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 "sysemu/char.h"
  12 #include "qemu/error-report.h"
  13 #include "qemu/sockets.h"
  14 #include "ccid.h"
  15 #include "libcacard/vscard_common.h"
  16
  17 #define DPRINTF(card, lvl, fmt, ...)                    \
  18 do {                                                    \
  19     if (lvl <= card->debug) {                           \
  20         printf("ccid-card-passthru: " fmt , ## __VA_ARGS__);     \
  21     }                                                   \
  22 } while (0)
  23
  24 #define D_WARN 1
  25 #define D_INFO 2
  26 #define D_MORE_INFO 3
  27 #define D_VERBOSE 4
  28
  29 /* TODO: do we still need this? */
  30 static const uint8_t DEFAULT_ATR[] = {
  31 /*
  32  * From some example somewhere
  33  * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
  34  */
  35
  36 /* From an Athena smart card */
  37  0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
  38  0x13, 0x08
  39 };
  40
  41
  42 #define PASSTHRU_DEV_NAME "ccid-card-passthru"
  43 #define VSCARD_IN_SIZE 65536
  44
  45 /* maximum size of ATR - from 7816-3 */
  46 #define MAX_ATR_SIZE        40
  47
  48 typedef struct PassthruState PassthruState;
  49
  50 struct PassthruState {
  51     CCIDCardState base;
  52     CharDriverState *cs;
  53     uint8_t  vscard_in_data[VSCARD_IN_SIZE];
  54     uint32_t vscard_in_pos;
  55     uint32_t vscard_in_hdr;
  56     uint8_t  atr[MAX_ATR_SIZE];
  57     uint8_t  atr_length;
  58     uint8_t  debug;
  59 };
  60
  61 /*
  62  * VSCard protocol over chardev
  63  * This code should not depend on the card type.
  64  */
  65
  66 static void ccid_card_vscard_send_msg(PassthruState *s,
  67         VSCMsgType type, uint32_t reader_id,
  68         const uint8_t *payload, uint32_t length)
  69 {
  70     VSCMsgHeader scr_msg_header;
  71
  72     scr_msg_header.type = htonl(type);
  73     scr_msg_header.reader_id = htonl(reader_id);
  74     scr_msg_header.length = htonl(length);
  75     qemu_chr_fe_write(s->cs, (uint8_t *)&scr_msg_header, sizeof(VSCMsgHeader));
  76     qemu_chr_fe_write(s->cs, payload, length);
  77 }
  78
  79 static void ccid_card_vscard_send_apdu(PassthruState *s,
  80     const uint8_t *apdu, uint32_t length)
  81 {
  82     ccid_card_vscard_send_msg(
  83         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
  84 }
  85
  86 static void ccid_card_vscard_send_error(PassthruState *s,
  87                     uint32_t reader_id, VSCErrorCode code)
  88 {
  89     VSCMsgError msg = {.code = htonl(code)};
  90
  91     ccid_card_vscard_send_msg(
  92         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
  93 }
  94
  95 static void ccid_card_vscard_send_init(PassthruState *s)
  96 {
  97     VSCMsgInit msg = {
  98         .version = htonl(VSCARD_VERSION),
  99         .magic = VSCARD_MAGIC,
 100         .capabilities = {0}
 101     };
 102
 103     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
 104                          (uint8_t *)&msg, sizeof(msg));
 105 }
 106
 107 static int ccid_card_vscard_can_read(void *opaque)
 108 {
 109     PassthruState *card = opaque;
 110
 111     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
 112            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
 113 }
 114
 115 static void ccid_card_vscard_handle_init(
 116     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
 117 {
 118     uint32_t *capabilities;
 119     int num_capabilities;
 120     int i;
 121
 122     capabilities = init->capabilities;
 123     num_capabilities =
 124         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
 125     init->version = ntohl(init->version);
 126     for (i = 0 ; i < num_capabilities; ++i) {
 127         capabilities[i] = ntohl(capabilities[i]);
 128     }
 129     if (init->magic != VSCARD_MAGIC) {
 130         error_report("wrong magic");
 131         /* we can't disconnect the chardev */
 132     }
 133     if (init->version != VSCARD_VERSION) {
 134         DPRINTF(card, D_WARN,
 135             "got version %d, have %d", init->version, VSCARD_VERSION);
 136     }
 137     /* future handling of capabilities, none exist atm */
 138     ccid_card_vscard_send_init(card);
 139 }
 140
 141 static int check_atr(PassthruState *card, uint8_t *data, int len)
 142 {
 143     int historical_length, opt_bytes;
 144     int td_count = 0;
 145     int td;
 146
 147     if (len < 2) {
 148         return 0;
 149     }
 150     historical_length = data[1] & 0xf;
 151     opt_bytes = 0;
 152     if (data[0] != 0x3b && data[0] != 0x3f) {
 153         DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
 154                 data[0]);
 155         return 0;
 156     }
 157     td_count = 0;
 158     td = data[1] >> 4;
 159     while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
 160         td_count++;
 161         if (td & 0x1) {
 162             opt_bytes++;
 163         }
 164         if (td & 0x2) {
 165             opt_bytes++;
 166         }
 167         if (td & 0x4) {
 168             opt_bytes++;
 169         }
 170         if (td & 0x8) {
 171             opt_bytes++;
 172             td = data[opt_bytes + 2] >> 4;
 173         }
 174     }
 175     if (len < 2 + historical_length + opt_bytes) {
 176         DPRINTF(card, D_WARN,
 177             "atr too short: len %d, but historical_len %d, T1 0x%X\n",
 178             len, historical_length, data[1]);
 179         return 0;
 180     }
 181     if (len > 2 + historical_length + opt_bytes) {
 182         DPRINTF(card, D_WARN,
 183             "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
 184             len, historical_length, opt_bytes, data[1]);
 185         /* let it through */
 186     }
 187     DPRINTF(card, D_VERBOSE,
 188             "atr passes check: %d total length, %d historical, %d optional\n",
 189             len, historical_length, opt_bytes);
 190
 191     return 1;
 192 }
 193
 194 static void ccid_card_vscard_handle_message(PassthruState *card,
 195     VSCMsgHeader *scr_msg_header)
 196 {
 197     uint8_t *data = (uint8_t *)&scr_msg_header[1];
 198
 199     switch (scr_msg_header->type) {
 200     case VSC_ATR:
 201         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
 202         if (scr_msg_header->length > MAX_ATR_SIZE) {
 203             error_report("ATR size exceeds spec, ignoring");
 204             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 205                                         VSC_GENERAL_ERROR);
 206             break;
 207         }
 208         if (!check_atr(card, data, scr_msg_header->length)) {
 209             error_report("ATR is inconsistent, ignoring");
 210             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 211                                         VSC_GENERAL_ERROR);
 212             break;
 213         }
 214         memcpy(card->atr, data, scr_msg_header->length);
 215         card->atr_length = scr_msg_header->length;
 216         ccid_card_card_inserted(&card->base);
 217         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 218                                     VSC_SUCCESS);
 219         break;
 220     case VSC_APDU:
 221         ccid_card_send_apdu_to_guest(
 222             &card->base, data, scr_msg_header->length);
 223         break;
 224     case VSC_CardRemove:
 225         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
 226         ccid_card_card_removed(&card->base);
 227         ccid_card_vscard_send_error(card,
 228             scr_msg_header->reader_id, VSC_SUCCESS);
 229         break;
 230     case VSC_Init:
 231         ccid_card_vscard_handle_init(
 232             card, scr_msg_header, (VSCMsgInit *)data);
 233         break;
 234     case VSC_Error:
 235         ccid_card_card_error(&card->base, *(uint32_t *)data);
 236         break;
 237     case VSC_ReaderAdd:
 238         if (ccid_card_ccid_attach(&card->base) < 0) {
 239             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
 240                                       VSC_CANNOT_ADD_MORE_READERS);
 241         } else {
 242             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
 243                                         VSC_SUCCESS);
 244         }
 245         break;
 246     case VSC_ReaderRemove:
 247         ccid_card_ccid_detach(&card->base);
 248         ccid_card_vscard_send_error(card,
 249             scr_msg_header->reader_id, VSC_SUCCESS);
 250         break;
 251     default:
 252         printf("usb-ccid: chardev: unexpected message of type %X\n",
 253                scr_msg_header->type);
 254         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 255             VSC_GENERAL_ERROR);
 256     }
 257 }
 258
 259 static void ccid_card_vscard_drop_connection(PassthruState *card)
 260 {
 261     qemu_chr_delete(card->cs);
 262     card->vscard_in_pos = card->vscard_in_hdr = 0;
 263 }
 264
 265 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
 266 {
 267     PassthruState *card = opaque;
 268     VSCMsgHeader *hdr;
 269
 270     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
 271         error_report(
 272             "no room for data: pos %d +  size %d > %d. dropping connection.",
 273             card->vscard_in_pos, size, VSCARD_IN_SIZE);
 274         ccid_card_vscard_drop_connection(card);
 275         return;
 276     }
 277     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
 278     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
 279     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
 280     card->vscard_in_pos += size;
 281     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 282
 283     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
 284          &&(card->vscard_in_pos - card->vscard_in_hdr >=
 285                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
 286         hdr->reader_id = ntohl(hdr->reader_id);
 287         hdr->length = ntohl(hdr->length);
 288         hdr->type = ntohl(hdr->type);
 289         ccid_card_vscard_handle_message(card, hdr);
 290         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
 291         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 292     }
 293     if (card->vscard_in_hdr == card->vscard_in_pos) {
 294         card->vscard_in_pos = card->vscard_in_hdr = 0;
 295     }
 296 }
 297
 298 static void ccid_card_vscard_event(void *opaque, int event)
 299 {
 300     PassthruState *card = opaque;
 301
 302     switch (event) {
 303     case CHR_EVENT_BREAK:
 304         card->vscard_in_pos = card->vscard_in_hdr = 0;
 305         break;
 306     case CHR_EVENT_FOCUS:
 307         break;
 308     case CHR_EVENT_OPENED:
 309         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
 310         break;
 311     }
 312 }
 313
 314 /* End VSCard handling */
 315
 316 static void passthru_apdu_from_guest(
 317     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
 318 {
 319     PassthruState *card = DO_UPCAST(PassthruState, base, base);
 320
 321     if (!card->cs) {
 322         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
 323         return;
 324     }
 325     ccid_card_vscard_send_apdu(card, apdu, len);
 326 }
 327
 328 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
 329 {
 330     PassthruState *card = DO_UPCAST(PassthruState, base, base);
 331
 332     *len = card->atr_length;
 333     return card->atr;
 334 }
 335
 336 static int passthru_initfn(CCIDCardState *base)
 337 {
 338     PassthruState *card = DO_UPCAST(PassthruState, base, base);
 339
 340     card->vscard_in_pos = 0;
 341     card->vscard_in_hdr = 0;
 342     if (card->cs) {
 343         DPRINTF(card, D_INFO, "initing chardev\n");
 344         qemu_chr_add_handlers(card->cs,
 345             ccid_card_vscard_can_read,
 346             ccid_card_vscard_read,
 347             ccid_card_vscard_event, card);
 348         ccid_card_vscard_send_init(card);
 349     } else {
 350         error_report("missing chardev");
 351         return -1;
 352     }
 353     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
 354                                   card->debug);
 355     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
 356     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
 357     card->atr_length = sizeof(DEFAULT_ATR);
 358     return 0;
 359 }
 360
 361 static int passthru_exitfn(CCIDCardState *base)
 362 {
 363     return 0;
 364 }
 365
 366 static VMStateDescription passthru_vmstate = {
 367     .name = "ccid-card-passthru",
 368     .version_id = 1,
 369     .minimum_version_id = 1,
 370     .fields = (VMStateField[]) {
 371         VMSTATE_BUFFER(vscard_in_data, PassthruState),
 372         VMSTATE_UINT32(vscard_in_pos, PassthruState),
 373         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
 374         VMSTATE_BUFFER(atr, PassthruState),
 375         VMSTATE_UINT8(atr_length, PassthruState),
 376         VMSTATE_END_OF_LIST()
 377     }
 378 };
 379
 380 static Property passthru_card_properties[] = {
 381     DEFINE_PROP_CHR("chardev", PassthruState, cs),
 382     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
 383     DEFINE_PROP_END_OF_LIST(),
 384 };
 385
 386 static void passthru_class_initfn(ObjectClass *klass, void *data)
 387 {
 388     DeviceClass *dc = DEVICE_CLASS(klass);
 389     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
 390
 391     cc->initfn = passthru_initfn;
 392     cc->exitfn = passthru_exitfn;
 393     cc->get_atr = passthru_get_atr;
 394     cc->apdu_from_guest = passthru_apdu_from_guest;
 395     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 396     dc->desc = "passthrough smartcard";
 397     dc->vmsd = &passthru_vmstate;
 398     dc->props = passthru_card_properties;
 399 }
 400
 401 static const TypeInfo passthru_card_info = {
 402     .name          = PASSTHRU_DEV_NAME,
 403     .parent        = TYPE_CCID_CARD,
 404     .instance_size = sizeof(PassthruState),
 405     .class_init    = passthru_class_initfn,
 406 };
 407
 408 static void ccid_card_passthru_register_types(void)
 409 {
 410     type_register_static(&passthru_card_info);
 411 }
 412
 413 type_init(ccid_card_passthru_register_types)