sudo/auth/fwtk.c

/*
 * Copyright (c) 1999-2003 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 4. Products derived from this software may not be called "Sudo" nor
 *    may "Sudo" appear in their names without specific prior written
 *    permission from the author.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
#  include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
#  include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_ERR_H
# include <err.h>
#else
# include "emul/err.h"
#endif /* HAVE_ERR_H */
#include <pwd.h>

#include <auth.h>
#include <firewall.h>

#include "sudo.h"
#include "sudo_auth.h"

#ifndef lint
static const char rcsid[] = "$Sudo$";
#endif /* lint */

int
fwtk_init(pw, promptp, auth)
    struct passwd *pw;
    char **promptp;
    sudo_auth *auth;
{
    static Cfg *confp;			/* Configuration entry struct */
    char resp[128];			/* Response from the server */

    if ((confp = cfg_read("sudo")) == (Cfg *)-1) {
	warnx("cannot read fwtk config");
	return(AUTH_FATAL);
    }

    if (auth_open(confp)) {
	warnx("cannot connect to authentication server");
	return(AUTH_FATAL);
    }

    /* Get welcome message from auth server */
    if (auth_recv(resp, sizeof(resp))) {
	warnx("lost connection to authentication server");
	return(AUTH_FATAL);
    }
    if (strncmp(resp, "Authsrv ready", 13) != 0) {
	warnx("authentication server error:\n%s", resp);
	return(AUTH_FATAL);
    }

    return(AUTH_SUCCESS);
}

int
fwtk_verify(pw, prompt, auth)
    struct passwd *pw;
    char *prompt;
    sudo_auth *auth;
{
    volatile char *pass;		/* Password from the user */
    volatile char buf[SUDO_PASS_MAX + 12]; /* General prupose buffer */
    char resp[128];			/* Response from the server */
    int error;
    extern int nil_pw;

    /* Send username to authentication server. */
    (void) snprintf(buf, sizeof(buf), "authorize %s 'sudo'", pw->pw_name);
    if (auth_send(buf) || auth_recv(resp, sizeof(resp))) {
	warnx("lost connection to authentication server");
	return(AUTH_FATAL);
    }

    /* Get the password/response from the user. */
    if (strncmp(resp, "challenge ", 10) == 0) {
	(void) snprintf(buf, sizeof(buf), "%s\nResponse: ", &resp[10]);
	pass = tgetpass(buf, def_passwd_timeout * 60, tgetpass_flags);
	if (pass && *pass == '\0') {
	    pass = tgetpass("Response [echo on]: ",
		def_passwd_timeout * 60, tgetpass_flags | TGP_ECHO);
	}
    } else if (strncmp(resp, "password", 8) == 0) {
	pass = tgetpass(prompt, def_passwd_timeout * 60,
	    tgetpass_flags);
    } else {
	warnx("%s", resp);
	return(AUTH_FATAL);
    }
    if (!pass) {			/* ^C or error */
	nil_pw = 1;
	return(AUTH_FAILURE);
    } else if (*pass == '\0')		/* empty password */
	nil_pw = 1;

    /* Send the user's response to the server */
    (void) snprintf(buf, sizeof(buf), "response '%s'", pass);
    if (auth_send(buf) || auth_recv(resp, sizeof(resp))) {
	warnx("lost connection to authentication server");
	error = AUTH_FATAL;
	goto done;
    }

    if (strncmp(resp, "ok", 2) == 0) {
	error = AUTH_SUCCESS;
	goto done;
    }

    /* Main loop prints "Permission Denied" or insult. */
    if (strcmp(resp, "Permission Denied.") != 0)
	warnx("%s", resp);
    error = AUTH_FAILURE;
done:
    memset(pass, 0, strlen(pass));
    memset(buf, 0, strlen(buf));
    return(error);
}

int
fwtk_cleanup(pw, auth)
    struct passwd *pw;
    sudo_auth *auth;
{

    auth_close();
    return(AUTH_SUCCESS);
}