This repository has been archived by the owner on Sep 20, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 6
/
Copy pathauthfile.c
1308 lines (1180 loc) · 33.5 KB
/
authfile.c
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
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* $OpenBSD: authfile.c,v 1.103 2014/02/02 03:44:31 djm Exp $ */
/*
* Author: Tatu Ylonen <[email protected]>
* Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
* All rights reserved
* This file contains functions for reading and writing identity files, and
* for reading the passphrase from the user.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
*
* Copyright (c) 2000, 2013 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.
*/
#include "includes.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
/* compatibility with old or broken OpenSSL versions */
#include "openbsd-compat/openssl-compat.h"
#include "crypto_api.h"
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#include "xmalloc.h"
#include "cipher.h"
#include "buffer.h"
#include "key.h"
#include "ssh.h"
#include "log.h"
#include "authfile.h"
#include "rsa.h"
#include "misc.h"
#include "atomicio.h"
#include "uuencode.h"
/* openssh private key file format */
#define MARK_BEGIN "-----BEGIN OPENSSH PRIVATE KEY-----\n"
#define MARK_END "-----END OPENSSH PRIVATE KEY-----\n"
#define KDFNAME "bcrypt"
#define AUTH_MAGIC "openssh-key-v1"
#define SALT_LEN 16
#define DEFAULT_CIPHERNAME "aes256-cbc"
#define DEFAULT_ROUNDS 16
#define MAX_KEY_FILE_SIZE (1024 * 1024)
/* Version identification string for SSH v1 identity files. */
static const char authfile_id_string[] =
"SSH PRIVATE KEY FILE FORMAT 1.1\n";
static int
key_private_to_blob2(Key *prv, Buffer *blob, const char *passphrase,
const char *comment, const char *ciphername, int rounds)
{
u_char *key, *cp, salt[SALT_LEN];
size_t keylen, ivlen, blocksize, authlen;
u_int len, check;
int i, n;
const Cipher *c;
Buffer encoded, b, kdf;
CipherContext ctx;
const char *kdfname = KDFNAME;
if (rounds <= 0)
rounds = DEFAULT_ROUNDS;
if (passphrase == NULL || !strlen(passphrase)) {
ciphername = "none";
kdfname = "none";
} else if (ciphername == NULL)
ciphername = DEFAULT_CIPHERNAME;
else if (cipher_number(ciphername) != SSH_CIPHER_SSH2)
fatal("invalid cipher");
if ((c = cipher_by_name(ciphername)) == NULL)
fatal("unknown cipher name");
buffer_init(&kdf);
blocksize = cipher_blocksize(c);
keylen = cipher_keylen(c);
ivlen = cipher_ivlen(c);
authlen = cipher_authlen(c);
key = xcalloc(1, keylen + ivlen);
if (strcmp(kdfname, "none") != 0) {
arc4random_buf(salt, SALT_LEN);
if (bcrypt_pbkdf(passphrase, strlen(passphrase),
salt, SALT_LEN, key, keylen + ivlen, rounds) < 0)
fatal("bcrypt_pbkdf failed");
buffer_put_string(&kdf, salt, SALT_LEN);
buffer_put_int(&kdf, rounds);
}
cipher_init(&ctx, c, key, keylen, key + keylen , ivlen, 1);
explicit_bzero(key, keylen + ivlen);
free(key);
buffer_init(&encoded);
buffer_append(&encoded, AUTH_MAGIC, sizeof(AUTH_MAGIC));
buffer_put_cstring(&encoded, ciphername);
buffer_put_cstring(&encoded, kdfname);
buffer_put_string(&encoded, buffer_ptr(&kdf), buffer_len(&kdf));
buffer_put_int(&encoded, 1); /* number of keys */
key_to_blob(prv, &cp, &len); /* public key */
buffer_put_string(&encoded, cp, len);
explicit_bzero(cp, len);
free(cp);
buffer_free(&kdf);
/* set up the buffer that will be encrypted */
buffer_init(&b);
/* Random check bytes */
check = arc4random();
buffer_put_int(&b, check);
buffer_put_int(&b, check);
/* append private key and comment*/
key_private_serialize(prv, &b);
buffer_put_cstring(&b, comment);
/* padding */
i = 0;
while (buffer_len(&b) % blocksize)
buffer_put_char(&b, ++i & 0xff);
/* length */
buffer_put_int(&encoded, buffer_len(&b));
/* encrypt */
cp = buffer_append_space(&encoded, buffer_len(&b) + authlen);
if (cipher_crypt(&ctx, 0, cp, buffer_ptr(&b), buffer_len(&b), 0,
authlen) != 0)
fatal("%s: cipher_crypt failed", __func__);
buffer_free(&b);
cipher_cleanup(&ctx);
/* uuencode */
len = 2 * buffer_len(&encoded);
cp = xmalloc(len);
n = uuencode(buffer_ptr(&encoded), buffer_len(&encoded),
(char *)cp, len);
if (n < 0)
fatal("%s: uuencode", __func__);
buffer_clear(blob);
buffer_append(blob, MARK_BEGIN, sizeof(MARK_BEGIN) - 1);
for (i = 0; i < n; i++) {
buffer_put_char(blob, cp[i]);
if (i % 70 == 69)
buffer_put_char(blob, '\n');
}
if (i % 70 != 69)
buffer_put_char(blob, '\n');
buffer_append(blob, MARK_END, sizeof(MARK_END) - 1);
free(cp);
return buffer_len(blob);
}
static Key *
key_parse_private2(Buffer *blob, int type, const char *passphrase,
char **commentp)
{
u_char *key = NULL, *cp, *salt = NULL, pad, last;
char *comment = NULL, *ciphername = NULL, *kdfname = NULL, *kdfp;
u_int keylen = 0, ivlen, blocksize, slen, klen, len, rounds, nkeys;
u_int check1, check2, m1len, m2len;
size_t authlen;
const Cipher *c;
Buffer b, encoded, copy, kdf;
CipherContext ctx;
Key *k = NULL;
int dlen, ret, i;
buffer_init(&b);
buffer_init(&kdf);
buffer_init(&encoded);
buffer_init(©);
/* uudecode */
m1len = sizeof(MARK_BEGIN) - 1;
m2len = sizeof(MARK_END) - 1;
cp = buffer_ptr(blob);
len = buffer_len(blob);
if (len < m1len || memcmp(cp, MARK_BEGIN, m1len)) {
debug("%s: missing begin marker", __func__);
goto out;
}
cp += m1len;
len -= m1len;
while (len) {
if (*cp != '\n' && *cp != '\r')
buffer_put_char(&encoded, *cp);
last = *cp;
len--;
cp++;
if (last == '\n') {
if (len >= m2len && !memcmp(cp, MARK_END, m2len)) {
buffer_put_char(&encoded, '\0');
break;
}
}
}
if (!len) {
debug("%s: no end marker", __func__);
goto out;
}
len = buffer_len(&encoded);
if ((cp = buffer_append_space(©, len)) == NULL) {
error("%s: buffer_append_space", __func__);
goto out;
}
if ((dlen = uudecode(buffer_ptr(&encoded), cp, len)) < 0) {
error("%s: uudecode failed", __func__);
goto out;
}
if ((u_int)dlen > len) {
error("%s: crazy uudecode length %d > %u", __func__, dlen, len);
goto out;
}
buffer_consume_end(©, len - dlen);
if (buffer_len(©) < sizeof(AUTH_MAGIC) ||
memcmp(buffer_ptr(©), AUTH_MAGIC, sizeof(AUTH_MAGIC))) {
error("%s: bad magic", __func__);
goto out;
}
buffer_consume(©, sizeof(AUTH_MAGIC));
ciphername = buffer_get_cstring_ret(©, NULL);
if (ciphername == NULL ||
(c = cipher_by_name(ciphername)) == NULL) {
error("%s: unknown cipher name", __func__);
goto out;
}
if ((passphrase == NULL || !strlen(passphrase)) &&
strcmp(ciphername, "none") != 0) {
/* passphrase required */
goto out;
}
kdfname = buffer_get_cstring_ret(©, NULL);
if (kdfname == NULL ||
(!strcmp(kdfname, "none") && !strcmp(kdfname, "bcrypt"))) {
error("%s: unknown kdf name", __func__);
goto out;
}
if (!strcmp(kdfname, "none") && strcmp(ciphername, "none") != 0) {
error("%s: cipher %s requires kdf", __func__, ciphername);
goto out;
}
/* kdf options */
kdfp = buffer_get_string_ptr_ret(©, &klen);
if (kdfp == NULL) {
error("%s: kdf options not set", __func__);
goto out;
}
if (klen > 0) {
if ((cp = buffer_append_space(&kdf, klen)) == NULL) {
error("%s: kdf alloc failed", __func__);
goto out;
}
memcpy(cp, kdfp, klen);
}
/* number of keys */
if (buffer_get_int_ret(&nkeys, ©) < 0) {
error("%s: key counter missing", __func__);
goto out;
}
if (nkeys != 1) {
error("%s: only one key supported", __func__);
goto out;
}
/* pubkey */
if ((cp = buffer_get_string_ret(©, &len)) == NULL) {
error("%s: pubkey not found", __func__);
goto out;
}
free(cp); /* XXX check pubkey against decrypted private key */
/* size of encrypted key blob */
len = buffer_get_int(©);
blocksize = cipher_blocksize(c);
authlen = cipher_authlen(c);
if (len < blocksize) {
error("%s: encrypted data too small", __func__);
goto out;
}
if (len % blocksize) {
error("%s: length not multiple of blocksize", __func__);
goto out;
}
/* setup key */
keylen = cipher_keylen(c);
ivlen = cipher_ivlen(c);
key = xcalloc(1, keylen + ivlen);
if (!strcmp(kdfname, "bcrypt")) {
if ((salt = buffer_get_string_ret(&kdf, &slen)) == NULL) {
error("%s: salt not set", __func__);
goto out;
}
if (buffer_get_int_ret(&rounds, &kdf) < 0) {
error("%s: rounds not set", __func__);
goto out;
}
if (bcrypt_pbkdf(passphrase, strlen(passphrase), salt, slen,
key, keylen + ivlen, rounds) < 0) {
error("%s: bcrypt_pbkdf failed", __func__);
goto out;
}
}
cp = buffer_append_space(&b, len);
cipher_init(&ctx, c, key, keylen, key + keylen, ivlen, 0);
ret = cipher_crypt(&ctx, 0, cp, buffer_ptr(©), len, 0, authlen);
cipher_cleanup(&ctx);
buffer_consume(©, len);
/* fail silently on decryption errors */
if (ret != 0) {
debug("%s: decrypt failed", __func__);
goto out;
}
if (buffer_len(©) != 0) {
error("%s: key blob has trailing data (len = %u)", __func__,
buffer_len(©));
goto out;
}
/* check bytes */
if (buffer_get_int_ret(&check1, &b) < 0 ||
buffer_get_int_ret(&check2, &b) < 0) {
error("check bytes missing");
goto out;
}
if (check1 != check2) {
debug("%s: decrypt failed: 0x%08x != 0x%08x", __func__,
check1, check2);
goto out;
}
k = key_private_deserialize(&b);
/* comment */
comment = buffer_get_cstring_ret(&b, NULL);
i = 0;
while (buffer_len(&b)) {
if (buffer_get_char_ret(&pad, &b) == -1 ||
pad != (++i & 0xff)) {
error("%s: bad padding", __func__);
key_free(k);
k = NULL;
goto out;
}
}
if (k && commentp) {
*commentp = comment;
comment = NULL;
}
/* XXX decode pubkey and check against private */
out:
free(ciphername);
free(kdfname);
free(salt);
free(comment);
if (key)
explicit_bzero(key, keylen + ivlen);
free(key);
buffer_free(&encoded);
buffer_free(©);
buffer_free(&kdf);
buffer_free(&b);
return k;
}
/*
* Serialises the authentication (private) key to a blob, encrypting it with
* passphrase. The identification of the blob (lowest 64 bits of n) will
* precede the key to provide identification of the key without needing a
* passphrase.
*/
static int
key_private_rsa1_to_blob(Key *key, Buffer *blob, const char *passphrase,
const char *comment)
{
Buffer buffer, encrypted;
u_char buf[100], *cp;
int i, cipher_num;
CipherContext ciphercontext;
const Cipher *cipher;
u_int32_t rnd;
/*
* If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
* to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
*/
cipher_num = (strcmp(passphrase, "") == 0) ?
SSH_CIPHER_NONE : SSH_AUTHFILE_CIPHER;
if ((cipher = cipher_by_number(cipher_num)) == NULL)
fatal("save_private_key_rsa: bad cipher");
/* This buffer is used to built the secret part of the private key. */
buffer_init(&buffer);
/* Put checkbytes for checking passphrase validity. */
rnd = arc4random();
buf[0] = rnd & 0xff;
buf[1] = (rnd >> 8) & 0xff;
buf[2] = buf[0];
buf[3] = buf[1];
buffer_append(&buffer, buf, 4);
/*
* Store the private key (n and e will not be stored because they
* will be stored in plain text, and storing them also in encrypted
* format would just give known plaintext).
*/
buffer_put_bignum(&buffer, key->rsa->d);
buffer_put_bignum(&buffer, key->rsa->iqmp);
buffer_put_bignum(&buffer, key->rsa->q); /* reverse from SSL p */
buffer_put_bignum(&buffer, key->rsa->p); /* reverse from SSL q */
/* Pad the part to be encrypted until its size is a multiple of 8. */
while (buffer_len(&buffer) % 8 != 0)
buffer_put_char(&buffer, 0);
/* This buffer will be used to contain the data in the file. */
buffer_init(&encrypted);
/* First store keyfile id string. */
for (i = 0; authfile_id_string[i]; i++)
buffer_put_char(&encrypted, authfile_id_string[i]);
buffer_put_char(&encrypted, 0);
/* Store cipher type. */
buffer_put_char(&encrypted, cipher_num);
buffer_put_int(&encrypted, 0); /* For future extension */
/* Store public key. This will be in plain text. */
buffer_put_int(&encrypted, BN_num_bits(key->rsa->n));
buffer_put_bignum(&encrypted, key->rsa->n);
buffer_put_bignum(&encrypted, key->rsa->e);
buffer_put_cstring(&encrypted, comment);
/* Allocate space for the private part of the key in the buffer. */
cp = buffer_append_space(&encrypted, buffer_len(&buffer));
cipher_set_key_string(&ciphercontext, cipher, passphrase,
CIPHER_ENCRYPT);
if (cipher_crypt(&ciphercontext, 0, cp,
buffer_ptr(&buffer), buffer_len(&buffer), 0, 0) != 0)
fatal("%s: cipher_crypt failed", __func__);
cipher_cleanup(&ciphercontext);
explicit_bzero(&ciphercontext, sizeof(ciphercontext));
/* Destroy temporary data. */
explicit_bzero(buf, sizeof(buf));
buffer_free(&buffer);
buffer_append(blob, buffer_ptr(&encrypted), buffer_len(&encrypted));
buffer_free(&encrypted);
return 1;
}
/* convert SSH v2 key in OpenSSL PEM format */
static int
key_private_pem_to_blob(Key *key, Buffer *blob, const char *_passphrase,
const char *comment)
{
int success = 0;
int blen, len = strlen(_passphrase);
u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL;
#if (OPENSSL_VERSION_NUMBER < 0x00907000L)
const EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL;
#else
const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL;
#endif
const u_char *bptr;
BIO *bio;
if (len > 0 && len <= 4) {
error("passphrase too short: have %d bytes, need > 4", len);
return 0;
}
if ((bio = BIO_new(BIO_s_mem())) == NULL) {
error("%s: BIO_new failed", __func__);
return 0;
}
switch (key->type) {
case KEY_DSA:
success = PEM_write_bio_DSAPrivateKey(bio, key->dsa,
cipher, passphrase, len, NULL, NULL);
break;
#ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa,
cipher, passphrase, len, NULL, NULL);
break;
#endif
case KEY_RSA:
success = PEM_write_bio_RSAPrivateKey(bio, key->rsa,
cipher, passphrase, len, NULL, NULL);
break;
}
if (success) {
if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0)
success = 0;
else
buffer_append(blob, bptr, blen);
}
BIO_free(bio);
return success;
}
/* Save a key blob to a file */
static int
key_save_private_blob(Buffer *keybuf, const char *filename)
{
int fd;
if ((fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600)) < 0) {
error("open %s failed: %s.", filename, strerror(errno));
return 0;
}
if (atomicio(vwrite, fd, buffer_ptr(keybuf),
buffer_len(keybuf)) != buffer_len(keybuf)) {
error("write to key file %s failed: %s", filename,
strerror(errno));
close(fd);
unlink(filename);
return 0;
}
close(fd);
return 1;
}
/* Serialise "key" to buffer "blob" */
static int
key_private_to_blob(Key *key, Buffer *blob, const char *passphrase,
const char *comment, int force_new_format, const char *new_format_cipher,
int new_format_rounds)
{
switch (key->type) {
case KEY_RSA1:
return key_private_rsa1_to_blob(key, blob, passphrase, comment);
case KEY_DSA:
case KEY_ECDSA:
case KEY_RSA:
if (force_new_format) {
return key_private_to_blob2(key, blob, passphrase,
comment, new_format_cipher, new_format_rounds);
}
return key_private_pem_to_blob(key, blob, passphrase, comment);
case KEY_ED25519:
return key_private_to_blob2(key, blob, passphrase,
comment, new_format_cipher, new_format_rounds);
default:
error("%s: cannot save key type %d", __func__, key->type);
return 0;
}
}
int
key_save_private(Key *key, const char *filename, const char *passphrase,
const char *comment, int force_new_format, const char *new_format_cipher,
int new_format_rounds)
{
Buffer keyblob;
int success = 0;
buffer_init(&keyblob);
if (!key_private_to_blob(key, &keyblob, passphrase, comment,
force_new_format, new_format_cipher, new_format_rounds))
goto out;
if (!key_save_private_blob(&keyblob, filename))
goto out;
success = 1;
out:
buffer_free(&keyblob);
return success;
}
/*
* Parse the public, unencrypted portion of a RSA1 key.
*/
static Key *
key_parse_public_rsa1(Buffer *blob, char **commentp)
{
Key *pub;
Buffer copy;
/* Check that it is at least big enough to contain the ID string. */
if (buffer_len(blob) < sizeof(authfile_id_string)) {
debug3("Truncated RSA1 identifier");
return NULL;
}
/*
* Make sure it begins with the id string. Consume the id string
* from the buffer.
*/
if (memcmp(buffer_ptr(blob), authfile_id_string,
sizeof(authfile_id_string)) != 0) {
debug3("Incorrect RSA1 identifier");
return NULL;
}
buffer_init(©);
buffer_append(©, buffer_ptr(blob), buffer_len(blob));
buffer_consume(©, sizeof(authfile_id_string));
/* Skip cipher type and reserved data. */
(void) buffer_get_char(©); /* cipher type */
(void) buffer_get_int(©); /* reserved */
/* Read the public key from the buffer. */
(void) buffer_get_int(©);
pub = key_new(KEY_RSA1);
buffer_get_bignum(©, pub->rsa->n);
buffer_get_bignum(©, pub->rsa->e);
if (commentp)
*commentp = buffer_get_string(©, NULL);
/* The encrypted private part is not parsed by this function. */
buffer_free(©);
return pub;
}
/* Load a key from a fd into a buffer */
int
key_load_file(int fd, const char *filename, Buffer *blob)
{
u_char buf[1024];
size_t len;
struct stat st;
if (fstat(fd, &st) < 0) {
error("%s: fstat of key file %.200s%sfailed: %.100s", __func__,
filename == NULL ? "" : filename,
filename == NULL ? "" : " ",
strerror(errno));
return 0;
}
if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
st.st_size > MAX_KEY_FILE_SIZE) {
toobig:
error("%s: key file %.200s%stoo large", __func__,
filename == NULL ? "" : filename,
filename == NULL ? "" : " ");
return 0;
}
buffer_clear(blob);
for (;;) {
if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
if (errno == EPIPE)
break;
debug("%s: read from key file %.200s%sfailed: %.100s",
__func__, filename == NULL ? "" : filename,
filename == NULL ? "" : " ", strerror(errno));
buffer_clear(blob);
explicit_bzero(buf, sizeof(buf));
return 0;
}
buffer_append(blob, buf, len);
if (buffer_len(blob) > MAX_KEY_FILE_SIZE) {
buffer_clear(blob);
explicit_bzero(buf, sizeof(buf));
goto toobig;
}
}
explicit_bzero(buf, sizeof(buf));
if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
st.st_size != buffer_len(blob)) {
debug("%s: key file %.200s%schanged size while reading",
__func__, filename == NULL ? "" : filename,
filename == NULL ? "" : " ");
buffer_clear(blob);
return 0;
}
return 1;
}
/*
* Loads the public part of the ssh v1 key file. Returns NULL if an error was
* encountered (the file does not exist or is not readable), and the key
* otherwise.
*/
static Key *
key_load_public_rsa1(int fd, const char *filename, char **commentp)
{
Buffer buffer;
Key *pub;
buffer_init(&buffer);
if (!key_load_file(fd, filename, &buffer)) {
buffer_free(&buffer);
return NULL;
}
pub = key_parse_public_rsa1(&buffer, commentp);
if (pub == NULL)
debug3("Could not load \"%s\" as a RSA1 public key", filename);
buffer_free(&buffer);
return pub;
}
/* load public key from private-key file, works only for SSH v1 */
Key *
key_load_public_type(int type, const char *filename, char **commentp)
{
Key *pub;
int fd;
if (type == KEY_RSA1) {
fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
pub = key_load_public_rsa1(fd, filename, commentp);
close(fd);
return pub;
}
return NULL;
}
static Key *
key_parse_private_rsa1(Buffer *blob, const char *passphrase, char **commentp)
{
int check1, check2, cipher_type;
Buffer decrypted;
u_char *cp;
CipherContext ciphercontext;
const Cipher *cipher;
Key *prv = NULL;
Buffer copy;
/* Check that it is at least big enough to contain the ID string. */
if (buffer_len(blob) < sizeof(authfile_id_string)) {
debug3("Truncated RSA1 identifier");
return NULL;
}
/*
* Make sure it begins with the id string. Consume the id string
* from the buffer.
*/
if (memcmp(buffer_ptr(blob), authfile_id_string,
sizeof(authfile_id_string)) != 0) {
debug3("Incorrect RSA1 identifier");
return NULL;
}
buffer_init(©);
buffer_append(©, buffer_ptr(blob), buffer_len(blob));
buffer_consume(©, sizeof(authfile_id_string));
/* Read cipher type. */
cipher_type = buffer_get_char(©);
(void) buffer_get_int(©); /* Reserved data. */
/* Read the public key from the buffer. */
(void) buffer_get_int(©);
prv = key_new_private(KEY_RSA1);
buffer_get_bignum(©, prv->rsa->n);
buffer_get_bignum(©, prv->rsa->e);
if (commentp)
*commentp = buffer_get_string(©, NULL);
else
(void)buffer_get_string_ptr(©, NULL);
/* Check that it is a supported cipher. */
cipher = cipher_by_number(cipher_type);
if (cipher == NULL) {
debug("Unsupported RSA1 cipher %d", cipher_type);
buffer_free(©);
goto fail;
}
/* Initialize space for decrypted data. */
buffer_init(&decrypted);
cp = buffer_append_space(&decrypted, buffer_len(©));
/* Rest of the buffer is encrypted. Decrypt it using the passphrase. */
cipher_set_key_string(&ciphercontext, cipher, passphrase,
CIPHER_DECRYPT);
if (cipher_crypt(&ciphercontext, 0, cp,
buffer_ptr(©), buffer_len(©), 0, 0) != 0)
fatal("%s: cipher_crypt failed", __func__);
cipher_cleanup(&ciphercontext);
explicit_bzero(&ciphercontext, sizeof(ciphercontext));
buffer_free(©);
check1 = buffer_get_char(&decrypted);
check2 = buffer_get_char(&decrypted);
if (check1 != buffer_get_char(&decrypted) ||
check2 != buffer_get_char(&decrypted)) {
if (strcmp(passphrase, "") != 0)
debug("Bad passphrase supplied for RSA1 key");
/* Bad passphrase. */
buffer_free(&decrypted);
goto fail;
}
/* Read the rest of the private key. */
buffer_get_bignum(&decrypted, prv->rsa->d);
buffer_get_bignum(&decrypted, prv->rsa->iqmp); /* u */
/* in SSL and SSH v1 p and q are exchanged */
buffer_get_bignum(&decrypted, prv->rsa->q); /* p */
buffer_get_bignum(&decrypted, prv->rsa->p); /* q */
/* calculate p-1 and q-1 */
rsa_generate_additional_parameters(prv->rsa);
buffer_free(&decrypted);
/* enable blinding */
if (RSA_blinding_on(prv->rsa, NULL) != 1) {
error("%s: RSA_blinding_on failed", __func__);
goto fail;
}
return prv;
fail:
if (commentp != NULL)
free(*commentp);
key_free(prv);
return NULL;
}
static Key *
key_parse_private_pem(Buffer *blob, int type, const char *passphrase,
char **commentp)
{
EVP_PKEY *pk = NULL;
Key *prv = NULL;
char *name = "<no key>";
BIO *bio;
if ((bio = BIO_new_mem_buf(buffer_ptr(blob),
buffer_len(blob))) == NULL) {
error("%s: BIO_new_mem_buf failed", __func__);
return NULL;
}
pk = PEM_read_bio_PrivateKey(bio, NULL, NULL, (char *)passphrase);
BIO_free(bio);
if (pk == NULL) {
debug("%s: PEM_read_PrivateKey failed", __func__);
(void)ERR_get_error();
} else if (pk->type == EVP_PKEY_RSA &&
(type == KEY_UNSPEC||type==KEY_RSA)) {
prv = key_new(KEY_UNSPEC);
prv->rsa = EVP_PKEY_get1_RSA(pk);
prv->type = KEY_RSA;
name = "rsa w/o comment";
#ifdef DEBUG_PK
RSA_print_fp(stderr, prv->rsa, 8);
#endif
if (RSA_blinding_on(prv->rsa, NULL) != 1) {
error("%s: RSA_blinding_on failed", __func__);
key_free(prv);
prv = NULL;
}
} else if (pk->type == EVP_PKEY_DSA &&
(type == KEY_UNSPEC||type==KEY_DSA)) {
prv = key_new(KEY_UNSPEC);
prv->dsa = EVP_PKEY_get1_DSA(pk);
prv->type = KEY_DSA;
name = "dsa w/o comment";
#ifdef DEBUG_PK
DSA_print_fp(stderr, prv->dsa, 8);
#endif
#ifdef OPENSSL_HAS_ECC
} else if (pk->type == EVP_PKEY_EC &&
(type == KEY_UNSPEC||type==KEY_ECDSA)) {
prv = key_new(KEY_UNSPEC);
prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
prv->type = KEY_ECDSA;
if ((prv->ecdsa_nid = key_ecdsa_key_to_nid(prv->ecdsa)) == -1 ||
key_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
key_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
key_ec_validate_private(prv->ecdsa) != 0) {
error("%s: bad ECDSA key", __func__);
key_free(prv);
prv = NULL;
}
name = "ecdsa w/o comment";
#ifdef DEBUG_PK
if (prv != NULL && prv->ecdsa != NULL)
key_dump_ec_key(prv->ecdsa);
#endif
#endif /* OPENSSL_HAS_ECC */
} else {
error("%s: PEM_read_PrivateKey: mismatch or "
"unknown EVP_PKEY save_type %d", __func__, pk->save_type);
}
if (pk != NULL)
EVP_PKEY_free(pk);
if (prv != NULL && commentp)
*commentp = xstrdup(name);
debug("read PEM private key done: type %s",
prv ? key_type(prv) : "<unknown>");
return prv;
}
Key *
key_load_private_pem(int fd, int type, const char *passphrase,
char **commentp)
{
Buffer buffer;
Key *prv;
buffer_init(&buffer);
if (!key_load_file(fd, NULL, &buffer)) {
buffer_free(&buffer);
return NULL;
}
prv = key_parse_private_pem(&buffer, type, passphrase, commentp);
buffer_free(&buffer);
return prv;
}
int
key_perm_ok(int fd, const char *filename)
{
struct stat st;
if (fstat(fd, &st) < 0)
return 0;
/*
* if a key owned by the user is accessed, then we check the
* permissions of the file. if the key owned by a different user,
* then we don't care.
*/
#ifdef HAVE_CYGWIN
if (check_ntsec(filename))
#endif
if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) {
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
error("Permissions 0%3.3o for '%s' are too open.",
(u_int)st.st_mode & 0777, filename);
error("It is required that your private key files are NOT accessible by others.");
error("This private key will be ignored.");
return 0;
}
return 1;
}
static Key *
key_parse_private_type(Buffer *blob, int type, const char *passphrase,
char **commentp)
{
Key *k;