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/*
* pop3.c -- POP3 protocol methods
*
* 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>
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#if defined(STDC_HEADERS)
#include <stdlib.h>
#endif
#include "fetchmail.h"
#include "socket.h"
#if OPIE
#include <opie.h>
#endif /* OPIE */
#ifndef strstr /* glibc-2.1 declares this as a macro */
extern char *strstr(); /* needed on sysV68 R3V7.1. */
#endif /* strstr */
static int phase;
#define PHASE_GETAUTH 0
#define PHASE_GETRANGE 1
#define PHASE_GETSIZES 2
#define PHASE_FETCH 3
#define PHASE_LOGOUT 4
static int last;
#if OPIE
static char lastok[POPBUFSIZE+1];
#endif /* OPIE */
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(*bufp))
bufp++;
if (*bufp)
*(bufp++) = '\0';
if (strcmp(buf,"+OK") == 0)
{
#if OPIE
strcpy(lastok, bufp);
#endif /* OPIE */
ok = 0;
}
else if (strcmp(buf,"-ERR") == 0)
{
if (phase > PHASE_GETAUTH)
ok = PS_PROTOCOL;
/*
* We're checking for "lock busy", "unable to lock",
* "already locked" etc. here. This indicates that we
* have to wait for the server to clean up before we
* can poll again.
*
* PS_LOCKBUSY check empirically verified with two recent
* versions the Berkeley popper; QPOP (version 2.2) and
* QUALCOMM Pop server derived from UCB (version 2.1.4-R3)
*/
else if (strstr(bufp,"lock")||strstr(bufp,"Lock")||strstr(bufp,"LOCK"))
ok = PS_LOCKBUSY;
else
ok = PS_AUTHFAIL;
if (*bufp)
error(0,0,bufp);
}
else
ok = PS_PROTOCOL;
if (argbuf != NULL)
strcpy(argbuf,bufp);
}
return(ok);
}
int pop3_getauth(int sock, struct query *ctl, char *greeting)
/* apply for connection authorization */
{
int ok;
char *start,*end;
char *msg;
#if OPIE
char *challenge;
#endif /* OPIE */
phase = PHASE_GETAUTH;
switch (ctl->server.protocol) {
case P_POP3:
ok = gen_transact(sock, "USER %s", ctl->remotename);
#ifdef RPA_ENABLE
/*
* CompuServe has changed its RPA behavior. Used to be they didn't
* accept PASS, but I'm told this changed in mid-November.
*/
if (strstr(greeting, "csi.com"))
{
/* temporary fix to get back out of cleartext authentication */
gen_transact(sock, "PASS %s", "dummypass");
/* 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 (buffer[0] == '.')
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 */
#if OPIE
/* see RFC1938: A One-Time Password System */
if (challenge = strstr(lastok, "otp-")) {
char response[OPIE_RESPONSE_MAX+1];
int i;
i = opiegenerator(challenge, !strcmp(ctl->password, "opie") ? "" : ctl->password, response);
if ((i == -2) && (cmd_daemon == -1)) {
char secret[OPIE_SECRET_MAX+1];
fprintf(stderr, "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 */
/* ordinary validation, no one-time password or RPA */
ok = gen_transact(sock, "PASS %s", ctl->password);
break;
case P_APOP:
/* build MD5 digest from greeting timestamp + password */
/* find start of timestamp */
for (start = greeting; *start != 0 && *start != '<'; start++)
continue;
if (*start == 0) {
error(0, -1, "Required APOP timestamp not found in greeting");
return(PS_AUTHFAIL);
}
/* find end of timestamp */
for (end = start; *end != 0 && *end != '>'; end++)
continue;
if (*end == 0 || end == start + 1) {
error(0, -1, "Timestamp syntax error in greeting");
return(PS_AUTHFAIL);
}
else
*++end = '\0';
/* copy timestamp and password into digestion buffer */
msg = (char *)xmalloc((end-start+1) + strlen(ctl->password) + 1);
strcpy(msg,start);
strcat(msg,ctl->password);
strcpy(ctl->digest, MD5Digest(msg));
free(msg);
ok = gen_transact(sock, "APOP %s %s", ctl->remotename, ctl->digest);
break;
case P_RPOP:
if ((ok = gen_transact(sock,"USER %s", ctl->remotename)) == 0)
ok = gen_transact(sock, "RPOP %s", ctl->password);
break;
default:
error(0, 0, "Undefined protocol request in POP3_auth");
ok = PS_ERROR;
}
/* maybe we detected a lock-busy condition? */
if (ok != 0)
{
if (ok == PS_LOCKBUSY)
{
error(0, 0, "lock busy! Is another session active?");
return(PS_LOCKBUSY);
}
}
/*
* Empirical experience shows some server/OS combinations
* may need a brief pause even after any lockfiles on the
* server are released, to give the server time to finish
* copying back very large mailfolders from the temp-file...
* this is only ever an issue with extremely large mailboxes.
*/
sleep(3); /* to be _really_ safe, probably need sleep(5)! */
/* we're approved */
return(PS_SUCCESS);
}
static int
pop3_gettopid( int sock, int num , char *id)
{
int ok;
int got_it;
char buf [POPBUFSIZE+1];
sprintf( buf, "TOP %d 1", num );
if( (ok = gen_transact(sock, buf ) ) != 0 )
return ok;
got_it = 0;
while((ok = gen_recv(sock, buf, sizeof(buf))) == 0) {
if( buf[0] == '.' )
break;
if( ! got_it && ! strncasecmp("Message-Id:", buf, 11 )) {
got_it = 1;
/* prevent stack overflows */
buf[IDLEN+12] = 0;
sscanf( buf+12, "%s", id);
}
}
return 0;
}
static int
pop3_slowuidl( int sock, struct query *ctl, int *countp, int *newp)
{
/* This approach tries to get the message headers from the
* remote hosts and compares the message-id to the already known
* ones:
* + if the first message containes a new id, all messages on
* the server will be new
* + if the first is known, try to estimate the last known message
* on the server and check. If this works you know the total number
* of messages to get.
* + Otherwise run a binary search to determine the last known message
*/
int ok, nolinear = 0;
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 )
return ok;
if( ( first_nr = str_nr_in_list(&ctl->oldsaved, id) ) == -1 ) {
/* the first message is unknown -> all messages are new */
*newp = *countp;
return 0;
}
/* check where we expect the latest known message */
list_len = count_list( &ctl->oldsaved );
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 )
return ok;
try_nr = str_nr_last_in_list(&ctl->oldsaved, id);
} else {
try_id = *countp+1;
try_nr = -1;
}
if( try_nr != list_len -1 ) {
/* some messages inbetween have been deleted... */
if( try_nr == -1 ) {
nolinear = 1;
for( add_id = 1<<30; add_id > try_id-1; add_id >>= 1 )
;
for( ; add_id; add_id >>= 1 ) {
if( try_nr == -1 ) {
if( try_id - add_id <= 1 ) {
continue;
}
try_id -= add_id;
} else
try_id += add_id;
if( (ok = pop3_gettopid( sock, try_id, id )) != 0 )
return ok;
try_nr = str_nr_in_list(&ctl->oldsaved, id);
}
if( try_nr == -1 ) {
try_id--;
}
} else {
error(0,0,"Messages inserted into list on server. "
"Cannot handle this.");
return -1;
}
}
}
/* The first try_id messages are known -> copy them to
the newsaved list */
for( num = first_nr; num < list_len; num++ )
save_str(&ctl->newsaved, num-first_nr + 1,
str_from_nr_list( &ctl->oldsaved, num ));
if( nolinear ) {
free_str_list(&ctl->oldsaved);
ctl->oldsaved = 0;
last = try_id;
}
*newp = *countp - try_id;
return 0;
}
static int pop3_getrange(int sock,
struct query *ctl,
const char *folder,
int *countp, int *newp)
/* get range of messages to be fetched */
{
int ok;
char buf [POPBUFSIZE+1];
phase = PHASE_GETRANGE;
/* Ensure that the new list is properly empty */
ctl->newsaved = (struct idlist *)NULL;
#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)
sscanf(buf,"%d %*d", countp);
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
* counting new messages intrinsically quadratic in the worst case.
*/
last = 0;
*newp = -1;
if (*countp > 0 && !ctl->fetchall)
{
char id [IDLEN+1];
if (!ctl->server.uidl) {
gen_send(sock, "LAST");
ok = pop3_ok(sock, buf);
} else
ok = 1;
if (ok == 0)
{
if (sscanf(buf, "%d", &last) == 0)
{
error(0, 0, "protocol error");
return(PS_ERROR);
}
*newp = (*countp - last);
}
else
{
/* grab the mailbox's UID list */
if ((ok = gen_transact(sock, "UIDL")) != 0)
{
/* don't worry, yet! do it the slow way */
if((ok = pop3_slowuidl( sock, ctl, countp, newp))!=0)
{
error(0, 0, "protocol error while fetching UIDLs");
return(PS_ERROR);
}
}
else
{
int num;
*newp = 0;
while ((ok = gen_recv(sock, buf, sizeof(buf))) == 0)
{
if (buf[0] == '.')
break;
else if (sscanf(buf, "%d %s", &num, id) == 2)
{
save_str(&ctl->newsaved, num, id);
/* note: ID comparison is caseblind */
if (!str_in_list(&ctl->oldsaved, id))
(*newp)++;
}
}
}
}
}
return(0);
}
static int pop3_getsizes(int sock, int count, int *sizes)
/* capture the sizes of all messages */
{
int ok;
/* phase = PHASE_GETSIZES */
if ((ok = gen_transact(sock, "LIST")) != 0)
return(ok);
else
{
char buf [POPBUFSIZE+1];
while ((ok = gen_recv(sock, buf, sizeof(buf))) == 0)
{
int num, size;
if (buf[0] == '.')
break;
else if (sscanf(buf, "%d %d", &num, &size) == 2)
sizes[num - 1] = size;
}
return(ok);
}
}
static int pop3_is_old(int sock, struct query *ctl, int num)
/* is the given message old? */
{
if (!ctl->oldsaved)
return (num <= last);
else
/* note: ID comparison is caseblind */
return (str_in_list(&ctl->oldsaved,
str_find (&ctl->newsaved, num)));
}
static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp)
/* request nth message */
{
int ok;
char buf [POPBUFSIZE+1];
/* phase = PHASE_FETCH */
gen_send(sock, "RETR %d", number);
if ((ok = pop3_ok(sock, buf)) != 0)
return(ok);
*lenp = -1; /* we got sizes from the LIST response */
return(0);
}
static int pop3_delete(int sock, struct query *ctl, int number)
/* delete a given message */
{
/* actually, mark for deletion -- doesn't happen until QUIT time */
return(gen_transact(sock, "DELE %d", number));
}
static int pop3_logout(int sock, struct query *ctl)
/* send logout command */
{
int ok;
/* phase = PHASE_LOGOUT */
ok = gen_transact(sock, "QUIT");
if (!ok)
expunge_uids(ctl);
return(ok);
}
const static struct method pop3 =
{
"POP3", /* Post Office Protocol v3 */
#if INET6
"pop3", /* standard POP3 port */
#else /* INET6 */
110, /* standard POP3 port */
#endif /* INET6 */
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_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_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,"Option --remote is not supported with POP3\n");
return(PS_SYNTAX);
}
#endif /* MBOX */
peek_capable = FALSE;
return(do_protocol(ctl, &pop3));
}
#endif /* POP3_ENABLE */
/* pop3.c ends here */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.