xref: /openbmc/qemu/hw/usb/ccid-card-passthru.c (revision 795c40b8)
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     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     Chardev *chr = qemu_chr_fe_get_driver(&card->cs);
268 
269     qemu_chr_fe_deinit(&card->cs);
270     object_unparent(OBJECT(chr));
271     card->vscard_in_pos = card->vscard_in_hdr = 0;
272 }
273 
274 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
275 {
276     PassthruState *card = opaque;
277     VSCMsgHeader *hdr;
278 
279     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
280         error_report(
281             "no room for data: pos %d +  size %d > %d. dropping connection.",
282             card->vscard_in_pos, size, VSCARD_IN_SIZE);
283         ccid_card_vscard_drop_connection(card);
284         return;
285     }
286     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
287     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
288     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
289     card->vscard_in_pos += size;
290     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
291 
292     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
293          &&(card->vscard_in_pos - card->vscard_in_hdr >=
294                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
295         hdr->reader_id = ntohl(hdr->reader_id);
296         hdr->length = ntohl(hdr->length);
297         hdr->type = ntohl(hdr->type);
298         ccid_card_vscard_handle_message(card, hdr);
299         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
300         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
301     }
302     if (card->vscard_in_hdr == card->vscard_in_pos) {
303         card->vscard_in_pos = card->vscard_in_hdr = 0;
304     }
305 }
306 
307 static void ccid_card_vscard_event(void *opaque, int event)
308 {
309     PassthruState *card = opaque;
310 
311     switch (event) {
312     case CHR_EVENT_BREAK:
313         card->vscard_in_pos = card->vscard_in_hdr = 0;
314         break;
315     case CHR_EVENT_OPENED:
316         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
317         break;
318     }
319 }
320 
321 /* End VSCard handling */
322 
323 static void passthru_apdu_from_guest(
324     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
325 {
326     PassthruState *card = PASSTHRU_CCID_CARD(base);
327 
328     if (!qemu_chr_fe_get_driver(&card->cs)) {
329         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
330         return;
331     }
332     ccid_card_vscard_send_apdu(card, apdu, len);
333 }
334 
335 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
336 {
337     PassthruState *card = PASSTHRU_CCID_CARD(base);
338 
339     *len = card->atr_length;
340     return card->atr;
341 }
342 
343 static int passthru_initfn(CCIDCardState *base)
344 {
345     PassthruState *card = PASSTHRU_CCID_CARD(base);
346 
347     card->vscard_in_pos = 0;
348     card->vscard_in_hdr = 0;
349     if (qemu_chr_fe_get_driver(&card->cs)) {
350         DPRINTF(card, D_INFO, "initing chardev\n");
351         qemu_chr_fe_set_handlers(&card->cs,
352             ccid_card_vscard_can_read,
353             ccid_card_vscard_read,
354             ccid_card_vscard_event, card, NULL, true);
355         ccid_card_vscard_send_init(card);
356     } else {
357         error_report("missing chardev");
358         return -1;
359     }
360     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
361                                   card->debug);
362     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
363     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
364     card->atr_length = sizeof(DEFAULT_ATR);
365     return 0;
366 }
367 
368 static VMStateDescription passthru_vmstate = {
369     .name = "ccid-card-passthru",
370     .version_id = 1,
371     .minimum_version_id = 1,
372     .fields = (VMStateField[]) {
373         VMSTATE_BUFFER(vscard_in_data, PassthruState),
374         VMSTATE_UINT32(vscard_in_pos, PassthruState),
375         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
376         VMSTATE_BUFFER(atr, PassthruState),
377         VMSTATE_UINT8(atr_length, PassthruState),
378         VMSTATE_END_OF_LIST()
379     }
380 };
381 
382 static Property passthru_card_properties[] = {
383     DEFINE_PROP_CHR("chardev", PassthruState, cs),
384     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
385     DEFINE_PROP_END_OF_LIST(),
386 };
387 
388 static void passthru_class_initfn(ObjectClass *klass, void *data)
389 {
390     DeviceClass *dc = DEVICE_CLASS(klass);
391     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
392 
393     cc->initfn = passthru_initfn;
394     cc->get_atr = passthru_get_atr;
395     cc->apdu_from_guest = passthru_apdu_from_guest;
396     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
397     dc->desc = "passthrough smartcard";
398     dc->vmsd = &passthru_vmstate;
399     dc->props = passthru_card_properties;
400 }
401 
402 static const TypeInfo passthru_card_info = {
403     .name          = TYPE_CCID_PASSTHRU,
404     .parent        = TYPE_CCID_CARD,
405     .instance_size = sizeof(PassthruState),
406     .class_init    = passthru_class_initfn,
407 };
408 
409 static void ccid_card_passthru_register_types(void)
410 {
411     type_register_static(&passthru_card_info);
412 }
413 
414 type_init(ccid_card_passthru_register_types)
415