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 <cacard/vscard_common.h> 13 #include "chardev/char-fe.h" 14 #include "qemu/error-report.h" 15 #include "qemu/sockets.h" 16 #include "ccid.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 CharBackend 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 /* XXX this blocks entire thread. Rewrite to use 79 * qemu_chr_fe_write and background I/O callbacks */ 80 qemu_chr_fe_write_all(&s->cs, (uint8_t *)&scr_msg_header, 81 sizeof(VSCMsgHeader)); 82 qemu_chr_fe_write_all(&s->cs, payload, length); 83 } 84 85 static void ccid_card_vscard_send_apdu(PassthruState *s, 86 const uint8_t *apdu, uint32_t length) 87 { 88 ccid_card_vscard_send_msg( 89 s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length); 90 } 91 92 static void ccid_card_vscard_send_error(PassthruState *s, 93 uint32_t reader_id, VSCErrorCode code) 94 { 95 VSCMsgError msg = {.code = htonl(code)}; 96 97 ccid_card_vscard_send_msg( 98 s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg)); 99 } 100 101 static void ccid_card_vscard_send_init(PassthruState *s) 102 { 103 VSCMsgInit msg = { 104 .version = htonl(VSCARD_VERSION), 105 .magic = VSCARD_MAGIC, 106 .capabilities = {0} 107 }; 108 109 ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID, 110 (uint8_t *)&msg, sizeof(msg)); 111 } 112 113 static int ccid_card_vscard_can_read(void *opaque) 114 { 115 PassthruState *card = opaque; 116 117 return VSCARD_IN_SIZE >= card->vscard_in_pos ? 118 VSCARD_IN_SIZE - card->vscard_in_pos : 0; 119 } 120 121 static void ccid_card_vscard_handle_init( 122 PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init) 123 { 124 uint32_t *capabilities; 125 int num_capabilities; 126 int i; 127 128 capabilities = init->capabilities; 129 num_capabilities = 130 1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t)); 131 init->version = ntohl(init->version); 132 for (i = 0 ; i < num_capabilities; ++i) { 133 capabilities[i] = ntohl(capabilities[i]); 134 } 135 if (init->magic != VSCARD_MAGIC) { 136 error_report("wrong magic"); 137 /* we can't disconnect the chardev */ 138 } 139 if (init->version != VSCARD_VERSION) { 140 DPRINTF(card, D_WARN, 141 "got version %d, have %d", init->version, VSCARD_VERSION); 142 } 143 /* future handling of capabilities, none exist atm */ 144 ccid_card_vscard_send_init(card); 145 } 146 147 static int check_atr(PassthruState *card, uint8_t *data, int len) 148 { 149 int historical_length, opt_bytes; 150 int td_count = 0; 151 int td; 152 153 if (len < 2) { 154 return 0; 155 } 156 historical_length = data[1] & 0xf; 157 opt_bytes = 0; 158 if (data[0] != 0x3b && data[0] != 0x3f) { 159 DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n", 160 data[0]); 161 return 0; 162 } 163 td_count = 0; 164 td = data[1] >> 4; 165 while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) { 166 td_count++; 167 if (td & 0x1) { 168 opt_bytes++; 169 } 170 if (td & 0x2) { 171 opt_bytes++; 172 } 173 if (td & 0x4) { 174 opt_bytes++; 175 } 176 if (td & 0x8) { 177 opt_bytes++; 178 td = data[opt_bytes + 2] >> 4; 179 } 180 } 181 if (len < 2 + historical_length + opt_bytes) { 182 DPRINTF(card, D_WARN, 183 "atr too short: len %d, but historical_len %d, T1 0x%X\n", 184 len, historical_length, data[1]); 185 return 0; 186 } 187 if (len > 2 + historical_length + opt_bytes) { 188 DPRINTF(card, D_WARN, 189 "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n", 190 len, historical_length, opt_bytes, data[1]); 191 /* let it through */ 192 } 193 DPRINTF(card, D_VERBOSE, 194 "atr passes check: %d total length, %d historical, %d optional\n", 195 len, historical_length, opt_bytes); 196 197 return 1; 198 } 199 200 static void ccid_card_vscard_handle_message(PassthruState *card, 201 VSCMsgHeader *scr_msg_header) 202 { 203 uint8_t *data = (uint8_t *)&scr_msg_header[1]; 204 205 switch (scr_msg_header->type) { 206 case VSC_ATR: 207 DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length); 208 if (scr_msg_header->length > MAX_ATR_SIZE) { 209 error_report("ATR size exceeds spec, ignoring"); 210 ccid_card_vscard_send_error(card, scr_msg_header->reader_id, 211 VSC_GENERAL_ERROR); 212 break; 213 } 214 if (!check_atr(card, data, scr_msg_header->length)) { 215 error_report("ATR is inconsistent, ignoring"); 216 ccid_card_vscard_send_error(card, scr_msg_header->reader_id, 217 VSC_GENERAL_ERROR); 218 break; 219 } 220 memcpy(card->atr, data, scr_msg_header->length); 221 card->atr_length = scr_msg_header->length; 222 ccid_card_card_inserted(&card->base); 223 ccid_card_vscard_send_error(card, scr_msg_header->reader_id, 224 VSC_SUCCESS); 225 break; 226 case VSC_APDU: 227 ccid_card_send_apdu_to_guest( 228 &card->base, data, scr_msg_header->length); 229 break; 230 case VSC_CardRemove: 231 DPRINTF(card, D_INFO, "VSC_CardRemove\n"); 232 ccid_card_card_removed(&card->base); 233 ccid_card_vscard_send_error(card, 234 scr_msg_header->reader_id, VSC_SUCCESS); 235 break; 236 case VSC_Init: 237 ccid_card_vscard_handle_init( 238 card, scr_msg_header, (VSCMsgInit *)data); 239 break; 240 case VSC_Error: 241 ccid_card_card_error(&card->base, *(uint32_t *)data); 242 break; 243 case VSC_ReaderAdd: 244 if (ccid_card_ccid_attach(&card->base) < 0) { 245 ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID, 246 VSC_CANNOT_ADD_MORE_READERS); 247 } else { 248 ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID, 249 VSC_SUCCESS); 250 } 251 break; 252 case VSC_ReaderRemove: 253 ccid_card_ccid_detach(&card->base); 254 ccid_card_vscard_send_error(card, 255 scr_msg_header->reader_id, VSC_SUCCESS); 256 break; 257 default: 258 printf("usb-ccid: chardev: unexpected message of type %X\n", 259 scr_msg_header->type); 260 ccid_card_vscard_send_error(card, scr_msg_header->reader_id, 261 VSC_GENERAL_ERROR); 262 } 263 } 264 265 static void ccid_card_vscard_drop_connection(PassthruState *card) 266 { 267 qemu_chr_fe_deinit(&card->cs, true); 268 card->vscard_in_pos = card->vscard_in_hdr = 0; 269 } 270 271 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size) 272 { 273 PassthruState *card = opaque; 274 VSCMsgHeader *hdr; 275 276 if (card->vscard_in_pos + size > VSCARD_IN_SIZE) { 277 error_report( 278 "no room for data: pos %d + size %d > %d. dropping connection.", 279 card->vscard_in_pos, size, VSCARD_IN_SIZE); 280 ccid_card_vscard_drop_connection(card); 281 return; 282 } 283 assert(card->vscard_in_pos < VSCARD_IN_SIZE); 284 assert(card->vscard_in_hdr < VSCARD_IN_SIZE); 285 memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size); 286 card->vscard_in_pos += size; 287 hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr); 288 289 while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader)) 290 &&(card->vscard_in_pos - card->vscard_in_hdr >= 291 sizeof(VSCMsgHeader) + ntohl(hdr->length))) { 292 hdr->reader_id = ntohl(hdr->reader_id); 293 hdr->length = ntohl(hdr->length); 294 hdr->type = ntohl(hdr->type); 295 ccid_card_vscard_handle_message(card, hdr); 296 card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader); 297 hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr); 298 } 299 if (card->vscard_in_hdr == card->vscard_in_pos) { 300 card->vscard_in_pos = card->vscard_in_hdr = 0; 301 } 302 } 303 304 static void ccid_card_vscard_event(void *opaque, int event) 305 { 306 PassthruState *card = opaque; 307 308 switch (event) { 309 case CHR_EVENT_BREAK: 310 card->vscard_in_pos = card->vscard_in_hdr = 0; 311 break; 312 case CHR_EVENT_OPENED: 313 DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__); 314 break; 315 } 316 } 317 318 /* End VSCard handling */ 319 320 static void passthru_apdu_from_guest( 321 CCIDCardState *base, const uint8_t *apdu, uint32_t len) 322 { 323 PassthruState *card = PASSTHRU_CCID_CARD(base); 324 325 if (!qemu_chr_fe_backend_connected(&card->cs)) { 326 printf("ccid-passthru: no chardev, discarding apdu length %d\n", len); 327 return; 328 } 329 ccid_card_vscard_send_apdu(card, apdu, len); 330 } 331 332 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len) 333 { 334 PassthruState *card = PASSTHRU_CCID_CARD(base); 335 336 *len = card->atr_length; 337 return card->atr; 338 } 339 340 static int passthru_initfn(CCIDCardState *base) 341 { 342 PassthruState *card = PASSTHRU_CCID_CARD(base); 343 344 card->vscard_in_pos = 0; 345 card->vscard_in_hdr = 0; 346 if (qemu_chr_fe_backend_connected(&card->cs)) { 347 DPRINTF(card, D_INFO, "initing chardev\n"); 348 qemu_chr_fe_set_handlers(&card->cs, 349 ccid_card_vscard_can_read, 350 ccid_card_vscard_read, 351 ccid_card_vscard_event, NULL, card, NULL, true); 352 ccid_card_vscard_send_init(card); 353 } else { 354 error_report("missing chardev"); 355 return -1; 356 } 357 card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE, 358 card->debug); 359 assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE); 360 memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR)); 361 card->atr_length = sizeof(DEFAULT_ATR); 362 return 0; 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->initfn = passthru_initfn; 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) 412