2 * socket.c -- socket library functions
4 * Copyright 1998 by Eric S. Raymond.
5 * For license terms, see the file COPYING in this directory.
12 #include <ctype.h> /* isspace() */
15 #endif /* HAVE_MEMORY_H */
16 #include <sys/types.h>
18 #ifndef HAVE_NET_SOCKET_H
19 #include <sys/socket.h>
21 #include <net/socket.h>
24 #include <netinet/in.h>
25 #ifdef HAVE_ARPA_INET_H
26 #include <arpa/inet.h>
29 #if defined(STDC_HEADERS)
32 #if defined(HAVE_UNISTD_H)
35 #if defined(HAVE_STDARG_H)
40 #if TIME_WITH_SYS_TIME
41 # include <sys/time.h>
45 # include <sys/time.h>
52 #include "fetchmail.h"
53 #include "getaddrinfo.h"
57 /* Defines to allow BeOS and Cygwin to play nice... */
60 #define fm_close(a) closesocket(a)
61 #define fm_write(a,b,c) send(a,b,c,0)
62 #define fm_peek(a,b,c) recv(a,b,c,0)
63 #define fm_read(a,b,c) recv(a,b,c,0)
65 #define fm_close(a) close(a)
66 #define fm_write(a,b,c) write(a,b,c)
67 #define fm_peek(a,b,c) recv(a,b,c, MSG_PEEK)
69 #define fm_read(a,b,c) cygwin_read(a,b,c)
70 static ssize_t cygwin_read(int sock, void *buf, size_t count);
71 #else /* ! __CYGWIN__ */
72 #define fm_read(a,b,c) read(a,b,c)
73 #endif /* __CYGWIN__ */
76 /* We need to define h_errno only if it is not already */
78 # if !HAVE_DECL_H_ERRNO
81 #endif /* ndef h_errno */
83 #ifdef HAVE_SOCKETPAIR
84 static char *const *parse_plugin(const char *plugin, const char *host, const char *service)
88 char *cp, *plugin_copy;
89 unsigned int plugin_copy_len;
90 unsigned int plugin_offset = 0, plugin_copy_offset = 0;
91 unsigned int i, s = 2 * sizeof(char*), host_count = 0, service_count = 0;
92 unsigned int plugin_len = strlen(plugin);
93 unsigned int host_len = strlen(host);
94 unsigned int service_len = strlen(service);
96 for (c = p = plugin; *c; c++)
97 { if (isspace((unsigned char)*c) && !isspace((unsigned char)*p))
99 if (*p == '%' && *c == 'h')
101 if (*p == '%' && *c == 'p')
106 plugin_copy_len = plugin_len + host_len * host_count + service_len * service_count;
107 plugin_copy = (char *)malloc(plugin_copy_len + 1);
110 report(stderr, GT_("fetchmail: malloc failed\n"));
114 while (plugin_copy_offset < plugin_copy_len)
115 { if ((plugin[plugin_offset] == '%') && (plugin[plugin_offset + 1] == 'h'))
116 { strcpy(plugin_copy + plugin_copy_offset, host);
118 plugin_copy_offset += host_len;
120 else if ((plugin[plugin_offset] == '%') && (plugin[plugin_offset + 1] == 'p'))
121 { strcpy(plugin_copy + plugin_copy_offset, service);
123 plugin_copy_offset += service_len;
126 { plugin_copy[plugin_copy_offset] = plugin[plugin_offset];
128 plugin_copy_offset++;
131 plugin_copy[plugin_copy_len] = 0;
133 argvec = (char **)malloc(s);
136 report(stderr, GT_("fetchmail: malloc failed\n"));
139 memset(argvec, 0, s);
140 for (p = cp = plugin_copy, i = 0; *cp; cp++)
141 { if ((!isspace((unsigned char)*cp)) && (cp == p ? 1 : isspace((unsigned char)*p))) {
147 for (cp = plugin_copy; *cp; cp++)
148 { if (isspace((unsigned char)*cp))
154 static int handle_plugin(const char *host,
155 const char *service, const char *plugin)
156 /* get a socket mediated through a given external command */
162 * The author of this code, Felix von Leitner <felix@convergence.de>, says:
163 * he chose socketpair() instead of pipe() because socketpair creates
164 * bidirectional sockets while allegedly some pipe() implementations don't.
166 if (socketpair(AF_UNIX,SOCK_STREAM,0,fds))
168 report(stderr, GT_("fetchmail: socketpair failed\n"));
174 report(stderr, GT_("fetchmail: fork failed\n"));
177 /* fds[1] is the parent's end; close it for proper EOF
179 (void) close(fds[1]);
180 if ( (dup2(fds[0],0) == -1) || (dup2(fds[0],1) == -1) ) {
181 report(stderr, GT_("dup2 failed\n"));
184 /* fds[0] is now connected to 0 and 1; close it */
185 (void) close(fds[0]);
186 if (outlevel >= O_VERBOSE)
187 report(stderr, GT_("running %s (host %s service %s)\n"), plugin, host, service);
188 argvec = parse_plugin(plugin,host,service);
189 execvp(*argvec, argvec);
190 report(stderr, GT_("execvp(%s) failed\n"), *argvec);
193 default: /* parent */
197 /* fds[0] is the child's end; close it for proper EOF detection */
198 (void) close(fds[0]);
201 #endif /* HAVE_SOCKETPAIR */
205 int SockCheckOpen(int fd)
206 /* poll given socket; is it selectable? */
214 FD_ZERO(&r); FD_ZERO(&w); FD_ZERO(&e);
217 tv.tv_sec = 0; tv.tv_usec = 0;
218 rt = select(fd+1, &r, &w, &e, &tv);
219 if (rt == -1 && (errno != EAGAIN && errno != EINTR))
225 #endif /* __UNUSED__ */
227 int UnixOpen(const char *path)
230 struct sockaddr_un ad;
231 memset(&ad, 0, sizeof(ad));
232 ad.sun_family = AF_UNIX;
233 strncpy(ad.sun_path, path, sizeof(ad.sun_path)-1);
235 sock = socket( AF_UNIX, SOCK_STREAM, 0 );
242 /* Socket opened saved. Usefull if connect timeout
243 * because it can be closed.
245 mailserver_socket_temp = sock;
247 if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
250 fm_close(sock); /* don't use SockClose, no traffic yet */
256 /* No connect timeout, then no need to set mailserver_socket_temp */
257 mailserver_socket_temp = -1;
262 int SockOpen(const char *host, const char *service,
263 const char *plugin, struct addrinfo **ai0)
265 struct addrinfo *ai, req;
268 char errbuf[8192] = "";
270 #ifdef HAVE_SOCKETPAIR
272 return handle_plugin(host,service,plugin);
273 #endif /* HAVE_SOCKETPAIR */
275 memset(&req, 0, sizeof(struct addrinfo));
276 req.ai_socktype = SOCK_STREAM;
278 req.ai_flags = AI_ADDRCONFIG;
281 i = fm_getaddrinfo(host, service, &req, ai0);
283 report(stderr, GT_("getaddrinfo(\"%s\",\"%s\") error: %s\n"),
284 host, service, gai_strerror(i));
285 if (i == EAI_SERVICE)
286 report(stderr, GT_("Try adding the --service option (see also FAQ item R12).\n"));
290 /* NOTE a Linux bug here - getaddrinfo will happily return 127.0.0.1
291 * twice if no IPv6 is configured */
293 for (ord = 0, ai = *ai0; ai; ord++, ai = ai->ai_next) {
294 char buf[256]; /* hostname */
295 char pb[256]; /* service name */
296 int gnie; /* getnameinfo result code */
298 gnie = getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof(buf), NULL, 0, NI_NUMERICHOST);
300 snprintf(buf, sizeof(buf), GT_("unknown (%s)"), gai_strerror(gnie));
301 gnie = getnameinfo(ai->ai_addr, ai->ai_addrlen, NULL, 0, pb, sizeof(pb), NI_NUMERICSERV);
303 snprintf(pb, sizeof(pb), GT_("unknown (%s)"), gai_strerror(gnie));
305 if (outlevel >= O_VERBOSE)
306 report_build(stdout, GT_("Trying to connect to %s/%s..."), buf, pb);
307 i = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
310 /* mask EAFNOSUPPORT errors, they confuse users for
311 * multihomed hosts */
312 if (errno != EAFNOSUPPORT)
314 if (outlevel >= O_VERBOSE)
315 report_complete(stdout, GT_("cannot create socket: %s\n"), strerror(e));
316 snprintf(errbuf+strlen(errbuf), sizeof(errbuf)-strlen(errbuf),\
317 GT_("name %d: cannot create socket family %d type %d: %s\n"), ord, ai->ai_family, ai->ai_socktype, strerror(e));
321 /* Save socket descriptor.
322 * Used to close the socket after connect timeout. */
323 mailserver_socket_temp = i;
325 if (connect(i, (struct sockaddr *) ai->ai_addr, ai->ai_addrlen) < 0) {
328 /* additionally, suppress IPv4 network unreach errors */
329 if (e != EAFNOSUPPORT)
332 if (outlevel >= O_VERBOSE)
333 report_complete(stdout, GT_("connection failed.\n"));
334 if (outlevel >= O_VERBOSE)
335 report(stderr, GT_("connection to %s:%s [%s/%s] failed: %s.\n"), host, service, buf, pb, strerror(e));
336 snprintf(errbuf+strlen(errbuf), sizeof(errbuf)-strlen(errbuf), GT_("name %d: connection to %s:%s [%s/%s] failed: %s.\n"), ord, host, service, buf, pb, strerror(e));
341 if (outlevel >= O_VERBOSE)
342 report_complete(stdout, GT_("connected.\n"));
345 /* No connect timeout, then no need to set mailserver_socket_temp */
346 mailserver_socket_temp = -1;
351 fm_freeaddrinfo(*ai0);
355 report(stderr, GT_("Connection errors for this poll:\n%s"), errbuf);
363 #if defined(HAVE_STDARG_H)
364 int SockPrintf(int sock, const char* format, ...)
367 int SockPrintf(sock,format,va_alist)
376 #if defined(HAVE_STDARG_H)
377 va_start(ap, format) ;
381 vsnprintf(buf, sizeof(buf), format, ap);
383 return SockWrite(sock, buf, strlen(buf));
388 #include <openssl/ssl.h>
389 #include <openssl/err.h>
390 #include <openssl/pem.h>
391 #include <openssl/x509v3.h>
392 #include <openssl/rand.h>
394 static SSL_CTX *_ctx[FD_SETSIZE];
395 static SSL *_ssl_context[FD_SETSIZE];
397 static SSL *SSLGetContext( int );
398 #endif /* SSL_ENABLE */
400 int SockWrite(int sock, const char *buf, int len)
410 if( NULL != ( ssl = SSLGetContext( sock ) ) )
411 n = SSL_write(ssl, buf, len);
413 #endif /* SSL_ENABLE */
414 n = fm_write(sock, buf, len);
424 int SockRead(int sock, char *buf, int len)
426 char *newline, *bp = buf;
444 * The reason for these gymnastics is that we want two things:
445 * (1) to read \n-terminated lines,
446 * (2) to return the true length of data read, even if the
447 * data coming in has embedded NULS.
450 if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
452 /* OK... SSL_peek works a little different from MSG_PEEK
453 Problem is that SSL_peek can return 0 if there
454 is no data currently available. If, on the other
455 hand, we loose the socket, we also get a zero, but
456 the SSL_read then SEGFAULTS! To deal with this,
457 we'll check the error code any time we get a return
458 of zero from SSL_peek. If we have an error, we bail.
459 If we don't, we read one character in SSL_read and
460 loop. This should continue to work even if they
461 later change the behavior of SSL_peek
462 to "fix" this problem... :-( */
463 if ((n = SSL_peek(ssl, bp, len)) < 0) {
464 (void)SSL_get_error(ssl, n);
468 /* SSL_peek says no data... Does he mean no data
469 or did the connection blow up? If we got an error
471 if (0 != SSL_get_error(ssl, n)) {
474 /* We didn't get an error so read at least one
475 character at this point and loop */
477 /* Make sure newline start out NULL!
478 * We don't have a string to pass through
479 * the strchr at this point yet */
481 } else if ((newline = (char *)memchr(bp, '\n', n)) != NULL)
482 n = newline - bp + 1;
483 /* Matthias Andree: SSL_read can return 0, in that case
484 * we must call SSL_get_error to figure if there was
485 * an error or just a "no data" condition */
486 if ((n = SSL_read(ssl, bp, n)) <= 0) {
487 if ((n = SSL_get_error(ssl, n))) {
491 /* Check for case where our single character turned out to
492 * be a newline... (It wasn't going to get caught by
493 * the strchr above if it came from the hack... ). */
494 if( NULL == newline && 1 == n && '\n' == *bp ) {
495 /* Got our newline - this will break
496 out of the loop now */
501 #endif /* SSL_ENABLE */
505 if ((n = fm_read(sock, bp, 1)) <= 0)
507 if ((n = fm_peek(sock, bp, len)) <= 0)
510 if ((newline = (char *)memchr(bp, '\n', n)) != NULL)
511 n = newline - bp + 1;
513 if ((n = fm_read(sock, bp, n)) == -1)
515 #endif /* __BEOS__ */
526 int SockPeek(int sock)
527 /* peek at the next socket character without actually reading it */
536 if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
537 n = SSL_peek(ssl, &ch, 1);
539 (void)SSL_get_error(ssl, n);
543 /* This code really needs to implement a "hold back"
544 * to simulate a functioning SSL_peek()... sigh...
545 * Has to be coordinated with the read code above.
546 * Next on the list todo... */
548 /* SSL_peek says 0... Does that mean no data
549 or did the connection blow up? If we got an error
551 if(0 != SSL_get_error(ssl, n)) {
555 /* Haven't seen this case actually occur, but...
556 if the problem in SockRead can occur, this should
557 be possible... Just not sure what to do here.
558 This should be a safe "punt" the "peek" but don't
559 "punt" the "session"... */
561 return 0; /* Give him a '\0' character */
565 #endif /* SSL_ENABLE */
566 n = fm_peek(sock, &ch, 1);
578 static char *_ssl_server_cname = NULL;
579 static int _check_fp;
580 static char *_check_digest;
581 static char *_server_label;
582 static int _depth0ck;
583 static int _firstrun;
584 static int _prev_err;
585 static int _verify_ok;
587 SSL *SSLGetContext( int sock )
589 if( sock < 0 || (unsigned)sock > FD_SETSIZE )
591 if( _ctx[sock] == NULL )
593 return _ssl_context[sock];
596 /** A picky certificate name check:
597 * check if the pattern or string in s1 (from a certificate) matches the
598 * hostname (in s2), returns true if matched.
600 * The only place where a wildcard is allowed is in the leftmost
602 static int name_match(const char *p1, const char *p2) {
603 const char *const dom = "0123456789.";
606 /* blank patterns never match */
610 /* disallow wildcards in certificates for domain literals
612 if (strspn(p1+(*p1 == '*' ? 1 : 0), dom) == strlen(p1))
615 /* disallow wildcards for domain literals */
616 if (strspn(p2, dom) == strlen(p2))
619 if (wildcard_ok && p1[0] == '*' && p1[1] == '.') {
629 return (0 == strcasecmp(p1, p2));
632 /* ok_return (preverify_ok) is 1 if this stage of certificate verification
633 passed, or 0 if it failed. This callback lets us display informative
634 errors, and perform additional validation (e.g. CN matches) */
635 static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
637 #define SSLverbose (((outlevel) >= O_DEBUG) || ((outlevel) >= O_VERBOSE && (depth) == 0))
641 unsigned char digest[EVP_MAX_MD_SIZE];
642 char text[EVP_MAX_MD_SIZE * 3 + 1], *tp, *te;
643 const EVP_MD *digest_tp;
644 unsigned int dsz, esz;
645 X509_NAME *subj, *issuer;
648 x509_cert = X509_STORE_CTX_get_current_cert(ctx);
649 err = X509_STORE_CTX_get_error(ctx);
650 depth = X509_STORE_CTX_get_error_depth(ctx);
652 subj = X509_get_subject_name(x509_cert);
653 issuer = X509_get_issuer_name(x509_cert);
655 if (outlevel >= O_VERBOSE) {
656 if (depth == 0 && SSLverbose)
657 report(stderr, GT_("Server certificate:\n"));
662 report(stdout, GT_("Certificate chain, from root to peer, starting at depth %d:\n"), depth);
665 report(stdout, GT_("Certificate at depth %d:\n"), depth);
670 if ((i = X509_NAME_get_text_by_NID(issuer, NID_organizationName, buf, sizeof(buf))) != -1) {
671 report(stdout, GT_("Issuer Organization: %s\n"), (tt = sdump(buf, i)));
673 if ((size_t)i >= sizeof(buf) - 1)
674 report(stdout, GT_("Warning: Issuer Organization Name too long (possibly truncated).\n"));
676 report(stdout, GT_("Unknown Organization\n"));
677 if ((i = X509_NAME_get_text_by_NID(issuer, NID_commonName, buf, sizeof(buf))) != -1) {
678 report(stdout, GT_("Issuer CommonName: %s\n"), (tt = sdump(buf, i)));
680 if ((size_t)i >= sizeof(buf) - 1)
681 report(stdout, GT_("Warning: Issuer CommonName too long (possibly truncated).\n"));
683 report(stdout, GT_("Unknown Issuer CommonName\n"));
687 if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) {
689 report(stdout, GT_("Subject CommonName: %s\n"), (tt = sdump(buf, i)));
692 if ((size_t)i >= sizeof(buf) - 1) {
693 /* Possible truncation. In this case, this is a DNS name, so this
694 * is really bad. We do not tolerate this even in the non-strict case. */
695 report(stderr, GT_("Bad certificate: Subject CommonName too long!\n"));
698 if ((size_t)i > strlen(buf)) {
699 /* Name contains embedded NUL characters, so we complain. This is likely
700 * a certificate spoofing attack. */
701 report(stderr, GT_("Bad certificate: Subject CommonName contains NUL, aborting!\n"));
706 if (depth == 0) { /* peer certificate */
711 if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) {
712 if (_ssl_server_cname != NULL) {
714 char *p2 = _ssl_server_cname;
716 STACK_OF(GENERAL_NAME) *gens;
718 /* RFC 2595 section 2.4: find a matching name
719 * first find a match among alternative names */
720 gens = (STACK_OF(GENERAL_NAME) *)X509_get_ext_d2i(x509_cert, NID_subject_alt_name, NULL, NULL);
723 for (j = 0, r = sk_GENERAL_NAME_num(gens); j < r; ++j) {
724 const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, j);
725 if (gn->type == GEN_DNS) {
726 char *p1 = (char *)gn->d.ia5->data;
727 char *p2 = _ssl_server_cname;
728 if (outlevel >= O_VERBOSE) {
729 report(stdout, GT_("Subject Alternative Name: %s\n"), (tt = sdump(p1, (size_t)gn->d.ia5->length)));
732 /* Name contains embedded NUL characters, so we complain. This
733 * is likely a certificate spoofing attack. */
734 if ((size_t)gn->d.ia5->length != strlen(p1)) {
735 report(stderr, GT_("Bad certificate: Subject Alternative Name contains NUL, aborting!\n"));
736 sk_GENERAL_NAME_free(gens);
739 if (name_match(p1, p2)) {
744 sk_GENERAL_NAME_free(gens);
746 if (name_match(p1, p2)) {
750 if (strict || SSLverbose) {
752 GT_("Server CommonName mismatch: %s != %s\n"),
753 (tt = sdump(buf, i)), _ssl_server_cname );
758 } else if (ok_return) {
759 report(stderr, GT_("Server name not set, could not verify certificate!\n"));
760 if (strict) return (0);
763 if (outlevel >= O_VERBOSE)
764 report(stdout, GT_("Unknown Server CommonName\n"));
765 if (ok_return && strict) {
766 report(stderr, GT_("Server name not specified in certificate!\n"));
770 /* Print the finger print. Note that on errors, we might print it more than once
771 * normally; we kluge around that by using a global variable. */
772 if (_check_fp == 1) {
776 digest_tp = EVP_md5();
777 if (digest_tp == NULL) {
778 report(stderr, GT_("EVP_md5() failed!\n"));
781 if (!X509_digest(x509_cert, digest_tp, digest, &dsz)) {
782 report(stderr, GT_("Out of memory!\n"));
786 te = text + sizeof(text);
787 for (dp = 0; dp < dsz; dp++) {
788 esz = snprintf(tp, te - tp, dp > 0 ? ":%02X" : "%02X", digest[dp]);
789 if (esz >= (size_t)(te - tp)) {
790 report(stderr, GT_("Digest text buffer too small!\n"));
795 if (outlevel > O_NORMAL)
796 report(stdout, GT_("%s key fingerprint: %s\n"), _server_label, text);
797 if (_check_digest != NULL) {
798 if (strcasecmp(text, _check_digest) == 0) {
799 if (outlevel > O_NORMAL)
800 report(stdout, GT_("%s fingerprints match.\n"), _server_label);
802 report(stderr, GT_("%s fingerprints do not match!\n"), _server_label);
805 } /* if (_check_digest != NULL) */
806 } /* if (_check_fp) */
807 } /* if (depth == 0 && !_depth0ck) */
809 if (err != X509_V_OK && err != _prev_err && !(_check_fp != 0 && _check_digest && !strict)) {
812 report(stderr, GT_("Server certificate verification error: %s\n"), X509_verify_cert_error_string(err));
813 /* We gave the error code, but maybe we can add some more details for debugging */
816 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
817 X509_NAME_oneline(issuer, buf, sizeof(buf));
818 buf[sizeof(buf) - 1] = '\0';
819 report(stderr, GT_("unknown issuer (first %d characters): %s\n"), (int)(sizeof(buf)-1), buf);
820 report(stderr, GT_("This error usually happens when the server provides an incomplete certificate "
821 "chain, which is nothing fetchmail could do anything about. For details, "
822 "please see the README.SSL-SERVER document that comes with fetchmail.\n"));
824 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
825 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
826 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
827 X509_NAME_oneline(subj, buf, sizeof(buf));
828 buf[sizeof(buf) - 1] = '\0';
829 report(stderr, GT_("This means that the root signing certificate (issued for %s) is not in the "
830 "trusted CA certificate locations, or that c_rehash needs to be run "
831 "on the certificate directory. For details, please "
832 "see the documentation of --sslcertpath and --sslcertfile in the manual page.\n"), buf);
839 * If not in strict checking mode (--sslcertck), override this
840 * and pretend that verification had succeeded.
842 _verify_ok &= ok_return;
848 static int SSL_nock_verify_callback( int ok_return, X509_STORE_CTX *ctx )
850 return SSL_verify_callback(ok_return, ctx, 0);
853 static int SSL_ck_verify_callback( int ok_return, X509_STORE_CTX *ctx )
855 return SSL_verify_callback(ok_return, ctx, 1);
859 /* get commonName from certificate set in file.
860 * commonName is stored in buffer namebuffer, limited with namebufferlen
862 static const char *SSLCertGetCN(const char *mycert,
863 char *namebuffer, size_t namebufferlen)
865 const char *ret = NULL;
867 X509 *x509_cert = NULL;
868 X509_NAME *certname = NULL;
870 if (namebuffer && namebufferlen > 0) {
871 namebuffer[0] = 0x00;
872 certBio = BIO_new_file(mycert,"r");
874 x509_cert = PEM_read_bio_X509(certBio,NULL,NULL,NULL);
878 certname = X509_get_subject_name(x509_cert);
880 X509_NAME_get_text_by_NID(certname, NID_commonName,
881 namebuffer, namebufferlen) > 0)
883 X509_free(x509_cert);
889 /* performs initial SSL handshake over the connected socket
890 * uses SSL *ssl global variable, which is currently defined
893 int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck,
894 char *cacertfile, char *certpath,
895 char *fingerprint, char *servercname, char *label, char **remotename)
897 struct stat randstat;
900 SSL_load_error_strings();
902 OpenSSL_add_all_algorithms(); /* see Debian Bug#576430 and manpage */
904 if (stat("/dev/random", &randstat) &&
905 stat("/dev/urandom", &randstat)) {
906 /* Neither /dev/random nor /dev/urandom are present, so add
907 entropy to the SSL PRNG a hard way. */
908 for (i = 0; i < 10000 && ! RAND_status (); ++i) {
911 gettimeofday (&tv, 0);
912 buf[0] = tv.tv_usec & 0xF;
913 buf[2] = (tv.tv_usec & 0xF0) >> 4;
914 buf[3] = (tv.tv_usec & 0xF00) >> 8;
915 buf[1] = (tv.tv_usec & 0xF000) >> 12;
916 RAND_add (buf, sizeof buf, 0.1);
920 if( sock < 0 || (unsigned)sock > FD_SETSIZE ) {
921 report(stderr, GT_("File descriptor out of range for SSL") );
925 /* Make sure a connection referring to an older context is not left */
926 _ssl_context[sock] = NULL;
928 if(!strcasecmp("ssl2",myproto)) {
929 _ctx[sock] = SSL_CTX_new(SSLv2_client_method());
930 } else if(!strcasecmp("ssl3",myproto)) {
931 _ctx[sock] = SSL_CTX_new(SSLv3_client_method());
932 } else if(!strcasecmp("tls1",myproto)) {
933 _ctx[sock] = SSL_CTX_new(TLSv1_client_method());
934 } else if (!strcasecmp("ssl23",myproto)) {
937 fprintf(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
942 _ctx[sock] = SSL_CTX_new(SSLv23_client_method());
944 if(_ctx[sock] == NULL) {
945 ERR_print_errors_fp(stderr);
949 SSL_CTX_set_options(_ctx[sock], SSL_OP_ALL);
952 SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_ck_verify_callback);
954 /* In this case, we do not fail if verification fails. However,
955 * we provide the callback for output and possible fingerprint
957 SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_nock_verify_callback);
960 /* Check which trusted X.509 CA certificate store(s) to load */
963 int want_default_cacerts = 0;
965 /* Load user locations if any is given */
966 if (certpath || cacertfile)
967 SSL_CTX_load_verify_locations(_ctx[sock],
968 cacertfile, certpath);
970 want_default_cacerts = 1;
972 tmp = getenv("FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS");
973 if (want_default_cacerts || (tmp && tmp[0])) {
974 SSL_CTX_set_default_verify_paths(_ctx[sock]);
978 _ssl_context[sock] = SSL_new(_ctx[sock]);
980 if(_ssl_context[sock] == NULL) {
981 ERR_print_errors_fp(stderr);
982 SSL_CTX_free(_ctx[sock]);
987 /* This static is for the verify callback */
988 _ssl_server_cname = servercname;
989 _server_label = label;
991 _check_digest = fingerprint;
997 if( mycert || mykey ) {
999 /* Ok... He has a certificate file defined, so lets declare it. If
1000 * he does NOT have a separate certificate and private key file then
1001 * assume that it's a combined key and certificate file.
1010 if ((!*remotename || !**remotename) && SSLCertGetCN(mycert, buffer, sizeof(buffer))) {
1012 *remotename = xstrdup(buffer);
1014 SSL_use_certificate_file(_ssl_context[sock], mycert, SSL_FILETYPE_PEM);
1015 SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM);
1018 if (SSL_set_fd(_ssl_context[sock], sock) == 0
1019 || SSL_connect(_ssl_context[sock]) < 1) {
1020 ERR_print_errors_fp(stderr);
1021 SSL_free( _ssl_context[sock] );
1022 _ssl_context[sock] = NULL;
1023 SSL_CTX_free(_ctx[sock]);
1028 /* Paranoia: was the callback not called as we expected? */
1030 report(stderr, GT_("Certificate/fingerprint verification was somehow skipped!\n"));
1032 if (fingerprint != NULL || certck) {
1033 if( NULL != SSLGetContext( sock ) ) {
1034 /* Clean up the SSL stack */
1035 SSL_shutdown( _ssl_context[sock] );
1036 SSL_free( _ssl_context[sock] );
1037 _ssl_context[sock] = NULL;
1038 SSL_CTX_free(_ctx[sock]);
1045 if (!certck && !fingerprint &&
1046 (SSL_get_verify_result(_ssl_context[sock]) != X509_V_OK || !_verify_ok)) {
1047 report(stderr, GT_("Warning: the connection is insecure, continuing anyways. (Better use --sslcertck!)\n"));
1054 int SockClose(int sock)
1055 /* close a socket gracefully */
1058 if( NULL != SSLGetContext( sock ) ) {
1059 /* Clean up the SSL stack */
1060 SSL_shutdown( _ssl_context[sock] );
1061 SSL_free( _ssl_context[sock] );
1062 _ssl_context[sock] = NULL;
1063 SSL_CTX_free(_ctx[sock]);
1070 * This hangs in RedHat 6.2 after fetchmail runs for a while a
1071 * FIN_WAIT2 comes up in netstat and fetchmail never returns from
1072 * the recv system call. (Reported from jtnews
1073 * <jtnews@bellatlantic.net>, Wed, 24 May 2000 21:26:02.)
1075 * Half-close the connection first so the other end gets notified.
1077 * This stops sends but allows receives (effectively, it sends a
1079 if (shutdown(sock, 1) == 0) {
1081 /* If there is any data still waiting in the queue, discard it.
1082 * Call recv() until either it returns 0 (meaning we received a FIN)
1083 * or any error occurs. This makes sure all data sent by the other
1084 * side is acknowledged at the TCP level.
1086 if (fm_peek(sock, &ch, 1) > 0)
1087 while (fm_read(sock, &ch, 1) > 0)
1090 #endif /* __UNUSED__ */
1092 /* if there's an error closing at this point, not much we can do */
1093 return(fm_close(sock)); /* this is guarded */
1098 * Workaround Microsoft Winsock recv/WSARecv(..., MSG_PEEK) bug.
1099 * See http://sources.redhat.com/ml/cygwin/2001-08/msg00628.html
1102 static ssize_t cygwin_read(int sock, void *buf, size_t count)
1107 if ((n = read(sock, bp, count)) == (size_t)-1)
1112 if (outlevel >= O_VERBOSE)
1113 report(stdout, GT_("Cygwin socket read retry\n"));
1114 n2 = read(sock, bp + n, count - n);
1115 if (n2 == (size_t)-1 || n + n2 != count) {
1116 report(stderr, GT_("Cygwin socket read retry failed!\n"));
1123 #endif /* __CYGWIN__ */
1127 * Use the chargen service to test input buffering directly.
1128 * You may have to uncomment the `chargen' service description in your
1129 * inetd.conf (and then SIGHUP inetd) for this to work. */
1132 int sock = SockOpen("localhost", "chargen", NULL);
1135 while (SockRead(sock, buf, sizeof(buf)-1))
1136 SockWrite(1, buf, strlen(buf));
1141 /* socket.c ends here */