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