pap.c

lwip-1.4.0

/*****************************************************************************
* pap.c - Network Password Authentication Protocol program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *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 CONTRIBUTORS 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.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <[e-mail]>
*   Ported to lwIP.
* 97-12-12 Guy Lancaster <[e-mail]>, Global Election Systems Inc.
*   Original.
*****************************************************************************/
/*
 * upap.c - User/Password Authentication Protocol.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "lwip/opt.h"

#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */

#if PAP_SUPPORT /* don't build if not configured for use in lwipopts.h */

#include "ppp.h"
#include "pppdebug.h"

#include "auth.h"
#include "pap.h"

#include <string.h>

#if 0 /* UNUSED */
static bool hide_password = 1;

/*
 * Command-line options.
 */
static option_t pap_option_list[] = {
    { "hide-password", o_bool, &hide_password,
      "Don't output passwords to log", 1 },
    { "show-password", o_bool, &hide_password,
      "Show password string in debug log messages", 0 },
    { "pap-restart", o_int, &upap[0].us_timeouttime,
      "Set retransmit timeout for PAP" },
    { "pap-max-authreq", o_int, &upap[0].us_maxtransmits,
      "Set max number of transmissions for auth-reqs" },
    { "pap-timeout", o_int, &upap[0].us_reqtimeout,
      "Set time limit for peer PAP authentication" },
    { NULL }
};
#endif

/*
 * Protocol entry points.
 */
static void upap_init      (int);
static void upap_lowerup   (int);
static void upap_lowerdown (int);
static void upap_input     (int, u_char *, int);
static void upap_protrej   (int);
#if PPP_ADDITIONAL_CALLBACKS
static int  upap_printpkt (u_char *, int, void (*)(void *, char *, ...), void *);
#endif /* PPP_ADDITIONAL_CALLBACKS */

struct protent pap_protent = {
  PPP_PAP,
  upap_init,
  upap_input,
  upap_protrej,
  upap_lowerup,
  upap_lowerdown,
  NULL,
  NULL,
#if PPP_ADDITIONAL_CALLBACKS
  upap_printpkt,
  NULL,
#endif /* PPP_ADDITIONAL_CALLBACKS */
  1,
  "PAP",
#if PPP_ADDITIONAL_CALLBACKS
  NULL,
  NULL,
  NULL
#endif /* PPP_ADDITIONAL_CALLBACKS */
};

upap_state upap[NUM_PPP]; /* UPAP state; one for each unit */

static void upap_timeout   (void *);
static void upap_reqtimeout(void *);
static void upap_rauthreq  (upap_state *, u_char *, u_char, int);
static void upap_rauthack  (upap_state *, u_char *, int, int);
static void upap_rauthnak  (upap_state *, u_char *, int, int);
static void upap_sauthreq  (upap_state *);
static void upap_sresp     (upap_state *, u_char, u_char, char *, int);


/*
 * upap_init - Initialize a UPAP unit.
 */
static void
upap_init(int unit)
{
  upap_state *u = &upap[unit];

  UPAPDEBUG(LOG_INFO, ("upap_init: %d\n", unit));
  u->us_unit         = unit;
  u->us_user         = NULL;
  u->us_userlen      = 0;
  u->us_passwd       = NULL;
  u->us_passwdlen    = 0;
  u->us_clientstate  = UPAPCS_INITIAL;
  u->us_serverstate  = UPAPSS_INITIAL;
  u->us_id           = 0;
  u->us_timeouttime  = UPAP_DEFTIMEOUT;
  u->us_maxtransmits = 10;
  u->us_reqtimeout   = UPAP_DEFREQTIME;
}

/*
 * upap_authwithpeer - Authenticate us with our peer (start client).
 *
 * Set new state and send authenticate's.
 */
void
upap_authwithpeer(int unit, char *user, char *password)
{
  upap_state *u = &upap[unit];

  UPAPDEBUG(LOG_INFO, ("upap_authwithpeer: %d user=%s password=%s s=%d\n",
             unit, user, password, u->us_clientstate));

  /* Save the username and password we're given */
  u->us_user = user;
  u->us_userlen = (int)strlen(user);
  u->us_passwd = password;
  u->us_passwdlen = (int)strlen(password);

  u->us_transmits = 0;

  /* Lower layer up yet? */
  if (u->us_clientstate == UPAPCS_INITIAL ||
      u->us_clientstate == UPAPCS_PENDING) {
    u->us_clientstate = UPAPCS_PENDING;
    return;
  }

  upap_sauthreq(u);      /* Start protocol */
}


/*
 * upap_authpeer - Authenticate our peer (start server).
 *
 * Set new state.
 */
void
upap_authpeer(int unit)
{
  upap_state *u = &upap[unit];

  /* Lower layer up yet? */
  if (u->us_serverstate == UPAPSS_INITIAL ||
      u->us_serverstate == UPAPSS_PENDING) {
    u->us_serverstate = UPAPSS_PENDING;
    return;
  }

  u->us_serverstate = UPAPSS_LISTEN;
  if (u->us_reqtimeout > 0) {
    TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);
  }
}

/*
 * upap_timeout - Retransmission timer for sending auth-reqs expired.
 */
static void
upap_timeout(void *arg)
{
  upap_state *u = (upap_state *) arg;

  UPAPDEBUG(LOG_INFO, ("upap_timeout: %d timeout %d expired s=%d\n", 
        u->us_unit, u->us_timeouttime, u->us_clientstate));

  if (u->us_clientstate != UPAPCS_AUTHREQ) {
	UPAPDEBUG(LOG_INFO, ("upap_timeout: not in AUTHREQ state!\n"));
    return;
  }

  if (u->us_transmits >= u->us_maxtransmits) {
    /* give up in disgust */
    UPAPDEBUG(LOG_ERR, ("No response to PAP authenticate-requests\n"));
    u->us_clientstate = UPAPCS_BADAUTH;
    auth_withpeer_fail(u->us_unit, PPP_PAP);
    return;
  }

  upap_sauthreq(u);    /* Send Authenticate-Request and set upap timeout*/
}


/*
 * upap_reqtimeout - Give up waiting for the peer to send an auth-req.
 */
static void
upap_reqtimeout(void *arg)
{
  upap_state *u = (upap_state *) arg;

  if (u->us_serverstate != UPAPSS_LISTEN) {
    return; /* huh?? */
  }

  auth_peer_fail(u->us_unit, PPP_PAP);
  u->us_serverstate = UPAPSS_BADAUTH;
}


/*
 * upap_lowerup - The lower layer is up.
 *
 * Start authenticating if pending.
 */
static void
upap_lowerup(int unit)
{
  upap_state *u = &upap[unit];

  UPAPDEBUG(LOG_INFO, ("upap_lowerup: init %d clientstate s=%d\n", unit, u->us_clientstate));

  if (u->us_clientstate == UPAPCS_INITIAL) {
    u->us_clientstate = UPAPCS_CLOSED;
  } else if (u->us_clientstate == UPAPCS_PENDING) {
    upap_sauthreq(u);  /* send an auth-request */
    /* now client state is UPAPCS__AUTHREQ */
  }

  if (u->us_serverstate == UPAPSS_INITIAL) {
    u->us_serverstate = UPAPSS_CLOSED;
  } else if (u->us_serverstate == UPAPSS_PENDING) {
    u->us_serverstate = UPAPSS_LISTEN;
    if (u->us_reqtimeout > 0) {
      TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);
    }
  }
}


/*
 * upap_lowerdown - The lower layer is down.
 *
 * Cancel all timeouts.
 */
static void
upap_lowerdown(int unit)
{
  upap_state *u = &upap[unit];

  UPAPDEBUG(LOG_INFO, ("upap_lowerdown: %d s=%d\n", unit, u->us_clientstate));

  if (u->us_clientstate == UPAPCS_AUTHREQ) { /* Timeout pending? */
    UNTIMEOUT(upap_timeout, u);    /* Cancel timeout */
  }
  if (u->us_serverstate == UPAPSS_LISTEN && u->us_reqtimeout > 0) {
    UNTIMEOUT(upap_reqtimeout, u);
  }

  u->us_clientstate = UPAPCS_INITIAL;
  u->us_serverstate = UPAPSS_INITIAL;
}


/*
 * upap_protrej - Peer doesn't speak this protocol.
 *
 * This shouldn't happen.  In any case, pretend lower layer went down.
 */
static void
upap_protrej(int unit)
{