/* Authentication (Client side) */
int auth_client(int fd, struct vtun_host *host, int * reason)
{
char buf[VTUN_MESG_SIZE], chal[VTUN_CHAL_SIZE];
int stage, success=0 ;
stage = ST_INIT;
*reason = D_NOREAD;
while( readn_t(fd, buf, VTUN_MESG_SIZE, vtun.timeout) > 0 ){
*reason = D_OTHER;
buf[sizeof(buf)-1]='\0';
switch( stage ){
case ST_INIT:
if (!strncmp(buf, "VTRUNKD", 7)) {
stage = ST_HOST;
print_p(fd,"HOST: %s\n",host->host);
continue;
}
*reason = D_GREET;
break;
case ST_HOST:
if( !strncmp(buf,"OK",2) && cs2cl(buf,chal)){
stage = ST_CHAL;
encrypt_chal(chal,host->passwd);
print_p(fd,"CHAL: %s\n", cl2cs(chal));
continue;
}
*reason = D_CHAL;
break;
case ST_CHAL:
if( !strncmp(buf,"OK",2) && cf2bf(buf,host) )
success = 1;
else *reason = D_PWD;
break;
}
break;
}
return success;
}
/* Authentication (Server side) */
struct vtun_host * auth_server(int fd)
{
char chal_req[VTUN_CHAL_SIZE], chal_res[VTUN_CHAL_SIZE];
char buf[VTUN_MESG_SIZE], *str1, *str2;
struct vtun_host *h = NULL;
char *host = NULL;
int stage;
set_title("authentication");
print_p(fd,"VTUN server ver %s\n",VTUN_VER);
stage = ST_HOST;
while( readn_t(fd, buf, VTUN_MESG_SIZE, vtun.timeout) > 0 ){
buf[sizeof(buf)-1]='\0';
strtok(buf,"\r\n");
if( !(str1=strtok(buf," :")) )
break;
if( !(str2=strtok(NULL," :")) )
break;
switch( stage ){
case ST_HOST:
if( !strcmp(str1,"HOST") ){
host = strdup(str2);
gen_chal(chal_req);
print_p(fd,"OK CHAL: %s\n", cl2cs(chal_req));
stage = ST_CHAL;
continue;
}
break;
case ST_CHAL:
if( !strcmp(str1,"CHAL") ){
if( !cs2cl(str2,chal_res) )
break;
if( !(h = find_host(host)) )
break;
decrypt_chal(chal_res, h->passwd);
if( !memcmp(chal_req, chal_res, VTUN_CHAL_SIZE) ){
/* Auth successeful. */
/* Lock host */
if( lock_host(h) < 0 ){
/* Multiple connections are denied */
h = NULL;
break;
}
print_p(fd,"OK FLAGS: %s\n", bf2cf(h));
} else
h = NULL;
}
break;
}
break;
}
if( host )
free(host);
if( !h )
print_p(fd,"ERR\n");
return h;
}
