/*
 * atomicpop3pass - advanced qmail POP3 authentification
 *
 * main.c - main file
 * __________________________________________________________
 *
 * Developed by Ondrej Jombik <nepto@platon.sk>
 * Copyright (c) 2002-2003 Platon SDG, http://platon.sk/
 * All rights reserved.
 *
 * See README file for more information about this software.
 * See COPYING file for license information.
 *
 * Download the latest version from
 * http://platon.sk/projects/libplaton/
 */

/* $Platon: */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

#include "main.h"
#include "sys/main.h"
#include "user/main.h"

#ifndef SYSLOG_LEVEL
#  error SYSLOG_LEVEL not defined
#else
#  if SYSLOG_LEVEL >= 1
#    include <syslog.h>
#  endif
#endif

char *login    = NULL;
char *password = NULL;

char remotehost[BUFLEN] = "\0";
char remoteip[BUFLEN]   = "\0";
char remoteinfo[BUFLEN] = "unknown\0";

int main(int argc, char **argv, char *envp[]) /* {{{ */
{
	int r;
	int i;
	int uplen;
	char up[513];
	char **me;

	if (! argv[1])
		exit(2);

#if SYSLOG_LEVEL >= 1
	/* Opening log */
	openlog(PROGRAM_NAME, LOG_PID, SYSLOG_FACILITY);
#endif

	if (atexit(atexit_function0) == -1) {
#if SYSLOG_LEVEL >= 1
		syslog(SYSLOG_ERROR, "cannot register atexit() function");
		exit(2);
#endif
	}

#if SYSLOG_LEVEL >= 9
	syslog(SYSLOG_DEBUG, "debug: started");
#endif

	for (me = envp; *me; me++) {
		long ptr;
		ptr = (long) *(me);

		if (strncmp(*me, "TCPREMOTEIP", 11) == 0) {
			ptr += 12;
			strcpy(remoteip, (char*)(ptr));
		}

		if (strncmp(*me, "TCPREMOTEHOST", 13) == 0) {
			ptr += 14;
			strcpy(remotehost, (char*)(ptr));
		}

		if (strncmp(*me, "TCPREMOTEINFO", 13) == 0) {
			ptr += 14;
			strcpy(remoteinfo, (char*)(ptr));
		}
	}

#if SYSLOG_LEVEL >= 9
	syslog(SYSLOG_DEBUG, "debug: POP3 connect from %s@%s [%s]",
			remoteinfo, remotehost, remoteip);
#endif

	if (argc < 2) {
#if SYSLOG_LEVEL >= 1
		syslog(SYSLOG_ERROR, "exit 2 at point 9 (bad argc)");
#endif
		exit(2);
	}

	uplen = 0;
	for (;;) {
		do {
			r = read(3, up + uplen,sizeof(up) - uplen);
		} while ((r == -1) && (errno == EINTR));
		if (r == -1)
			exit(111);
		if (r == 0)
			break;
		uplen += r;
		if (uplen >= sizeof(up))
			exit(1);
	}

	close(3);

	i = 0;
	login = up + i;
	while (up[i++])
		if (i == uplen) {
#if SYSLOG_LEVEL >= 1
			syslog(SYSLOG_ERROR, "exit 2 at point 10");
#endif
			exit(2);
		}

#if SYSLOG_LEVEL >= 5
	syslog(SYSLOG_INFO, "POP3 user %s connected from %s@%s [%s]",
			login, remoteinfo, remotehost, remoteip);
#endif

	password = up + i;
	if (i == uplen) {
#if SYSLOG_LEVEL >= 1
		syslog(SYSLOG_ERROR, "exit 2 at point 11");
#endif
		exit(2);
	}
	while (up[i++])
		if (i == uplen) {
#if SYSLOG_LEVEL >= 1
			syslog(SYSLOG_ERROR, "exit 2 at point 12");
#endif
			exit(2);
		}

	if (! login || ! password) {
#if SYSLOG_LEVEL >= 1
		syslog(SYSLOG_ERROR, "sorry, NULL login or password, cannot proceed");
#endif
		exit(2);
	}
	else {
#if SYSLOG_LEVEL >= 9
		syslog(SYSLOG_DEBUG, "debug: login = %s, pass = %s", login, password);
#endif
	}

	login    = strdup(login);
	password = strdup(password);

	/* Clear input username/passwd stack. */
	for (i = 0; i < sizeof(up); ++i)
		up[i] = 0;

	if (main_sys(argc, argv) < 0) {
		/* System login failed.
		   We are going to try user defined login. */

#if SYSLOG_LEVEL >= 5
		syslog(SYSLOG_INFO, "system login failed, trying user login");
#endif

		if (main_user(argc, argv, envp) < 0) {
#if SYSLOG_LEVEL >= 5
			syslog(SYSLOG_INFO, "user login failed, aborting");
#endif

			/* sleep() to
			   1. allow syslog to work and
			   2. hinder pop3 brute force hacks
			   */
			sleep(SLEEP);
		}
		else {
#if SYSLOG_LEVEL >= 1
			syslog(SYSLOG_ERROR, "execvp() failure in user login");
#endif
		}
	}
	else {
#if SYSLOG_LEVEL >= 1
		syslog(SYSLOG_ERROR, "pathexec()/execve() failure in system login");
#endif
	}

	nuke_dynamic_string(&login);
	nuke_dynamic_string(&password);

	exit(111);

	/* We should never reach this. */
	return 0;
} /* }}} */

void atexit_function0(void) /* {{{ */
{
#if SYSLOG_LEVEL >= 1
	closelog();
#endif
} /* }}} */

void nuke_dynamic_string(char **str) /* {{{ */
{
	if (str != NULL || *str != NULL) {
		register char *s;

		for (s = *str; *s != '\0'; s++)
			*s = '\0';

		free(*str);
		*str = NULL;
	}
} /* }}} */

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