2 * pop3.c -- POP3 protocol methods
4 * Copyright 1998 by Eric S. Raymond.
5 * For license terms, see the file COPYING in this directory.
13 #if defined(HAVE_UNISTD_H)
16 #if defined(STDC_HEADERS)
21 #include "fetchmail.h"
33 #endif /* OPIE_ENABLE */
35 /* global variables: please reinitialize them explicitly for proper
36 * working in daemon mode */
38 /* TODO: session variables to be initialized before server greeting */
40 static char lastok[POPBUFSIZE+1];
41 #endif /* OPIE_ENABLE */
43 /* session variables initialized in capa_probe() or pop3_getauth() */
44 flag done_capa = FALSE;
46 flag has_gssapi = FALSE;
47 #endif /* defined(GSSAPI) */
48 #if defined(KERBEROS_V4) || defined(KERBEROS_V5)
49 flag has_kerberos = FALSE;
50 #endif /* defined(KERBEROS_V4) || defined(KERBEROS_V5) */
51 static flag has_cram = FALSE;
54 #endif /* OPIE_ENABLE */
56 flag has_ntlm = FALSE;
57 #endif /* NTLM_ENABLE */
59 static flag has_stls = FALSE;
60 #endif /* SSL_ENABLE */
62 /* mailbox variables initialized in pop3_getrange() */
65 /* mail variables initialized in pop3_fetch() */
69 #endif /* SDPS_ENABLE */
75 * NTLM support by Grant Edwards.
77 * Handle MS-Exchange NTLM authentication method. This is the same
78 * as the NTLM auth used by Samba for SMB related services. We just
79 * encode the packets in base64 instead of sending them out via a
82 * Much source (ntlm.h, smb*.c smb*.h) was borrowed from Samba.
85 static int do_pop3_ntlm(int sock, struct query *ctl,
86 int msn_instead /** if true, send AUTH MSN, else send AUTH NTLM */)
88 char msgbuf[POPBUFSIZE+1];
91 gen_send(sock, msn_instead ? "AUTH MSN" : "AUTH NTLM");
93 if ((result = ntlm_helper(sock, ctl, "POP3")))
96 if ((result = gen_recv (sock, msgbuf, sizeof msgbuf)))
99 if (strstr (msgbuf, "OK"))
107 #define DOTLINE(s) (s[0] == '.' && (s[1]=='\r'||s[1]=='\n'||s[1]=='\0'))
109 static int pop3_ok (int sock, char *argbuf)
110 /* parse command response */
113 char buf [POPBUFSIZE+1];
116 if ((ok = gen_recv(sock, buf, sizeof(buf))) == 0)
118 if (*bufp == '+' || *bufp == '-')
123 while (isalpha((unsigned char)*bufp))
129 if (strcmp(buf,"+OK") == 0)
132 strcpy(lastok, bufp);
133 #endif /* OPIE_ENABLE */
136 else if (strncmp(buf,"-ERR", 4) == 0)
138 if (stage == STAGE_FETCH)
140 else if (stage > STAGE_GETAUTH)
143 * We're checking for "lock busy", "unable to lock",
144 * "already locked", "wait a few minutes" etc. here.
145 * This indicates that we have to wait for the server to
146 * unwedge itself before we can poll again.
148 * PS_LOCKBUSY check empirically verified with two recent
149 * versions of the Berkeley popper; QPOP (version 2.2) and
150 * QUALCOMM Pop server derived from UCB (version 2.1.4-R3)
151 * These are caught by the case-indifferent "lock" check.
152 * The "wait" catches "mail storage services unavailable,
153 * wait a few minutes and try again" on the InterMail server.
155 * If these aren't picked up on correctly, fetchmail will
156 * think there is an authentication failure and wedge the
157 * connection in order to prevent futile polls.
161 else if (strstr(bufp,"lock")
162 || strstr(bufp,"Lock")
163 || strstr(bufp,"LOCK")
164 || strstr(bufp,"wait")
165 /* these are blessed by RFC 2449 */
166 || strstr(bufp,"[IN-USE]")||strstr(bufp,"[LOGIN-DELAY]"))
168 else if ((strstr(bufp,"Service")
169 || strstr(bufp,"service"))
170 && (strstr(bufp,"unavailable")))
175 * We always want to pass the user lock-busy messages, because
176 * they're red flags. Other stuff (like AUTH failures on non-
177 * RFC1734 servers) only if we're debugging.
179 if (*bufp && (ok == PS_LOCKBUSY || outlevel >= O_MONITOR))
180 report(stderr, "%s\n", bufp);
185 #if POPBUFSIZE > MSGBUFSIZE
186 #error "POPBUFSIZE must not be larger than MSGBUFSIZE"
197 static int capa_probe(int sock)
198 /* probe the capabilities of the remote server */
207 #endif /* defined(GSSAPI) */
208 #if defined(KERBEROS_V4) || defined(KERBEROS_V5)
209 has_kerberos = FALSE;
210 #endif /* defined(KERBEROS_V4) || defined(KERBEROS_V5) */
214 #endif /* OPIE_ENABLE */
217 #endif /* NTLM_ENABLE */
219 ok = gen_transact(sock, "CAPA");
220 if (ok == PS_SUCCESS)
224 /* determine what authentication methods we have available */
225 while ((ok = gen_recv(sock, buffer, sizeof(buffer))) == 0)
231 if (strstr(buffer, "STLS"))
233 #endif /* SSL_ENABLE */
236 if (strstr(buffer, "GSSAPI"))
238 #endif /* defined(GSSAPI) */
240 #if defined(KERBEROS_V4)
241 if (strstr(buffer, "KERBEROS_V4"))
243 #endif /* defined(KERBEROS_V4) */
246 if (strstr(buffer, "X-OTP"))
248 #endif /* OPIE_ENABLE */
251 if (strstr(buffer, "NTLM"))
253 #endif /* NTLM_ENABLE */
255 if (strstr(buffer, "CRAM-MD5"))
263 static void set_peek_capable(struct query *ctl)
265 /* we're peek-capable means that the use of TOP is enabled,
266 * see pop3_fetch for details - short story, we can use TOP if
267 * we have a means of reliably tracking which mail we need to
268 * refetch should the connection abort in the middle.
269 * fetchall forces RETR, as does keep without UIDL */
270 peek_capable = !ctl->fetchall && (!ctl->keep || ctl->server.uidl);
273 static int pop3_getauth(int sock, struct query *ctl, char *greeting)
274 /* apply for connection authorization */
281 #endif /* OPIE_ENABLE */
283 flag connection_may_have_tls_errors = FALSE;
284 #endif /* SSL_ENABLE */
289 #endif /* defined(GSSAPI) */
290 #if defined(KERBEROS_V4) || defined(KERBEROS_V5)
291 has_kerberos = FALSE;
292 #endif /* defined(KERBEROS_V4) || defined(KERBEROS_V5) */
296 #endif /* OPIE_ENABLE */
299 #endif /* SSL_ENABLE */
301 /* Set this up before authentication quits early. */
302 set_peek_capable(ctl);
304 /* Hack: allow user to force RETR. */
305 if (peek_capable && getenv("FETCHMAIL_POP3_FORCE_RETR")) {
310 * The "Maillennium POP3/PROXY server" deliberately truncates
311 * TOP replies after c. 64 or 80 kByte (we have varying reports), so
312 * disable TOP. Comcast once spewed marketing babble to the extent
313 * of protecting Outlook -- pretty overzealous to break a protocol
314 * for that that Microsoft could have read, too. Comcast aren't
315 * alone in using this software though.
316 * <http://lists.ccil.org/pipermail/fetchmail-friends/2004-April/008523.html>
317 * (Thanks to Ed Wilts for reminding me of that.)
319 * The warning is printed once per server, until fetchmail exits.
320 * It will be suppressed when --fetchall or other circumstances make
321 * us use RETR anyhow.
325 if (peek_capable && strstr(greeting, "Maillennium POP3/PROXY server")) {
326 if ((ctl->server.workarounds & WKA_TOP) == 0) {
327 report(stdout, GT_("Warning: \"Maillennium POP3/PROXY server\" found, using RETR command instead of TOP.\n"));
328 ctl->server.workarounds |= WKA_TOP;
332 if (ctl->server.authenticate == A_SSH) {
338 * This needs to catch both demon.co.uk and demon.net.
339 * If we see either, and we're in multidrop mode, try to use
340 * the SDPS *ENV extension.
342 if (!(ctl->server.sdps) && MULTIDROP(ctl) && strstr(greeting, "demon."))
343 ctl->server.sdps = TRUE;
344 #endif /* SDPS_ENABLE */
346 switch (ctl->server.protocol) {
349 /* XXX FIXME: AUTH probing (RFC1734) should become global */
350 /* CompuServe POP3 Servers as of 990730 want AUTH first for RPA */
351 if (strstr(ctl->remotename, "@compuserve.com"))
353 /* AUTH command should return a list of available mechanisms */
354 if (gen_transact(sock, "AUTH") == 0)
357 flag has_rpa = FALSE;
359 while ((ok = gen_recv(sock, buffer, sizeof(buffer))) == 0)
363 if (strncasecmp(buffer, "rpa", 3) == 0)
366 if (has_rpa && !POP3_auth_rpa(ctl->remotename,
367 ctl->password, sock))
373 #endif /* RPA_ENABLE */
376 * CAPA command may return a list including available
377 * authentication mechanisms and STLS capability.
379 * If it doesn't, no harm done, we just fall back to a plain
380 * login -- if the user allows it.
382 * Note that this code latches the server's authentication type,
383 * so that in daemon mode the CAPA check only needs to be done
384 * once at start of run.
386 * If CAPA fails, then force the authentication method to
387 * PASSWORD, switch off opportunistic and repoll immediately.
388 * If TLS is mandatory, fail up front.
390 if ((ctl->server.authenticate == A_ANY) ||
391 (ctl->server.authenticate == A_GSSAPI) ||
392 (ctl->server.authenticate == A_KERBEROS_V4) ||
393 (ctl->server.authenticate == A_KERBEROS_V5) ||
394 (ctl->server.authenticate == A_OTP) ||
395 (ctl->server.authenticate == A_CRAM_MD5) ||
398 if ((ok = capa_probe(sock)) != PS_SUCCESS)
399 /* we are in STAGE_GETAUTH => failure is PS_AUTHFAIL! */
400 if (ok == PS_AUTHFAIL ||
401 /* Some servers directly close the socket. However, if we
402 * have already authenticated before, then a previous CAPA
403 * must have succeeded. In that case, treat this as a
404 * genuine socket error and do not change the auth method.
406 (ok == PS_SOCKET && !ctl->wehaveauthed))
410 /* fail with mandatory STLS without repoll */
411 report(stderr, GT_("TLS is mandatory for this session, but server refused CAPA command.\n"));
412 report(stderr, GT_("The CAPA command is however necessary for TLS.\n"));
414 } else if (maybe_tls(ctl)) {
415 /* defeat opportunistic STLS */
416 xfree(ctl->sslproto);
417 ctl->sslproto = xstrdup("");
420 /* If strong authentication was opportunistic, retry without, else fail. */
421 switch (ctl->server.authenticate) {
423 ctl->server.authenticate = A_PASSWORD;
425 case A_PASSWORD: /* this should only happen with TLS enabled */
434 if (maybe_tls(ctl)) {
437 commonname = ctl->server.pollname;
439 commonname = ctl->server.via;
440 if (ctl->sslcommonname)
441 commonname = ctl->sslcommonname;
444 || must_tls(ctl)) /* if TLS is mandatory, ignore capabilities */
446 /* Use "tls1" rather than ctl->sslproto because tls1 is the only
447 * protocol that will work with STARTTLS. Don't need to worry
448 * whether TLS is mandatory or opportunistic unless SSLOpen() fails
450 if (gen_transact(sock, "STLS") == PS_SUCCESS
451 && SSLOpen(sock, ctl->sslcert, ctl->sslkey, "tls1", ctl->sslcertck,
452 ctl->sslcertfile, ctl->sslcertpath, ctl->sslfingerprint, commonname,
453 ctl->server.pollname, &ctl->remotename) != -1)
456 * RFC 2595 says this:
458 * "Once TLS has been started, the client MUST discard cached
459 * information about server capabilities and SHOULD re-issue the
460 * CAPABILITY command. This is necessary to protect against
461 * man-in-the-middle attacks which alter the capabilities list prior
462 * to STARTTLS. The server MAY advertise different capabilities
465 * Now that we're confident in our TLS connection we can
466 * guarantee a secure capability re-probe.
469 ok = capa_probe(sock);
470 if (ok != PS_SUCCESS) {
473 if (outlevel >= O_VERBOSE)
475 report(stdout, GT_("%s: upgrade to TLS succeeded.\n"), commonname);
477 } else if (must_tls(ctl)) {
478 /* Config required TLS but we couldn't guarantee it, so we must
480 report(stderr, GT_("%s: upgrade to TLS failed.\n"), commonname);
483 /* We don't know whether the connection is usable, and there's
484 * no command we can reasonably issue to test it (NOOP isn't
485 * allowed til post-authentication), so leave it in an unknown
486 * state, mark it as such, and check more carefully if things
487 * go wrong when we try to authenticate. */
488 connection_may_have_tls_errors = TRUE;
489 if (outlevel >= O_VERBOSE)
491 report(stdout, GT_("%s: opportunistic upgrade to TLS failed, trying to continue.\n"), commonname);
496 #endif /* SSL_ENABLE */
499 * OK, we have an authentication type now.
501 #if defined(KERBEROS_V4)
503 * Servers doing KPOP have to go through a dummy login sequence
504 * rather than doing SASL.
507 ctl->server.service && (strcmp(ctl->server.service, KPOP_PORT)!=0)
508 && (ctl->server.authenticate == A_KERBEROS_V4
509 || ctl->server.authenticate == A_KERBEROS_V5
510 || ctl->server.authenticate == A_ANY))
512 ok = do_rfc1731(sock, "AUTH", ctl->server.truename);
513 if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
516 #endif /* defined(KERBEROS_V4) || defined(KERBEROS_V5) */
520 (ctl->server.authenticate == A_GSSAPI ||
521 (ctl->server.authenticate == A_ANY
522 && check_gss_creds("pop", ctl->server.truename) == PS_SUCCESS)))
524 ok = do_gssauth(sock,"AUTH","pop",ctl->server.truename,ctl->remotename);
525 if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
528 #endif /* defined(GSSAPI) */
532 (ctl->server.authenticate == A_OTP ||
533 ctl->server.authenticate == A_ANY))
535 ok = do_otp(sock, "AUTH", ctl);
536 if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
539 #endif /* OPIE_ENABLE */
542 /* MSN servers require the use of NTLM (MSN) authentication */
543 if (!strcasecmp(ctl->server.pollname, "pop3.email.msn.com") ||
544 ctl->server.authenticate == A_MSN)
545 return (do_pop3_ntlm(sock, ctl, 1) == 0) ? PS_SUCCESS : PS_AUTHFAIL;
546 if (ctl->server.authenticate == A_NTLM || (has_ntlm && ctl->server.authenticate == A_ANY)) {
547 ok = do_pop3_ntlm(sock, ctl, 0);
548 if (ok == 0 || ctl->server.authenticate != A_ANY)
552 if (ctl->server.authenticate == A_NTLM || ctl->server.authenticate == A_MSN)
555 GT_("Required NTLM capability not compiled into fetchmail\n"));
559 if (ctl->server.authenticate == A_CRAM_MD5 ||
560 (has_cram && ctl->server.authenticate == A_ANY))
562 ok = do_cram_md5(sock, "AUTH", ctl, NULL);
563 if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
567 /* ordinary validation, no one-time password or RPA */
568 if ((ok = gen_transact(sock, "USER %s", ctl->remotename)))
572 /* see RFC1938: A One-Time Password System */
573 if ((challenge = strstr(lastok, "otp-"))) {
574 char response[OPIE_RESPONSE_MAX+1];
576 char *n = xstrdup("");
578 i = opiegenerator(challenge, !strcmp(ctl->password, "opie") ? n : ctl->password, response);
580 if ((i == -2) && !run.poll_interval) {
581 char secret[OPIE_SECRET_MAX+1];
582 fprintf(stderr, GT_("Secret pass phrase: "));
583 if (opiereadpass(secret, sizeof(secret), 0))
584 i = opiegenerator(challenge, secret, response);
585 memset(secret, 0, sizeof(secret));
593 ok = gen_transact(sock, "PASS %s", response);
596 #endif /* OPIE_ENABLE */
598 /* KPOP uses out-of-band authentication and does not check what
599 * we send here, so send some random fixed string, to avoid
600 * users switching *to* KPOP accidentally revealing their
602 if ((ctl->server.authenticate == A_ANY
603 || ctl->server.authenticate == A_KERBEROS_V4
604 || ctl->server.authenticate == A_KERBEROS_V5)
605 && (ctl->server.service != NULL
606 && strcmp(ctl->server.service, KPOP_PORT) == 0))
608 ok = gen_transact(sock, "PASS krb_ticket");
612 /* check if we are actually allowed to send the password */
613 if (ctl->server.authenticate == A_ANY
614 || ctl->server.authenticate == A_PASSWORD) {
615 strlcpy(shroud, ctl->password, sizeof(shroud));
616 ok = gen_transact(sock, "PASS %s", ctl->password);
618 report(stderr, GT_("We've run out of allowed authenticators and cannot continue.\n"));
621 memset(shroud, 0x55, sizeof(shroud));
626 /* build MD5 digest from greeting timestamp + password */
627 /* find start of timestamp */
628 for (start = greeting; *start != 0 && *start != '<'; start++)
632 GT_("Required APOP timestamp not found in greeting\n"));
636 /* find end of timestamp */
637 for (end = start; *end != 0 && *end != '>'; end++)
639 if (*end == 0 || end == start + 1) {
641 GT_("Timestamp syntax error in greeting\n"));
647 /* SECURITY: 2007-03-17
648 * Strictly validating the presented challenge for RFC-822
649 * conformity (it must be a msg-id in terms of that standard) is
650 * supposed to make attacks against the MD5 implementation
653 * [1] "Security vulnerability in APOP authentication",
654 * Gaëtan Leurent, fetchmail-devel, 2007-03-17 */
655 if (!rfc822_valid_msgid((unsigned char *)start)) {
657 GT_("Invalid APOP timestamp.\n"));
661 /* copy timestamp and password into digestion buffer */
662 msg = (char *)xmalloc((end-start+1) + strlen(ctl->password) + 1);
664 strcat(msg,ctl->password);
665 strcpy((char *)ctl->digest, MD5Digest((unsigned char *)msg));
668 ok = gen_transact(sock, "APOP %s %s", ctl->remotename, (char *)ctl->digest);
672 if ((ok = gen_transact(sock,"USER %s", ctl->remotename)) == 0) {
673 strlcpy(shroud, ctl->password, sizeof(shroud));
674 ok = gen_transact(sock, "RPOP %s", ctl->password);
675 memset(shroud, 0x55, sizeof(shroud));
681 report(stderr, GT_("Undefined protocol request in POP3_auth\n"));
686 /* this is for servers which claim to support TLS, but actually
688 if (connection_may_have_tls_errors
689 && (ok == PS_SOCKET || ok == PS_PROTOCOL))
691 xfree(ctl->sslproto);
692 ctl->sslproto = xstrdup("");
693 /* repoll immediately without TLS */
700 /* maybe we detected a lock-busy condition? */
701 if (ok == PS_LOCKBUSY)
702 report(stderr, GT_("lock busy! Is another session active?\n"));
707 /* Disable the sleep. Based on patch by Brian Candler 2004-04-19/2004-11-08,
708 * accepted by Matthias Andree.
710 * Rationale: the server must have locked the spool before returning +OK;
711 * this sleep just wastes time and hence, for modem and GSM CSD users, money. */
714 * Empirical experience shows some server/OS combinations
715 * may need a brief pause even after any lockfiles on the
716 * server are released, to give the server time to finish
717 * copying back very large mailfolders from the temp-file...
718 * this is only ever an issue with extremely large mailboxes.
720 sleep(3); /* to be _really_ safe, probably need sleep(5)! */
727 /* cut off C string at first POSIX space */
728 static void trim(char *s) {
729 s += strcspn(s, POSIX_space);
733 /* XXX FIXME: using the Message-ID is unsafe, some messages (spam,
734 * broken messages) do not have Message-ID headers, and messages without
735 * those appear to break this code and cause fetchmail (at least version
736 * 6.2.3) to not delete such messages properly after retrieval.
737 * See Sourceforge Bug #780933.
739 * The other problem is that the TOP command itself is optional, too... */
740 static int pop3_gettopid(int sock, int num , char *id, size_t idsize)
744 char buf [POPBUFSIZE+1];
745 snprintf(buf, sizeof(buf), "TOP %d 1", num);
746 if ((ok = gen_transact(sock, "%s", buf)) != 0)
749 while (gen_recv(sock, buf, sizeof(buf)) == 0)
753 if (!got_it && 0 == strncasecmp("Message-Id:", buf, 11)) {
756 p += strspn(p, POSIX_space);
757 strlcpy(id, p, idsize);
761 /* XXX FIXME: do not return success here if no Message-ID header was
766 /** Parse the UID response (leading +OK must have been
767 * stripped off) in buf, store the number in gotnum, and store the ID
768 * into the caller-provided buffer "id" of size "idsize".
769 * Returns PS_SUCCESS or PS_PROTOCOL for failure. */
770 static int parseuid(const char *buf, unsigned long *gotnum, char *id, size_t idsize)
775 /* skip leading blanks ourselves */
777 i += strspn(i, POSIX_space);
779 *gotnum = strtoul(i, &j, 10);
780 if (j == i || !*j || errno || NULL == strchr(POSIX_space, *j)) {
781 report(stderr, GT_("Cannot handle UIDL response from upstream server.\n"));
784 j += strspn(j, POSIX_space);
785 strlcpy(id, j, idsize);
790 /** request UIDL for single message \a num and stuff the result into the
791 * buffer \a id which can hold \a idsize bytes */
792 static int pop3_getuidl(int sock, int num, char *id /** output */, size_t idsize)
795 char buf [POPBUFSIZE+1];
796 unsigned long gotnum;
798 gen_send(sock, "UIDL %d", num);
799 if ((ok = pop3_ok(sock, buf)) != 0)
801 if ((ok = parseuid(buf, &gotnum, id, idsize)))
803 if (gotnum != (unsigned long)num) {
804 report(stderr, GT_("Server responded with UID for wrong message.\n"));
810 static int pop3_fastuidl( int sock, struct query *ctl, unsigned int count, int *newp)
813 unsigned int first_nr, last_nr, try_nr;
815 struct idlist *savep = NULL; /** pointer to cache save_str result, speeds up saves */
819 while (first_nr < last_nr - 1)
823 try_nr = (first_nr + last_nr) / 2;
824 if ((ok = pop3_getuidl(sock, try_nr, id, sizeof(id))) != 0)
826 if ((newl = str_in_list(&ctl->oldsaved, id, FALSE)))
828 flag mark = newl->val.status.mark;
829 if (mark == UID_DELETED || mark == UID_EXPUNGED)
831 if (outlevel >= O_VERBOSE)
832 report(stderr, GT_("id=%s (num=%u) was deleted, but is still present!\n"), id, try_nr);
833 /* just mark it as seen now! */
834 newl->val.status.mark = mark = UID_SEEN;
837 /* narrow the search region! */
838 if (mark == UID_UNSEEN)
840 if (outlevel >= O_DEBUG)
841 report(stdout, GT_("%u is unseen\n"), try_nr);
847 /* save the number */
848 newl->val.status.num = try_nr;
852 if (outlevel >= O_DEBUG)
853 report(stdout, GT_("%u is unseen\n"), try_nr);
857 savep = save_str(savep ? &savep : &ctl->oldsaved, id, UID_UNSEEN);
858 savep->val.status.num = try_nr;
861 if (outlevel >= O_DEBUG && last_nr <= count)
862 report(stdout, GT_("%u is first unseen\n"), last_nr);
865 *newp = count - first_nr;
870 static int pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp)
872 /* XXX FIXME: this code is severely broken. A Cc:d mailing list
873 * message will arrive twice with the same Message-ID, so this
874 * slowuidl code will break. Same goes for messages without
875 * Message-ID headers at all. This code would best be removed. */
876 /* This approach tries to get the message headers from the
877 * remote hosts and compares the message-id to the already known
879 * + if the first message containes a new id, all messages on
880 * the server will be new
881 * + if the first is known, try to estimate the last known message
882 * on the server and check. If this works you know the total number
883 * of messages to get.
884 * + Otherwise run a binary search to determine the last known message
886 int ok, nolinear = 0;
887 int first_nr, list_len, try_id, try_nr, add_id;
891 if ((ok = pop3_gettopid(sock, 1, id, sizeof(id))) != 0)
894 if( ( first_nr = str_nr_in_list(&ctl->oldsaved, id) ) == -1 ) {
895 /* the first message is unknown -> all messages are new */
900 /* check where we expect the latest known message */
901 list_len = count_list( &ctl->oldsaved );
902 try_id = list_len - first_nr; /* -1 + 1 */
904 if( try_id <= *countp ) {
905 if ((ok = pop3_gettopid(sock, try_id, id, sizeof(id))) != 0)
908 try_nr = str_nr_last_in_list(&ctl->oldsaved, id);
913 if( try_nr != list_len -1 ) {
914 /* some messages inbetween have been deleted... */
918 for( add_id = 1<<30; add_id > try_id-1; add_id >>= 1 )
920 for( ; add_id; add_id >>= 1 ) {
922 if( try_id - add_id <= 1 ) {
929 if ((ok = pop3_gettopid(sock, try_id, id, sizeof(id))) != 0)
931 try_nr = str_nr_in_list(&ctl->oldsaved, id);
938 GT_("Messages inserted into list on server. Cannot handle this.\n"));
943 /* the first try_id messages are known -> copy them to the newsaved list */
944 for( num = first_nr; num < list_len; num++ )
946 struct idlist *newl = save_str(&ctl->newsaved,
947 str_from_nr_list(&ctl->oldsaved, num),
949 newl->val.status.num = num - first_nr + 1;
953 free_str_list(&ctl->oldsaved);
958 *newp = *countp - try_id;
962 static int pop3_getrange(int sock,
965 int *countp, int *newp, int *bytes)
966 /* get range of messages to be fetched */
969 char buf [POPBUFSIZE+1];
972 /* Ensure that the new list is properly empty */
973 ctl->newsaved = (struct idlist *)NULL;
976 /* Alain Knaff suggests this, but it's not RFC standard */
978 if ((ok = gen_transact(sock, "MBOX %s", folder)))
982 /* get the total message count */
983 gen_send(sock, "STAT");
984 ok = pop3_ok(sock, buf);
988 asgn = sscanf(buf,"%d %d", countp, bytes);
995 * Newer, RFC-1725/1939-conformant POP servers may not have the LAST
996 * command. We work as hard as possible to hide this, but it makes
997 * counting new messages intrinsically quadratic in the worst case.
1001 /* if there are messages, and UIDL is desired, use UIDL
1002 * also use UIDL if fetchall is unset */
1003 if (*countp > 0 && (!ctl->fetchall || ctl->server.uidl))
1008 /* should we do fast uidl this time? */
1009 fastuidl = ctl->fastuidl;
1010 if (*countp > 7 && /* linear search is better if there are few mails! */
1011 !ctl->fetchall && /* with fetchall, all uids are required */
1012 !ctl->flush && /* with flush, it is safer to disable fastuidl */
1013 NUM_NONZERO (fastuidl))
1018 dofastuidl = ctl->fastuidlcount != 0;
1023 if (!ctl->server.uidl) {
1024 gen_send(sock, "LAST");
1025 ok = pop3_ok(sock, buf);
1031 /* scan LAST reply */
1032 if (sscanf(buf, "%d", &last) == 0)
1034 report(stderr, GT_("protocol error\n"));
1037 *newp = (*countp - last);
1043 return(pop3_fastuidl( sock, ctl, *countp, newp));
1044 /* grab the mailbox's UID list */
1045 if (gen_transact(sock, "UIDL") != 0)
1047 /* don't worry, yet! do it the slow way */
1048 if (pop3_slowuidl(sock, ctl, countp, newp))
1050 report(stderr, GT_("protocol error while fetching UIDLs\n"));
1056 /* UIDL worked - parse reply */
1058 struct idlist *newl = NULL;
1061 while (gen_recv(sock, buf, sizeof(buf)) == PS_SUCCESS)
1066 if (parseuid(buf, &unum, id, sizeof(id)) == PS_SUCCESS)
1070 newl = save_str(newl ? &newl : &ctl->newsaved, id, UID_UNSEEN);
1071 newl->val.status.num = unum;
1073 if ((old = str_in_list(&ctl->oldsaved, id, FALSE)))
1075 flag mark = old->val.status.mark;
1076 if (mark == UID_DELETED || mark == UID_EXPUNGED)
1078 /* XXX FIXME: switch 3 occurrences from
1079 * (int)unum or (unsigned int)unum to
1080 * remove the cast and use %lu - not now
1081 * though, time for new release */
1082 if (outlevel >= O_VERBOSE)
1083 report(stderr, GT_("id=%s (num=%d) was deleted, but is still present!\n"), id, (int)unum);
1084 /* just mark it as seen now! */
1085 old->val.status.mark = mark = UID_SEEN;
1087 newl->val.status.mark = mark;
1088 if (mark == UID_UNSEEN)
1091 if (outlevel >= O_DEBUG)
1092 report(stdout, GT_("%u is unseen\n"), (unsigned int)unum);
1098 if (outlevel >= O_DEBUG)
1099 report(stdout, GT_("%u is unseen\n"), (unsigned int)unum);
1100 /* add it to oldsaved also! In case, we do not
1101 * swap the lists (say, due to socket error),
1102 * the same mail will not be downloaded again.
1104 old = save_str(&ctl->oldsaved, id, UID_UNSEEN);
1106 /* save the number */
1107 old->val.status.num = unum;
1110 } /* multi-line loop for UIDL reply */
1118 static int pop3_getpartialsizes(int sock, int first, int last, int *sizes)
1119 /* capture the size of message #first */
1122 char buf [POPBUFSIZE+1];
1125 for (i = first; i <= last; i++) {
1126 gen_send(sock, "LIST %d", i);
1127 if ((ok = pop3_ok(sock, buf)) != 0)
1129 if (sscanf(buf, "%d %u", &num, &size) == 2) {
1131 sizes[i - first] = size;
1133 /* warn about possible attempt to induce buffer overrun
1135 * we expect server reply message number and requested
1136 * message number to match */
1137 report(stderr, "Warning: ignoring bogus data for message sizes returned by server.\n");
1143 static int pop3_getsizes(int sock, int count, int *sizes)
1144 /* capture the sizes of all messages */
1148 if ((ok = gen_transact(sock, "LIST")) != 0)
1152 char buf [POPBUFSIZE+1];
1154 while ((ok = gen_recv(sock, buf, sizeof(buf))) == 0)
1156 unsigned int num, size;
1160 else if (sscanf(buf, "%u %u", &num, &size) == 2) {
1161 if (num > 0 && num <= (unsigned)count)
1162 sizes[num - 1] = size;
1164 /* warn about possible attempt to induce buffer overrun */
1165 report(stderr, "Warning: ignoring bogus data for message sizes returned by server.\n");
1173 static int pop3_is_old(int sock, struct query *ctl, int num)
1174 /* is the given message old? */
1176 struct idlist *newl;
1178 return (num <= last);
1179 else if (dofastuidl)
1186 /* in fast uidl, we manipulate the old list only! */
1188 if ((newl = id_find(&ctl->oldsaved, num)))
1190 /* we already have the id! */
1191 return(newl->val.status.mark != UID_UNSEEN);
1194 /* get the uidl first! */
1195 if (pop3_getuidl(sock, num, id, sizeof(id)) != PS_SUCCESS)
1198 if ((newl = str_in_list(&ctl->oldsaved, id, FALSE))) {
1199 /* we already have the id! */
1200 newl->val.status.num = num;
1201 return(newl->val.status.mark != UID_UNSEEN);
1205 newl = save_str(&ctl->oldsaved, id, UID_UNSEEN);
1206 newl->val.status.num = num;
1210 return ((newl = id_find(&ctl->newsaved, num)) != NULL &&
1211 newl->val.status.mark != UID_UNSEEN);
1216 * We could use this to fetch headers only as we do for IMAP. The trouble
1217 * is that there's no way to fetch the body only. So the following RETR
1218 * would have to re-fetch the header. Enough messages have longer headers
1219 * than bodies to make this a net loss.
1221 static int pop_fetch_headers(int sock, struct query *ctl,int number,int *lenp)
1222 /* request headers of nth message */
1225 char buf[POPBUFSIZE+1];
1227 gen_send(sock, "TOP %d 0", number);
1228 if ((ok = pop3_ok(sock, buf)) != 0)
1231 *lenp = -1; /* we got sizes from the LIST response */
1237 static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp)
1238 /* request nth message */
1241 char buf[POPBUFSIZE+1];
1245 * See http://www.demon.net/helpdesk/producthelp/mail/sdps-tech.html/
1246 * for a description of what we're parsing here.
1247 * -- updated 2006-02-22
1249 if (ctl->server.sdps)
1253 sdps_envfrom = (char *)NULL;
1254 sdps_envto = (char *)NULL;
1255 gen_send(sock, "*ENV %d", number);
1257 if (gen_recv(sock, buf, sizeof(buf)))
1262 switch (linecount) {
1264 /* No need to wrap envelope from address */
1265 /* FIXME: some parts of fetchmail don't handle null
1266 * envelope senders, so use <> to mark null sender
1267 * as a workaround. */
1268 if (strspn(buf, " \t") == strlen(buf))
1270 sdps_envfrom = (char *)xmalloc(strlen(buf)+1);
1271 strcpy(sdps_envfrom,buf);
1274 /* Wrap address with To: <> so nxtaddr() likes it */
1275 sdps_envto = (char *)xmalloc(strlen(buf)+7);
1276 sprintf(sdps_envto,"To: <%s>",buf);
1280 (!(buf[0] == '.' && (buf[1] == '\r' || buf[1] == '\n' || buf[1] == '\0')));
1284 #endif /* SDPS_ENABLE */
1287 * Though the POP RFCs don't document this fact, on almost every
1288 * POP3 server I know of messages are marked "seen" only at the
1289 * time the OK response to a RETR is issued.
1291 * This means we can use TOP to fetch the message without setting its
1292 * seen flag. This is good! It means that if the protocol exchange
1293 * craps out during the message, it will still be marked `unseen' on
1294 * the server. (Exception: in early 1999 SpryNet's POP3 servers were
1295 * reported to mark messages seen on a TOP fetch.)
1297 * However...*don't* do this if we're using keep to suppress deletion!
1298 * In that case, marking the seen flag is the only way to prevent the
1299 * message from being re-fetched on subsequent runs.
1301 * Also use RETR (that means no TOP, no peek) if fetchall is on.
1302 * This gives us a workaround for servers like usa.net's that bungle
1303 * TOP. It's pretty harmless because fetchall guarantees that any
1304 * message dropped by an interrupted RETR will be picked up on the
1305 * next poll of the site.
1307 * We take advantage here of the fact that, according to all the
1308 * POP RFCs, "if the number of lines requested by the POP3 client
1309 * is greater than than the number of lines in the body, then the
1310 * POP3 server sends the entire message.").
1312 * The line count passed (99999999) is the maximum value CompuServe will
1313 * accept; it's much lower than the natural value 2147483646 (the maximum
1314 * twos-complement signed 32-bit integer minus 1) */
1316 gen_send(sock, "RETR %d", number);
1318 gen_send(sock, "TOP %d 99999999", number);
1319 if ((ok = pop3_ok(sock, buf)) != 0)
1322 *lenp = -1; /* we got sizes from the LIST response */
1327 static void mark_uid_seen(struct query *ctl, int number)
1328 /* Tell the UID code we've seen this. */
1332 if ((sdp = id_find(&ctl->newsaved, number)))
1333 sdp->val.status.mark = UID_SEEN;
1334 /* mark it as seen in oldsaved also! In case, we do not swap the lists
1335 * (say, due to socket error), the same mail will not be downloaded
1338 if ((sdp = id_find(&ctl->oldsaved, number)))
1339 sdp->val.status.mark = UID_SEEN;
1342 static int pop3_delete(int sock, struct query *ctl, int number)
1343 /* delete a given message */
1346 mark_uid_seen(ctl, number);
1347 /* actually, mark for deletion -- doesn't happen until QUIT time */
1348 ok = gen_transact(sock, "DELE %d", number);
1349 if (ok != PS_SUCCESS)
1351 delete_str(dofastuidl ? &ctl->oldsaved : &ctl->newsaved, number);
1355 static int pop3_mark_seen(int sock, struct query *ctl, int number)
1356 /* mark a given message as seen */
1359 mark_uid_seen(ctl, number);
1363 static int pop3_logout(int sock, struct query *ctl)
1364 /* send logout command */
1370 * We used to do this in case the server marks messages deleted when seen.
1371 * (Yes, this has been reported, in the MercuryP/NLM server.
1372 * It's even legal under RFC 1939 (section 8) as a site policy.)
1373 * It interacted badly with UIDL, though. Thomas Zajic wrote:
1374 * "Running 'fetchmail -F -v' and checking the logs, I found out
1375 * that fetchmail did in fact flush my mailbox properly, but sent
1376 * a RSET just before sending QUIT to log off. This caused the
1377 * POP3 server to undo/forget about the previous DELEs, resetting
1378 * my mailbox to its original (ie. unflushed) state. The
1379 * ~/.fetchids file did get flushed though, so the next time
1380 * fetchmail was run it saw all the old messages as new ones ..."
1383 gen_transact(sock, "RSET");
1384 #endif /* __UNUSED__ */
1386 ok = gen_transact(sock, "QUIT");
1393 static const struct method pop3 =
1395 "POP3", /* Post Office Protocol v3 */
1396 "pop3", /* port for plain and TLS POP3 */
1397 "pop3s", /* port for SSL POP3 */
1398 FALSE, /* this is not a tagged protocol */
1399 TRUE, /* this uses a message delimiter */
1400 pop3_ok, /* parse command response */
1401 pop3_getauth, /* get authorization */
1402 pop3_getrange, /* query range of messages */
1403 pop3_getsizes, /* we can get a list of sizes */
1404 pop3_getpartialsizes, /* we can get the size of 1 mail */
1405 pop3_is_old, /* how do we tell a message is old? */
1406 pop3_fetch, /* request given message */
1407 NULL, /* no way to fetch body alone */
1408 NULL, /* no message trailer */
1409 pop3_delete, /* how to delete a message */
1410 pop3_mark_seen, /* how to mark a message as seen */
1411 NULL, /* no action at end of mailbox */
1412 pop3_logout, /* log out, we're done */
1413 FALSE, /* no, we can't re-poll */
1416 int doPOP3 (struct query *ctl)
1417 /* retrieve messages using POP3 */
1420 if (ctl->mailboxes->id) {
1421 fprintf(stderr,GT_("Option --folder is not supported with POP3\n"));
1426 return(do_protocol(ctl, &pop3));
1428 #endif /* POP3_ENABLE */
1430 /* pop3.c ends here */