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/*
* pop3.c -- POP3 protocol methods
*
* Copyright 1998 by Eric S. Raymond.
* For license terms, see the file COPYING in this directory.
*/
#include "config.h"
#ifdef POP3_ENABLE
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include "fetchmail.h"
#include "socket.h"
#include "gettext.h"
#include "uid_db.h"
#ifdef OPIE_ENABLE
#ifdef __cplusplus
extern "C" {
#endif
#include <opie.h>
#ifdef __cplusplus
}
#endif
#endif /* OPIE_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 */
/* session variables initialized in capa_probe() or pop3_getauth() */
flag done_capa = FALSE;
#if defined(GSSAPI)
flag has_gssapi = FALSE;
#endif /* defined(GSSAPI) */
#if defined(KERBEROS_V5)
flag has_kerberos = FALSE;
#endif /* defined(KERBEROS_V5) */
static flag has_cram = FALSE;
#ifdef OPIE_ENABLE
flag has_otp = FALSE;
#endif /* OPIE_ENABLE */
#ifdef NTLM_ENABLE
flag has_ntlm = FALSE;
#endif /* NTLM_ENABLE */
#ifdef SSL_ENABLE
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"
/*
* NTLM support by Grant Edwards.
*
* Handle MS-Exchange NTLM authentication method. This is the same
* as the NTLM auth used by Samba for SMB related services. We just
* encode the packets in base64 instead of sending them out via a
* network interface.
*
* Much source (ntlm.h, smb*.c smb*.h) was borrowed from Samba.
*/
static int do_pop3_ntlm(int sock, struct query *ctl,
int msn_instead /** if true, send AUTH MSN, else send AUTH NTLM */)
{
char msgbuf[POPBUFSIZE+1];
int result;
gen_send(sock, msn_instead ? "AUTH MSN" : "AUTH NTLM");
if ((result = ntlm_helper(sock, ctl, "POP3")))
return result;
if ((result = gen_recv (sock, msgbuf, sizeof msgbuf)))
return result;
if (strstr (msgbuf, "OK"))
return PS_SUCCESS;
else
return PS_AUTHFAIL;
}
#endif /* NTLM */
#define DOTLINE(s) (s[0] == '.' && (s[1]=='\r'||s[1]=='\n'||s[1]=='\0'))
static int pop3_ok (int sock, char *argbuf)
/* parse command response */
{
int ok;
char buf [POPBUFSIZE+1];
char *bufp;
if ((ok = gen_recv(sock, buf, sizeof(buf))) == 0)
{ bufp = buf;
if (*bufp == '+' || *bufp == '-')
bufp++;
else
return(PS_PROTOCOL);
while (isalpha((unsigned char)*bufp))
bufp++;
if (*bufp)
*(bufp++) = '\0';
if (strcmp(buf,"+OK") == 0)
{
#ifdef OPIE_ENABLE
strcpy(lastok, bufp);
#endif /* OPIE_ENABLE */
ok = 0;
}
else if (strncmp(buf,"-ERR", 4) == 0)
{
if (stage == STAGE_FETCH)
ok = PS_TRANSIENT;
else if (stage > STAGE_GETAUTH)
ok = PS_PROTOCOL;
/*
* We're checking for "lock busy", "unable to lock",
* "already locked", "wait a few minutes" etc. here.
* This indicates that we have to wait for the server to
* unwedge itself before we can poll again.
*
* PS_LOCKBUSY check empirically verified with two recent
* versions of the Berkeley popper; QPOP (version 2.2) and
* QUALCOMM Pop server derived from UCB (version 2.1.4-R3)
* These are caught by the case-indifferent "lock" check.
* The "wait" catches "mail storage services unavailable,
* wait a few minutes and try again" on the InterMail server.
*
* If these aren't picked up on correctly, fetchmail will
* think there is an authentication failure and wedge the
* connection in order to prevent futile polls.
*
* Gad, what a kluge.
*/
else if (strstr(bufp,"lock")
|| strstr(bufp,"Lock")
|| strstr(bufp,"LOCK")
|| strstr(bufp,"wait")
/* these are blessed by RFC 2449 */
|| strstr(bufp,"[IN-USE]")||strstr(bufp,"[LOGIN-DELAY]"))
ok = PS_LOCKBUSY;
else if ((strstr(bufp,"Service")
|| strstr(bufp,"service"))
&& (strstr(bufp,"unavailable")))
ok = PS_SERVBUSY;
else
ok = PS_AUTHFAIL;
/*
* We always want to pass the user lock-busy messages, because
* they're red flags. Other stuff (like AUTH failures on non-
* RFC1734 servers) only if we're debugging.
*/
if (*bufp && (ok == PS_LOCKBUSY || outlevel >= O_MONITOR))
report(stderr, "%s\n", bufp);
}
else
ok = PS_PROTOCOL;
#if POPBUFSIZE > MSGBUFSIZE
#error "POPBUFSIZE must not be larger than MSGBUFSIZE"
#endif
if (argbuf != NULL)
strcpy(argbuf,bufp);
}
return(ok);
}
static int capa_probe(int sock)
/* probe the capabilities of the remote server */
{
int ok;
if (done_capa) {
return PS_SUCCESS;
}
#if defined(GSSAPI)
has_gssapi = FALSE;
#endif /* defined(GSSAPI) */
#if defined(KERBEROS_V5)
has_kerberos = FALSE;
#endif /* defined(KERBEROS_V5) */
has_cram = FALSE;
#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)
{
char buffer[64];
/* determine what authentication methods we have available */
while ((ok = gen_recv(sock, buffer, sizeof(buffer))) == 0)
{
if (DOTLINE(buffer))
break;
#ifdef SSL_ENABLE
if (strstr(buffer, "STLS"))
has_stls = TRUE;
#endif /* SSL_ENABLE */
#if defined(GSSAPI)
if (strstr(buffer, "GSSAPI"))
has_gssapi = TRUE;
#endif /* defined(GSSAPI) */
#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;
}
static int do_apop(int sock, struct query *ctl, char *greeting)
{
char *start, *end;
/* build MD5 digest from greeting timestamp + password */
/* find start of timestamp */
start = strchr(greeting, '<');
if (!start) {
report(stderr,
GT_("Required APOP timestamp not found in greeting\n"));
return PS_AUTHFAIL;
}
/* find end of timestamp */
end = strchr(start + 1, '>');
if (!end || end == start + 1) {
report(stderr,
GT_("Timestamp syntax error in greeting\n"));
return(PS_AUTHFAIL);
} 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 */
char *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);
return gen_transact(sock, "APOP %s %s", ctl->remotename, (char *)ctl->digest);
}
static int pop3_getauth(int sock, struct query *ctl, char *greeting)
/* apply for connection authorization */
{
int ok;
#ifdef OPIE_ENABLE
char *challenge;
#endif /* OPIE_ENABLE */
#ifdef SSL_ENABLE
flag connection_may_have_tls_errors = FALSE;
#endif /* SSL_ENABLE */
done_capa = FALSE;
#if defined(GSSAPI)
has_gssapi = FALSE;
#endif /* defined(GSSAPI) */
#if defined(KERBEROS_V5)
has_kerberos = FALSE;
#endif /* defined(KERBEROS_V5) */
has_cram = FALSE;
#ifdef OPIE_ENABLE
has_otp = FALSE;
#endif /* OPIE_ENABLE */
#ifdef SSL_ENABLE
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.
* <http://lists.ccil.org/pipermail/fetchmail-friends/2004-April/008523.html>
* (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;
}
#ifdef SDPS_ENABLE
/*
* This needs to catch both demon.co.uk and demon.net.
* If we see either, and we're in multidrop mode, try to use
* the SDPS *ENV extension.
*/
if (!(ctl->server.sdps) && MULTIDROP(ctl) && strstr(greeting, "demon."))
ctl->server.sdps = TRUE;
#endif /* SDPS_ENABLE */
/* this is a leftover from the times 6.3.X and older when APOP was a
* "protocol" (P_APOP) rather than an authenticator (A_APOP),
* however, the switch is still useful because we can break; after
* an authenticator failed. */
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"))
{
/* AUTH command should return a list of available mechanisms */
if (gen_transact(sock, "AUTH") == 0)
{
char buffer[10];
flag has_rpa = FALSE;
while ((ok = gen_recv(sock, buffer, sizeof(buffer))) == 0)
{
if (DOTLINE(buffer))
break;
if (strncasecmp(buffer, "rpa", 3) == 0)
has_rpa = TRUE;
}
if (has_rpa && !POP3_auth_rpa(ctl->remotename,
ctl->password, sock))
return(PS_SUCCESS);
}
return(PS_AUTHFAIL);
}
#endif /* RPA_ENABLE */
/*
* CAPA command may return a list including available
* 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.
*
* 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.
*
* 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->server.authenticate == A_ANY) ||
(ctl->server.authenticate == A_GSSAPI) ||
(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 => 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
* must have succeeded. In that case, treat this as a
* genuine socket error and do not change the auth method.
*/
(ok == PS_SOCKET && !ctl->wehaveauthed))
{
#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 (maybe_tls(ctl)) {
char *commonname;
commonname = ctl->server.pollname;
if (ctl->server.via)
commonname = ctl->server.via;
if (ctl->sslcommonname)
commonname = ctl->sslcommonname;
if (has_stls
|| must_tls(ctl)) /* if TLS is mandatory, ignore capabilities */
{
/* 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)
{
/*
* 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);
}
}
}
} /* maybe_tls() */
#endif /* SSL_ENABLE */
/*
* OK, we have an authentication type now.
*/
#if defined(GSSAPI)
if (has_gssapi &&
(ctl->server.authenticate == A_GSSAPI ||
(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)
break;
}
#endif /* defined(GSSAPI) */
#ifdef OPIE_ENABLE
if (has_otp &&
(ctl->server.authenticate == A_OTP ||
ctl->server.authenticate == A_ANY))
{
ok = do_otp(sock, "AUTH", ctl);
if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
break;
}
#endif /* OPIE_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_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);
if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
break;
}
if (ctl->server.authenticate == A_APOP
|| ctl->server.authenticate == A_ANY)
{
ok = do_apop(sock, ctl, greeting);
if (ok == PS_SUCCESS || ctl->server.authenticate != A_ANY)
break;
}
/* ordinary validation, no one-time password or RPA */
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") ? n : ctl->password, response);
free(n);
if ((i == -2) && !run.poll_interval) {
char secret[OPIE_SECRET_MAX+1];
fprintf(stderr, GT_("Secret pass phrase: "));
if (opiereadpass(secret, sizeof(secret), 0))
i = opiegenerator(challenge, secret, response);
memset(secret, 0, sizeof(secret));
};
if (i) {
ok = PS_ERROR;
break;
};
ok = gen_transact(sock, "PASS %s", response);
break;
}
#endif /* OPIE_ENABLE */
/* 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_V5)
&& (ctl->server.service != NULL
&& strcmp(ctl->server.service, KPOP_PORT) == 0))
{
ok = gen_transact(sock, "PASS krb_ticket");
break;
}
/* 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;
default:
report(stderr, GT_("Undefined protocol request in POP3_auth\n"));
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? */
if (ok == PS_LOCKBUSY)
report(stderr, GT_("lock busy! Is another session active?\n"));
return(ok);
}
/* we're approved */
return(PS_SUCCESS);
}
/* cut off C string at first POSIX space */
static void trim(char *s) {
s += strcspn(s, POSIX_space);
s[0] = '\0';
}
/** 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 ((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);
}
static int pop3_fastuidl( int sock, struct query *ctl, unsigned int count, int *newp)
{
int ok;
unsigned int first_nr, last_nr, try_nr;
char id [IDLEN+1];
first_nr = 0;
last_nr = count + 1;
while (first_nr < last_nr - 1)
{
struct uid_db_record *rec;
try_nr = (first_nr + last_nr) / 2;
if ((ok = pop3_getuidl(sock, try_nr, id, sizeof(id))) != 0)
return ok;
if ((rec = find_uid_by_id(&ctl->oldsaved, id)))
{
flag mark = rec->status;
if (mark == UID_DELETED || mark == UID_EXPUNGED)
{
if (outlevel >= O_VERBOSE)
report(stderr, GT_("id=%s (num=%u) was deleted, but is still present!\n"), id, try_nr);
/* just mark it as seen now! */
rec->status = mark = UID_SEEN;
}
/* narrow the search region! */
if (mark == UID_UNSEEN)
{
if (outlevel >= O_DEBUG)
report(stdout, GT_("%u is unseen\n"), try_nr);
last_nr = try_nr;
}
else
first_nr = try_nr;
/* save the number */
set_uid_db_num(&ctl->oldsaved, rec, try_nr);
}
else
{
if (outlevel >= O_DEBUG)
report(stdout, GT_("%u is unseen\n"), try_nr);
last_nr = try_nr;
/* save it */
rec = uid_db_insert(&ctl->oldsaved, id, UID_UNSEEN);
set_uid_db_num(&ctl->oldsaved, rec, try_nr);
}
}
if (outlevel >= O_DEBUG && last_nr <= count)
report(stdout, GT_("%u is first unseen\n"), last_nr);
/* update last! */
*newp = count - first_nr;
last = first_nr;
return 0;
}
static int pop3_getrange(int sock,
struct query *ctl,
const char *folder,
int *countp, int *newp, int *bytes)
/* get range of messages to be fetched */
{
int ok;
char buf [POPBUFSIZE+1];
(void)folder;
/* Ensure that the new list is properly empty */
clear_uid_db(&ctl->newsaved);
#ifdef MBOX
/* Alain Knaff suggests this, but it's not RFC standard */
if (folder)
if ((ok = gen_transact(sock, "MBOX %s", folder)))
return ok;
#endif /* MBOX */
/* get the total message count */
gen_send(sock, "STAT");
ok = pop3_ok(sock, buf);
if (ok == 0) {
int asgn;
asgn = sscanf(buf,"%d %d", countp, bytes);
if (asgn != 2)
return PS_PROTOCOL;
} else
return(ok);
/* unless fetching all mail, get UID list (UIDL) */
last = 0;
*newp = -1;
if (*countp > 0)
{
int fastuidl;
char id [IDLEN+1];
set_uid_db_num_pos_0(&ctl->oldsaved, *countp);
set_uid_db_num_pos_0(&ctl->newsaved, *countp);
/* 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))
{
if (fastuidl == 1)
dofastuidl = 1;
else
dofastuidl = ctl->fastuidlcount != 0;
}
else
dofastuidl = 0;
{
/* do UIDL */
if (dofastuidl)
return(pop3_fastuidl( sock, ctl, *countp, newp));
/* grab the mailbox's UID list */
if (gen_transact(sock, "UIDL") != 0)
{
if (!ctl->fetchall) {
report(stderr, GT_("protocol error while fetching UIDLs\n"));
return(PS_ERROR);
}
}
else
{
/* UIDL worked - parse reply */
unsigned long unum;
*newp = 0;
while (gen_recv(sock, buf, sizeof(buf)) == PS_SUCCESS)
{
if (DOTLINE(buf))
break;
if (parseuid(buf, &unum, id, sizeof(id)) == PS_SUCCESS)
{
struct uid_db_record *old_rec, *new_rec;
new_rec = uid_db_insert(&ctl->newsaved, id, UID_UNSEEN);
if ((old_rec = find_uid_by_id(&ctl->oldsaved, id)))
{
flag mark = old_rec->status;
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, (int)unum);
/* just mark it as seen now! */
old_rec->status = mark = UID_SEEN;
}
new_rec->status = mark;
if (mark == UID_UNSEEN)
{
(*newp)++;
if (outlevel >= O_DEBUG)
report(stdout, GT_("%u is unseen\n"), (unsigned int)unum);
}
}
else
{
(*newp)++;
if (outlevel >= O_DEBUG)
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_rec = uid_db_insert(&ctl->oldsaved, id, UID_UNSEEN);
}
/*
* save the number if it will be needed later on
* (messsage will either be fetched or deleted)
*/
if (new_rec->status == UID_UNSEEN || ctl->flush) {
set_uid_db_num(&ctl->oldsaved, old_rec, unum);
set_uid_db_num(&ctl->newsaved, new_rec, unum);
}
} else
return PS_ERROR;
} /* multi-line loop for UIDL reply */
} /* UIDL parser */
} /* do UIDL */
}
return(PS_SUCCESS);
}
static int pop3_getpartialsizes(int sock, int first, int last, int *sizes)
/* capture the size of message #first */
{
int ok = 0, i, num;
char buf [POPBUFSIZE+1];
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, "%d %u", &num, &size) == 2) {
if (num == i)
sizes[i - first] = size;
else
/* warn about possible attempt to induce buffer overrun
*
* we expect server reply message number and requested
* message number to match */
report(stderr, "Warning: ignoring bogus data for message sizes returned by server.\n");
}
}
return(ok);
}
static int pop3_getsizes(int sock, int count, int *sizes)
/* capture the sizes of all messages */
{
int ok;
if ((ok = gen_transact(sock, "LIST")) != 0)
return(ok);
else
{
char buf [POPBUFSIZE+1];
while ((ok = gen_recv(sock, buf, sizeof(buf))) == 0)
{
unsigned int num, size;
if (DOTLINE(buf))
break;
else if (sscanf(buf, "%u %u", &num, &size) == 2) {
if (num > 0 && num <= (unsigned)count)
sizes[num - 1] = size;
else
/* warn about possible attempt to induce buffer overrun */
report(stderr, "Warning: ignoring bogus data for message sizes returned by server.\n");
}
}
return(ok);
}
}
static int pop3_is_old(int sock, struct query *ctl, int num)
/* is the given message old? */
{
struct uid_db_record *rec;
if (!uid_db_n_records(&ctl->oldsaved))
return (num <= last);
else if (dofastuidl)
{
char id [IDLEN+1];
if (num <= last)
return(TRUE);
/* in fast uidl, we manipulate the old list only! */
if ((rec = find_uid_by_num(&ctl->oldsaved, num)))
{
/* we already have the id! */
return(rec->status != UID_UNSEEN);
}
/* get the uidl first! */
if (pop3_getuidl(sock, num, id, sizeof(id)) != PS_SUCCESS)
return(TRUE);
if ((rec = find_uid_by_id(&ctl->oldsaved, id))) {
/* we already have the id! */
set_uid_db_num(&ctl->oldsaved, rec, num);
return(rec->status != UID_UNSEEN);
}
/* save it */
rec = uid_db_insert(&ctl->oldsaved, id, UID_UNSEEN);
set_uid_db_num(&ctl->oldsaved, rec, num);
return(FALSE);
} else {
rec = find_uid_by_num(&ctl->newsaved, num);
return !rec || rec->status != UID_UNSEEN;
}
}
static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp)
/* request nth message */
{
int ok;
char buf[POPBUFSIZE+1];
#ifdef SDPS_ENABLE
/*
* 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)
{
int linecount = 0;
sdps_envfrom = (char *)NULL;
sdps_envto = (char *)NULL;
gen_send(sock, "*ENV %d", number);
do {
if (gen_recv(sock, buf, sizeof(buf)))
{
break;
}
linecount++;
switch (linecount) {
case 4:
/* No need to wrap envelope from address */
/* 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 = (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 */
/*
* Though the POP RFCs don't document this fact, on almost every
* POP3 server I know of messages are marked "seen" only at the
* time the OK response to a RETR is issued.
*
* This means we can use TOP to fetch the message without setting its
* seen flag. This is good! It means that if the protocol exchange
* craps out during the message, it will still be marked `unseen' on
* the server. (Exception: in early 1999 SpryNet's POP3 servers were
* reported to mark messages seen on a TOP fetch.)
*
* However...*don't* do this if we're using keep to suppress deletion!
* 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 (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
* is greater than than the number of lines in the body, then the
* POP3 server sends the entire message.").
*
* The line count passed (99999999) is the maximum value CompuServe will
* accept; it's much lower than the natural value 2147483646 (the maximum
* twos-complement signed 32-bit integer minus 1) */
if (!peek_capable)
gen_send(sock, "RETR %d", number);
else
gen_send(sock, "TOP %d 99999999", number);
if ((ok = pop3_ok(sock, buf)) != 0)
return(ok);
*lenp = -1; /* we got sizes from the LIST response */
return(PS_SUCCESS);
}
static void mark_uid_seen(struct query *ctl, int number)
/* Tell the UID code we've seen this. */
{
struct uid_db_record *rec;
if ((rec = find_uid_by_num(&ctl->newsaved, number)))
rec->status = UID_SEEN;
/* mark it as seen in oldsaved also! In case, we do not swap the lists
* (say, due to socket error), the same mail will not be downloaded
* again.
*/
if ((rec = find_uid_by_num(&ctl->oldsaved, number)))
rec->status = UID_SEEN;
}
static int pop3_delete(int sock, struct query *ctl, int number)
/* delete a given message */
{
struct uid_db_record *rec;
int ok;
mark_uid_seen(ctl, number);
/* actually, mark for deletion -- doesn't happen until QUIT time */
ok = gen_transact(sock, "DELE %d", number);
if (ok != PS_SUCCESS)
return(ok);
rec = find_uid_by_num(dofastuidl ? &ctl->oldsaved : &ctl->newsaved, number);
rec->status = UID_DELETED;
return(PS_SUCCESS);
}
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);
}
static int pop3_logout(int sock, struct query *ctl)
/* send logout command */
{
int ok;
ok = gen_transact(sock, "QUIT");
if (!ok)
expunge_uids(ctl);
return(ok);
}
static const struct method pop3 =
{
"POP3", /* Post Office Protocol v3 */
"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 */
pop3_getauth, /* get authorization */
pop3_getrange, /* query range of messages */
pop3_getsizes, /* we can get a list of sizes */
pop3_getpartialsizes, /* we can get the size of 1 mail */
pop3_is_old, /* how do we tell a message is old? */
pop3_fetch, /* request given message */
NULL, /* no way to fetch body alone */
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 */
};
int doPOP3 (struct query *ctl)
/* retrieve messages using POP3 */
{
#ifndef MBOX
if (ctl->mailboxes->id) {
fprintf(stderr,GT_("Option --folder is not supported with POP3\n"));
return(PS_SYNTAX);
}
#endif /* MBOX */
return(do_protocol(ctl, &pop3));
}
#endif /* POP3_ENABLE */
/* pop3.c ends here */
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