X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=pop3.c;h=9cf8494416073967342ae4a5ad0cd1181d0f51b0;hb=2629c4511c68729d98acfd08637c1f00d3807f49;hp=8ee3686e30419981665c70ef0807681ccfd07362;hpb=ee94fbacd209210eb19335636894ab4c9bbf89f1;p=~andy%2Ffetchmail diff --git a/pop3.c b/pop3.c index 8ee3686e..9cf84944 100644 --- a/pop3.c +++ b/pop3.c @@ -16,47 +16,61 @@ #if defined(STDC_HEADERS) #include #endif - +#include + #include "fetchmail.h" #include "socket.h" #include "i18n.h" #ifdef OPIE_ENABLE +#ifdef __cplusplus +extern "C" { +#endif #include +#ifdef __cplusplus +} +#endif #endif /* OPIE_ENABLE */ -static int last; -#ifdef SDPS_ENABLE -char *sdps_envfrom; -char *sdps_envto; -#endif /* SDPS_ENABLE */ +/* global variables: please reinitialize them explicitly for proper + * working in daemon mode */ +/* TODO: session variables to be initialized before server greeting */ #ifdef OPIE_ENABLE static char lastok[POPBUFSIZE+1]; #endif /* OPIE_ENABLE */ -/* these variables are shared between the CAPA probe and the authenticator */ +/* session variables initialized in capa_probe() or pop3_getauth() */ +flag done_capa = FALSE; #if defined(GSSAPI) - flag has_gssapi = FALSE; +flag has_gssapi = FALSE; #endif /* defined(GSSAPI) */ #if defined(KERBEROS_V4) || defined(KERBEROS_V5) - flag has_kerberos = FALSE; +flag has_kerberos = FALSE; #endif /* defined(KERBEROS_V4) || defined(KERBEROS_V5) */ - static flag has_cram = FALSE; +static flag has_cram = FALSE; #ifdef OPIE_ENABLE - flag has_otp = FALSE; +flag has_otp = FALSE; #endif /* OPIE_ENABLE */ +#ifdef NTLM_ENABLE +flag has_ntlm = FALSE; +#endif /* NTLM_ENABLE */ #ifdef SSL_ENABLE - static flag has_ssl = FALSE; +static flag has_stls = FALSE; #endif /* SSL_ENABLE */ +/* mailbox variables initialized in pop3_getrange() */ +static int last; + +/* mail variables initialized in pop3_fetch() */ +#ifdef SDPS_ENABLE +char *sdps_envfrom; +char *sdps_envto; +#endif /* SDPS_ENABLE */ + #ifdef NTLM_ENABLE #include "ntlm.h" -static tSmbNtlmAuthRequest request; -static tSmbNtlmAuthChallenge challenge; -static tSmbNtlmAuthResponse response; - /* * NTLM support by Grant Edwards. * @@ -68,58 +82,20 @@ static tSmbNtlmAuthResponse response; * Much source (ntlm.h, smb*.c smb*.h) was borrowed from Samba. */ -static int do_pop3_ntlm(int sock, struct query *ctl) +static int do_pop3_ntlm(int sock, struct query *ctl, + int msn_instead /** if true, send AUTH MSN, else send AUTH NTLM */) { - char msgbuf[2048]; - int result,len; - - gen_send(sock, "AUTH MSN"); + char msgbuf[POPBUFSIZE+1]; + int result; - if ((result = gen_recv(sock, msgbuf, sizeof msgbuf))) - return result; - - if (msgbuf[0] != '+') - return PS_AUTHFAIL; - - buildSmbNtlmAuthRequest(&request,ctl->remotename,NULL); - - if (outlevel >= O_DEBUG) - dumpSmbNtlmAuthRequest(stdout, &request); - - memset(msgbuf,0,sizeof msgbuf); - to64frombits (msgbuf, (unsigned char*)&request, SmbLength(&request)); - - if (outlevel >= O_MONITOR) - report(stdout, "POP3> %s\n", msgbuf); - - strcat(msgbuf,"\r\n"); - SockWrite (sock, msgbuf, strlen (msgbuf)); - - if ((gen_recv(sock, msgbuf, sizeof msgbuf))) + gen_send(sock, msn_instead ? "AUTH MSN" : "AUTH NTLM"); + + if ((result = ntlm_helper(sock, ctl, "POP3"))) return result; - - len = from64tobits ((unsigned char*)&challenge, msgbuf, sizeof(msgbuf)); - - if (outlevel >= O_DEBUG) - dumpSmbNtlmAuthChallenge(stdout, &challenge); - - buildSmbNtlmAuthResponse(&challenge, &response,ctl->remotename,ctl->password); - - if (outlevel >= O_DEBUG) - dumpSmbNtlmAuthResponse(stdout, &response); - - memset(msgbuf,0,sizeof msgbuf); - to64frombits (msgbuf, (unsigned char*)&response, SmbLength(&response)); - - if (outlevel >= O_MONITOR) - report(stdout, "POP3> %s\n", msgbuf); - - strcat(msgbuf,"\r\n"); - SockWrite (sock, msgbuf, strlen (msgbuf)); - + if ((result = gen_recv (sock, msgbuf, sizeof msgbuf))) return result; - + if (strstr (msgbuf, "OK")) return PS_SUCCESS; else @@ -206,6 +182,9 @@ static int pop3_ok (int sock, char *argbuf) else ok = PS_PROTOCOL; +#if POPBUFSIZE > MSGBUFSIZE +#error "POPBUFSIZE must not be larger than MSGBUFSIZE" +#endif if (argbuf != NULL) strcpy(argbuf,bufp); } @@ -220,6 +199,9 @@ static int capa_probe(int sock) { int ok; + if (done_capa) { + return PS_SUCCESS; + } #if defined(GSSAPI) has_gssapi = FALSE; #endif /* defined(GSSAPI) */ @@ -230,6 +212,9 @@ static int capa_probe(int sock) #ifdef OPIE_ENABLE has_otp = FALSE; #endif /* OPIE_ENABLE */ +#ifdef NTLM_ENABLE + has_ntlm = FALSE; +#endif /* NTLM_ENABLE */ ok = gen_transact(sock, "CAPA"); if (ok == PS_SUCCESS) @@ -241,29 +226,50 @@ static int capa_probe(int sock) { if (DOTLINE(buffer)) break; + #ifdef SSL_ENABLE if (strstr(buffer, "STLS")) - has_ssl = TRUE; + has_stls = TRUE; #endif /* SSL_ENABLE */ + #if defined(GSSAPI) if (strstr(buffer, "GSSAPI")) has_gssapi = TRUE; #endif /* defined(GSSAPI) */ + #if defined(KERBEROS_V4) if (strstr(buffer, "KERBEROS_V4")) has_kerberos = TRUE; #endif /* defined(KERBEROS_V4) */ + #ifdef OPIE_ENABLE if (strstr(buffer, "X-OTP")) has_otp = TRUE; #endif /* OPIE_ENABLE */ + +#ifdef NTLM_ENABLE + if (strstr(buffer, "NTLM")) + has_ntlm = TRUE; +#endif /* NTLM_ENABLE */ + if (strstr(buffer, "CRAM-MD5")) has_cram = TRUE; } } + done_capa = TRUE; return(ok); } +static void set_peek_capable(struct query *ctl) +{ + /* we're peek-capable means that the use of TOP is enabled, + * see pop3_fetch for details - short story, we can use TOP if + * we have a means of reliably tracking which mail we need to + * refetch should the connection abort in the middle. + * fetchall forces RETR, as does keep without UIDL */ + peek_capable = !ctl->fetchall && (!ctl->keep || ctl->server.uidl); +} + static int pop3_getauth(int sock, struct query *ctl, char *greeting) /* apply for connection authorization */ { @@ -274,9 +280,10 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) char *challenge; #endif /* OPIE_ENABLE */ #ifdef SSL_ENABLE - flag did_stls = FALSE; + flag connection_may_have_tls_errors = FALSE; #endif /* SSL_ENABLE */ + done_capa = FALSE; #if defined(GSSAPI) has_gssapi = FALSE; #endif /* defined(GSSAPI) */ @@ -288,9 +295,40 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) has_otp = FALSE; #endif /* OPIE_ENABLE */ #ifdef SSL_ENABLE - has_ssl = FALSE; + has_stls = FALSE; #endif /* SSL_ENABLE */ + /* Set this up before authentication quits early. */ + set_peek_capable(ctl); + + /* Hack: allow user to force RETR. */ + if (peek_capable && getenv("FETCHMAIL_POP3_FORCE_RETR")) { + peek_capable = 0; + } + + /* + * The "Maillennium POP3/PROXY server" deliberately truncates + * TOP replies after c. 64 or 80 kByte (we have varying reports), so + * disable TOP. Comcast once spewed marketing babble to the extent + * of protecting Outlook -- pretty overzealous to break a protocol + * for that that Microsoft could have read, too. Comcast aren't + * alone in using this software though. + * + * (Thanks to Ed Wilts for reminding me of that.) + * + * The warning is printed once per server, until fetchmail exits. + * It will be suppressed when --fetchall or other circumstances make + * us use RETR anyhow. + * + * Matthias Andree + */ + if (peek_capable && strstr(greeting, "Maillennium POP3/PROXY server")) { + if ((ctl->server.workarounds & WKA_TOP) == 0) { + report(stdout, GT_("Warning: \"Maillennium POP3/PROXY server\" found, using RETR command instead of TOP.\n")); + ctl->server.workarounds |= WKA_TOP; + } + peek_capable = 0; + } if (ctl->server.authenticate == A_SSH) { return PS_SUCCESS; } @@ -304,25 +342,11 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) if (!(ctl->server.sdps) && MULTIDROP(ctl) && strstr(greeting, "demon.")) ctl->server.sdps = TRUE; #endif /* SDPS_ENABLE */ -#ifdef NTLM_ENABLE - /* MSN servers require the use of NTLM (MSN) authentication */ - if (!strcasecmp(ctl->server.pollname, "pop3.email.msn.com") || - ctl->server.authenticate == A_NTLM) - { - if (!do_pop3_ntlm(sock, ctl)) - { - return(PS_SUCCESS); - } - else - { - return(PS_AUTHFAIL); - } - } -#endif - switch (ctl->server.protocol) { + switch (ctl->server.protocol) { case P_POP3: #ifdef RPA_ENABLE + /* XXX FIXME: AUTH probing (RFC1734) should become global */ /* CompuServe POP3 Servers as of 990730 want AUTH first for RPA */ if (strstr(ctl->remotename, "@compuserve.com")) { @@ -350,26 +374,29 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) /* * CAPA command may return a list including available - * authentication mechanisms. if it doesn't, no harm done, we - * just fall back to a plain login. Note that this code - * latches the server's authentication type, so that in daemon mode - * the CAPA check only needs to be done once at start of run. + * authentication mechanisms and STLS capability. + * + * If it doesn't, no harm done, we just fall back to a plain + * login -- if the user allows it. * - * If CAPA fails, then force the authentication method to PASSORD - * and repoll immediately. + * Note that this code latches the server's authentication type, + * so that in daemon mode the CAPA check only needs to be done + * once at start of run. * - * These authentication methods are blessed by RFC1734, - * describing the POP3 AUTHentication command. + * If CAPA fails, then force the authentication method to + * PASSWORD, switch off opportunistic and repoll immediately. + * If TLS is mandatory, fail up front. */ - if ((ctl->use_ssl != FLAG_FALSE) || - (ctl->server.authenticate == A_ANY) || - (ctl->server.authenticate == A_GSSAPI) || - (ctl->server.authenticate == A_KERBEROS_V4) || - (ctl->server.authenticate == A_OTP) || - (ctl->server.authenticate == A_CRAM_MD5)) + if ((ctl->server.authenticate == A_ANY) || + (ctl->server.authenticate == A_GSSAPI) || + (ctl->server.authenticate == A_KERBEROS_V4) || + (ctl->server.authenticate == A_KERBEROS_V5) || + (ctl->server.authenticate == A_OTP) || + (ctl->server.authenticate == A_CRAM_MD5) || + maybe_tls(ctl)) { if ((ok = capa_probe(sock)) != PS_SUCCESS) - /* we are in STAGE_GETAUTH! */ + /* we are in STAGE_GETAUTH => failure is PS_AUTHFAIL! */ if (ok == PS_AUTHFAIL || /* Some servers directly close the socket. However, if we * have already authenticated before, then a previous CAPA @@ -378,53 +405,97 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) */ (ok == PS_SOCKET && !ctl->wehaveauthed)) { - ctl->server.authenticate = A_PASSWORD; - /* repoll immediately */ - ok = PS_REPOLL; - break; +#ifdef SSL_ENABLE + if (must_tls(ctl)) { + /* fail with mandatory STLS without repoll */ + report(stderr, GT_("TLS is mandatory for this session, but server refused CAPA command.\n")); + report(stderr, GT_("The CAPA command is however necessary for TLS.\n")); + return ok; + } else if (maybe_tls(ctl)) { + /* defeat opportunistic STLS */ + xfree(ctl->sslproto); + ctl->sslproto = xstrdup(""); + } +#endif + /* If strong authentication was opportunistic, retry without, else fail. */ + switch (ctl->server.authenticate) { + case A_ANY: + ctl->server.authenticate = A_PASSWORD; + /* FALLTHROUGH */ + case A_PASSWORD: /* this should only happen with TLS enabled */ + return PS_REPOLL; + default: + return PS_AUTHFAIL; + } } } #ifdef SSL_ENABLE - if (has_ssl - && !ctl->use_ssl - && (!ctl->sslproto || !strcmp(ctl->sslproto,"tls1"))) - { - char *realhost; + if (maybe_tls(ctl)) { + char *commonname; - realhost = ctl->server.via ? ctl->server.via : ctl->server.pollname; - ok = gen_transact(sock, "STLS"); + commonname = ctl->server.pollname; + if (ctl->server.via) + commonname = ctl->server.via; + if (ctl->sslcommonname) + commonname = ctl->sslcommonname; - /* We use "tls1" instead of ctl->sslproto, as we want STLS, - * not other SSL protocols - */ - if (ok == PS_SUCCESS && - SSLOpen(sock,ctl->sslcert,ctl->sslkey,"tls1",ctl->sslcertck, ctl->sslcertpath,ctl->sslfingerprint,realhost,ctl->server.pollname) == -1) + if (has_stls + || must_tls(ctl)) /* if TLS is mandatory, ignore capabilities */ { - if (!ctl->sslproto && !ctl->wehaveauthed) + /* Use "tls1" rather than ctl->sslproto because tls1 is the only + * protocol that will work with STARTTLS. Don't need to worry + * whether TLS is mandatory or opportunistic unless SSLOpen() fails + * (see below). */ + if (gen_transact(sock, "STLS") == PS_SUCCESS + && (set_timeout(mytimeout), SSLOpen(sock, ctl->sslcert, ctl->sslkey, "tls1", ctl->sslcertck, + ctl->sslcertfile, ctl->sslcertpath, ctl->sslfingerprint, commonname, + ctl->server.pollname, &ctl->remotename)) != -1) { - ctl->sslproto = xstrdup(""); - /* repoll immediately */ - return(PS_REPOLL); + /* + * RFC 2595 says this: + * + * "Once TLS has been started, the client MUST discard cached + * information about server capabilities and SHOULD re-issue the + * CAPABILITY command. This is necessary to protect against + * man-in-the-middle attacks which alter the capabilities list prior + * to STARTTLS. The server MAY advertise different capabilities + * after STARTTLS." + * + * Now that we're confident in our TLS connection we can + * guarantee a secure capability re-probe. + */ + set_timeout(0); + done_capa = FALSE; + ok = capa_probe(sock); + if (ok != PS_SUCCESS) { + return ok; + } + if (outlevel >= O_VERBOSE) + { + report(stdout, GT_("%s: upgrade to TLS succeeded.\n"), commonname); + } + } else if (must_tls(ctl)) { + /* Config required TLS but we couldn't guarantee it, so we must + * stop. */ + set_timeout(0); + report(stderr, GT_("%s: upgrade to TLS failed.\n"), commonname); + return PS_SOCKET; + } else { + /* We don't know whether the connection is usable, and there's + * no command we can reasonably issue to test it (NOOP isn't + * allowed til post-authentication), so leave it in an unknown + * state, mark it as such, and check more carefully if things + * go wrong when we try to authenticate. */ + set_timeout(0); + connection_may_have_tls_errors = TRUE; + if (outlevel >= O_VERBOSE) + { + report(stdout, GT_("%s: opportunistic upgrade to TLS failed, trying to continue.\n"), commonname); + } } - report(stderr, - GT_("SSL connection failed.\n")); - return(PS_AUTHFAIL); - } - did_stls = TRUE; - - /* - * RFC 2595 says this: - * - * "Once TLS has been started, the client MUST discard cached - * information about server capabilities and SHOULD re-issue the - * CAPABILITY command. This is necessary to protect against - * man-in-the-middle attacks which alter the capabilities list prior - * to STARTTLS. The server MAY advertise different capabilities - * after STARTTLS." - */ - capa_probe(sock); - } + } + } /* maybe_tls() */ #endif /* SSL_ENABLE */ /* @@ -436,11 +507,7 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) * rather than doing SASL. */ if (has_kerberos && -#ifdef INET6_ENABLE ctl->server.service && (strcmp(ctl->server.service, KPOP_PORT)!=0) -#else /* INET6_ENABLE */ - ctl->server.port != KPOP_PORT -#endif /* INET6_ENABLE */ && (ctl->server.authenticate == A_KERBEROS_V4 || ctl->server.authenticate == A_KERBEROS_V5 || ctl->server.authenticate == A_ANY)) @@ -454,7 +521,8 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) #if defined(GSSAPI) if (has_gssapi && (ctl->server.authenticate == A_GSSAPI || - ctl->server.authenticate == A_ANY)) + (ctl->server.authenticate == A_ANY + && check_gss_creds("pop", ctl->server.truename) == PS_SUCCESS))) { ok = do_gssauth(sock,"AUTH","pop",ctl->server.truename,ctl->remotename); if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY) @@ -473,7 +541,25 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) } #endif /* OPIE_ENABLE */ - if (ctl->server.authenticate == A_CRAM_MD5 || +#ifdef NTLM_ENABLE + /* MSN servers require the use of NTLM (MSN) authentication */ + if (!strcasecmp(ctl->server.pollname, "pop3.email.msn.com") || + ctl->server.authenticate == A_MSN) + return (do_pop3_ntlm(sock, ctl, 1) == 0) ? PS_SUCCESS : PS_AUTHFAIL; + if (ctl->server.authenticate == A_NTLM || (has_ntlm && ctl->server.authenticate == A_ANY)) { + ok = do_pop3_ntlm(sock, ctl, 0); + if (ok == 0 || ctl->server.authenticate != A_ANY) + break; + } +#else + if (ctl->server.authenticate == A_NTLM || ctl->server.authenticate == A_MSN) + { + report(stderr, + GT_("Required NTLM capability not compiled into fetchmail\n")); + } +#endif + + if (ctl->server.authenticate == A_CRAM_MD5 || (has_cram && ctl->server.authenticate == A_ANY)) { ok = do_cram_md5(sock, "AUTH", ctl, NULL); @@ -482,15 +568,18 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) } /* ordinary validation, no one-time password or RPA */ - gen_transact(sock, "USER %s", ctl->remotename); + if ((ok = gen_transact(sock, "USER %s", ctl->remotename))) + break; #ifdef OPIE_ENABLE /* see RFC1938: A One-Time Password System */ if ((challenge = strstr(lastok, "otp-"))) { char response[OPIE_RESPONSE_MAX+1]; int i; + char *n = xstrdup(""); - i = opiegenerator(challenge, !strcmp(ctl->password, "opie") ? "" : ctl->password, response); + i = opiegenerator(challenge, !strcmp(ctl->password, "opie") ? n : ctl->password, response); + free(n); if ((i == -2) && !run.poll_interval) { char secret[OPIE_SECRET_MAX+1]; fprintf(stderr, GT_("Secret pass phrase: ")); @@ -509,19 +598,31 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) } #endif /* OPIE_ENABLE */ - strcpy(shroud, ctl->password); - ok = gen_transact(sock, "PASS %s", ctl->password); - shroud[0] = '\0'; -#ifdef SSL_ENABLE - /* this is for servers which claim to support TLS, but actually - * don't! */ - if (did_stls && ok == PS_SOCKET && !ctl->sslproto && !ctl->wehaveauthed) + /* KPOP uses out-of-band authentication and does not check what + * we send here, so send some random fixed string, to avoid + * users switching *to* KPOP accidentally revealing their + * password */ + if ((ctl->server.authenticate == A_ANY + || ctl->server.authenticate == A_KERBEROS_V4 + || ctl->server.authenticate == A_KERBEROS_V5) + && (ctl->server.service != NULL + && strcmp(ctl->server.service, KPOP_PORT) == 0)) { - ctl->sslproto = xstrdup(""); - /* repoll immediately */ - ok = PS_REPOLL; + ok = gen_transact(sock, "PASS krb_ticket"); + break; } -#endif + + /* check if we are actually allowed to send the password */ + if (ctl->server.authenticate == A_ANY + || ctl->server.authenticate == A_PASSWORD) { + strlcpy(shroud, ctl->password, sizeof(shroud)); + ok = gen_transact(sock, "PASS %s", ctl->password); + } else { + report(stderr, GT_("We've run out of allowed authenticators and cannot continue.\n")); + ok = PS_AUTHFAIL; + } + memset(shroud, 0x55, sizeof(shroud)); + shroud[0] = '\0'; break; case P_APOP: @@ -546,19 +647,37 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) else *++end = '\0'; + /* SECURITY: 2007-03-17 + * Strictly validating the presented challenge for RFC-822 + * conformity (it must be a msg-id in terms of that standard) is + * supposed to make attacks against the MD5 implementation + * harder[1] + * + * [1] "Security vulnerability in APOP authentication", + * Gaëtan Leurent, fetchmail-devel, 2007-03-17 */ + if (!rfc822_valid_msgid((unsigned char *)start)) { + report(stderr, + GT_("Invalid APOP timestamp.\n")); + return PS_AUTHFAIL; + } + /* copy timestamp and password into digestion buffer */ - xalloca(msg, char *, (end-start+1) + strlen(ctl->password) + 1); + msg = (char *)xmalloc((end-start+1) + strlen(ctl->password) + 1); strcpy(msg,start); strcat(msg,ctl->password); + strcpy((char *)ctl->digest, MD5Digest((unsigned char *)msg)); + free(msg); - strcpy(ctl->digest, MD5Digest((unsigned char *)msg)); - - ok = gen_transact(sock, "APOP %s %s", ctl->remotename, ctl->digest); + ok = gen_transact(sock, "APOP %s %s", ctl->remotename, (char *)ctl->digest); break; case P_RPOP: - if ((ok = gen_transact(sock,"USER %s", ctl->remotename)) == 0) + if ((ok = gen_transact(sock,"USER %s", ctl->remotename)) == 0) { + strlcpy(shroud, ctl->password, sizeof(shroud)); ok = gen_transact(sock, "RPOP %s", ctl->password); + memset(shroud, 0x55, sizeof(shroud)); + shroud[0] = '\0'; + } break; default: @@ -566,6 +685,19 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) ok = PS_ERROR; } +#ifdef SSL_ENABLE + /* this is for servers which claim to support TLS, but actually + * don't! */ + if (connection_may_have_tls_errors + && (ok == PS_SOCKET || ok == PS_PROTOCOL)) + { + xfree(ctl->sslproto); + ctl->sslproto = xstrdup(""); + /* repoll immediately without TLS */ + ok = PS_REPOLL; + } +#endif + if (ok != 0) { /* maybe we detected a lock-busy condition? */ @@ -579,7 +711,7 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) * accepted by Matthias Andree. * * Rationale: the server must have locked the spool before returning +OK; - * this sleep just wastes time and hence, for modem and CSD users, money. */ + * this sleep just wastes time and hence, for modem and GSM CSD users, money. */ #ifdef WANT_BOGUS /* * Empirical experience shows some server/OS combinations @@ -591,45 +723,90 @@ static int pop3_getauth(int sock, struct query *ctl, char *greeting) sleep(3); /* to be _really_ safe, probably need sleep(5)! */ #endif - /* we're peek-capable if use of TOP is enabled */ - peek_capable = !(ctl->fetchall || (ctl->keep && !ctl->server.uidl)); - /* we're approved */ return(PS_SUCCESS); } -static int pop3_gettopid( int sock, int num , char *id) +/* cut off C string at first POSIX space */ +static void trim(char *s) { + s += strcspn(s, POSIX_space); + s[0] = '\0'; +} + +/* XXX FIXME: using the Message-ID is unsafe, some messages (spam, + * broken messages) do not have Message-ID headers, and messages without + * those appear to break this code and cause fetchmail (at least version + * 6.2.3) to not delete such messages properly after retrieval. + * See Sourceforge Bug #780933. + * + * The other problem is that the TOP command itself is optional, too... */ +static int pop3_gettopid(int sock, int num , char *id, size_t idsize) { int ok; int got_it; char buf [POPBUFSIZE+1]; snprintf(buf, sizeof(buf), "TOP %d 1", num); - if ((ok = gen_transact(sock, buf )) != 0) + if ((ok = gen_transact(sock, "%s", buf)) != 0) return ok; got_it = 0; - while ((ok = gen_recv(sock, buf, sizeof(buf))) == 0) + while (gen_recv(sock, buf, sizeof(buf)) == 0) { if (DOTLINE(buf)) break; - if ( ! got_it && ! strncasecmp("Message-Id:", buf, 11 )) { + if (!got_it && 0 == strncasecmp("Message-Id:", buf, 11)) { + char *p = buf + 11; got_it = 1; - /* prevent stack overflows */ - buf[IDLEN+12] = 0; - sscanf( buf+12, "%s", id); + p += strspn(p, POSIX_space); + strlcpy(id, p, idsize); + trim(id); } } + /* XXX FIXME: do not return success here if no Message-ID header was + * found. */ return 0; } -static int pop3_getuidl( int sock, int num , char *id) +/** Parse the UID response (leading +OK must have been + * stripped off) in buf, store the number in gotnum, and store the ID + * into the caller-provided buffer "id" of size "idsize". + * Returns PS_SUCCESS or PS_PROTOCOL for failure. */ +static int parseuid(const char *buf, unsigned long *gotnum, char *id, size_t idsize) +{ + const char *i; + char *j; + + /* skip leading blanks ourselves */ + i = buf; + i += strspn(i, POSIX_space); + errno = 0; + *gotnum = strtoul(i, &j, 10); + if (j == i || !*j || errno || NULL == strchr(POSIX_space, *j)) { + report(stderr, GT_("Cannot handle UIDL response from upstream server.\n")); + return PS_PROTOCOL; + } + j += strspn(j, POSIX_space); + strlcpy(id, j, idsize); + trim(id); + return PS_SUCCESS; +} + +/** request UIDL for single message \a num and stuff the result into the + * buffer \a id which can hold \a idsize bytes */ +static int pop3_getuidl(int sock, int num, char *id /** output */, size_t idsize) { int ok; char buf [POPBUFSIZE+1]; + unsigned long gotnum; + gen_send(sock, "UIDL %d", num); if ((ok = pop3_ok(sock, buf)) != 0) return(ok); - if (sscanf(buf, "%d %s", &num, id) != 2) - return(PS_PROTOCOL); + if ((ok = parseuid(buf, &gotnum, id, idsize))) + return ok; + if (gotnum != (unsigned long)num) { + report(stderr, GT_("Server responded with UID for wrong message.\n")); + return PS_PROTOCOL; + } return(PS_SUCCESS); } @@ -638,25 +815,26 @@ static int pop3_fastuidl( int sock, struct query *ctl, unsigned int count, int int ok; unsigned int first_nr, last_nr, try_nr; char id [IDLEN+1]; + struct idlist *savep = NULL; /** pointer to cache save_str result, speeds up saves */ first_nr = 0; last_nr = count + 1; while (first_nr < last_nr - 1) { - struct idlist *new; + struct idlist *newl; try_nr = (first_nr + last_nr) / 2; - if( (ok = pop3_getuidl( sock, try_nr, id )) != 0 ) + if ((ok = pop3_getuidl(sock, try_nr, id, sizeof(id))) != 0) return ok; - if ((new = str_in_list(&ctl->oldsaved, id, FALSE))) + if ((newl = str_in_list(&ctl->oldsaved, id, FALSE))) { - flag mark = new->val.status.mark; + flag mark = newl->val.status.mark; if (mark == UID_DELETED || mark == UID_EXPUNGED) { if (outlevel >= O_VERBOSE) - report(stderr, GT_("id=%s (num=%d) was deleted, but is still present!\n"), id, try_nr); + report(stderr, GT_("id=%s (num=%u) was deleted, but is still present!\n"), id, try_nr); /* just mark it as seen now! */ - new->val.status.mark = mark = UID_SEEN; + newl->val.status.mark = mark = UID_SEEN; } /* narrow the search region! */ @@ -670,7 +848,7 @@ static int pop3_fastuidl( int sock, struct query *ctl, unsigned int count, int first_nr = try_nr; /* save the number */ - new->val.status.num = try_nr; + newl->val.status.num = try_nr; } else { @@ -679,8 +857,8 @@ static int pop3_fastuidl( int sock, struct query *ctl, unsigned int count, int last_nr = try_nr; /* save it */ - new = save_str(&ctl->oldsaved, id, UID_UNSEEN); - new->val.status.num = try_nr; + savep = save_str(savep ? &savep : &ctl->oldsaved, id, UID_UNSEEN); + savep->val.status.num = try_nr; } } if (outlevel >= O_DEBUG && last_nr <= count) @@ -694,6 +872,10 @@ static int pop3_fastuidl( int sock, struct query *ctl, unsigned int count, int static int pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp) { + /* XXX FIXME: this code is severely broken. A Cc:d mailing list + * message will arrive twice with the same Message-ID, so this + * slowuidl code will break. Same goes for messages without + * Message-ID headers at all. This code would best be removed. */ /* This approach tries to get the message headers from the * remote hosts and compares the message-id to the already known * ones: @@ -708,10 +890,10 @@ static int pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp) int first_nr, list_len, try_id, try_nr, add_id; int num; char id [IDLEN+1]; - - if( (ok = pop3_gettopid( sock, 1, id )) != 0 ) + + if ((ok = pop3_gettopid(sock, 1, id, sizeof(id))) != 0) return ok; - + if( ( first_nr = str_nr_in_list(&ctl->oldsaved, id) ) == -1 ) { /* the first message is unknown -> all messages are new */ *newp = *countp; @@ -723,7 +905,7 @@ static int pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp) try_id = list_len - first_nr; /* -1 + 1 */ if( try_id > 1 ) { if( try_id <= *countp ) { - if( (ok = pop3_gettopid( sock, try_id, id )) != 0 ) + if ((ok = pop3_gettopid(sock, try_id, id, sizeof(id))) != 0) return ok; try_nr = str_nr_last_in_list(&ctl->oldsaved, id); @@ -747,7 +929,7 @@ static int pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp) } else try_id += add_id; - if( (ok = pop3_gettopid( sock, try_id, id )) != 0 ) + if ((ok = pop3_gettopid(sock, try_id, id, sizeof(id))) != 0) return ok; try_nr = str_nr_in_list(&ctl->oldsaved, id); } @@ -764,10 +946,10 @@ static int pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp) /* the first try_id messages are known -> copy them to the newsaved list */ for( num = first_nr; num < list_len; num++ ) { - struct idlist *new = save_str(&ctl->newsaved, + struct idlist *newl = save_str(&ctl->newsaved, str_from_nr_list(&ctl->oldsaved, num), UID_UNSEEN); - new->val.status.num = num - first_nr + 1; + newl->val.status.num = num - first_nr + 1; } if( nolinear ) { @@ -789,6 +971,7 @@ static int pop3_getrange(int sock, int ok; char buf [POPBUFSIZE+1]; + (void)folder; /* Ensure that the new list is properly empty */ ctl->newsaved = (struct idlist *)NULL; @@ -802,19 +985,25 @@ static int pop3_getrange(int sock, /* get the total message count */ gen_send(sock, "STAT"); ok = pop3_ok(sock, buf); - if (ok == 0) - sscanf(buf,"%d %d", countp, bytes); - else + if (ok == 0) { + int asgn; + + asgn = sscanf(buf,"%d %d", countp, bytes); + if (asgn != 2) + return PS_PROTOCOL; + } else return(ok); /* - * Newer, RFC-1725-conformant POP servers may not have the LAST command. - * We work as hard as possible to hide this ugliness, but it makes + * Newer, RFC-1725/1939-conformant POP servers may not have the LAST + * command. We work as hard as possible to hide this, but it makes * counting new messages intrinsically quadratic in the worst case. */ last = 0; *newp = -1; - if (*countp > 0 && !ctl->fetchall) + /* if there are messages, and UIDL is desired, use UIDL + * also use UIDL if fetchall is unset */ + if (*countp > 0 && (!ctl->fetchall || ctl->server.uidl)) { int fastuidl; char id [IDLEN+1]; @@ -822,6 +1011,7 @@ static int pop3_getrange(int sock, /* should we do fast uidl this time? */ fastuidl = ctl->fastuidl; if (*countp > 7 && /* linear search is better if there are few mails! */ + !ctl->fetchall && /* with fetchall, all uids are required */ !ctl->flush && /* with flush, it is safer to disable fastuidl */ NUM_NONZERO (fastuidl)) { @@ -838,8 +1028,10 @@ static int pop3_getrange(int sock, ok = pop3_ok(sock, buf); } else ok = 1; + if (ok == 0) { + /* scan LAST reply */ if (sscanf(buf, "%d", &last) == 0) { report(stderr, GT_("protocol error\n")); @@ -847,15 +1039,16 @@ static int pop3_getrange(int sock, } *newp = (*countp - last); } - else - { + else + { + /* do UIDL */ if (dofastuidl) return(pop3_fastuidl( sock, ctl, *countp, newp)); /* grab the mailbox's UID list */ - if ((ok = gen_transact(sock, "UIDL")) != 0) + if (gen_transact(sock, "UIDL") != 0) { /* don't worry, yet! do it the slow way */ - if((ok = pop3_slowuidl( sock, ctl, countp, newp))!=0) + if (pop3_slowuidl(sock, ctl, countp, newp)) { report(stderr, GT_("protocol error while fetching UIDLs\n")); return(PS_ERROR); @@ -863,54 +1056,63 @@ static int pop3_getrange(int sock, } else { - int num; + /* UIDL worked - parse reply */ + unsigned long unum; + struct idlist *newl = NULL; *newp = 0; - while ((ok = gen_recv(sock, buf, sizeof(buf))) == 0) + while (gen_recv(sock, buf, sizeof(buf)) == PS_SUCCESS) { - if (DOTLINE(buf)) - break; - else if (sscanf(buf, "%d %s", &num, id) == 2) + if (DOTLINE(buf)) + break; + + if (parseuid(buf, &unum, id, sizeof(id)) == PS_SUCCESS) { - struct idlist *old, *new; + struct idlist *old; - new = save_str(&ctl->newsaved, id, UID_UNSEEN); - new->val.status.num = num; + newl = save_str(newl ? &newl : &ctl->newsaved, id, UID_UNSEEN); + newl->val.status.num = unum; if ((old = str_in_list(&ctl->oldsaved, id, FALSE))) { flag mark = old->val.status.mark; if (mark == UID_DELETED || mark == UID_EXPUNGED) { + /* XXX FIXME: switch 3 occurrences from + * (int)unum or (unsigned int)unum to + * remove the cast and use %lu - not now + * though, time for new release */ if (outlevel >= O_VERBOSE) - report(stderr, GT_("id=%s (num=%d) was deleted, but is still present!\n"), id, num); + report(stderr, GT_("id=%s (num=%d) was deleted, but is still present!\n"), id, (int)unum); /* just mark it as seen now! */ old->val.status.mark = mark = UID_SEEN; } - new->val.status.mark = mark; + newl->val.status.mark = mark; if (mark == UID_UNSEEN) { (*newp)++; if (outlevel >= O_DEBUG) - report(stdout, GT_("%u is unseen\n"), num); + report(stdout, GT_("%u is unseen\n"), (unsigned int)unum); } } else { (*newp)++; if (outlevel >= O_DEBUG) - report(stdout, GT_("%u is unseen\n"), num); + report(stdout, GT_("%u is unseen\n"), (unsigned int)unum); /* add it to oldsaved also! In case, we do not * swap the lists (say, due to socket error), * the same mail will not be downloaded again. */ old = save_str(&ctl->oldsaved, id, UID_UNSEEN); - old->val.status.num = num; } - } - } - } - } + /* save the number */ + old->val.status.num = unum; + } else + return PS_ERROR; + } /* multi-line loop for UIDL reply */ + } /* UIDL parser */ + } /* do UIDL */ } return(PS_SUCCESS); @@ -919,15 +1121,15 @@ static int pop3_getrange(int sock, static int pop3_getpartialsizes(int sock, int first, int last, int *sizes) /* capture the size of message #first */ { - int ok = 0, i; + int ok = 0, i, num; char buf [POPBUFSIZE+1]; - unsigned int num, size; + unsigned int size; for (i = first; i <= last; i++) { gen_send(sock, "LIST %d", i); if ((ok = pop3_ok(sock, buf)) != 0) return(ok); - if (sscanf(buf, "%u %u", &num, &size) == 2) { + if (sscanf(buf, "%d %u", &num, &size) == 2) { if (num == i) sizes[i - first] = size; else @@ -959,7 +1161,7 @@ static int pop3_getsizes(int sock, int count, int *sizes) if (DOTLINE(buf)) break; else if (sscanf(buf, "%u %u", &num, &size) == 2) { - if (num > 0 && num <= count) + if (num > 0 && num <= (unsigned)count) sizes[num - 1] = size; else /* warn about possible attempt to induce buffer overrun */ @@ -974,7 +1176,7 @@ static int pop3_getsizes(int sock, int count, int *sizes) static int pop3_is_old(int sock, struct query *ctl, int num) /* is the given message old? */ { - struct idlist *new; + struct idlist *newl; if (!ctl->oldsaved) return (num <= last); else if (dofastuidl) @@ -986,30 +1188,30 @@ static int pop3_is_old(int sock, struct query *ctl, int num) /* in fast uidl, we manipulate the old list only! */ - if ((new = id_find(&ctl->oldsaved, num))) + if ((newl = id_find(&ctl->oldsaved, num))) { /* we already have the id! */ - return(new->val.status.mark != UID_UNSEEN); + return(newl->val.status.mark != UID_UNSEEN); } /* get the uidl first! */ - if (pop3_getuidl(sock, num, id) != PS_SUCCESS) + if (pop3_getuidl(sock, num, id, sizeof(id)) != PS_SUCCESS) return(TRUE); - if ((new = str_in_list(&ctl->oldsaved, id, FALSE))) { + if ((newl = str_in_list(&ctl->oldsaved, id, FALSE))) { /* we already have the id! */ - new->val.status.num = num; - return(new->val.status.mark != UID_UNSEEN); + newl->val.status.num = num; + return(newl->val.status.mark != UID_UNSEEN); } /* save it */ - new = save_str(&ctl->oldsaved, id, UID_UNSEEN); - new->val.status.num = num; + newl = save_str(&ctl->oldsaved, id, UID_UNSEEN); + newl->val.status.num = num; return(FALSE); } else - return ((new = id_find(&ctl->newsaved, num)) != NULL && - new->val.status.mark != UID_UNSEEN); + return ((newl = id_find(&ctl->newsaved, num)) != NULL && + newl->val.status.mark != UID_UNSEEN); } #ifdef UNUSED @@ -1043,8 +1245,9 @@ static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp) #ifdef SDPS_ENABLE /* - * See http://www.demon.net/services/mail/sdps-tech.html + * See http://www.demon.net/helpdesk/producthelp/mail/sdps-tech.html/ * for a description of what we're parsing here. + * -- updated 2006-02-22 */ if (ctl->server.sdps) { @@ -1062,18 +1265,25 @@ static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp) switch (linecount) { case 4: /* No need to wrap envelope from address */ - sdps_envfrom = xmalloc(strlen(buf)+1); + /* FIXME: some parts of fetchmail don't handle null + * envelope senders, so use <> to mark null sender + * as a workaround. */ + if (strspn(buf, " \t") == strlen(buf)) + strcpy(buf, "<>"); + sdps_envfrom = (char *)xmalloc(strlen(buf)+1); strcpy(sdps_envfrom,buf); break; case 5: /* Wrap address with To: <> so nxtaddr() likes it */ - sdps_envto = xmalloc(strlen(buf)+7); + sdps_envto = (char *)xmalloc(strlen(buf)+7); sprintf(sdps_envto,"To: <%s>",buf); break; } } while (!(buf[0] == '.' && (buf[1] == '\r' || buf[1] == '\n' || buf[1] == '\0'))); } +#else + (void)ctl; #endif /* SDPS_ENABLE */ /* @@ -1091,11 +1301,11 @@ static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp) * In that case, marking the seen flag is the only way to prevent the * message from being re-fetched on subsequent runs. * - * Also use RETR if fetchall is on. This gives us a workaround - * for servers like usa.net's that bungle TOP. It's pretty - * harmless because fetchall guarantees that any message dropped - * by an interrupted RETR will be picked up on the next poll of the - * site. + * Also use RETR (that means no TOP, no peek) if fetchall is on. + * This gives us a workaround for servers like usa.net's that bungle + * TOP. It's pretty harmless because fetchall guarantees that any + * message dropped by an interrupted RETR will be picked up on the + * next poll of the site. * * We take advantage here of the fact that, according to all the * POP RFCs, "if the number of lines requested by the POP3 client @@ -1148,6 +1358,7 @@ static int pop3_delete(int sock, struct query *ctl, int number) static int pop3_mark_seen(int sock, struct query *ctl, int number) /* mark a given message as seen */ { + (void)sock; mark_uid_seen(ctl, number); return(PS_SUCCESS); } @@ -1185,13 +1396,8 @@ static int pop3_logout(int sock, struct query *ctl) static const struct method pop3 = { "POP3", /* Post Office Protocol v3 */ -#ifdef INET6_ENABLE - "pop3", /* standard POP3 port */ - "pop3s", /* ssl POP3 port */ -#else /* INET6_ENABLE */ - 110, /* standard POP3 port */ - 995, /* ssl POP3 port */ -#endif /* INET6_ENABLE */ + "pop3", /* port for plain and TLS POP3 */ + "pop3s", /* port for SSL POP3 */ FALSE, /* this is not a tagged protocol */ TRUE, /* this uses a message delimiter */ pop3_ok, /* parse command response */ @@ -1205,6 +1411,7 @@ static const struct method pop3 = NULL, /* no message trailer */ pop3_delete, /* how to delete a message */ pop3_mark_seen, /* how to mark a message as seen */ + NULL, /* no action at end of mailbox */ pop3_logout, /* log out, we're done */ FALSE, /* no, we can't re-poll */ }; @@ -1214,11 +1421,11 @@ int doPOP3 (struct query *ctl) { #ifndef MBOX if (ctl->mailboxes->id) { - fprintf(stderr,GT_("Option --remote is not supported with POP3\n")); + fprintf(stderr,GT_("Option --folder is not supported with POP3\n")); return(PS_SYNTAX); } #endif /* MBOX */ - peek_capable = !ctl->fetchall; + return(do_protocol(ctl, &pop3)); } #endif /* POP3_ENABLE */