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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
|
/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
* Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
* Copyright (C) 2006-2010, Brainspark B.V.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file Control Channel PolarSSL Backend
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif
#include "syshead.h"
#if defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL)
#include "errlevel.h"
#include "ssl_backend.h"
#include "base64.h"
#include "buffer.h"
#include "misc.h"
#include "manage.h"
#include "ssl_common.h"
#include <polarssl/havege.h>
#include "ssl_verify_polarssl.h"
#include <polarssl/error.h>
#include <polarssl/oid.h>
#include <polarssl/pem.h>
#include <polarssl/sha256.h>
#include <polarssl/version.h>
void
tls_init_lib()
{
}
void
tls_free_lib()
{
}
void
tls_clear_error()
{
}
void
tls_ctx_server_new(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
CLEAR(*ctx);
ALLOC_OBJ_CLEAR(ctx->dhm_ctx, dhm_context);
ALLOC_OBJ_CLEAR(ctx->priv_key, pk_context);
ALLOC_OBJ_CLEAR(ctx->ca_chain, x509_crt);
ALLOC_OBJ_CLEAR(ctx->crt_chain, x509_crt);
ctx->endpoint = SSL_IS_SERVER;
ctx->initialised = true;
}
void
tls_ctx_client_new(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
CLEAR(*ctx);
ALLOC_OBJ_CLEAR(ctx->dhm_ctx, dhm_context);
ALLOC_OBJ_CLEAR(ctx->priv_key, pk_context);
ALLOC_OBJ_CLEAR(ctx->ca_chain, x509_crt);
ALLOC_OBJ_CLEAR(ctx->crt_chain, x509_crt);
ctx->endpoint = SSL_IS_CLIENT;
ctx->initialised = true;
}
void
tls_ctx_free(struct tls_root_ctx *ctx)
{
if (ctx)
{
pk_free(ctx->priv_key);
free(ctx->priv_key);
x509_crt_free(ctx->ca_chain);
free(ctx->ca_chain);
x509_crt_free(ctx->crt_chain);
free(ctx->crt_chain);
dhm_free(ctx->dhm_ctx);
free(ctx->dhm_ctx);
#if defined(ENABLE_PKCS11)
if (ctx->priv_key_pkcs11 != NULL) {
pkcs11_priv_key_free(ctx->priv_key_pkcs11);
free(ctx->priv_key_pkcs11);
}
#endif
#if defined(MANAGMENT_EXTERNAL_KEY)
if (ctx->external_key != NULL)
free(ctx->external_key);
#endif
if (ctx->allowed_ciphers)
free(ctx->allowed_ciphers);
CLEAR(*ctx);
ctx->initialised = false;
}
}
bool
tls_ctx_initialised(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
return ctx->initialised;
}
void
tls_ctx_set_options (struct tls_root_ctx *ctx, unsigned int ssl_flags)
{
}
static const char *
tls_translate_cipher_name (const char * cipher_name) {
const tls_cipher_name_pair * pair = tls_get_cipher_name_pair(cipher_name, strlen(cipher_name));
if (NULL == pair)
{
// No translation found, return original
return cipher_name;
}
if (0 != strcmp(cipher_name, pair->iana_name))
{
// Deprecated name found, notify user
msg(M_WARN, "Deprecated cipher suite name '%s', please use IANA name '%s'", pair->openssl_name, pair->iana_name);
}
return pair->iana_name;
}
void
tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
{
char *tmp_ciphers, *tmp_ciphers_orig, *token;
int i, cipher_count;
int ciphers_len;
if (NULL == ciphers)
return; /* Nothing to do */
ciphers_len = strlen (ciphers);
ASSERT (NULL != ctx);
ASSERT (0 != ciphers_len);
/* Get number of ciphers */
for (i = 0, cipher_count = 1; i < ciphers_len; i++)
if (ciphers[i] == ':')
cipher_count++;
/* Allocate an array for them */
ALLOC_ARRAY_CLEAR(ctx->allowed_ciphers, int, cipher_count+1)
/* Parse allowed ciphers, getting IDs */
i = 0;
tmp_ciphers_orig = tmp_ciphers = strdup(ciphers);
token = strtok (tmp_ciphers, ":");
while(token)
{
ctx->allowed_ciphers[i] = ssl_get_ciphersuite_id (
tls_translate_cipher_name (token));
if (0 != ctx->allowed_ciphers[i])
i++;
token = strtok (NULL, ":");
}
free(tmp_ciphers_orig);
}
void
tls_ctx_load_dh_params (struct tls_root_ctx *ctx, const char *dh_file,
const char *dh_inline
)
{
if (!strcmp (dh_file, INLINE_FILE_TAG) && dh_inline)
{
if (0 != dhm_parse_dhm(ctx->dhm_ctx, (const unsigned char *) dh_inline,
strlen(dh_inline)))
msg (M_FATAL, "Cannot read inline DH parameters");
}
else
{
if (0 != dhm_parse_dhmfile(ctx->dhm_ctx, dh_file))
msg (M_FATAL, "Cannot read DH parameters from file %s", dh_file);
}
msg (D_TLS_DEBUG_LOW, "Diffie-Hellman initialized with " counter_format " bit key",
(counter_type) 8 * mpi_size(&ctx->dhm_ctx->P));
}
void
tls_ctx_load_ecdh_params (struct tls_root_ctx *ctx, const char *curve_name
)
{
if (NULL != curve_name)
msg(M_WARN, "WARNING: PolarSSL builds do not support specifying an ECDH "
"curve, using default curves.");
}
int
tls_ctx_load_pkcs12(struct tls_root_ctx *ctx, const char *pkcs12_file,
const char *pkcs12_file_inline,
bool load_ca_file
)
{
msg(M_FATAL, "PKCS #12 files not yet supported for PolarSSL.");
return 0;
}
#ifdef ENABLE_CRYPTOAPI
void
tls_ctx_load_cryptoapi(struct tls_root_ctx *ctx, const char *cryptoapi_cert)
{
msg(M_FATAL, "Windows CryptoAPI not yet supported for PolarSSL.");
}
#endif /* WIN32 */
void
tls_ctx_load_cert_file (struct tls_root_ctx *ctx, const char *cert_file,
const char *cert_inline
)
{
ASSERT(NULL != ctx);
if (!strcmp (cert_file, INLINE_FILE_TAG) && cert_inline)
{
if (0 != x509_crt_parse(ctx->crt_chain,
(const unsigned char *) cert_inline, strlen(cert_inline)))
msg (M_FATAL, "Cannot load inline certificate file");
}
else
{
int retval = x509_crt_parse_file(ctx->crt_chain, cert_file);
if (0 != retval)
{
char errstr[128];
polarssl_strerror(retval, errstr, sizeof(errstr));
msg (M_FATAL, "Cannot load certificate file %s (%s)", cert_file, errstr);
}
}
}
int
tls_ctx_load_priv_file (struct tls_root_ctx *ctx, const char *priv_key_file,
const char *priv_key_inline
)
{
int status;
ASSERT(NULL != ctx);
if (!strcmp (priv_key_file, INLINE_FILE_TAG) && priv_key_inline)
{
status = pk_parse_key(ctx->priv_key,
(const unsigned char *) priv_key_inline, strlen(priv_key_inline),
NULL, 0);
if (POLARSSL_ERR_PEM_PASSWORD_REQUIRED == status)
{
char passbuf[512] = {0};
pem_password_callback(passbuf, 512, 0, NULL);
status = pk_parse_key(ctx->priv_key,
(const unsigned char *) priv_key_inline, strlen(priv_key_inline),
(unsigned char *) passbuf, strlen(passbuf));
}
}
else
{
status = pk_parse_keyfile(ctx->priv_key, priv_key_file, NULL);
if (POLARSSL_ERR_PEM_PASSWORD_REQUIRED == status)
{
char passbuf[512] = {0};
pem_password_callback(passbuf, 512, 0, NULL);
status = pk_parse_keyfile(ctx->priv_key, priv_key_file, passbuf);
}
}
if (0 != status)
{
#ifdef ENABLE_MANAGEMENT
if (management && (POLARSSL_ERR_PEM_PASSWORD_MISMATCH == status))
management_auth_failure (management, UP_TYPE_PRIVATE_KEY, NULL);
#endif
msg (M_WARN, "Cannot load private key file %s", priv_key_file);
return 1;
}
warn_if_group_others_accessible (priv_key_file);
/* TODO: Check Private Key */
#if 0
if (!SSL_CTX_check_private_key (ctx))
msg (M_SSLERR, "Private key does not match the certificate");
#endif
return 0;
}
#ifdef MANAGMENT_EXTERNAL_KEY
struct external_context {
size_t signature_length;
};
int
tls_ctx_use_external_private_key (struct tls_root_ctx *ctx,
const char *cert_file, const char *cert_file_inline)
{
ASSERT(NULL != ctx);
tls_ctx_load_cert_file(ctx, cert_file, cert_file_inline);
if (ctx->crt_chain == NULL)
return 0;
/* Most of the initialization happens in key_state_ssl_init() */
ALLOC_OBJ_CLEAR (ctx->external_key, struct external_context);
ctx->external_key->signature_length = pk_get_len(&ctx->crt_chain->pk);
return 1;
}
/**
* external_pkcs1_sign implements a PolarSSL rsa_sign_func callback, that uses
* the management interface to request an RSA signature for the supplied hash.
*
* @param ctx_voidptr Management external key context.
* @param f_rng (Unused)
* @param p_rng (Unused)
* @param mode RSA mode (should be RSA_PRIVATE).
* @param md_alg Message digest ('hash') algorithm type.
* @param hashlen Length of hash (overridden by length specified by md_alg
* if md_alg != POLARSSL_MD_NONE).
* @param hash The digest ('hash') to sign. Should have a size
* matching the length of md_alg (if != POLARSSL_MD_NONE),
* or hashlen otherwise.
* @param sig Buffer that returns the signature. Should be at least of
* size ctx->signature_length.
*
* @return 0 on success, non-zero polarssl error code on failure.
*/
static inline int external_pkcs1_sign( void *ctx_voidptr,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode,
md_type_t md_alg, unsigned int hashlen, const unsigned char *hash,
unsigned char *sig )
{
struct external_context * const ctx = ctx_voidptr;
char *in_b64 = NULL;
char *out_b64 = NULL;
int rv;
unsigned char *p = sig;
size_t asn_len = 0, oid_size = 0, sig_len = 0;
const char *oid = NULL;
if( NULL == ctx )
return POLARSSL_ERR_RSA_BAD_INPUT_DATA;
if( RSA_PRIVATE != mode )
return POLARSSL_ERR_RSA_BAD_INPUT_DATA;
/*
* Support a wide range of hashes. TLSv1.1 and before only need SIG_RSA_RAW,
* but TLSv1.2 needs the full suite of hashes.
*
* This code has been taken from PolarSSL pkcs11_sign(), under the GPLv2.0+.
*/
if( md_alg != POLARSSL_MD_NONE )
{
const md_info_t *md_info = md_info_from_type( md_alg );
if( md_info == NULL )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
if( oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 )
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hashlen = md_get_size( md_info );
asn_len = 10 + oid_size;
}
sig_len = ctx->signature_length;
if ( (SIZE_MAX - hashlen) < asn_len || (hashlen + asn_len) > sig_len )
return POLARSSL_ERR_RSA_BAD_INPUT_DATA;
if( md_alg != POLARSSL_MD_NONE )
{
/*
* DigestInfo ::= SEQUENCE {
* digestAlgorithm DigestAlgorithmIdentifier,
* digest Digest }
*
* DigestAlgorithmIdentifier ::= AlgorithmIdentifier
*
* Digest ::= OCTET STRING
*/
*p++ = ASN1_SEQUENCE | ASN1_CONSTRUCTED;
*p++ = (unsigned char) ( 0x08 + oid_size + hashlen );
*p++ = ASN1_SEQUENCE | ASN1_CONSTRUCTED;
*p++ = (unsigned char) ( 0x04 + oid_size );
*p++ = ASN1_OID;
*p++ = oid_size & 0xFF;
memcpy( p, oid, oid_size );
p += oid_size;
*p++ = ASN1_NULL;
*p++ = 0x00;
*p++ = ASN1_OCTET_STRING;
*p++ = hashlen;
/* Determine added ASN length */
asn_len = p - sig;
}
/* Copy the hash to be signed */
memcpy( p, hash, hashlen );
/* convert 'from' to base64 */
if (openvpn_base64_encode (sig, asn_len + hashlen, &in_b64) <= 0)
{
rv = POLARSSL_ERR_RSA_BAD_INPUT_DATA;
goto done;
}
/* call MI for signature */
if (management)
out_b64 = management_query_rsa_sig (management, in_b64);
if (!out_b64)
{
rv = POLARSSL_ERR_RSA_PRIVATE_FAILED;
goto done;
}
/* decode base64 signature to binary and verify length */
if ( openvpn_base64_decode (out_b64, sig, ctx->signature_length) !=
ctx->signature_length )
{
rv = POLARSSL_ERR_RSA_PRIVATE_FAILED;
goto done;
}
rv = 0;
done:
if (in_b64)
free (in_b64);
if (out_b64)
free (out_b64);
return rv;
}
static inline size_t external_key_len(void *vctx)
{
struct external_context * const ctx = vctx;
return ctx->signature_length;
}
#endif
void tls_ctx_load_ca (struct tls_root_ctx *ctx, const char *ca_file,
const char *ca_file_inline,
const char *ca_path, bool tls_server
)
{
if (ca_path)
msg(M_FATAL, "ERROR: PolarSSL cannot handle the capath directive");
if (ca_file && !strcmp (ca_file, INLINE_FILE_TAG) && ca_file_inline)
{
if (0 != x509_crt_parse(ctx->ca_chain, (unsigned char *) ca_file_inline,
strlen(ca_file_inline)))
msg (M_FATAL, "Cannot load inline CA certificates");
}
else
{
/* Load CA file for verifying peer supplied certificate */
int retval = x509_crt_parse_file(ctx->ca_chain, ca_file);
if (0 != retval)
{
char errstr[128];
polarssl_strerror(retval, errstr, sizeof(errstr));
msg (M_FATAL, "Cannot load CA certificate file %s (%s)", ca_file, errstr);
}
}
}
void
tls_ctx_load_extra_certs (struct tls_root_ctx *ctx, const char *extra_certs_file,
const char *extra_certs_file_inline
)
{
ASSERT(NULL != ctx);
if (!strcmp (extra_certs_file, INLINE_FILE_TAG) && extra_certs_file_inline)
{
if (0 != x509_crt_parse(ctx->crt_chain,
(unsigned char *) extra_certs_file_inline,
strlen(extra_certs_file_inline)))
msg (M_FATAL, "Cannot load inline extra-certs file");
}
else
{
if (0 != x509_crt_parse_file(ctx->crt_chain, extra_certs_file))
msg (M_FATAL, "Cannot load extra-certs file: %s", extra_certs_file);
}
}
/* **************************************
*
* Key-state specific functions
*
***************************************/
/*
* "Endless buffer"
*/
static inline void buf_free_entry(buffer_entry *entry)
{
if (NULL != entry)
{
free(entry->data);
free(entry);
}
}
static void buf_free_entries(endless_buffer *buf)
{
while(buf->first_block)
{
buffer_entry *cur_block = buf->first_block;
buf->first_block = cur_block->next_block;
buf_free_entry(cur_block);
}
buf->last_block = NULL;
}
static int endless_buf_read( void * ctx, unsigned char * out, size_t out_len )
{
endless_buffer *in = (endless_buffer *) ctx;
size_t read_len = 0;
if (in->first_block == NULL)
return POLARSSL_ERR_NET_WANT_READ;
while (in->first_block != NULL && read_len < out_len)
{
int block_len = in->first_block->length - in->data_start;
if (block_len <= out_len - read_len)
{
buffer_entry *cur_entry = in->first_block;
memcpy(out + read_len, cur_entry->data + in->data_start,
block_len);
read_len += block_len;
in->first_block = cur_entry->next_block;
in->data_start = 0;
if (in->first_block == NULL)
in->last_block = NULL;
buf_free_entry(cur_entry);
}
else
{
memcpy(out + read_len, in->first_block->data + in->data_start,
out_len - read_len);
in->data_start += out_len - read_len;
read_len = out_len;
}
}
return read_len;
}
static int endless_buf_write( void *ctx, const unsigned char *in, size_t len )
{
endless_buffer *out = (endless_buffer *) ctx;
buffer_entry *new_block = malloc(sizeof(buffer_entry));
if (NULL == new_block)
return POLARSSL_ERR_NET_SEND_FAILED;
new_block->data = malloc(len);
if (NULL == new_block->data)
{
free(new_block);
return POLARSSL_ERR_NET_SEND_FAILED;
}
new_block->length = len;
new_block->next_block = NULL;
memcpy(new_block->data, in, len);
if (NULL == out->first_block)
out->first_block = new_block;
if (NULL != out->last_block)
out->last_block->next_block = new_block;
out->last_block = new_block;
return len;
}
static void my_debug( void *ctx, int level, const char *str )
{
if (level == 1)
{
dmsg (D_HANDSHAKE_VERBOSE, "PolarSSL alert: %s", str);
}
}
/*
* Further personalise the RNG using a hash of the public key
*/
void tls_ctx_personalise_random(struct tls_root_ctx *ctx)
{
static char old_sha256_hash[32] = {0};
unsigned char sha256_hash[32] = {0};
ctr_drbg_context *cd_ctx = rand_ctx_get();
if (NULL != ctx->crt_chain)
{
x509_crt *cert = ctx->crt_chain;
sha256(cert->tbs.p, cert->tbs.len, sha256_hash, false);
if ( 0 != memcmp(old_sha256_hash, sha256_hash, sizeof(sha256_hash)))
{
ctr_drbg_update(cd_ctx, sha256_hash, 32);
memcpy(old_sha256_hash, sha256_hash, sizeof(old_sha256_hash));
}
}
}
int
tls_version_max(void)
{
#if defined(SSL_MAJOR_VERSION_3) && defined(SSL_MINOR_VERSION_3)
return TLS_VER_1_2;
#elif defined(SSL_MAJOR_VERSION_3) && defined(SSL_MINOR_VERSION_2)
return TLS_VER_1_1;
#else
return TLS_VER_1_0;
#endif
}
void key_state_ssl_init(struct key_state_ssl *ks_ssl,
const struct tls_root_ctx *ssl_ctx, bool is_server, struct tls_session *session)
{
ASSERT(NULL != ssl_ctx);
ASSERT(ks_ssl);
CLEAR(*ks_ssl);
ALLOC_OBJ_CLEAR(ks_ssl->ctx, ssl_context);
if (0 == ssl_init(ks_ssl->ctx))
{
/* Initialise SSL context */
ssl_set_dbg (ks_ssl->ctx, my_debug, NULL);
ssl_set_endpoint (ks_ssl->ctx, ssl_ctx->endpoint);
ssl_set_rng (ks_ssl->ctx, ctr_drbg_random, rand_ctx_get());
if (ssl_ctx->allowed_ciphers)
ssl_set_ciphersuites (ks_ssl->ctx, ssl_ctx->allowed_ciphers);
/* Initialise authentication information */
if (is_server)
ssl_set_dh_param_ctx (ks_ssl->ctx, ssl_ctx->dhm_ctx );
#if defined(ENABLE_PKCS11)
if (ssl_ctx->priv_key_pkcs11 != NULL)
ssl_set_own_cert_alt( ks_ssl->ctx, ssl_ctx->crt_chain,
ssl_ctx->priv_key_pkcs11, ssl_pkcs11_decrypt, ssl_pkcs11_sign,
ssl_pkcs11_key_len );
else
#endif
#if defined(MANAGMENT_EXTERNAL_KEY)
if (ssl_ctx->external_key != NULL)
ssl_set_own_cert_alt( ks_ssl->ctx, ssl_ctx->crt_chain,
ssl_ctx->external_key, NULL, external_pkcs1_sign,
external_key_len );
else
#endif
ssl_set_own_cert( ks_ssl->ctx, ssl_ctx->crt_chain, ssl_ctx->priv_key );
/* Initialise SSL verification */
#if P2MP_SERVER
if (session->opt->ssl_flags & SSLF_CLIENT_CERT_NOT_REQUIRED)
{
msg (M_WARN, "WARNING: POTENTIALLY DANGEROUS OPTION "
"--client-cert-not-required may accept clients which do not present "
"a certificate");
}
else
#endif
{
ssl_set_authmode (ks_ssl->ctx, SSL_VERIFY_REQUIRED);
ssl_set_verify (ks_ssl->ctx, verify_callback, session);
}
/* TODO: PolarSSL does not currently support sending the CA chain to the client */
ssl_set_ca_chain (ks_ssl->ctx, ssl_ctx->ca_chain, NULL, NULL );
/* Initialize minimum TLS version */
{
const int tls_version_min = (session->opt->ssl_flags >> SSLF_TLS_VERSION_SHIFT) & SSLF_TLS_VERSION_MASK;
int polar_major;
int polar_minor;
switch (tls_version_min)
{
case TLS_VER_1_0:
default:
polar_major = SSL_MAJOR_VERSION_3;
polar_minor = SSL_MINOR_VERSION_1;
break;
#if defined(SSL_MAJOR_VERSION_3) && defined(SSL_MINOR_VERSION_2)
case TLS_VER_1_1:
polar_major = SSL_MAJOR_VERSION_3;
polar_minor = SSL_MINOR_VERSION_2;
break;
#endif
#if defined(SSL_MAJOR_VERSION_3) && defined(SSL_MINOR_VERSION_3)
case TLS_VER_1_2:
polar_major = SSL_MAJOR_VERSION_3;
polar_minor = SSL_MINOR_VERSION_3;
break;
#endif
}
ssl_set_min_version(ks_ssl->ctx, polar_major, polar_minor);
}
/* Initialise BIOs */
ALLOC_OBJ_CLEAR (ks_ssl->ct_in, endless_buffer);
ALLOC_OBJ_CLEAR (ks_ssl->ct_out, endless_buffer);
ssl_set_bio (ks_ssl->ctx, endless_buf_read, ks_ssl->ct_in,
endless_buf_write, ks_ssl->ct_out);
}
}
void
key_state_ssl_free(struct key_state_ssl *ks_ssl)
{
if (ks_ssl) {
if (ks_ssl->ctx)
{
ssl_free(ks_ssl->ctx);
free(ks_ssl->ctx);
}
if (ks_ssl->ct_in) {
buf_free_entries(ks_ssl->ct_in);
free(ks_ssl->ct_in);
}
if (ks_ssl->ct_out) {
buf_free_entries(ks_ssl->ct_out);
free(ks_ssl->ct_out);
}
CLEAR(*ks_ssl);
}
}
int
key_state_write_plaintext (struct key_state_ssl *ks, struct buffer *buf)
{
int retval = 0;
perf_push (PERF_BIO_WRITE_PLAINTEXT);
ASSERT (NULL != ks);
ASSERT (buf);
ASSERT (buf->len >= 0);
if (0 == buf->len)
{
return 0;
perf_pop ();
}
retval = ssl_write(ks->ctx, BPTR(buf), buf->len);
if (retval < 0)
{
perf_pop ();
if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
return 0;
msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_plaintext error");
return -1;
}
if (retval != buf->len)
{
msg (D_TLS_ERRORS,
"TLS ERROR: write tls_write_plaintext incomplete %d/%d",
retval, buf->len);
perf_pop ();
return -1;
}
/* successful write */
dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_plaintext %d bytes", retval);
memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
buf->len = 0;
perf_pop ();
return 1;
}
int
key_state_write_plaintext_const (struct key_state_ssl *ks, const uint8_t *data, int len)
{
int retval = 0;
perf_push (PERF_BIO_WRITE_PLAINTEXT);
ASSERT (NULL != ks);
ASSERT (len >= 0);
if (0 == len)
{
perf_pop ();
return 0;
}
ASSERT (data);
retval = ssl_write(ks->ctx, data, len);
if (retval < 0)
{
perf_pop ();
if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
return 0;
msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_plaintext_const error");
return -1;
}
if (retval != len)
{
msg (D_TLS_ERRORS,
"TLS ERROR: write tls_write_plaintext_const incomplete %d/%d",
retval, len);
perf_pop ();
return -1;
}
/* successful write */
dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_plaintext_const %d bytes", retval);
perf_pop ();
return 1;
}
int
key_state_read_ciphertext (struct key_state_ssl *ks, struct buffer *buf,
int maxlen)
{
int retval = 0;
int len = 0;
char error_message[1024];
perf_push (PERF_BIO_READ_CIPHERTEXT);
ASSERT (NULL != ks);
ASSERT (buf);
ASSERT (buf->len >= 0);
if (buf->len)
{
perf_pop ();
return 0;
}
len = buf_forward_capacity (buf);
if (maxlen < len)
len = maxlen;
retval = endless_buf_read(ks->ct_out, BPTR(buf), len);
/* Error during read, check for retry error */
if (retval < 0)
{
perf_pop ();
if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
return 0;
error_strerror(retval, error_message, sizeof(error_message));
msg (D_TLS_ERRORS, "TLS_ERROR: read tls_read_ciphertext error: %d %s", retval, error_message);
buf->len = 0;
return -1;
}
/* Nothing read, try again */
if (0 == retval)
{
buf->len = 0;
perf_pop ();
return 0;
}
/* successful read */
dmsg (D_HANDSHAKE_VERBOSE, "read tls_read_ciphertext %d bytes", retval);
buf->len = retval;
perf_pop ();
return 1;
}
int
key_state_write_ciphertext (struct key_state_ssl *ks, struct buffer *buf)
{
int retval = 0;
perf_push (PERF_BIO_WRITE_CIPHERTEXT);
ASSERT (NULL != ks);
ASSERT (buf);
ASSERT (buf->len >= 0);
if (0 == buf->len)
{
perf_pop ();
return 0;
}
retval = endless_buf_write(ks->ct_in, BPTR(buf), buf->len);
if (retval < 0)
{
perf_pop ();
if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
return 0;
msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_ciphertext error");
return -1;
}
if (retval != buf->len)
{
msg (D_TLS_ERRORS,
"TLS ERROR: write tls_write_ciphertext incomplete %d/%d",
retval, buf->len);
perf_pop ();
return -1;
}
/* successful write */
dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_ciphertext %d bytes", retval);
memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
buf->len = 0;
perf_pop ();
return 1;
}
int
key_state_read_plaintext (struct key_state_ssl *ks, struct buffer *buf,
int maxlen)
{
int retval = 0;
int len = 0;
char error_message[1024];
perf_push (PERF_BIO_READ_PLAINTEXT);
ASSERT (NULL != ks);
ASSERT (buf);
ASSERT (buf->len >= 0);
if (buf->len)
{
perf_pop ();
return 0;
}
len = buf_forward_capacity (buf);
if (maxlen < len)
len = maxlen;
retval = ssl_read(ks->ctx, BPTR(buf), len);
/* Error during read, check for retry error */
if (retval < 0)
{
if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
return 0;
error_strerror(retval, error_message, sizeof(error_message));
msg (D_TLS_ERRORS, "TLS_ERROR: read tls_read_plaintext error: %d %s", retval, error_message);
buf->len = 0;
perf_pop ();
return -1;
}
/* Nothing read, try again */
if (0 == retval)
{
buf->len = 0;
perf_pop ();
return 0;
}
/* successful read */
dmsg (D_HANDSHAKE_VERBOSE, "read tls_read_plaintext %d bytes", retval);
buf->len = retval;
perf_pop ();
return 1;
}
/* **************************************
*
* Information functions
*
* Print information for the end user.
*
***************************************/
void
print_details (struct key_state_ssl * ks_ssl, const char *prefix)
{
const x509_crt *cert;
char s1[256];
char s2[256];
s1[0] = s2[0] = 0;
openvpn_snprintf (s1, sizeof (s1), "%s %s, cipher %s",
prefix,
ssl_get_version (ks_ssl->ctx),
ssl_get_ciphersuite(ks_ssl->ctx));
cert = ssl_get_peer_cert(ks_ssl->ctx);
if (cert != NULL)
{
openvpn_snprintf (s2, sizeof (s2), ", %zu bit key", pk_get_size(&cert->pk));
}
msg (D_HANDSHAKE, "%s%s", s1, s2);
}
void
show_available_tls_ciphers (const char *cipher_list)
{
struct tls_root_ctx tls_ctx;
const int *ciphers = ssl_list_ciphersuites();
tls_ctx_server_new(&tls_ctx);
tls_ctx_restrict_ciphers(&tls_ctx, cipher_list);
if (tls_ctx.allowed_ciphers)
ciphers = tls_ctx.allowed_ciphers;
#ifndef ENABLE_SMALL
printf ("Available TLS Ciphers,\n");
printf ("listed in order of preference:\n\n");
#endif
while (*ciphers != 0)
{
printf ("%s\n", ssl_get_ciphersuite_name(*ciphers));
ciphers++;
}
printf ("\n");
tls_ctx_free(&tls_ctx);
}
void
show_available_curves (void)
{
const ecp_curve_info *pcurve = ecp_curve_list();
if (NULL == pcurve)
msg (M_FATAL, "Cannot retrieve curve list from PolarSSL");
/* Print curve list */
printf ("Available Elliptic curves, listed in order of preference:\n\n");
while (POLARSSL_ECP_DP_NONE != pcurve->grp_id)
{
printf("%s\n", pcurve->name);
pcurve++;
}
}
void
get_highest_preference_tls_cipher (char *buf, int size)
{
const char *cipher_name;
const int *ciphers = ssl_list_ciphersuites();
if (*ciphers == 0)
msg (M_FATAL, "Cannot retrieve list of supported SSL ciphers.");
cipher_name = ssl_get_ciphersuite_name(*ciphers);
strncpynt (buf, cipher_name, size);
}
const char *
get_ssl_library_version(void)
{
static char polar_version[30];
unsigned int pv = version_get_number();
sprintf( polar_version, "PolarSSL %d.%d.%d",
(pv>>24)&0xff, (pv>>16)&0xff, (pv>>8)&0xff );
return polar_version;
}
#endif /* defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL) */
|