xref: /openbmc/qemu/hw/usb/ccid-card-passthru.c (revision 2b74dd91)
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"
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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