freebsd-dev/crypto/telnet/libtelnet/sra.c

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#ifdef SRA
#include <sys/types.h>
#include <arpa/telnet.h>
#include <stdio.h>
#ifdef __STDC__
#include <stdlib.h>
#endif
#ifdef NO_STRING_H
#include <strings.h>
#else
#include <string.h>
#endif
#include "auth.h"
#include "misc.h"
#include "encrypt.h"
#include "pk.h"
char pka[HEXKEYBYTES+1], ska[HEXKEYBYTES+1], pkb[HEXKEYBYTES+1];
char *user,*pass,*xuser,*xpass;
DesData ck;
IdeaData ik;
extern int auth_debug_mode;
static sra_valid = 0;
static passwd_sent = 0;
static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
AUTHTYPE_SRA, };
#define SRA_KEY 0
#define SRA_USER 1
#define SRA_CONTINUE 2
#define SRA_PASS 3
#define SRA_ACCEPT 4
#define SRA_REJECT 5
/* support routine to send out authentication message */
static int Data(ap, type, d, c)
Authenticator *ap;
int type;
void *d;
int c;
{
unsigned char *p = str_data + 4;
unsigned char *cd = (unsigned char *)d;
if (c == -1)
c = strlen((char *)cd);
if (auth_debug_mode) {
printf("%s:%d: [%d] (%d)",
str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
str_data[3],
type, c);
printd(d, c);
printf("\r\n");
}
*p++ = ap->type;
*p++ = ap->way;
*p++ = type;
while (c-- > 0) {
if ((*p++ = *cd++) == IAC)
*p++ = IAC;
}
*p++ = IAC;
*p++ = SE;
if (str_data[3] == TELQUAL_IS)
printsub('>', &str_data[2], p - (&str_data[2]));
return(net_write(str_data, p - str_data));
}
int sra_init(ap, server)
Authenticator *ap;
int server;
{
if (server)
str_data[3] = TELQUAL_REPLY;
else
str_data[3] = TELQUAL_IS;
user = (char *)malloc(256);
xuser = (char *)malloc(512);
pass = (char *)malloc(256);
xpass = (char *)malloc(512);
passwd_sent = 0;
genkeys(pka,ska);
return(1);
}
/* client received a go-ahead for sra */
int sra_send(ap)
Authenticator *ap;
{
/* send PKA */
if (auth_debug_mode)
printf("Sent PKA to server.\r\n" );
printf("Trying SRA secure login:\r\n");
if (!Data(ap, SRA_KEY, (void *)pka, HEXKEYBYTES)) {
if (auth_debug_mode)
printf("Not enough room for authentication data\r\n");
return(0);
}
return(1);
}
/* server received an IS -- could be SRA KEY, USER, or PASS */
void sra_is(ap, data, cnt)
Authenticator *ap;
unsigned char *data;
int cnt;
{
int valid;
Session_Key skey;
if (cnt-- < 1)
return;
switch (*data++) {
case SRA_KEY:
if (cnt < HEXKEYBYTES) {
Data(ap, SRA_REJECT, (void *)0, 0);
auth_finished(ap, AUTH_USER);
if (auth_debug_mode) {
printf("SRA user rejected for bad PKB\r\n");
}
return;
}
if (auth_debug_mode)
printf("Sent pka\r\n");
if (!Data(ap, SRA_KEY, (void *)pka, HEXKEYBYTES)) {
if (auth_debug_mode)
printf("Not enough room\r\n");
return;
}
memcpy(pkb,data,HEXKEYBYTES);
pkb[HEXKEYBYTES] = '\0';
common_key(ska,pkb,&ik,&ck);
break;
case SRA_USER:
/* decode KAB(u) */
memcpy(xuser,data,cnt);
xuser[cnt] = '\0';
pk_decode(xuser,user,&ck);
auth_encrypt_user(user);
Data(ap, SRA_CONTINUE, (void *)0, 0);
break;
case SRA_PASS:
/* decode KAB(P) */
memcpy(xpass,data,cnt);
xpass[cnt] = '\0';
pk_decode(xpass,pass,&ck);
/* check user's password */
valid = check_user(user,pass);
if(valid) {
Data(ap, SRA_ACCEPT, (void *)0, 0);
#ifdef DES_ENCRYPTION
skey.data = ck;
skey.type = SK_DES;
skey.length = 8;
encrypt_session_key(&skey, 1);
#endif
sra_valid = 1;
auth_finished(ap, AUTH_VALID);
if (auth_debug_mode) {
printf("SRA user accepted\r\n");
}
}
else {
Data(ap, SRA_CONTINUE, (void *)0, 0);
/*
Data(ap, SRA_REJECT, (void *)0, 0);
sra_valid = 0;
auth_finished(ap, AUTH_REJECT);
*/
if (auth_debug_mode) {
printf("SRA user failed\r\n");
}
}
break;
default:
if (auth_debug_mode)
printf("Unknown SRA option %d\r\n", data[-1]);
Data(ap, SRA_REJECT, 0, 0);
sra_valid = 0;
auth_finished(ap, AUTH_REJECT);
break;
}
}
extern char *getpass();
/* client received REPLY -- could be SRA KEY, CONTINUE, ACCEPT, or REJECT */
void sra_reply(ap, data, cnt)
Authenticator *ap;
unsigned char *data;
int cnt;
{
extern char *telnet_gets();
char uprompt[256],tuser[256];
Session_Key skey;
int i;
if (cnt-- < 1)
return;
switch (*data++) {
case SRA_KEY:
/* calculate common key */
if (cnt < HEXKEYBYTES) {
if (auth_debug_mode) {
printf("SRA user rejected for bad PKB\r\n");
}
return;
}
memcpy(pkb,data,HEXKEYBYTES);
pkb[HEXKEYBYTES] = '\0';
common_key(ska,pkb,&ik,&ck);
enc_user:
/* encode user */
memset(tuser,0,sizeof(tuser));
sprintf(uprompt,"User (%s): ",UserNameRequested);
telnet_gets(uprompt,tuser,255,1);
if (tuser[0] == '\n' || tuser[0] == '\r' )
strcpy(user,UserNameRequested);
else {
/* telnet_gets leaves the newline on */
for(i=0;i<sizeof(tuser);i++) {
if (tuser[i] == '\n') {
tuser[i] = '\0';
break;
}
}
strcpy(user,tuser);
}
pk_encode(user,xuser,&ck);
/* send it off */
if (auth_debug_mode)
printf("Sent KAB(U)\r\n");
if (!Data(ap, SRA_USER, (void *)xuser, strlen(xuser))) {
if (auth_debug_mode)
printf("Not enough room\r\n");
return;
}
break;
case SRA_CONTINUE:
if (passwd_sent) {
passwd_sent = 0;
printf("[ SRA login failed ]\r\n");
goto enc_user;
}
/* encode password */
memset(pass,0,sizeof(pass));
telnet_gets("Password: ",pass,255,0);
pk_encode(pass,xpass,&ck);
/* send it off */
if (auth_debug_mode)
printf("Sent KAB(P)\r\n");
if (!Data(ap, SRA_PASS, (void *)xpass, strlen(xpass))) {
if (auth_debug_mode)
printf("Not enough room\r\n");
return;
}
passwd_sent = 1;
break;
case SRA_REJECT:
printf("[ SRA refuses authentication ]\r\n");
printf("Trying plaintext login:\r\n");
auth_finished(0,AUTH_REJECT);
return;
case SRA_ACCEPT:
printf("[ SRA accepts you ]\r\n");
#ifdef DES_ENCRYPTION
skey.data = ck;
skey.type = SK_DES;
skey.length = 8;
encrypt_session_key(&skey, 0);
#endif
auth_finished(ap, AUTH_VALID);
return;
default:
if (auth_debug_mode)
printf("Unknown SRA option %d\r\n", data[-1]);
return;
}
}
int sra_status(ap, name, level)
Authenticator *ap;
char *name;
int level;
{
if (level < AUTH_USER)
return(level);
if (UserNameRequested && sra_valid) {
strcpy(name, UserNameRequested);
return(AUTH_VALID);
} else
return(AUTH_USER);
}
#define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
#define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
void sra_printsub(data, cnt, buf, buflen)
unsigned char *data, *buf;
int cnt, buflen;
{
char lbuf[32];
register int i;
buf[buflen-1] = '\0'; /* make sure its NULL terminated */
buflen -= 1;
switch(data[3]) {
case SRA_CONTINUE:
strncpy((char *)buf, " CONTINUE ", buflen);
goto common;
case SRA_REJECT: /* Rejected (reason might follow) */
strncpy((char *)buf, " REJECT ", buflen);
goto common;
case SRA_ACCEPT: /* Accepted (name might follow) */
strncpy((char *)buf, " ACCEPT ", buflen);
common:
BUMP(buf, buflen);
if (cnt <= 4)
break;
ADDC(buf, buflen, '"');
for (i = 4; i < cnt; i++)
ADDC(buf, buflen, data[i]);
ADDC(buf, buflen, '"');
ADDC(buf, buflen, '\0');
break;
case SRA_KEY: /* Authentication data follows */
strncpy((char *)buf, " KEY ", buflen);
goto common2;
case SRA_USER:
strncpy((char *)buf, " USER ", buflen);
goto common2;
case SRA_PASS:
strncpy((char *)buf, " PASS ", buflen);
goto common2;
default:
sprintf(lbuf, " %d (unknown)", data[3]);
strncpy((char *)buf, lbuf, buflen);
common2:
BUMP(buf, buflen);
for (i = 4; i < cnt; i++) {
sprintf(lbuf, " %d", data[i]);
strncpy((char *)buf, lbuf, buflen);
BUMP(buf, buflen);
}
break;
}
}
struct passwd *pw;
/*
* Helper function for sgetpwnam().
*/
char *
sgetsave(s)
char *s;
{
char *new = malloc((unsigned) strlen(s) + 1);
if (new == NULL) {
return(NULL);
}
(void) strcpy(new, s);
return (new);
}
#include <pwd.h>
#include <syslog.h>
#ifdef USE_SHADOW
#include <shadow.h>
#endif
struct passwd *
sgetpwnam(name)
char *name;
{
static struct passwd save;
register struct passwd *p;
char *sgetsave();
if ((p = getpwnam(name)) == NULL)
return (p);
if (save.pw_name) {
free(save.pw_name);
free(save.pw_passwd);
free(save.pw_gecos);
free(save.pw_dir);
free(save.pw_shell);
}
save = *p;
save.pw_name = sgetsave(p->pw_name);
save.pw_passwd = sgetsave(p->pw_passwd);
save.pw_gecos = sgetsave(p->pw_gecos);
save.pw_dir = sgetsave(p->pw_dir);
save.pw_shell = sgetsave(p->pw_shell);
#if 0
syslog(LOG_WARNING,"%s\n",save.pw_name);
syslog(LOG_WARNING,"%s\n",save.pw_passwd);
syslog(LOG_WARNING,"%s\n",save.pw_gecos);
syslog(LOG_WARNING,"%s\n",save.pw_dir);
#endif
#ifdef USE_SHADOW
{
struct spwd *sp;
sp = getspnam(name);
free(save.pw_passwd);
save.pw_passwd = sgetsave(sp->sp_pwdp);
}
#endif
return (&save);
}
char *crypt();
int check_user(name, pass)
char *name;
char *pass;
{
register char *cp;
char *xpasswd, *salt;
if (pw = sgetpwnam(name)) {
if (pw->pw_shell == NULL) {
pw = (struct passwd *) NULL;
return(0);
}
salt = pw->pw_passwd;
xpasswd = crypt(pass, salt);
/* The strcmp does not catch null passwords! */
if (pw == NULL || *pw->pw_passwd == '\0' ||
strcmp(xpasswd, pw->pw_passwd)) {
pw = (struct passwd *) NULL;
return(0);
}
return(1);
}
return(0);
}
#endif