forked from marinosi/libfetch_c
-
Notifications
You must be signed in to change notification settings - Fork 0
/
common.c
1403 lines (1259 loc) · 32.2 KB
/
common.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
/*-
* Copyright (c) 1998-2014 Dag-Erling Smørgrav
* Copyright (c) 2013 Michael Gmelin <[email protected]>
* 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
* in this position and unchanged.
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/10/lib/libfetch/common.c 262560 2014-02-27 13:27:04Z des $");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <poll.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#ifdef WITH_SSL
#include <openssl/x509v3.h>
#endif
#include "fetch.h"
#include "common.h"
#include "debug.h"
/*** Local data **************************************************************/
/*
* Error messages for resolver errors
*/
static struct fetcherr netdb_errlist[] = {
#ifdef EAI_NODATA
{ EAI_NODATA, FETCH_RESOLV, "Host not found" },
#endif
{ EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" },
{ EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" },
{ EAI_NONAME, FETCH_RESOLV, "No address record" },
{ -1, FETCH_UNKNOWN, "Unknown resolver error" }
};
/* End-of-Line */
static const char ENDL[2] = "\r\n";
/*** Error-reporting functions ***********************************************/
/*
* Map error code to string
*/
static struct fetcherr *
fetch_finderr(struct fetcherr *p, int e)
{
while (p->num != -1 && p->num != e)
p++;
return (p);
}
/*
* Set error code
*/
void
fetch_seterr(struct fetcherr *p, int e)
{
p = fetch_finderr(p, e);
fetchLastErrCode = p->cat;
snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
}
/*
* Set error code according to errno
*/
void
fetch_syserr(void)
{
switch (errno) {
case 0:
fetchLastErrCode = FETCH_OK;
break;
case EPERM:
case EACCES:
case EROFS:
case EAUTH:
case ENEEDAUTH:
fetchLastErrCode = FETCH_AUTH;
break;
case ENOENT:
case EISDIR: /* XXX */
fetchLastErrCode = FETCH_UNAVAIL;
break;
case ENOMEM:
fetchLastErrCode = FETCH_MEMORY;
break;
case EBUSY:
case EAGAIN:
fetchLastErrCode = FETCH_TEMP;
break;
case EEXIST:
fetchLastErrCode = FETCH_EXISTS;
break;
case ENOSPC:
fetchLastErrCode = FETCH_FULL;
break;
case EADDRINUSE:
case EADDRNOTAVAIL:
case ENETDOWN:
case ENETUNREACH:
case ENETRESET:
case EHOSTUNREACH:
fetchLastErrCode = FETCH_NETWORK;
break;
case ECONNABORTED:
case ECONNRESET:
fetchLastErrCode = FETCH_ABORT;
break;
case ETIMEDOUT:
fetchLastErrCode = FETCH_TIMEOUT;
break;
case ECONNREFUSED:
case EHOSTDOWN:
fetchLastErrCode = FETCH_DOWN;
break;
default:
fetchLastErrCode = FETCH_UNKNOWN;
}
snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
}
/*
* Emit status message
*/
void
fetch_info(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fputc('\n', stderr);
}
/*** Network-related utility functions ***************************************/
/*
* Return the default port for a scheme
*/
int
fetch_default_port(const struct url *URL)
{
struct servent *se;
getservbyname_cb getservbyname_fn = (URL->getserv_fn) ? URL->getserv_fn : getservbyname;
const char *scheme = URL->scheme;
if ((se = getservbyname_fn(scheme, "tcp")) != NULL)
return (ntohs(se->s_port));
if (strcasecmp(scheme, SCHEME_FTP) == 0)
return (FTP_DEFAULT_PORT);
if (strcasecmp(scheme, SCHEME_HTTP) == 0)
return (HTTP_DEFAULT_PORT);
return (0);
}
/*
* Return the default proxy port for a scheme
*/
int
fetch_default_proxy_port(const char *scheme)
{
if (strcasecmp(scheme, SCHEME_FTP) == 0)
return (FTP_DEFAULT_PROXY_PORT);
if (strcasecmp(scheme, SCHEME_HTTP) == 0)
return (HTTP_DEFAULT_PROXY_PORT);
return (0);
}
/*
* Create a connection for an existing descriptor.
*/
conn_t *
fetch_reopen(int sd)
{
conn_t *conn;
int opt = 1;
/* allocate and fill connection structure */
if ((conn = calloc(1, sizeof(*conn))) == NULL)
return (NULL);
fcntl(sd, F_SETFD, FD_CLOEXEC);
setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt);
conn->sd = sd;
++conn->ref;
return (conn);
}
/*
* Bump a connection's reference count.
*/
conn_t *
fetch_ref(conn_t *conn)
{
++conn->ref;
return (conn);
}
/*
* Bind a socket to a specific local address
*/
int
fetch_bind(int sd, int af, const char *addr)
{
struct addrinfo hints, *res, *res0;
int err;
memset(&hints, 0, sizeof(hints));
hints.ai_family = af;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
if ((err = getaddrinfo(addr, NULL, &hints, &res0)) != 0)
return (-1);
for (res = res0; res; res = res->ai_next)
if (bind(sd, res->ai_addr, res->ai_addrlen) == 0)
return (0);
return (-1);
}
/*
* Establish a TCP connection to the specified port on the specified host.
*/
conn_t *
fetch_connect(const char *host, int port, int af, int verbose)
{
conn_t *conn;
char pbuf[10];
const char *bindaddr;
struct addrinfo hints, *res, *res0;
int sd, err;
DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));
if (verbose)
fetch_info("looking up %s", host);
/* look up host name and set up socket address structure */
snprintf(pbuf, sizeof(pbuf), "%d", port);
memset(&hints, 0, sizeof(hints));
hints.ai_family = af;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) {
netdb_seterr(err);
return (NULL);
}
bindaddr = getenv("FETCH_BIND_ADDRESS");
if (verbose)
fetch_info("connecting to %s:%d", host, port);
/* try to connect */
for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) {
if ((sd = socket(res->ai_family, res->ai_socktype,
res->ai_protocol)) == -1)
continue;
if (bindaddr != NULL && *bindaddr != '\0' &&
fetch_bind(sd, res->ai_family, bindaddr) != 0) {
fetch_info("failed to bind to '%s'", bindaddr);
close(sd);
continue;
}
if (connect(sd, res->ai_addr, res->ai_addrlen) == 0 &&
fcntl(sd, F_SETFL, O_NONBLOCK) == 0)
break;
close(sd);
}
freeaddrinfo(res0);
if (sd == -1) {
fetch_syserr();
return (NULL);
}
if ((conn = fetch_reopen(sd)) == NULL) {
fetch_syserr();
close(sd);
}
return (conn);
}
#ifdef WITH_SSL
/*
* Convert characters A-Z to lowercase (intentionally avoid any locale
* specific conversions).
*/
static char
fetch_ssl_tolower(char in)
{
if (in >= 'A' && in <= 'Z')
return (in + 32);
else
return (in);
}
/*
* isalpha implementation that intentionally avoids any locale specific
* conversions.
*/
static int
fetch_ssl_isalpha(char in)
{
return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
}
/*
* Check if passed hostnames a and b are equal.
*/
static int
fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
size_t blen)
{
size_t i;
if (alen != blen)
return (0);
for (i = 0; i < alen; ++i) {
if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
return (0);
}
return (1);
}
/*
* Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
* and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
* numeric characters. Double hyphens (like they're found in IDN a-labels
* 'xn--') are not allowed. Empty labels are invalid.
*/
static int
fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
{
size_t i;
if (!len || l[0] == '-' || l[len-1] == '-')
return (0);
for (i = 0; i < len; ++i) {
if (!isdigit(l[i]) &&
!fetch_ssl_isalpha(l[i]) &&
!(l[i] == '*' && wcok) &&
!(l[i] == '-' && l[i - 1] != '-'))
return (0);
}
return (1);
}
/*
* Check if host name consists only of numbers. This might indicate an IP
* address, which is not a good idea for CN wildcard comparison.
*/
static int
fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
{
size_t i;
for (i = 0; i < len; ++i) {
if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
hostname[i] == '.'))
return (0);
}
return (1);
}
/*
* Check if the host name h passed matches the pattern passed in m which
* is usually part of subjectAltName or CN of a certificate presented to
* the client. This includes wildcard matching. The algorithm is based on
* RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
*/
static int
fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
size_t mlen)
{
int delta, hdotidx, mdot1idx, wcidx;
const char *hdot, *mdot1, *mdot2;
const char *wc; /* wildcard */
if (!(h && *h && m && *m))
return (0);
if ((wc = strnstr(m, "*", mlen)) == NULL)
return (fetch_ssl_hname_equal(h, hlen, m, mlen));
wcidx = wc - m;
/* hostname should not be just dots and numbers */
if (fetch_ssl_hname_is_only_numbers(h, hlen))
return (0);
/* only one wildcard allowed in pattern */
if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
return (0);
/*
* there must be at least two more domain labels and
* wildcard has to be in the leftmost label (RFC6125)
*/
mdot1 = strnstr(m, ".", mlen);
if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
return (0);
mdot1idx = mdot1 - m;
mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
return (0);
/* hostname must contain a dot and not be the 1st char */
hdot = strnstr(h, ".", hlen);
if (hdot == NULL || hdot == h)
return (0);
hdotidx = hdot - h;
/*
* host part of hostname must be at least as long as
* pattern it's supposed to match
*/
if (hdotidx < mdot1idx)
return (0);
/*
* don't allow wildcards in non-traditional domain names
* (IDN, A-label, U-label...)
*/
if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
!fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
return (0);
/* match domain part (part after first dot) */
if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
mlen - mdot1idx))
return (0);
/* match part left of wildcard */
if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
return (0);
/* match part right of wildcard */
delta = mdot1idx - wcidx - 1;
if (!fetch_ssl_hname_equal(hdot - delta, delta,
mdot1 - delta, delta))
return (0);
/* all tests succeded, it's a match */
return (1);
}
/*
* Get numeric host address info - returns NULL if host was not an IP
* address. The caller is responsible for deallocation using
* freeaddrinfo(3).
*/
static struct addrinfo *
fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
{
struct addrinfo hints, *res;
char *host;
host = (char *)malloc(len + 1);
memcpy(host, hostname, len);
host[len] = '\0';
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
hints.ai_flags = AI_NUMERICHOST;
/* port is not relevant for this purpose */
getaddrinfo(host, "443", &hints, &res);
free(host);
return res;
}
/*
* Compare ip address in addrinfo with address passes.
*/
static int
fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
size_t rhostlen)
{
const void *left;
if (lhost->ai_family == AF_INET && rhostlen == 4) {
left = (void *)&((struct sockaddr_in*)(void *)
lhost->ai_addr)->sin_addr.s_addr;
#ifdef INET6
} else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
left = (void *)&((struct sockaddr_in6 *)(void *)
lhost->ai_addr)->sin6_addr;
#endif
} else
return (0);
return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
}
/*
* Compare ip address in addrinfo with host passed. If host is not an IP
* address, comparison will fail.
*/
static int
fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
size_t rlen)
{
struct addrinfo *raddr;
int ret;
char *rip;
ret = 0;
if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
return 0; /* not a numeric host */
if (laddr->ai_family == raddr->ai_family) {
if (laddr->ai_family == AF_INET) {
rip = (char *)&((struct sockaddr_in *)(void *)
raddr->ai_addr)->sin_addr.s_addr;
ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
#ifdef INET6
} else if (laddr->ai_family == AF_INET6) {
rip = (char *)&((struct sockaddr_in6 *)(void *)
raddr->ai_addr)->sin6_addr;
ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
#endif
}
}
freeaddrinfo(raddr);
return (ret);
}
/*
* Verify server certificate by subjectAltName.
*/
static int
fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
const char *host, struct addrinfo *ip)
{
const GENERAL_NAME *name;
size_t nslen;
int i;
const char *ns;
for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
#if OPENSSL_VERSION_NUMBER < 0x10000000L
/*
* This is a workaround, since the following line causes
* alignment issues in clang:
* name = sk_GENERAL_NAME_value(altnames, i);
* OpenSSL explicitly warns not to use those macros
* directly, but there isn't much choice (and there
* shouldn't be any ill side effects)
*/
name = (GENERAL_NAME *)SKM_sk_value(void, altnames, i);
#else
name = sk_GENERAL_NAME_value(altnames, i);
#endif
ns = (const char *)ASN1_STRING_data(name->d.ia5);
nslen = (size_t)ASN1_STRING_length(name->d.ia5);
if (name->type == GEN_DNS && ip == NULL &&
fetch_ssl_hname_match(host, strlen(host), ns, nslen))
return (1);
else if (name->type == GEN_IPADD && ip != NULL &&
fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
return (1);
}
return (0);
}
/*
* Verify server certificate by CN.
*/
static int
fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
struct addrinfo *ip)
{
ASN1_STRING *namedata;
X509_NAME_ENTRY *nameentry;
int cnlen, lastpos, loc, ret;
unsigned char *cn;
ret = 0;
lastpos = -1;
loc = -1;
cn = NULL;
/* get most specific CN (last entry in list) and compare */
while ((lastpos = X509_NAME_get_index_by_NID(subject,
NID_commonName, lastpos)) != -1)
loc = lastpos;
if (loc > -1) {
nameentry = X509_NAME_get_entry(subject, loc);
namedata = X509_NAME_ENTRY_get_data(nameentry);
cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
if (ip == NULL &&
fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
ret = 1;
else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
ret = 1;
OPENSSL_free(cn);
}
return (ret);
}
/*
* Verify that server certificate subjectAltName/CN matches
* hostname. First check, if there are alternative subject names. If yes,
* those have to match. Only if those don't exist it falls back to
* checking the subject's CN.
*/
static int
fetch_ssl_verify_hname(X509 *cert, const char *host)
{
struct addrinfo *ip;
STACK_OF(GENERAL_NAME) *altnames;
X509_NAME *subject;
int ret;
ret = 0;
ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
NULL, NULL);
if (altnames != NULL) {
ret = fetch_ssl_verify_altname(altnames, host, ip);
} else {
subject = X509_get_subject_name(cert);
if (subject != NULL)
ret = fetch_ssl_verify_cn(subject, host, ip);
}
if (ip != NULL)
freeaddrinfo(ip);
if (altnames != NULL)
GENERAL_NAMES_free(altnames);
return (ret);
}
/*
* Configure transport security layer based on environment.
*/
static void
fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
{
long ssl_ctx_options;
ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_TICKET;
if (getenv("SSL_ALLOW_SSL2") == NULL)
ssl_ctx_options |= SSL_OP_NO_SSLv2;
if (getenv("SSL_NO_SSL3") != NULL)
ssl_ctx_options |= SSL_OP_NO_SSLv3;
if (getenv("SSL_NO_TLS1") != NULL)
ssl_ctx_options |= SSL_OP_NO_TLSv1;
if (verbose)
fetch_info("SSL options: %lx", ssl_ctx_options);
SSL_CTX_set_options(ctx, ssl_ctx_options);
}
/*
* Configure peer verification based on environment.
*/
static int
fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
{
X509_LOOKUP *crl_lookup;
X509_STORE *crl_store;
const char *ca_cert_file, *ca_cert_path, *crl_file;
if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
ca_cert_file = getenv("SSL_CA_CERT_FILE") != NULL ?
getenv("SSL_CA_CERT_FILE") : "/etc/ssl/cert.pem";
ca_cert_path = getenv("SSL_CA_CERT_PATH");
if (verbose) {
fetch_info("Peer verification enabled");
if (ca_cert_file != NULL)
fetch_info("Using CA cert file: %s",
ca_cert_file);
if (ca_cert_path != NULL)
fetch_info("Using CA cert path: %s",
ca_cert_path);
}
SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
fetch_ssl_cb_verify_crt);
SSL_CTX_load_verify_locations(ctx, ca_cert_file,
ca_cert_path);
if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
if (verbose)
fetch_info("Using CRL file: %s", crl_file);
crl_store = SSL_CTX_get_cert_store(ctx);
crl_lookup = X509_STORE_add_lookup(crl_store,
X509_LOOKUP_file());
if (crl_lookup == NULL ||
!X509_load_crl_file(crl_lookup, crl_file,
X509_FILETYPE_PEM)) {
fprintf(stderr,
"Could not load CRL file %s\n",
crl_file);
return (0);
}
X509_STORE_set_flags(crl_store,
X509_V_FLAG_CRL_CHECK |
X509_V_FLAG_CRL_CHECK_ALL);
}
}
return (1);
}
/*
* Configure client certificate based on environment.
*/
static int
fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
{
const char *client_cert_file, *client_key_file;
if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
if (verbose) {
fetch_info("Using client cert file: %s",
client_cert_file);
fetch_info("Using client key file: %s",
client_key_file);
}
if (SSL_CTX_use_certificate_chain_file(ctx,
client_cert_file) != 1) {
fprintf(stderr,
"Could not load client certificate %s\n",
client_cert_file);
return (0);
}
if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
SSL_FILETYPE_PEM) != 1) {
fprintf(stderr,
"Could not load client key %s\n",
client_key_file);
return (0);
}
}
return (1);
}
/*
* Callback for SSL certificate verification, this is called on server
* cert verification. It takes no decision, but informs the user in case
* verification failed.
*/
int
fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
{
X509 *crt;
X509_NAME *name;
char *str;
str = NULL;
if (!verified) {
if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
(name = X509_get_subject_name(crt)) != NULL)
str = X509_NAME_oneline(name, 0, 0);
fprintf(stderr, "Certificate verification failed for %s\n",
str != NULL ? str : "no relevant certificate");
OPENSSL_free(str);
}
return (verified);
}
#endif
/*
* Enable SSL on a connection.
*/
int
fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
{
#ifdef WITH_SSL
int ret, ssl_err;
X509_NAME *name;
char *str;
/* Init the SSL library and context */
if (!SSL_library_init()){
fprintf(stderr, "SSL library init failed\n");
return (-1);
}
SSL_load_error_strings();
conn->ssl_meth = SSLv23_client_method();
conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
return (-1);
if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
return (-1);
conn->ssl = SSL_new(conn->ssl_ctx);
if (conn->ssl == NULL) {
fprintf(stderr, "SSL context creation failed\n");
return (-1);
}
SSL_set_fd(conn->ssl, conn->sd);
#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
if (!SSL_set_tlsext_host_name(conn->ssl,
__DECONST(struct url *, URL)->host)) {
fprintf(stderr,
"TLS server name indication extension failed for host %s\n",
URL->host);
return (-1);
}
#endif
while ((ret = SSL_connect(conn->ssl)) == -1) {
ssl_err = SSL_get_error(conn->ssl, ret);
if (ssl_err != SSL_ERROR_WANT_READ &&
ssl_err != SSL_ERROR_WANT_WRITE) {
ERR_print_errors_fp(stderr);
return (-1);
}
}
conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
if (conn->ssl_cert == NULL) {
fprintf(stderr, "No server SSL certificate\n");
return (-1);
}
if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
if (verbose)
fetch_info("Verify hostname");
if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
fprintf(stderr,
"SSL certificate subject doesn't match host %s\n",
URL->host);
return (-1);
}
}
if (verbose) {
fetch_info("SSL connection established using %s",
SSL_get_cipher(conn->ssl));
name = X509_get_subject_name(conn->ssl_cert);
str = X509_NAME_oneline(name, 0, 0);
fetch_info("Certificate subject: %s", str);
OPENSSL_free(str);
name = X509_get_issuer_name(conn->ssl_cert);
str = X509_NAME_oneline(name, 0, 0);
fetch_info("Certificate issuer: %s", str);
OPENSSL_free(str);
}
return (0);
#else
(void)conn;
(void)verbose;
fprintf(stderr, "SSL support disabled\n");
return (-1);
#endif
}
#define FETCH_READ_WAIT -2
#define FETCH_READ_ERROR -1
#define FETCH_READ_DONE 0
#ifdef WITH_SSL
ssize_t
fetch_ssl_read(SSL *ssl, char *buf, size_t len)
{
ssize_t rlen;
int ssl_err;
rlen = SSL_read(ssl, buf, len);
if (rlen < 0) {
ssl_err = SSL_get_error(ssl, rlen);
if (ssl_err == SSL_ERROR_WANT_READ ||
ssl_err == SSL_ERROR_WANT_WRITE) {
return (FETCH_READ_WAIT);
} else {
ERR_print_errors_fp(stderr);
return (FETCH_READ_ERROR);
}
}
return (rlen);
}
ssize_t
fetch_ssl_write(SSL *ssl, char *buf, size_t len)
{
return (SSL_write(ssl, buf, len));
}
void
fetch_ssl_shutdown(conn_t *conn)
{
if (conn->ssl) {
SSL_shutdown(conn->ssl);
SSL_set_connect_state(conn->ssl);
SSL_free(conn->ssl);
conn->ssl = NULL;
}
if (conn->ssl_ctx) {
SSL_CTX_free(conn->ssl_ctx);
conn->ssl_ctx = NULL;
}
if (conn->ssl_cert) {
X509_free(conn->ssl_cert);
conn->ssl_cert = NULL;
}
}
#endif
static ssize_t
fetch_socket_read(int sd, char *buf, size_t len)
{
ssize_t rlen;
rlen = read(sd, buf, len);
if (rlen < 0) {
if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
return (FETCH_READ_WAIT);
else
return (FETCH_READ_ERROR);
}
return (rlen);
}
/*
* Read a character from a connection w/ timeout
*/
ssize_t
fetch_read(conn_t *conn, char *buf, size_t len)
{
struct timeval now, timeout, delta;
struct pollfd pfd;
ssize_t rlen;
int deltams;
if (fetchTimeout > 0) {
gettimeofday(&timeout, NULL);
timeout.tv_sec += fetchTimeout;
}
deltams = INFTIM;
memset(&pfd, 0, sizeof pfd);
pfd.fd = conn->sd;
pfd.events = POLLIN | POLLERR;
for (;;) {
/*
* The socket is non-blocking. Instead of the canonical
* poll() -> read(), we do the following:
*
* 1) call read() or SSL_read().
* 2) if we received some data, return it.
* 3) if an error occurred, return -1.
* 4) if read() or SSL_read() signaled EOF, return.
* 5) if we did not receive any data but we're not at EOF,
* call poll().
*
* In the SSL case, this is necessary because if we
* receive a close notification, we have to call
* SSL_read() one additional time after we've read
* everything we received.
*
* In the non-SSL case, it may improve performance (very
* slightly) when reading small amounts of data.