1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
|
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef SMARTCARD
#include "includes.h"
RCSID("$OpenBSD: scard.c,v 1.28 2003/06/12 19:12:02 markus Exp $");
#include <openssl/evp.h>
#include <sectok.h>
#include "key.h"
#include "log.h"
#include "xmalloc.h"
#include "readpass.h"
#include "scard.h"
#if OPENSSL_VERSION_NUMBER < 0x00907000L
#define USE_ENGINE
#define RSA_get_default_method RSA_get_default_openssl_method
#else
#endif
#ifdef USE_ENGINE
#include <openssl/engine.h>
#define sc_get_rsa sc_get_engine
#else
#define sc_get_rsa sc_get_rsa_method
#endif
#define CLA_SSH 0x05
#define INS_DECRYPT 0x10
#define INS_GET_KEYLENGTH 0x20
#define INS_GET_PUBKEY 0x30
#define INS_GET_RESPONSE 0xc0
#define MAX_BUF_SIZE 256
u_char DEFAUT0[] = {0xad, 0x9f, 0x61, 0xfe, 0xfa, 0x20, 0xce, 0x63};
static int sc_fd = -1;
static char *sc_reader_id = NULL;
static char *sc_pin = NULL;
static int cla = 0x00; /* class */
static void sc_mk_digest(const char *pin, u_char *digest);
static int get_AUT0(u_char *aut0);
static int try_AUT0(void);
/* interface to libsectok */
static int
sc_open(void)
{
int sw;
if (sc_fd >= 0)
return sc_fd;
sc_fd = sectok_friendly_open(sc_reader_id, STONOWAIT, &sw);
if (sc_fd < 0) {
error("sectok_open failed: %s", sectok_get_sw(sw));
return SCARD_ERROR_FAIL;
}
if (! sectok_cardpresent(sc_fd)) {
debug("smartcard in reader %s not present, skipping",
sc_reader_id);
sc_close();
return SCARD_ERROR_NOCARD;
}
if (sectok_reset(sc_fd, 0, NULL, &sw) <= 0) {
error("sectok_reset failed: %s", sectok_get_sw(sw));
sc_fd = -1;
return SCARD_ERROR_FAIL;
}
if ((cla = cyberflex_inq_class(sc_fd)) < 0)
cla = 0;
debug("sc_open ok %d", sc_fd);
return sc_fd;
}
static int
sc_enable_applet(void)
{
static u_char aid[] = {0xfc, 0x53, 0x73, 0x68, 0x2e, 0x62, 0x69, 0x6e};
int sw = 0;
/* select applet id */
sectok_apdu(sc_fd, cla, 0xa4, 0x04, 0, sizeof aid, aid, 0, NULL, &sw);
if (!sectok_swOK(sw)) {
error("sectok_apdu failed: %s", sectok_get_sw(sw));
sc_close();
return -1;
}
return 0;
}
static int
sc_init(void)
{
int status;
status = sc_open();
if (status == SCARD_ERROR_NOCARD) {
return SCARD_ERROR_NOCARD;
}
if (status < 0 ) {
error("sc_open failed");
return status;
}
if (sc_enable_applet() < 0) {
error("sc_enable_applet failed");
return SCARD_ERROR_APPLET;
}
return 0;
}
static int
sc_read_pubkey(Key * k)
{
u_char buf[2], *n;
char *p;
int len, sw, status = -1;
len = sw = 0;
n = NULL;
if (sc_fd < 0) {
if (sc_init() < 0)
goto err;
}
/* get key size */
sectok_apdu(sc_fd, CLA_SSH, INS_GET_KEYLENGTH, 0, 0, 0, NULL,
sizeof(buf), buf, &sw);
if (!sectok_swOK(sw)) {
error("could not obtain key length: %s", sectok_get_sw(sw));
goto err;
}
len = (buf[0] << 8) | buf[1];
len /= 8;
debug("INS_GET_KEYLENGTH: len %d sw %s", len, sectok_get_sw(sw));
n = xmalloc(len);
/* get n */
sectok_apdu(sc_fd, CLA_SSH, INS_GET_PUBKEY, 0, 0, 0, NULL, len, n, &sw);
if (sw == 0x6982) {
if (try_AUT0() < 0)
goto err;
sectok_apdu(sc_fd, CLA_SSH, INS_GET_PUBKEY, 0, 0, 0, NULL, len, n, &sw);
}
if (!sectok_swOK(sw)) {
error("could not obtain public key: %s", sectok_get_sw(sw));
goto err;
}
debug("INS_GET_KEYLENGTH: sw %s", sectok_get_sw(sw));
if (BN_bin2bn(n, len, k->rsa->n) == NULL) {
error("c_read_pubkey: BN_bin2bn failed");
goto err;
}
/* currently the java applet just stores 'n' */
if (!BN_set_word(k->rsa->e, 35)) {
error("c_read_pubkey: BN_set_word(e, 35) failed");
goto err;
}
status = 0;
p = key_fingerprint(k, SSH_FP_MD5, SSH_FP_HEX);
debug("fingerprint %u %s", key_size(k), p);
xfree(p);
err:
if (n != NULL)
xfree(n);
sc_close();
return status;
}
/* private key operations */
static int
sc_private_decrypt(int flen, u_char *from, u_char *to, RSA *rsa,
int padding)
{
u_char *padded = NULL;
int sw, len, olen, status = -1;
debug("sc_private_decrypt called");
olen = len = sw = 0;
if (sc_fd < 0) {
status = sc_init();
if (status < 0 )
goto err;
}
if (padding != RSA_PKCS1_PADDING)
goto err;
len = BN_num_bytes(rsa->n);
padded = xmalloc(len);
sectok_apdu(sc_fd, CLA_SSH, INS_DECRYPT, 0, 0, len, from, len, padded, &sw);
if (sw == 0x6982) {
if (try_AUT0() < 0)
goto err;
sectok_apdu(sc_fd, CLA_SSH, INS_DECRYPT, 0, 0, len, from, len, padded, &sw);
}
if (!sectok_swOK(sw)) {
error("sc_private_decrypt: INS_DECRYPT failed: %s",
sectok_get_sw(sw));
goto err;
}
olen = RSA_padding_check_PKCS1_type_2(to, len, padded + 1, len - 1,
len);
err:
if (padded)
xfree(padded);
sc_close();
return (olen >= 0 ? olen : status);
}
static int
sc_private_encrypt(int flen, u_char *from, u_char *to, RSA *rsa,
int padding)
{
u_char *padded = NULL;
int sw, len, status = -1;
len = sw = 0;
if (sc_fd < 0) {
status = sc_init();
if (status < 0 )
goto err;
}
if (padding != RSA_PKCS1_PADDING)
goto err;
debug("sc_private_encrypt called");
len = BN_num_bytes(rsa->n);
padded = xmalloc(len);
if (RSA_padding_add_PKCS1_type_1(padded, len, (u_char *)from, flen) <= 0) {
error("RSA_padding_add_PKCS1_type_1 failed");
goto err;
}
sectok_apdu(sc_fd, CLA_SSH, INS_DECRYPT, 0, 0, len, padded, len, to, &sw);
if (sw == 0x6982) {
if (try_AUT0() < 0)
goto err;
sectok_apdu(sc_fd, CLA_SSH, INS_DECRYPT, 0, 0, len, padded, len, to, &sw);
}
if (!sectok_swOK(sw)) {
error("sc_private_encrypt: INS_DECRYPT failed: %s",
sectok_get_sw(sw));
goto err;
}
err:
if (padded)
xfree(padded);
sc_close();
return (len >= 0 ? len : status);
}
/* called on free */
static int (*orig_finish)(RSA *rsa) = NULL;
static int
sc_finish(RSA *rsa)
{
if (orig_finish)
orig_finish(rsa);
sc_close();
return 1;
}
/* engine for overloading private key operations */
static RSA_METHOD *
sc_get_rsa_method(void)
{
static RSA_METHOD smart_rsa;
const RSA_METHOD *def = RSA_get_default_method();
/* use the OpenSSL version */
memcpy(&smart_rsa, def, sizeof(smart_rsa));
smart_rsa.name = "sectok";
/* overload */
smart_rsa.rsa_priv_enc = sc_private_encrypt;
smart_rsa.rsa_priv_dec = sc_private_decrypt;
/* save original */
orig_finish = def->finish;
smart_rsa.finish = sc_finish;
return &smart_rsa;
}
#ifdef USE_ENGINE
static ENGINE *
sc_get_engine(void)
{
static ENGINE *smart_engine = NULL;
if ((smart_engine = ENGINE_new()) == NULL)
fatal("ENGINE_new failed");
ENGINE_set_id(smart_engine, "sectok");
ENGINE_set_name(smart_engine, "libsectok");
ENGINE_set_RSA(smart_engine, sc_get_rsa_method());
ENGINE_set_DSA(smart_engine, DSA_get_default_openssl_method());
ENGINE_set_DH(smart_engine, DH_get_default_openssl_method());
ENGINE_set_RAND(smart_engine, RAND_SSLeay());
ENGINE_set_BN_mod_exp(smart_engine, BN_mod_exp);
return smart_engine;
}
#endif
void
sc_close(void)
{
if (sc_fd >= 0) {
sectok_close(sc_fd);
sc_fd = -1;
}
}
Key **
sc_get_keys(const char *id, const char *pin)
{
Key *k, *n, **keys;
int status, nkeys = 2;
if (sc_reader_id != NULL)
xfree(sc_reader_id);
sc_reader_id = xstrdup(id);
if (sc_pin != NULL)
xfree(sc_pin);
sc_pin = (pin == NULL) ? NULL : xstrdup(pin);
k = key_new(KEY_RSA);
if (k == NULL) {
return NULL;
}
status = sc_read_pubkey(k);
if (status == SCARD_ERROR_NOCARD) {
key_free(k);
return NULL;
}
if (status < 0 ) {
error("sc_read_pubkey failed");
key_free(k);
return NULL;
}
keys = xmalloc((nkeys+1) * sizeof(Key *));
n = key_new(KEY_RSA1);
BN_copy(n->rsa->n, k->rsa->n);
BN_copy(n->rsa->e, k->rsa->e);
RSA_set_method(n->rsa, sc_get_rsa());
n->flags |= KEY_FLAG_EXT;
keys[0] = n;
n = key_new(KEY_RSA);
BN_copy(n->rsa->n, k->rsa->n);
BN_copy(n->rsa->e, k->rsa->e);
RSA_set_method(n->rsa, sc_get_rsa());
n->flags |= KEY_FLAG_EXT;
keys[1] = n;
keys[2] = NULL;
key_free(k);
return keys;
}
#define NUM_RSA_KEY_ELEMENTS 5+1
#define COPY_RSA_KEY(x, i) \
do { \
len = BN_num_bytes(prv->rsa->x); \
elements[i] = xmalloc(len); \
debug("#bytes %d", len); \
if (BN_bn2bin(prv->rsa->x, elements[i]) < 0) \
goto done; \
} while (0)
static void
sc_mk_digest(const char *pin, u_char *digest)
{
const EVP_MD *evp_md = EVP_sha1();
EVP_MD_CTX md;
EVP_DigestInit(&md, evp_md);
EVP_DigestUpdate(&md, pin, strlen(pin));
EVP_DigestFinal(&md, digest, NULL);
}
static int
get_AUT0(u_char *aut0)
{
char *pass;
pass = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
if (pass == NULL)
return -1;
if (!strcmp(pass, "-")) {
memcpy(aut0, DEFAUT0, sizeof DEFAUT0);
return 0;
}
sc_mk_digest(pass, aut0);
memset(pass, 0, strlen(pass));
xfree(pass);
return 0;
}
static int
try_AUT0(void)
{
u_char aut0[EVP_MAX_MD_SIZE];
/* permission denied; try PIN if provided */
if (sc_pin && strlen(sc_pin) > 0) {
sc_mk_digest(sc_pin, aut0);
if (cyberflex_verify_AUT0(sc_fd, cla, aut0, 8) < 0) {
error("smartcard passphrase incorrect");
return (-1);
}
} else {
/* try default AUT0 key */
if (cyberflex_verify_AUT0(sc_fd, cla, DEFAUT0, 8) < 0) {
/* default AUT0 key failed; prompt for passphrase */
if (get_AUT0(aut0) < 0 ||
cyberflex_verify_AUT0(sc_fd, cla, aut0, 8) < 0) {
error("smartcard passphrase incorrect");
return (-1);
}
}
}
return (0);
}
int
sc_put_key(Key *prv, const char *id)
{
u_char *elements[NUM_RSA_KEY_ELEMENTS];
u_char key_fid[2];
u_char AUT0[EVP_MAX_MD_SIZE];
int len, status = -1, i, fd = -1, ret;
int sw = 0, cla = 0x00;
for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
elements[i] = NULL;
COPY_RSA_KEY(q, 0);
COPY_RSA_KEY(p, 1);
COPY_RSA_KEY(iqmp, 2);
COPY_RSA_KEY(dmq1, 3);
COPY_RSA_KEY(dmp1, 4);
COPY_RSA_KEY(n, 5);
len = BN_num_bytes(prv->rsa->n);
fd = sectok_friendly_open(id, STONOWAIT, &sw);
if (fd < 0) {
error("sectok_open failed: %s", sectok_get_sw(sw));
goto done;
}
if (! sectok_cardpresent(fd)) {
error("smartcard in reader %s not present", id);
goto done;
}
ret = sectok_reset(fd, 0, NULL, &sw);
if (ret <= 0) {
error("sectok_reset failed: %s", sectok_get_sw(sw));
goto done;
}
if ((cla = cyberflex_inq_class(fd)) < 0) {
error("cyberflex_inq_class failed");
goto done;
}
memcpy(AUT0, DEFAUT0, sizeof(DEFAUT0));
if (cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
if (get_AUT0(AUT0) < 0 ||
cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
memset(AUT0, 0, sizeof(DEFAUT0));
error("smartcard passphrase incorrect");
goto done;
}
}
memset(AUT0, 0, sizeof(DEFAUT0));
key_fid[0] = 0x00;
key_fid[1] = 0x12;
if (cyberflex_load_rsa_priv(fd, cla, key_fid, 5, 8*len, elements,
&sw) < 0) {
error("cyberflex_load_rsa_priv failed: %s", sectok_get_sw(sw));
goto done;
}
if (!sectok_swOK(sw))
goto done;
logit("cyberflex_load_rsa_priv done");
key_fid[0] = 0x73;
key_fid[1] = 0x68;
if (cyberflex_load_rsa_pub(fd, cla, key_fid, len, elements[5],
&sw) < 0) {
error("cyberflex_load_rsa_pub failed: %s", sectok_get_sw(sw));
goto done;
}
if (!sectok_swOK(sw))
goto done;
logit("cyberflex_load_rsa_pub done");
status = 0;
done:
memset(elements[0], '\0', BN_num_bytes(prv->rsa->q));
memset(elements[1], '\0', BN_num_bytes(prv->rsa->p));
memset(elements[2], '\0', BN_num_bytes(prv->rsa->iqmp));
memset(elements[3], '\0', BN_num_bytes(prv->rsa->dmq1));
memset(elements[4], '\0', BN_num_bytes(prv->rsa->dmp1));
memset(elements[5], '\0', BN_num_bytes(prv->rsa->n));
for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
if (elements[i])
xfree(elements[i]);
if (fd != -1)
sectok_close(fd);
return (status);
}
char *
sc_get_key_label(Key *key)
{
return xstrdup("smartcard key");
}
#endif /* SMARTCARD */
|