/***********************************************************************

RADIUS
Remote Authentication Dial In User Service

Lucent Technologies Remote Access
4464 Willow Road
Pleasanton, CA   94588

Copyright 1992-1999 Lucent Technologies Inc.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

   * Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

   * 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.

   * All advertising materials mentioning features or use of this
     software must display the following acknowledgement:

	  This product includes software developed by Lucent
	  Technologies and its contributors.

   * Neither the name of the copyright holder nor the names of its
     contributors may be used to endorse or promote products derived
     from this software without specific prior written permission.

This software is provided by the copyright holders and 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 copyright
holder or 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.

************************************************************************/

static char sccsid[] =
"$Id: radpass.c,v 1.9 1999/06/23 23:40:43 cdr Exp $ Copyright 1992-1999 Lucent Technologies Inc";

#include	<sys/types.h>
#include	<sys/socket.h>
#include	<netinet/in.h>

#include	<stdio.h>
#include	<unistd.h>
#include	<netdb.h>
#include	<pwd.h>

#include	"radius.h"

#define MAXPWNAM	8
#define MAXPASS		16

u_char		recv_buffer[4096];
u_char		send_buffer[4096];
u_char		*progname;
int		sockfd;
u_char		vector[AUTH_VECTOR_LEN];
u_char		oldpass[AUTH_PASS_LEN];

main(argc, argv)
int	argc;
u_char	*argv[];
{
	int			salen;
	int			result;
	struct	sockaddr	salocal;
	struct	sockaddr	saremote;
	struct	sockaddr_in	*sin;
	struct	servent		*svp;
        u_short                 svc_port;
	AUTH_HDR		*auth;
	u_char			*username;
	u_char			newpass1[AUTH_PASS_LEN];
	u_char			newpass2[AUTH_PASS_LEN];
	u_char			passbuf[AUTH_PASS_LEN];
	u_char			md5buf[256];
	u_char			*oldvector;
	UINT4			get_ipaddr();
	UINT4			auth_ipaddr;
	u_short			local_port;
	int			total_length;
	u_char			*ptr;
	int			length;
	int			secretlen;
	int			i;
	char			*getpass();

	progname = argv[0];

	if(argc != 2) {
		usage();
	}
	/* Get the user name */
	username = argv[1];

	svp = getservbyname ("radius", "udp");
	if (svp == (struct servent *) 0) {
		fprintf (stderr, "No such service: %s/%s\n", "radius", "udp");
		exit(-1);
	}
	svc_port = ntohs((u_short) svp->s_port);

	/* Get the IP address of the authentication server */
	if((auth_ipaddr = get_ipaddr("radius-server")) == (UINT4)0) {
		fprintf(stderr, "Couldn't find host radius-server\n");
		exit(-1);
	}

	sockfd = socket (AF_INET, SOCK_DGRAM, 0);
	if (sockfd < 0) {
		(void) perror ("socket");
		exit(-1);
	}

	sin = (struct sockaddr_in *) & salocal;
        memset ((char *) sin, '\0', sizeof (salocal));
	sin->sin_family = AF_INET;
	sin->sin_addr.s_addr = INADDR_ANY;

	local_port = 1025;
	do {
		local_port++;
		sin->sin_port = htons((u_short)local_port);
	} while((bind(sockfd, &salocal, sizeof (struct sockaddr_in)) < 0) &&
						local_port < 64000);
	if(local_port >= 64000) {
		close(sockfd);
		(void) perror ("bind");
		exit(-1);
	}

	printf("Changing Password for user %s\n", username);

	/* Get their old password */
	strcpy((char *)oldpass, getpass("Old Password:"));
	if(*oldpass == '\0') {
		exit(0);
	}

	/* Get their new password */
	strcpy((char *)newpass1, getpass("New Password:"));
	if(*newpass1 == '\0') {
		exit(0);
	}

	/* Get their new password again */
	strcpy((char *)newpass2, getpass("Re-type New Password:"));
	if(strcmp(newpass1, newpass2) != 0) {
		printf("New Passwords didn't match\n");
		exit(-1);
	}

	/* Build a password change request */
	auth = (AUTH_HDR *)send_buffer;
	auth->code = PW_PASSWORD_REQUEST;
	auth->id = 0;
	random_vector(vector);
	memcpy(auth->vector, vector, AUTH_VECTOR_LEN);
	total_length = AUTH_HDR_LEN;
	ptr = auth->data;

	/* User Name */
	*ptr++ = PW_USER_NAME;
	length = strlen(username);
	if(length > MAXPWNAM) {
		length = MAXPWNAM;
	}
	*ptr++ = length + 2;
	memcpy(ptr, username, length);
	ptr += length;
	total_length += length + 2;

	/* New Password */
	*ptr++ = PW_PASSWORD;
	*ptr++ = AUTH_PASS_LEN + 2;

	/* Encrypt the Password */
	length = strlen(newpass1);
	if(length > MAXPASS) {
		length = MAXPASS;
	}
	memset(passbuf, 0, AUTH_PASS_LEN);
	memcpy(passbuf, newpass1, length);
	/* Calculate the MD5 Digest */
	secretlen = strlen(oldpass);
	strcpy(md5buf, oldpass);
	memcpy(md5buf + secretlen, auth->vector, AUTH_VECTOR_LEN);
	md5_calc(ptr, md5buf, secretlen + AUTH_VECTOR_LEN);
	oldvector = ptr;
	/* Xor the password into the MD5 digest */
	for(i = 0;i < AUTH_PASS_LEN;i++) {
		*ptr++ ^= passbuf[i];
	}
	total_length += AUTH_PASS_LEN + 2;

	/* Old Password */
	*ptr++ = PW_OLD_PASSWORD;
	*ptr++ = AUTH_PASS_LEN + 2;

	/* Encrypt the Password */
	length = strlen(oldpass);
	if(length > MAXPASS) {
		length = MAXPASS;
	}
	memset(passbuf, 0, AUTH_PASS_LEN);
	memcpy(passbuf, oldpass, length);
	/* Calculate the MD5 Digest */
	secretlen = strlen(oldpass);
	strcpy(md5buf, oldpass);
	memcpy(md5buf + secretlen, oldvector, AUTH_VECTOR_LEN);
	md5_calc(ptr, md5buf, secretlen + AUTH_VECTOR_LEN);

	/* Xor the password into the MD5 digest */
	for(i = 0;i < AUTH_PASS_LEN;i++) {
		*ptr++ ^= passbuf[i];
	}
	total_length += AUTH_PASS_LEN + 2;

	auth->length = htonl(total_length);

	sin = (struct sockaddr_in *) & saremote;
        memset ((char *) sin, '\0', sizeof (saremote));
	sin->sin_family = AF_INET;
	sin->sin_addr.s_addr = htonl(auth_ipaddr);
	sin->sin_port = htons(svc_port);

	sendto(sockfd, (char *)auth, (int)total_length, (int)0,
			&saremote, sizeof(struct sockaddr_in));

	salen = sizeof (saremote);
	result = recvfrom (sockfd, (char *) recv_buffer,
			(int) sizeof(recv_buffer),
			(int) 0, & saremote, & salen);

	if(result > 0) {
		result_recv(sin->sin_addr.s_addr,
					sin->sin_port, recv_buffer, result);
		exit(0);
	}
	(void) perror ("recv");
	close(sockfd);
	exit(0);
}

result_recv(host, udp_port, buffer, length)
UINT4	host;
u_short	udp_port;
u_char	*buffer;
int	length;
{
	AUTH_HDR	*auth;
	int		totallen;
	char		*ip_hostname();
	u_char		reply_digest[AUTH_VECTOR_LEN];
	u_char		calc_digest[AUTH_VECTOR_LEN];
	int		secretlen;

	auth = (AUTH_HDR *)buffer;
	totallen = ntohs(auth->length);

	if(totallen != AUTH_HDR_LEN) {
		printf("Received invalid reply length from server\n");
		exit(-1);
	}

	/* Verify the reply digest */
	memcpy(reply_digest, auth->vector, AUTH_VECTOR_LEN);
	memcpy(auth->vector, vector, AUTH_VECTOR_LEN);
	secretlen = strlen(oldpass);
	memcpy(buffer + AUTH_HDR_LEN, oldpass, secretlen);
	md5_calc(calc_digest, (char *)auth, AUTH_HDR_LEN);

	if(memcmp(reply_digest, calc_digest, AUTH_VECTOR_LEN) != 0) {
		printf("Warning: Received invalid reply digest from server\n");
	}

	if(auth->code == PW_PASSWORD_ACK) {
		printf("Password successfully changed\n");
	}
	else {
		printf("Request Denied\n");
	}
}

usage()
{
	printf("Usage: %s username\n", progname);
	exit(-1);
}

random_vector(vector)
u_char	*vector;
{
	int	randno;
	int	i;

	srand(time(0));
	for(i = 0;i < AUTH_VECTOR_LEN;) {
		randno = rand();
		memcpy(vector, &randno, sizeof(int));
		vector += sizeof(int);
		i += sizeof(int);
	}
}