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