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