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/cutils.h"
13 #include "qemu/units.h"
14 #include <libcacard.h>
15 #include "chardev/char-fe.h"
16 #include "hw/qdev-properties.h"
17 #include "hw/qdev-properties-system.h"
18 #include "migration/vmstate.h"
19 #include "qemu/error-report.h"
20 #include "qemu/module.h"
21 #include "qemu/sockets.h"
22 #include "ccid.h"
23 #include "qapi/error.h"
24 #include "qom/object.h"
25
26 #define DPRINTF(card, lvl, fmt, ...) \
27 do { \
28 if (lvl <= card->debug) { \
29 printf("ccid-card-passthru: " fmt , ## __VA_ARGS__); \
30 } \
31 } while (0)
32
33 #define D_WARN 1
34 #define D_INFO 2
35 #define D_MORE_INFO 3
36 #define D_VERBOSE 4
37
38 /* TODO: do we still need this? */
39 static const uint8_t DEFAULT_ATR[] = {
40 /*
41 * From some example somewhere
42 * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
43 */
44
45 /* From an Athena smart card */
46 0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
47 0x13, 0x08
48 };
49
50 #define VSCARD_IN_SIZE (64 * KiB)
51
52 /* maximum size of ATR - from 7816-3 */
53 #define MAX_ATR_SIZE 40
54
55 typedef struct PassthruState PassthruState;
56
57 struct PassthruState {
58 CCIDCardState base;
59 CharBackend cs;
60 uint8_t vscard_in_data[VSCARD_IN_SIZE];
61 uint32_t vscard_in_pos;
62 uint32_t vscard_in_hdr;
63 uint8_t atr[MAX_ATR_SIZE];
64 uint8_t atr_length;
65 uint8_t debug;
66 };
67
68 #define TYPE_CCID_PASSTHRU "ccid-card-passthru"
DECLARE_INSTANCE_CHECKER(PassthruState,PASSTHRU_CCID_CARD,TYPE_CCID_PASSTHRU)69 DECLARE_INSTANCE_CHECKER(PassthruState, PASSTHRU_CCID_CARD,
70 TYPE_CCID_PASSTHRU)
71
72 /*
73 * VSCard protocol over chardev
74 * This code should not depend on the card type.
75 */
76
77 static void ccid_card_vscard_send_msg(PassthruState *s,
78 VSCMsgType type, uint32_t reader_id,
79 const uint8_t *payload, uint32_t length)
80 {
81 VSCMsgHeader scr_msg_header;
82
83 scr_msg_header.type = htonl(type);
84 scr_msg_header.reader_id = htonl(reader_id);
85 scr_msg_header.length = htonl(length);
86 /* XXX this blocks entire thread. Rewrite to use
87 * qemu_chr_fe_write and background I/O callbacks */
88 qemu_chr_fe_write_all(&s->cs, (uint8_t *)&scr_msg_header,
89 sizeof(VSCMsgHeader));
90 qemu_chr_fe_write_all(&s->cs, payload, length);
91 }
92
ccid_card_vscard_send_apdu(PassthruState * s,const uint8_t * apdu,uint32_t length)93 static void ccid_card_vscard_send_apdu(PassthruState *s,
94 const uint8_t *apdu, uint32_t length)
95 {
96 ccid_card_vscard_send_msg(
97 s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
98 }
99
ccid_card_vscard_send_error(PassthruState * s,uint32_t reader_id,VSCErrorCode code)100 static void ccid_card_vscard_send_error(PassthruState *s,
101 uint32_t reader_id, VSCErrorCode code)
102 {
103 VSCMsgError msg = {.code = htonl(code)};
104
105 ccid_card_vscard_send_msg(
106 s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
107 }
108
ccid_card_vscard_send_init(PassthruState * s)109 static void ccid_card_vscard_send_init(PassthruState *s)
110 {
111 VSCMsgInit msg = {
112 .version = htonl(VSCARD_VERSION),
113 .magic = VSCARD_MAGIC,
114 .capabilities = {0}
115 };
116
117 ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
118 (uint8_t *)&msg, sizeof(msg));
119 }
120
ccid_card_vscard_can_read(void * opaque)121 static int ccid_card_vscard_can_read(void *opaque)
122 {
123 PassthruState *card = opaque;
124
125 return VSCARD_IN_SIZE >= card->vscard_in_pos ?
126 VSCARD_IN_SIZE - card->vscard_in_pos : 0;
127 }
128
ccid_card_vscard_handle_init(PassthruState * card,VSCMsgHeader * hdr,VSCMsgInit * init)129 static void ccid_card_vscard_handle_init(
130 PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
131 {
132 uint32_t *capabilities;
133 int num_capabilities;
134 int i;
135
136 capabilities = init->capabilities;
137 num_capabilities =
138 1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
139 init->version = ntohl(init->version);
140 for (i = 0 ; i < num_capabilities; ++i) {
141 capabilities[i] = ntohl(capabilities[i]);
142 }
143 if (init->magic != VSCARD_MAGIC) {
144 error_report("wrong magic");
145 /* we can't disconnect the chardev */
146 }
147 if (init->version != VSCARD_VERSION) {
148 DPRINTF(card, D_WARN,
149 "got version %d, have %d", init->version, VSCARD_VERSION);
150 }
151 /* future handling of capabilities, none exist atm */
152 ccid_card_vscard_send_init(card);
153 }
154
check_atr(PassthruState * card,uint8_t * data,int len)155 static int check_atr(PassthruState *card, uint8_t *data, int len)
156 {
157 int historical_length, opt_bytes;
158 int td_count = 0;
159 int td;
160
161 if (len < 2) {
162 return 0;
163 }
164 historical_length = data[1] & 0xf;
165 opt_bytes = 0;
166 if (data[0] != 0x3b && data[0] != 0x3f) {
167 DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
168 data[0]);
169 return 0;
170 }
171 td_count = 0;
172 td = data[1] >> 4;
173 while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
174 td_count++;
175 if (td & 0x1) {
176 opt_bytes++;
177 }
178 if (td & 0x2) {
179 opt_bytes++;
180 }
181 if (td & 0x4) {
182 opt_bytes++;
183 }
184 if (td & 0x8) {
185 opt_bytes++;
186 td = data[opt_bytes + 2] >> 4;
187 }
188 }
189 if (len < 2 + historical_length + opt_bytes) {
190 DPRINTF(card, D_WARN,
191 "atr too short: len %d, but historical_len %d, T1 0x%X\n",
192 len, historical_length, data[1]);
193 return 0;
194 }
195 if (len > 2 + historical_length + opt_bytes) {
196 DPRINTF(card, D_WARN,
197 "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
198 len, historical_length, opt_bytes, data[1]);
199 /* let it through */
200 }
201 DPRINTF(card, D_VERBOSE,
202 "atr passes check: %d total length, %d historical, %d optional\n",
203 len, historical_length, opt_bytes);
204
205 return 1;
206 }
207
ccid_card_vscard_handle_message(PassthruState * card,VSCMsgHeader * scr_msg_header)208 static void ccid_card_vscard_handle_message(PassthruState *card,
209 VSCMsgHeader *scr_msg_header)
210 {
211 uint8_t *data = (uint8_t *)&scr_msg_header[1];
212
213 switch (scr_msg_header->type) {
214 case VSC_ATR:
215 DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
216 if (scr_msg_header->length > MAX_ATR_SIZE) {
217 error_report("ATR size exceeds spec, ignoring");
218 ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
219 VSC_GENERAL_ERROR);
220 break;
221 }
222 if (!check_atr(card, data, scr_msg_header->length)) {
223 error_report("ATR is inconsistent, ignoring");
224 ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
225 VSC_GENERAL_ERROR);
226 break;
227 }
228 memcpy(card->atr, data, scr_msg_header->length);
229 card->atr_length = scr_msg_header->length;
230 ccid_card_card_inserted(&card->base);
231 ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
232 VSC_SUCCESS);
233 break;
234 case VSC_APDU:
235 ccid_card_send_apdu_to_guest(
236 &card->base, data, scr_msg_header->length);
237 break;
238 case VSC_CardRemove:
239 DPRINTF(card, D_INFO, "VSC_CardRemove\n");
240 ccid_card_card_removed(&card->base);
241 ccid_card_vscard_send_error(card,
242 scr_msg_header->reader_id, VSC_SUCCESS);
243 break;
244 case VSC_Init:
245 ccid_card_vscard_handle_init(
246 card, scr_msg_header, (VSCMsgInit *)data);
247 break;
248 case VSC_Error:
249 ccid_card_card_error(&card->base, *(uint32_t *)data);
250 break;
251 case VSC_ReaderAdd:
252 if (ccid_card_ccid_attach(&card->base) < 0) {
253 ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
254 VSC_CANNOT_ADD_MORE_READERS);
255 } else {
256 ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
257 VSC_SUCCESS);
258 }
259 break;
260 case VSC_ReaderRemove:
261 ccid_card_ccid_detach(&card->base);
262 ccid_card_vscard_send_error(card,
263 scr_msg_header->reader_id, VSC_SUCCESS);
264 break;
265 default:
266 printf("usb-ccid: chardev: unexpected message of type %X\n",
267 scr_msg_header->type);
268 ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
269 VSC_GENERAL_ERROR);
270 }
271 }
272
ccid_card_vscard_drop_connection(PassthruState * card)273 static void ccid_card_vscard_drop_connection(PassthruState *card)
274 {
275 qemu_chr_fe_deinit(&card->cs, true);
276 card->vscard_in_pos = card->vscard_in_hdr = 0;
277 }
278
ccid_card_vscard_read(void * opaque,const uint8_t * buf,int size)279 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
280 {
281 PassthruState *card = opaque;
282 VSCMsgHeader *hdr;
283
284 if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
285 error_report("no room for data: pos %u + size %d > %" PRId64 "."
286 " dropping connection.",
287 card->vscard_in_pos, size, VSCARD_IN_SIZE);
288 ccid_card_vscard_drop_connection(card);
289 return;
290 }
291 assert(card->vscard_in_pos < VSCARD_IN_SIZE);
292 assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
293 memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
294 card->vscard_in_pos += size;
295 hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
296
297 while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
298 &&(card->vscard_in_pos - card->vscard_in_hdr >=
299 sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
300 hdr->reader_id = ntohl(hdr->reader_id);
301 hdr->length = ntohl(hdr->length);
302 hdr->type = ntohl(hdr->type);
303 ccid_card_vscard_handle_message(card, hdr);
304 card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
305 hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
306 }
307 if (card->vscard_in_hdr == card->vscard_in_pos) {
308 card->vscard_in_pos = card->vscard_in_hdr = 0;
309 }
310 }
311
ccid_card_vscard_event(void * opaque,QEMUChrEvent event)312 static void ccid_card_vscard_event(void *opaque, QEMUChrEvent event)
313 {
314 PassthruState *card = opaque;
315
316 switch (event) {
317 case CHR_EVENT_BREAK:
318 card->vscard_in_pos = card->vscard_in_hdr = 0;
319 break;
320 case CHR_EVENT_OPENED:
321 DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
322 break;
323 case CHR_EVENT_MUX_IN:
324 case CHR_EVENT_MUX_OUT:
325 case CHR_EVENT_CLOSED:
326 /* Ignore */
327 break;
328 }
329 }
330
331 /* End VSCard handling */
332
passthru_apdu_from_guest(CCIDCardState * base,const uint8_t * apdu,uint32_t len)333 static void passthru_apdu_from_guest(
334 CCIDCardState *base, const uint8_t *apdu, uint32_t len)
335 {
336 PassthruState *card = PASSTHRU_CCID_CARD(base);
337
338 if (!qemu_chr_fe_backend_connected(&card->cs)) {
339 printf("ccid-passthru: no chardev, discarding apdu length %u\n", len);
340 return;
341 }
342 ccid_card_vscard_send_apdu(card, apdu, len);
343 }
344
passthru_get_atr(CCIDCardState * base,uint32_t * len)345 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
346 {
347 PassthruState *card = PASSTHRU_CCID_CARD(base);
348
349 *len = card->atr_length;
350 return card->atr;
351 }
352
passthru_realize(CCIDCardState * base,Error ** errp)353 static void passthru_realize(CCIDCardState *base, Error **errp)
354 {
355 PassthruState *card = PASSTHRU_CCID_CARD(base);
356
357 card->vscard_in_pos = 0;
358 card->vscard_in_hdr = 0;
359 if (qemu_chr_fe_backend_connected(&card->cs)) {
360 DPRINTF(card, D_INFO, "ccid-card-passthru: initing chardev");
361 qemu_chr_fe_set_handlers(&card->cs,
362 ccid_card_vscard_can_read,
363 ccid_card_vscard_read,
364 ccid_card_vscard_event, NULL, card, NULL, true);
365 ccid_card_vscard_send_init(card);
366 } else {
367 error_setg(errp, "missing chardev");
368 return;
369 }
370 card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
371 card->debug);
372 assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
373 memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
374 card->atr_length = sizeof(DEFAULT_ATR);
375 }
376
377 static const VMStateDescription passthru_vmstate = {
378 .name = "ccid-card-passthru",
379 .version_id = 1,
380 .minimum_version_id = 1,
381 .fields = (const VMStateField[]) {
382 VMSTATE_BUFFER(vscard_in_data, PassthruState),
383 VMSTATE_UINT32(vscard_in_pos, PassthruState),
384 VMSTATE_UINT32(vscard_in_hdr, PassthruState),
385 VMSTATE_BUFFER(atr, PassthruState),
386 VMSTATE_UINT8(atr_length, PassthruState),
387 VMSTATE_END_OF_LIST()
388 }
389 };
390
391 static Property passthru_card_properties[] = {
392 DEFINE_PROP_CHR("chardev", PassthruState, cs),
393 DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
394 DEFINE_PROP_END_OF_LIST(),
395 };
396
passthru_class_initfn(ObjectClass * klass,void * data)397 static void passthru_class_initfn(ObjectClass *klass, void *data)
398 {
399 DeviceClass *dc = DEVICE_CLASS(klass);
400 CCIDCardClass *cc = CCID_CARD_CLASS(klass);
401
402 cc->realize = passthru_realize;
403 cc->get_atr = passthru_get_atr;
404 cc->apdu_from_guest = passthru_apdu_from_guest;
405 set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
406 dc->desc = "passthrough smartcard";
407 dc->vmsd = &passthru_vmstate;
408 device_class_set_props(dc, passthru_card_properties);
409 }
410
411 static const TypeInfo passthru_card_info = {
412 .name = TYPE_CCID_PASSTHRU,
413 .parent = TYPE_CCID_CARD,
414 .instance_size = sizeof(PassthruState),
415 .class_init = passthru_class_initfn,
416 };
417 module_obj(TYPE_CCID_PASSTHRU);
418 module_kconfig(USB);
419
ccid_card_passthru_register_types(void)420 static void ccid_card_passthru_register_types(void)
421 {
422 type_register_static(&passthru_card_info);
423 }
424
425 type_init(ccid_card_passthru_register_types)
426