emulated_exitfn(CCIDCardState *base)
 557{
 558    EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
 559    VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
 560
 561    vevent_queue_vevent(vevent); /* stop vevent thread */
 562    qemu_thread_join(&card->event_thread_id);
 563
 564    card->quit_apdu_thread = 1; /* stop handle_apdu thread */
 565    qemu_cond_signal(&card->handle_apdu_cond);
 566    qemu_thread_join(&card->apdu_thread_id);
 567
 568    /* threads exited, can destroy all condvars/mutexes */
 569    qemu_cond_destroy(&card->handle_apdu_cond);
 570    qemu_mutex_destroy(&card->handle_apdu_mutex);
 571    qemu_mutex_destroy(&card->vreader_mutex);
 572    qemu_mutex_destroy(&card->event_list_mutex);
 573    return 0;
 574}
 575
 576static Property emulated_card_properties[] = {
 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
 586static void emulated_class_initfn(ObjectClass *klass, void *data)
 587{
 588    DeviceClass *dc = DEVICE_CLASS(klass);
 589    CCIDCardClass *cc = CCID_CARD_CLASS(klass);
 590
 591    cc->initfn = emulated_initfn;
 592    cc->exitfn = emulated_exitfn;
 593    cc->get_atr = emulated_get_atr;
 594    cc->apdu_from_guest = emulated_apdu_from_guest;
 595    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 596    dc->desc = "emulated smartcard";
 597    dc->props = emulated_card_properties;
 598}
 599
 600static const TypeInfo emulated_card_info = {
 601    .name          = EMULATED_DEV_NAME,
 602    .parent        = TYPE_CCID_CARD,
 603    .instance_size = sizeof(EmulatedState),
 604    .class_init    = emulated_class_initfn,
 605};
 606
 607static void ccid_card_emulated_register_types(void)
 608{
 609    type_register_static(&emulated_card_info);
 610}
 611
 612type_init(ccid_card_emulated_register_types)
 613