xref: /openbmc/qemu/hw/usb/ccid-card-passthru.c (revision b917da4c)
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 "sysemu/char.h"
13 #include "qemu/error-report.h"
14 #include "qemu/sockets.h"
15 #include "ccid.h"
16 #include "cacard/vscard_common.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     CharDriverState *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     qemu_chr_fe_write(s->cs, (uint8_t *)&scr_msg_header, sizeof(VSCMsgHeader));
79     qemu_chr_fe_write(s->cs, payload, length);
80 }
81 
82 static void ccid_card_vscard_send_apdu(PassthruState *s,
83     const uint8_t *apdu, uint32_t length)
84 {
85     ccid_card_vscard_send_msg(
86         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
87 }
88 
89 static void ccid_card_vscard_send_error(PassthruState *s,
90                     uint32_t reader_id, VSCErrorCode code)
91 {
92     VSCMsgError msg = {.code = htonl(code)};
93 
94     ccid_card_vscard_send_msg(
95         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
96 }
97 
98 static void ccid_card_vscard_send_init(PassthruState *s)
99 {
100     VSCMsgInit msg = {
101         .version = htonl(VSCARD_VERSION),
102         .magic = VSCARD_MAGIC,
103         .capabilities = {0}
104     };
105 
106     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
107                          (uint8_t *)&msg, sizeof(msg));
108 }
109 
110 static int ccid_card_vscard_can_read(void *opaque)
111 {
112     PassthruState *card = opaque;
113 
114     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
115            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
116 }
117 
118 static void ccid_card_vscard_handle_init(
119     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
120 {
121     uint32_t *capabilities;
122     int num_capabilities;
123     int i;
124 
125     capabilities = init->capabilities;
126     num_capabilities =
127         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
128     init->version = ntohl(init->version);
129     for (i = 0 ; i < num_capabilities; ++i) {
130         capabilities[i] = ntohl(capabilities[i]);
131     }
132     if (init->magic != VSCARD_MAGIC) {
133         error_report("wrong magic");
134         /* we can't disconnect the chardev */
135     }
136     if (init->version != VSCARD_VERSION) {
137         DPRINTF(card, D_WARN,
138             "got version %d, have %d", init->version, VSCARD_VERSION);
139     }
140     /* future handling of capabilities, none exist atm */
141     ccid_card_vscard_send_init(card);
142 }
143 
144 static int check_atr(PassthruState *card, uint8_t *data, int len)
145 {
146     int historical_length, opt_bytes;
147     int td_count = 0;
148     int td;
149 
150     if (len < 2) {
151         return 0;
152     }
153     historical_length = data[1] & 0xf;
154     opt_bytes = 0;
155     if (data[0] != 0x3b && data[0] != 0x3f) {
156         DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
157                 data[0]);
158         return 0;
159     }
160     td_count = 0;
161     td = data[1] >> 4;
162     while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
163         td_count++;
164         if (td & 0x1) {
165             opt_bytes++;
166         }
167         if (td & 0x2) {
168             opt_bytes++;
169         }
170         if (td & 0x4) {
171             opt_bytes++;
172         }
173         if (td & 0x8) {
174             opt_bytes++;
175             td = data[opt_bytes + 2] >> 4;
176         }
177     }
178     if (len < 2 + historical_length + opt_bytes) {
179         DPRINTF(card, D_WARN,
180             "atr too short: len %d, but historical_len %d, T1 0x%X\n",
181             len, historical_length, data[1]);
182         return 0;
183     }
184     if (len > 2 + historical_length + opt_bytes) {
185         DPRINTF(card, D_WARN,
186             "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
187             len, historical_length, opt_bytes, data[1]);
188         /* let it through */
189     }
190     DPRINTF(card, D_VERBOSE,
191             "atr passes check: %d total length, %d historical, %d optional\n",
192             len, historical_length, opt_bytes);
193 
194     return 1;
195 }
196 
197 static void ccid_card_vscard_handle_message(PassthruState *card,
198     VSCMsgHeader *scr_msg_header)
199 {
200     uint8_t *data = (uint8_t *)&scr_msg_header[1];
201 
202     switch (scr_msg_header->type) {
203     case VSC_ATR:
204         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
205         if (scr_msg_header->length > MAX_ATR_SIZE) {
206             error_report("ATR size exceeds spec, ignoring");
207             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
208                                         VSC_GENERAL_ERROR);
209             break;
210         }
211         if (!check_atr(card, data, scr_msg_header->length)) {
212             error_report("ATR is inconsistent, ignoring");
213             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
214                                         VSC_GENERAL_ERROR);
215             break;
216         }
217         memcpy(card->atr, data, scr_msg_header->length);
218         card->atr_length = scr_msg_header->length;
219         ccid_card_card_inserted(&card->base);
220         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
221                                     VSC_SUCCESS);
222         break;
223     case VSC_APDU:
224         ccid_card_send_apdu_to_guest(
225             &card->base, data, scr_msg_header->length);
226         break;
227     case VSC_CardRemove:
228         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
229         ccid_card_card_removed(&card->base);
230         ccid_card_vscard_send_error(card,
231             scr_msg_header->reader_id, VSC_SUCCESS);
232         break;
233     case VSC_Init:
234         ccid_card_vscard_handle_init(
235             card, scr_msg_header, (VSCMsgInit *)data);
236         break;
237     case VSC_Error:
238         ccid_card_card_error(&card->base, *(uint32_t *)data);
239         break;
240     case VSC_ReaderAdd:
241         if (ccid_card_ccid_attach(&card->base) < 0) {
242             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
243                                       VSC_CANNOT_ADD_MORE_READERS);
244         } else {
245             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
246                                         VSC_SUCCESS);
247         }
248         break;
249     case VSC_ReaderRemove:
250         ccid_card_ccid_detach(&card->base);
251         ccid_card_vscard_send_error(card,
252             scr_msg_header->reader_id, VSC_SUCCESS);
253         break;
254     default:
255         printf("usb-ccid: chardev: unexpected message of type %X\n",
256                scr_msg_header->type);
257         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
258             VSC_GENERAL_ERROR);
259     }
260 }
261 
262 static void ccid_card_vscard_drop_connection(PassthruState *card)
263 {
264     qemu_chr_delete(card->cs);
265     card->vscard_in_pos = card->vscard_in_hdr = 0;
266 }
267 
268 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
269 {
270     PassthruState *card = opaque;
271     VSCMsgHeader *hdr;
272 
273     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
274         error_report(
275             "no room for data: pos %d +  size %d > %d. dropping connection.",
276             card->vscard_in_pos, size, VSCARD_IN_SIZE);
277         ccid_card_vscard_drop_connection(card);
278         return;
279     }
280     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
281     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
282     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
283     card->vscard_in_pos += size;
284     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
285 
286     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
287          &&(card->vscard_in_pos - card->vscard_in_hdr >=
288                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
289         hdr->reader_id = ntohl(hdr->reader_id);
290         hdr->length = ntohl(hdr->length);
291         hdr->type = ntohl(hdr->type);
292         ccid_card_vscard_handle_message(card, hdr);
293         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
294         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
295     }
296     if (card->vscard_in_hdr == card->vscard_in_pos) {
297         card->vscard_in_pos = card->vscard_in_hdr = 0;
298     }
299 }
300 
301 static void ccid_card_vscard_event(void *opaque, int event)
302 {
303     PassthruState *card = opaque;
304 
305     switch (event) {
306     case CHR_EVENT_BREAK:
307         card->vscard_in_pos = card->vscard_in_hdr = 0;
308         break;
309     case CHR_EVENT_FOCUS:
310         break;
311     case CHR_EVENT_OPENED:
312         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
313         break;
314     }
315 }
316 
317 /* End VSCard handling */
318 
319 static void passthru_apdu_from_guest(
320     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
321 {
322     PassthruState *card = PASSTHRU_CCID_CARD(base);
323 
324     if (!card->cs) {
325         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
326         return;
327     }
328     ccid_card_vscard_send_apdu(card, apdu, len);
329 }
330 
331 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
332 {
333     PassthruState *card = PASSTHRU_CCID_CARD(base);
334 
335     *len = card->atr_length;
336     return card->atr;
337 }
338 
339 static int passthru_initfn(CCIDCardState *base)
340 {
341     PassthruState *card = PASSTHRU_CCID_CARD(base);
342 
343     card->vscard_in_pos = 0;
344     card->vscard_in_hdr = 0;
345     if (card->cs) {
346         DPRINTF(card, D_INFO, "initing chardev\n");
347         qemu_chr_add_handlers(card->cs,
348             ccid_card_vscard_can_read,
349             ccid_card_vscard_read,
350             ccid_card_vscard_event, card);
351         ccid_card_vscard_send_init(card);
352     } else {
353         error_report("missing chardev");
354         return -1;
355     }
356     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
357                                   card->debug);
358     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
359     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
360     card->atr_length = sizeof(DEFAULT_ATR);
361     return 0;
362 }
363 
364 static int passthru_exitfn(CCIDCardState *base)
365 {
366     return 0;
367 }
368 
369 static VMStateDescription passthru_vmstate = {
370     .name = "ccid-card-passthru",
371     .version_id = 1,
372     .minimum_version_id = 1,
373     .fields = (VMStateField[]) {
374         VMSTATE_BUFFER(vscard_in_data, PassthruState),
375         VMSTATE_UINT32(vscard_in_pos, PassthruState),
376         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
377         VMSTATE_BUFFER(atr, PassthruState),
378         VMSTATE_UINT8(atr_length, PassthruState),
379         VMSTATE_END_OF_LIST()
380     }
381 };
382 
383 static Property passthru_card_properties[] = {
384     DEFINE_PROP_CHR("chardev", PassthruState, cs),
385     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
386     DEFINE_PROP_END_OF_LIST(),
387 };
388 
389 static void passthru_class_initfn(ObjectClass *klass, void *data)
390 {
391     DeviceClass *dc = DEVICE_CLASS(klass);
392     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
393 
394     cc->initfn = passthru_initfn;
395     cc->exitfn = passthru_exitfn;
396     cc->get_atr = passthru_get_atr;
397     cc->apdu_from_guest = passthru_apdu_from_guest;
398     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
399     dc->desc = "passthrough smartcard";
400     dc->vmsd = &passthru_vmstate;
401     dc->props = passthru_card_properties;
402 }
403 
404 static const TypeInfo passthru_card_info = {
405     .name          = TYPE_CCID_PASSTHRU,
406     .parent        = TYPE_CCID_CARD,
407     .instance_size = sizeof(PassthruState),
408     .class_init    = passthru_class_initfn,
409 };
410 
411 static void ccid_card_passthru_register_types(void)
412 {
413     type_register_static(&passthru_card_info);
414 }
415 
416 type_init(ccid_card_passthru_register_types)
417