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 "sysemu/char.h"
  13 #include "qemu/error-report.h"
  14 #include "qemu/sockets.h"
  15 #include "ccid.h"
  16 #include "cacard/vscard_common.h"
  17
  18 #define DPRINTF(card, lvl, fmt, ...)                    \
  19 do {                                                    \
  20     if (lvl <= card->debug) {                           \
  21         printf("ccid-card-passthru: " fmt , ## __VA_ARGS__);     \
  22     }                                                   \
  23 } while (0)
  24
  25 #define D_WARN 1
  26 #define D_INFO 2
  27 #define D_MORE_INFO 3
  28 #define D_VERBOSE 4
  29
  30 /* TODO: do we still need this? */
  31 static const uint8_t DEFAULT_ATR[] = {
  32 /*
  33  * From some example somewhere
  34  * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
  35  */
  36
  37 /* From an Athena smart card */
  38  0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
  39  0x13, 0x08
  40 };
  41
  42 #define VSCARD_IN_SIZE 65536
  43
  44 /* maximum size of ATR - from 7816-3 */
  45 #define MAX_ATR_SIZE        40
  46
  47 typedef struct PassthruState PassthruState;
  48
  49 struct PassthruState {
  50     CCIDCardState base;
  51     CharDriverState *cs;
  52     uint8_t  vscard_in_data[VSCARD_IN_SIZE];
  53     uint32_t vscard_in_pos;
  54     uint32_t vscard_in_hdr;
  55     uint8_t  atr[MAX_ATR_SIZE];
  56     uint8_t  atr_length;
  57     uint8_t  debug;
  58 };
  59
  60 #define TYPE_CCID_PASSTHRU "ccid-card-passthru"
  61 #define PASSTHRU_CCID_CARD(obj) \
  62     OBJECT_CHECK(PassthruState, (obj), TYPE_CCID_PASSTHRU)
  63
  64 /*
  65  * VSCard protocol over chardev
  66  * This code should not depend on the card type.
  67  */
  68
  69 static void ccid_card_vscard_send_msg(PassthruState *s,
  70         VSCMsgType type, uint32_t reader_id,
  71         const uint8_t *payload, uint32_t length)
  72 {
  73     VSCMsgHeader scr_msg_header;
  74
  75     scr_msg_header.type = htonl(type);
  76     scr_msg_header.reader_id = htonl(reader_id);
  77     scr_msg_header.length = htonl(length);
  78     qemu_chr_fe_write(s->cs, (uint8_t *)&scr_msg_header, sizeof(VSCMsgHeader));
  79     qemu_chr_fe_write(s->cs, payload, length);
  80 }
  81
  82 static void ccid_card_vscard_send_apdu(PassthruState *s,
  83     const uint8_t *apdu, uint32_t length)
  84 {
  85     ccid_card_vscard_send_msg(
  86         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
  87 }
  88
  89 static void ccid_card_vscard_send_error(PassthruState *s,
  90                     uint32_t reader_id, VSCErrorCode code)
  91 {
  92     VSCMsgError msg = {.code = htonl(code)};
  93
  94     ccid_card_vscard_send_msg(
  95         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
  96 }
  97
  98 static void ccid_card_vscard_send_init(PassthruState *s)
  99 {
 100     VSCMsgInit msg = {
 101         .version = htonl(VSCARD_VERSION),
 102         .magic = VSCARD_MAGIC,
 103         .capabilities = {0}
 104     };
 105
 106     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
 107                          (uint8_t *)&msg, sizeof(msg));
 108 }
 109
 110 static int ccid_card_vscard_can_read(void *opaque)
 111 {
 112     PassthruState *card = opaque;
 113
 114     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
 115            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
 116 }
 117
 118 static void ccid_card_vscard_handle_init(
 119     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
 120 {
 121     uint32_t *capabilities;
 122     int num_capabilities;
 123     int i;
 124
 125     capabilities = init->capabilities;
 126     num_capabilities =
 127         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
 128     init->version = ntohl(init->version);
 129     for (i = 0 ; i < num_capabilities; ++i) {
 130         capabilities[i] = ntohl(capabilities[i]);
 131     }
 132     if (init->magic != VSCARD_MAGIC) {
 133         error_report("wrong magic");
 134         /* we can't disconnect the chardev */
 135     }
 136     if (init->version != VSCARD_VERSION) {
 137         DPRINTF(card, D_WARN,
 138             "got version %d, have %d", init->version, VSCARD_VERSION);
 139     }
 140     /* future handling of capabilities, none exist atm */
 141     ccid_card_vscard_send_init(card);
 142 }
 143
 144 static int check_atr(PassthruState *card, uint8_t *data, int len)
 145 {
 146     int historical_length, opt_bytes;
 147     int td_count = 0;
 148     int td;
 149
 150     if (len < 2) {
 151         return 0;
 152     }
 153     historical_length = data[1] & 0xf;
 154     opt_bytes = 0;
 155     if (data[0] != 0x3b && data[0] != 0x3f) {
 156         DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
 157                 data[0]);
 158         return 0;
 159     }
 160     td_count = 0;
 161     td = data[1] >> 4;
 162     while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
 163         td_count++;
 164         if (td & 0x1) {
 165             opt_bytes++;
 166         }
 167         if (td & 0x2) {
 168             opt_bytes++;
 169         }
 170         if (td & 0x4) {
 171             opt_bytes++;
 172         }
 173         if (td & 0x8) {
 174             opt_bytes++;
 175             td = data[opt_bytes + 2] >> 4;
 176         }
 177     }
 178     if (len < 2 + historical_length + opt_bytes) {
 179         DPRINTF(card, D_WARN,
 180             "atr too short: len %d, but historical_len %d, T1 0x%X\n",
 181             len, historical_length, data[1]);
 182         return 0;
 183     }
 184     if (len > 2 + historical_length + opt_bytes) {
 185         DPRINTF(card, D_WARN,
 186             "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
 187             len, historical_length, opt_bytes, data[1]);
 188         /* let it through */
 189     }
 190     DPRINTF(card, D_VERBOSE,
 191             "atr passes check: %d total length, %d historical, %d optional\n",
 192             len, historical_length, opt_bytes);
 193
 194     return 1;
 195 }
 196
 197 static void ccid_card_vscard_handle_message(PassthruState *card,
 198     VSCMsgHeader *scr_msg_header)
 199 {
 200     uint8_t *data = (uint8_t *)&scr_msg_header[1];
 201
 202     switch (scr_msg_header->type) {
 203     case VSC_ATR:
 204         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
 205         if (scr_msg_header->length > MAX_ATR_SIZE) {
 206             error_report("ATR size exceeds spec, ignoring");
 207             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 208                                         VSC_GENERAL_ERROR);
 209             break;
 210         }
 211         if (!check_atr(card, data, scr_msg_header->length)) {
 212             error_report("ATR is inconsistent, ignoring");
 213             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 214                                         VSC_GENERAL_ERROR);
 215             break;
 216         }
 217         memcpy(card->atr, data, scr_msg_header->length);
 218         card->atr_length = scr_msg_header->length;
 219         ccid_card_card_inserted(&card->base);
 220         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 221                                     VSC_SUCCESS);
 222         break;
 223     case VSC_APDU:
 224         ccid_card_send_apdu_to_guest(
 225             &card->base, data, scr_msg_header->length);
 226         break;
 227     case VSC_CardRemove:
 228         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
 229         ccid_card_card_removed(&card->base);
 230         ccid_card_vscard_send_error(card,
 231             scr_msg_header->reader_id, VSC_SUCCESS);
 232         break;
 233     case VSC_Init:
 234         ccid_card_vscard_handle_init(
 235             card, scr_msg_header, (VSCMsgInit *)data);
 236         break;
 237     case VSC_Error:
 238         ccid_card_card_error(&card->base, *(uint32_t *)data);
 239         break;
 240     case VSC_ReaderAdd:
 241         if (ccid_card_ccid_attach(&card->base) < 0) {
 242             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
 243                                       VSC_CANNOT_ADD_MORE_READERS);
 244         } else {
 245             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
 246                                         VSC_SUCCESS);
 247         }
 248         break;
 249     case VSC_ReaderRemove:
 250         ccid_card_ccid_detach(&card->base);
 251         ccid_card_vscard_send_error(card,
 252             scr_msg_header->reader_id, VSC_SUCCESS);
 253         break;
 254     default:
 255         printf("usb-ccid: chardev: unexpected message of type %X\n",
 256                scr_msg_header->type);
 257         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 258             VSC_GENERAL_ERROR);
 259     }
 260 }
 261
 262 static void ccid_card_vscard_drop_connection(PassthruState *card)
 263 {
 264     qemu_chr_delete(card->cs);
 265     card->vscard_in_pos = card->vscard_in_hdr = 0;
 266 }
 267
 268 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
 269 {
 270     PassthruState *card = opaque;
 271     VSCMsgHeader *hdr;
 272
 273     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
 274         error_report(
 275             "no room for data: pos %d +  size %d > %d. dropping connection.",
 276             card->vscard_in_pos, size, VSCARD_IN_SIZE);
 277         ccid_card_vscard_drop_connection(card);
 278         return;
 279     }
 280     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
 281     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
 282     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
 283     card->vscard_in_pos += size;
 284     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 285
 286     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
 287          &&(card->vscard_in_pos - card->vscard_in_hdr >=
 288                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
 289         hdr->reader_id = ntohl(hdr->reader_id);
 290         hdr->length = ntohl(hdr->length);
 291         hdr->type = ntohl(hdr->type);
 292         ccid_card_vscard_handle_message(card, hdr);
 293         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
 294         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 295     }
 296     if (card->vscard_in_hdr == card->vscard_in_pos) {
 297         card->vscard_in_pos = card->vscard_in_hdr = 0;
 298     }
 299 }
 300
 301 static void ccid_card_vscard_event(void *opaque, int event)
 302 {
 303     PassthruState *card = opaque;
 304
 305     switch (event) {
 306     case CHR_EVENT_BREAK:
 307         card->vscard_in_pos = card->vscard_in_hdr = 0;
 308         break;
 309     case CHR_EVENT_FOCUS:
 310         break;
 311     case CHR_EVENT_OPENED:
 312         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
 313         break;
 314     }
 315 }
 316
 317 /* End VSCard handling */
 318
 319 static void passthru_apdu_from_guest(
 320     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
 321 {
 322     PassthruState *card = PASSTHRU_CCID_CARD(base);
 323
 324     if (!card->cs) {
 325         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
 326         return;
 327     }
 328     ccid_card_vscard_send_apdu(card, apdu, len);
 329 }
 330
 331 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
 332 {
 333     PassthruState *card = PASSTHRU_CCID_CARD(base);
 334
 335     *len = card->atr_length;
 336     return card->atr;
 337 }
 338
 339 static int passthru_initfn(CCIDCardState *base)
 340 {
 341     PassthruState *card = PASSTHRU_CCID_CARD(base);
 342
 343     card->vscard_in_pos = 0;
 344     card->vscard_in_hdr = 0;
 345     if (card->cs) {
 346         DPRINTF(card, D_INFO, "initing chardev\n");
 347         qemu_chr_add_handlers(card->cs,
 348             ccid_card_vscard_can_read,
 349             ccid_card_vscard_read,
 350             ccid_card_vscard_event, card);
 351         ccid_card_vscard_send_init(card);
 352     } else {
 353         error_report("missing chardev");
 354         return -1;
 355     }
 356     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
 357                                   card->debug);
 358     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
 359     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
 360     card->atr_length = sizeof(DEFAULT_ATR);
 361     return 0;
 362 }
 363
 364 static int passthru_exitfn(CCIDCardState *base)
 365 {
 366     return 0;
 367 }
 368
 369 static VMStateDescription passthru_vmstate = {
 370     .name = "ccid-card-passthru",
 371     .version_id = 1,
 372     .minimum_version_id = 1,
 373     .fields = (VMStateField[]) {
 374         VMSTATE_BUFFER(vscard_in_data, PassthruState),
 375         VMSTATE_UINT32(vscard_in_pos, PassthruState),
 376         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
 377         VMSTATE_BUFFER(atr, PassthruState),
 378         VMSTATE_UINT8(atr_length, PassthruState),
 379         VMSTATE_END_OF_LIST()
 380     }
 381 };
 382
 383 static Property passthru_card_properties[] = {
 384     DEFINE_PROP_CHR("chardev", PassthruState, cs),
 385     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
 386     DEFINE_PROP_END_OF_LIST(),
 387 };
 388
 389 static void passthru_class_initfn(ObjectClass *klass, void *data)
 390 {
 391     DeviceClass *dc = DEVICE_CLASS(klass);
 392     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
 393
 394     cc->initfn = passthru_initfn;
 395     cc->exitfn = passthru_exitfn;
 396     cc->get_atr = passthru_get_atr;
 397     cc->apdu_from_guest = passthru_apdu_from_guest;
 398     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 399     dc->desc = "passthrough smartcard";
 400     dc->vmsd = &passthru_vmstate;
 401     dc->props = passthru_card_properties;
 402 }
 403
 404 static const TypeInfo passthru_card_info = {
 405     .name          = TYPE_CCID_PASSTHRU,
 406     .parent        = TYPE_CCID_CARD,
 407     .instance_size = sizeof(PassthruState),
 408     .class_init    = passthru_class_initfn,
 409 };
 410
 411 static void ccid_card_passthru_register_types(void)
 412 {
 413     type_register_static(&passthru_card_info);
 414 }
 415
 416 type_init(ccid_card_passthru_register_types)