hw/usb/ccid-card-passthru.c

   1 /*
   2  * CCID Passthru Card Device emulation
   3  *
   4  * Copyright (c) 2011 Red Hat.
   5  * Written by Alon Levy.
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2.1 or later.
   8  * See the COPYING file in the top-level directory.
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "qemu-common.h"
  13 #include "qemu/units.h"
  14 #include <libcacard.h>
  15 #include "chardev/char-fe.h"
  16 #include "hw/qdev-properties.h"
  17 #include "hw/qdev-properties-system.h"
  18 #include "migration/vmstate.h"
  19 #include "qemu/error-report.h"
  20 #include "qemu/module.h"
  21 #include "qemu/sockets.h"
  22 #include "ccid.h"
  23 #include "qapi/error.h"
  24 #include "qom/object.h"
  25
  26 #define DPRINTF(card, lvl, fmt, ...)                    \
  27 do {                                                    \
  28     if (lvl <= card->debug) {                           \
  29         printf("ccid-card-passthru: " fmt , ## __VA_ARGS__);     \
  30     }                                                   \
  31 } while (0)
  32
  33 #define D_WARN 1
  34 #define D_INFO 2
  35 #define D_MORE_INFO 3
  36 #define D_VERBOSE 4
  37
  38 /* TODO: do we still need this? */
  39 static const uint8_t DEFAULT_ATR[] = {
  40 /*
  41  * From some example somewhere
  42  * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
  43  */
  44
  45 /* From an Athena smart card */
  46  0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
  47  0x13, 0x08
  48 };
  49
  50 #define VSCARD_IN_SIZE      (64 * KiB)
  51
  52 /* maximum size of ATR - from 7816-3 */
  53 #define MAX_ATR_SIZE        40
  54
  55 typedef struct PassthruState PassthruState;
  56
  57 struct PassthruState {
  58     CCIDCardState base;
  59     CharBackend cs;
  60     uint8_t  vscard_in_data[VSCARD_IN_SIZE];
  61     uint32_t vscard_in_pos;
  62     uint32_t vscard_in_hdr;
  63     uint8_t  atr[MAX_ATR_SIZE];
  64     uint8_t  atr_length;
  65     uint8_t  debug;
  66 };
  67
  68 #define TYPE_CCID_PASSTHRU "ccid-card-passthru"
  69 DECLARE_INSTANCE_CHECKER(PassthruState, PASSTHRU_CCID_CARD,
  70                          TYPE_CCID_PASSTHRU)
  71
  72 /*
  73  * VSCard protocol over chardev
  74  * This code should not depend on the card type.
  75  */
  76
  77 static void ccid_card_vscard_send_msg(PassthruState *s,
  78         VSCMsgType type, uint32_t reader_id,
  79         const uint8_t *payload, uint32_t length)
  80 {
  81     VSCMsgHeader scr_msg_header;
  82
  83     scr_msg_header.type = htonl(type);
  84     scr_msg_header.reader_id = htonl(reader_id);
  85     scr_msg_header.length = htonl(length);
  86     /* XXX this blocks entire thread. Rewrite to use
  87      * qemu_chr_fe_write and background I/O callbacks */
  88     qemu_chr_fe_write_all(&s->cs, (uint8_t *)&scr_msg_header,
  89                           sizeof(VSCMsgHeader));
  90     qemu_chr_fe_write_all(&s->cs, payload, length);
  91 }
  92
  93 static void ccid_card_vscard_send_apdu(PassthruState *s,
  94     const uint8_t *apdu, uint32_t length)
  95 {
  96     ccid_card_vscard_send_msg(
  97         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
  98 }
  99
 100 static void ccid_card_vscard_send_error(PassthruState *s,
 101                     uint32_t reader_id, VSCErrorCode code)
 102 {
 103     VSCMsgError msg = {.code = htonl(code)};
 104
 105     ccid_card_vscard_send_msg(
 106         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
 107 }
 108
 109 static void ccid_card_vscard_send_init(PassthruState *s)
 110 {
 111     VSCMsgInit msg = {
 112         .version = htonl(VSCARD_VERSION),
 113         .magic = VSCARD_MAGIC,
 114         .capabilities = {0}
 115     };
 116
 117     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
 118                          (uint8_t *)&msg, sizeof(msg));
 119 }
 120
 121 static int ccid_card_vscard_can_read(void *opaque)
 122 {
 123     PassthruState *card = opaque;
 124
 125     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
 126            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
 127 }
 128
 129 static void ccid_card_vscard_handle_init(
 130     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
 131 {
 132     uint32_t *capabilities;
 133     int num_capabilities;
 134     int i;
 135
 136     capabilities = init->capabilities;
 137     num_capabilities =
 138         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
 139     init->version = ntohl(init->version);
 140     for (i = 0 ; i < num_capabilities; ++i) {
 141         capabilities[i] = ntohl(capabilities[i]);
 142     }
 143     if (init->magic != VSCARD_MAGIC) {
 144         error_report("wrong magic");
 145         /* we can't disconnect the chardev */
 146     }
 147     if (init->version != VSCARD_VERSION) {
 148         DPRINTF(card, D_WARN,
 149             "got version %d, have %d", init->version, VSCARD_VERSION);
 150     }
 151     /* future handling of capabilities, none exist atm */
 152     ccid_card_vscard_send_init(card);
 153 }
 154
 155 static int check_atr(PassthruState *card, uint8_t *data, int len)
 156 {
 157     int historical_length, opt_bytes;
 158     int td_count = 0;
 159     int td;
 160
 161     if (len < 2) {
 162         return 0;
 163     }
 164     historical_length = data[1] & 0xf;
 165     opt_bytes = 0;
 166     if (data[0] != 0x3b && data[0] != 0x3f) {
 167         DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
 168                 data[0]);
 169         return 0;
 170     }
 171     td_count = 0;
 172     td = data[1] >> 4;
 173     while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
 174         td_count++;
 175         if (td & 0x1) {
 176             opt_bytes++;
 177         }
 178         if (td & 0x2) {
 179             opt_bytes++;
 180         }
 181         if (td & 0x4) {
 182             opt_bytes++;
 183         }
 184         if (td & 0x8) {
 185             opt_bytes++;
 186             td = data[opt_bytes + 2] >> 4;
 187         }
 188     }
 189     if (len < 2 + historical_length + opt_bytes) {
 190         DPRINTF(card, D_WARN,
 191             "atr too short: len %d, but historical_len %d, T1 0x%X\n",
 192             len, historical_length, data[1]);
 193         return 0;
 194     }
 195     if (len > 2 + historical_length + opt_bytes) {
 196         DPRINTF(card, D_WARN,
 197             "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
 198             len, historical_length, opt_bytes, data[1]);
 199         /* let it through */
 200     }
 201     DPRINTF(card, D_VERBOSE,
 202             "atr passes check: %d total length, %d historical, %d optional\n",
 203             len, historical_length, opt_bytes);
 204
 205     return 1;
 206 }
 207
 208 static void ccid_card_vscard_handle_message(PassthruState *card,
 209     VSCMsgHeader *scr_msg_header)
 210 {
 211     uint8_t *data = (uint8_t *)&scr_msg_header[1];
 212
 213     switch (scr_msg_header->type) {
 214     case VSC_ATR:
 215         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
 216         if (scr_msg_header->length > MAX_ATR_SIZE) {
 217             error_report("ATR size exceeds spec, ignoring");
 218             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 219                                         VSC_GENERAL_ERROR);
 220             break;
 221         }
 222         if (!check_atr(card, data, scr_msg_header->length)) {
 223             error_report("ATR is inconsistent, ignoring");
 224             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 225                                         VSC_GENERAL_ERROR);
 226             break;
 227         }
 228         memcpy(card->atr, data, scr_msg_header->length);
 229         card->atr_length = scr_msg_header->length;
 230         ccid_card_card_inserted(&card->base);
 231         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 232                                     VSC_SUCCESS);
 233         break;
 234     case VSC_APDU:
 235         ccid_card_send_apdu_to_guest(
 236             &card->base, data, scr_msg_header->length);
 237         break;
 238     case VSC_CardRemove:
 239         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
 240         ccid_card_card_removed(&card->base);
 241         ccid_card_vscard_send_error(card,
 242             scr_msg_header->reader_id, VSC_SUCCESS);
 243         break;
 244     case VSC_Init:
 245         ccid_card_vscard_handle_init(
 246             card, scr_msg_header, (VSCMsgInit *)data);
 247         break;
 248     case VSC_Error:
 249         ccid_card_card_error(&card->base, *(uint32_t *)data);
 250         break;
 251     case VSC_ReaderAdd:
 252         if (ccid_card_ccid_attach(&card->base) < 0) {
 253             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
 254                                       VSC_CANNOT_ADD_MORE_READERS);
 255         } else {
 256             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
 257                                         VSC_SUCCESS);
 258         }
 259         break;
 260     case VSC_ReaderRemove:
 261         ccid_card_ccid_detach(&card->base);
 262         ccid_card_vscard_send_error(card,
 263             scr_msg_header->reader_id, VSC_SUCCESS);
 264         break;
 265     default:
 266         printf("usb-ccid: chardev: unexpected message of type %X\n",
 267                scr_msg_header->type);
 268         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 269             VSC_GENERAL_ERROR);
 270     }
 271 }
 272
 273 static void ccid_card_vscard_drop_connection(PassthruState *card)
 274 {
 275     qemu_chr_fe_deinit(&card->cs, true);
 276     card->vscard_in_pos = card->vscard_in_hdr = 0;
 277 }
 278
 279 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
 280 {
 281     PassthruState *card = opaque;
 282     VSCMsgHeader *hdr;
 283
 284     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
 285         error_report("no room for data: pos %u +  size %d > %" PRId64 "."
 286                      " dropping connection.",
 287                      card->vscard_in_pos, size, VSCARD_IN_SIZE);
 288         ccid_card_vscard_drop_connection(card);
 289         return;
 290     }
 291     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
 292     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
 293     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
 294     card->vscard_in_pos += size;
 295     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 296
 297     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
 298          &&(card->vscard_in_pos - card->vscard_in_hdr >=
 299                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
 300         hdr->reader_id = ntohl(hdr->reader_id);
 301         hdr->length = ntohl(hdr->length);
 302         hdr->type = ntohl(hdr->type);
 303         ccid_card_vscard_handle_message(card, hdr);
 304         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
 305         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 306     }
 307     if (card->vscard_in_hdr == card->vscard_in_pos) {
 308         card->vscard_in_pos = card->vscard_in_hdr = 0;
 309     }
 310 }
 311
 312 static void ccid_card_vscard_event(void *opaque, QEMUChrEvent event)
 313 {
 314     PassthruState *card = opaque;
 315
 316     switch (event) {
 317     case CHR_EVENT_BREAK:
 318         card->vscard_in_pos = card->vscard_in_hdr = 0;
 319         break;
 320     case CHR_EVENT_OPENED:
 321         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
 322         break;
 323     case CHR_EVENT_MUX_IN:
 324     case CHR_EVENT_MUX_OUT:
 325     case CHR_EVENT_CLOSED:
 326         /* Ignore */
 327         break;
 328     }
 329 }
 330
 331 /* End VSCard handling */
 332
 333 static void passthru_apdu_from_guest(
 334     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
 335 {
 336     PassthruState *card = PASSTHRU_CCID_CARD(base);
 337
 338     if (!qemu_chr_fe_backend_connected(&card->cs)) {
 339         printf("ccid-passthru: no chardev, discarding apdu length %u\n", len);
 340         return;
 341     }
 342     ccid_card_vscard_send_apdu(card, apdu, len);
 343 }
 344
 345 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
 346 {
 347     PassthruState *card = PASSTHRU_CCID_CARD(base);
 348
 349     *len = card->atr_length;
 350     return card->atr;
 351 }
 352
 353 static void passthru_realize(CCIDCardState *base, Error **errp)
 354 {
 355     PassthruState *card = PASSTHRU_CCID_CARD(base);
 356
 357     card->vscard_in_pos = 0;
 358     card->vscard_in_hdr = 0;
 359     if (qemu_chr_fe_backend_connected(&card->cs)) {
 360         DPRINTF(card, D_INFO, "ccid-card-passthru: initing chardev");
 361         qemu_chr_fe_set_handlers(&card->cs,
 362             ccid_card_vscard_can_read,
 363             ccid_card_vscard_read,
 364             ccid_card_vscard_event, NULL, card, NULL, true);
 365         ccid_card_vscard_send_init(card);
 366     } else {
 367         error_setg(errp, "missing chardev");
 368         return;
 369     }
 370     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
 371                                   card->debug);
 372     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
 373     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
 374     card->atr_length = sizeof(DEFAULT_ATR);
 375 }
 376
 377 static VMStateDescription passthru_vmstate = {
 378     .name = "ccid-card-passthru",
 379     .version_id = 1,
 380     .minimum_version_id = 1,
 381     .fields = (VMStateField[]) {
 382         VMSTATE_BUFFER(vscard_in_data, PassthruState),
 383         VMSTATE_UINT32(vscard_in_pos, PassthruState),
 384         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
 385         VMSTATE_BUFFER(atr, PassthruState),
 386         VMSTATE_UINT8(atr_length, PassthruState),
 387         VMSTATE_END_OF_LIST()
 388     }
 389 };
 390
 391 static Property passthru_card_properties[] = {
 392     DEFINE_PROP_CHR("chardev", PassthruState, cs),
 393     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
 394     DEFINE_PROP_END_OF_LIST(),
 395 };
 396
 397 static void passthru_class_initfn(ObjectClass *klass, void *data)
 398 {
 399     DeviceClass *dc = DEVICE_CLASS(klass);
 400     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
 401
 402     cc->realize = passthru_realize;
 403     cc->get_atr = passthru_get_atr;
 404     cc->apdu_from_guest = passthru_apdu_from_guest;
 405     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 406     dc->desc = "passthrough smartcard";
 407     dc->vmsd = &passthru_vmstate;
 408     device_class_set_props(dc, passthru_card_properties);
 409 }
 410
 411 static const TypeInfo passthru_card_info = {
 412     .name          = TYPE_CCID_PASSTHRU,
 413     .parent        = TYPE_CCID_CARD,
 414     .instance_size = sizeof(PassthruState),
 415     .class_init    = passthru_class_initfn,
 416 };
 417
 418 static void ccid_card_passthru_register_types(void)
 419 {
 420     type_register_static(&passthru_card_info);
 421 }
 422
 423 type_init(ccid_card_passthru_register_types)