Beispiel #1
0
static int
fb64_start(struct fb *fbp, int dir, int server __unused)
{
	size_t x;
	unsigned char *p;
	int state;

	switch (dir) {
	case DIR_DECRYPT:
		/*
		 * This is simply a request to have the other side
		 * start output (our input).  He will negotiate an
		 * IV so we need not look for it.
		 */
		state = fbp->state[dir-1];
		if (state == FAILED)
			state = IN_PROGRESS;
		break;

	case DIR_ENCRYPT:
		state = fbp->state[dir-1];
		if (state == FAILED)
			state = IN_PROGRESS;
		else if ((state & NO_SEND_IV) == 0)
			break;

		if (!VALIDKEY(fbp->krbdes_key)) {
			fbp->need_start = 1;
			break;
		}
		state &= ~NO_SEND_IV;
		state |= NO_RECV_IV;
		if (encrypt_debug_mode)
			printf("Creating new feed\r\n");
		/*
		 * Create a random feed and send it over.
		 */
		des_random_key((Block *)fbp->temp_feed);
		des_ecb_encrypt((Block *)fbp->temp_feed, (Block *)fbp->temp_feed,
				fbp->krbdes_sched, 1);
		p = fbp->fb_feed + 3;
		*p++ = ENCRYPT_IS;
		p++;
		*p++ = FB64_IV;
		for (x = 0; x < sizeof(Block); ++x) {
			if ((*p++ = fbp->temp_feed[x]) == IAC)
				*p++ = IAC;
		}
		*p++ = IAC;
		*p++ = SE;
		printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
		net_write(fbp->fb_feed, p - fbp->fb_feed);
		break;
	default:
		return(FAILED);
	}
	return(fbp->state[dir-1] = state);
}
Beispiel #2
0
void
kerberos4_is(Authenticator *ap, unsigned char *data, int cnt)
{
    struct sockaddr_in addr;
    char realm[REALM_SZ];
    char instance[INST_SZ];
    int r;
    int addr_len;

    if (cnt-- < 1)
	return;
    switch (*data++) {
    case KRB_AUTH:
	if (krb_get_lrealm(realm, 1) != KSUCCESS) {
	    Data(ap, KRB_REJECT, (void *)"No local V4 Realm.", -1);
	    auth_finished(ap, AUTH_REJECT);
	    if (auth_debug_mode)
		printf("No local realm\r\n");
	    return;
	}
	memmove(auth.dat, data, auth.length = cnt);
	if (auth_debug_mode) {
	    printf("Got %d bytes of authentication data\r\n", cnt);
	    printf("CK: %d:", kerberos4_cksum(auth.dat, auth.length));
	    printd(auth.dat, auth.length);
	    printf("\r\n");
	}
	k_getsockinst(0, instance, sizeof(instance));
	addr_len = sizeof(addr);
	if(getpeername(0, (struct sockaddr *)&addr, &addr_len) < 0) {
	    if(auth_debug_mode)
		printf("getpeername failed\r\n");
	    Data(ap, KRB_REJECT, "getpeername failed", -1);
	    auth_finished(ap, AUTH_REJECT);
	    return;
	}
	r = krb_rd_req(&auth, KRB_SERVICE_NAME,
		       instance, addr.sin_addr.s_addr, &adat, "");
	if (r) {
	    if (auth_debug_mode)
		printf("Kerberos failed him as %s\r\n", name);
	    Data(ap, KRB_REJECT, (void *)krb_get_err_text(r), -1);
	    auth_finished(ap, AUTH_REJECT);
	    return;
	}
	/* save the session key */
	memmove(session_key, adat.session, sizeof(adat.session));
	krb_kntoln(&adat, name);

	if (UserNameRequested && !kuserok(&adat, UserNameRequested)){
	    char ts[MAXPATHLEN];
	    struct passwd *pw = getpwnam(UserNameRequested);

	    if(pw){
		snprintf(ts, sizeof(ts),
			 "%s%u",
			 TKT_ROOT,
			 (unsigned)pw->pw_uid);
		setenv("KRBTKFILE", ts, 1);
	    }
	    Data(ap, KRB_ACCEPT, NULL, 0);
	} else {
	    char *msg;

	    asprintf (&msg, "user `%s' is not authorized to "
		      "login as `%s'", 
		      krb_unparse_name_long(adat.pname, 
					    adat.pinst, 
					    adat.prealm), 
		      UserNameRequested ? UserNameRequested : "<nobody>");
	    if (msg == NULL)
		Data(ap, KRB_REJECT, NULL, 0);
	    else {
		Data(ap, KRB_REJECT, (void *)msg, -1);
		free(msg);
	    }
	}
	auth_finished(ap, AUTH_USER);
	break;
	
    case KRB_CHALLENGE:
#ifndef ENCRYPTION
	Data(ap, KRB_RESPONSE, NULL, 0);
#else
	if(!VALIDKEY(session_key)){
	    Data(ap, KRB_RESPONSE, NULL, 0);
	    break;
	}
	des_key_sched(&session_key, sched);
	{
	    des_cblock d_block;
	    int i;
	    Session_Key skey;

	    memmove(d_block, data, sizeof(d_block));

	    /* make a session key for encryption */
	    des_ecb_encrypt(&d_block, &session_key, sched, 1);
	    skey.type=SK_DES;
	    skey.length=8;
	    skey.data=session_key;
	    encrypt_session_key(&skey, 1);

	    /* decrypt challenge, add one and encrypt it */
	    des_ecb_encrypt(&d_block, &challenge, sched, 0);
	    for (i = 7; i >= 0; i--)
		if(++challenge[i] != 0)
		    break;
	    des_ecb_encrypt(&challenge, &challenge, sched, 1);
	    Data(ap, KRB_RESPONSE, (void *)challenge, sizeof(challenge));
	}
#endif
	break;

    case KRB_FORWARD:
	{
	    des_key_schedule ks;
	    unsigned char netcred[sizeof(CREDENTIALS)];
	    CREDENTIALS cred;
	    int ret;
	    if(cnt > sizeof(cred))
		abort();

	    des_set_key(&session_key, ks);
	    des_pcbc_encrypt((void*)data, (void*)netcred, cnt, 
			     ks, &session_key, DES_DECRYPT);
	    unpack_cred(netcred, cnt, &cred);
	    {
		if(strcmp(cred.service, KRB_TICKET_GRANTING_TICKET) ||
		   strncmp(cred.instance, cred.realm, sizeof(cred.instance)) ||
		   cred.lifetime < 0 || cred.lifetime > 255 ||
		   cred.kvno < 0 || cred.kvno > 255 ||
		   cred.issue_date < 0 || 
		   cred.issue_date > time(0) + CLOCK_SKEW ||
		   strncmp(cred.pname, adat.pname, sizeof(cred.pname)) ||
		   strncmp(cred.pinst, adat.pinst, sizeof(cred.pname))){
		    Data(ap, KRB_FORWARD_REJECT, "Bad credentials", -1);
		}else{
		    if((ret = tf_setup(&cred,
				       cred.pname,
				       cred.pinst)) == KSUCCESS){
		        struct passwd *pw = getpwnam(UserNameRequested);

			if (pw)
			  chown(tkt_string(), pw->pw_uid, pw->pw_gid);
			Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
		    } else{
			Data(ap, KRB_FORWARD_REJECT, 
			     krb_get_err_text(ret), -1);
		    }
		}
	    }
	    memset(data, 0, cnt);
	    memset(ks, 0, sizeof(ks));
	    memset(&cred, 0, sizeof(cred));
	}
	
	break;

    default:
	if (auth_debug_mode)
	    printf("Unknown Kerberos option %d\r\n", data[-1]);
	Data(ap, KRB_REJECT, 0, 0);
	break;
    }
}
Beispiel #3
0
static int fb64_start(struct fb *fbp, int dir, int server)
{
	int x;
	unsigned char *p;
	int state;

	switch (dir) {
	case DIR_DECRYPT:
		/*
		 * This is simply a request to have the other side
		 * start output (our input).  He will negotiate an
		 * IV so we need not look for it.
		 */
		state = fbp->state[dir-1];
		if (state == FAILED)
			state = IN_PROGRESS;
		break;

	case DIR_ENCRYPT:
		state = fbp->state[dir-1];
		if (state == FAILED)
			state = IN_PROGRESS;
		else if ((state & NO_SEND_IV) == 0) {
			break;
		}

		if (!VALIDKEY(fbp->krbdes_key)) {
		        fbp->need_start = 1;
			break;
		}

		state &= ~NO_SEND_IV;
		state |= NO_RECV_IV;
		if (encrypt_debug_mode)
			printf("Creating new feed\r\n");
		/*
		 * Create a random feed and send it over.
		 */
		do {
		    if (RAND_bytes(fbp->temp_feed,
				   sizeof(*fbp->temp_feed)) != 1)
			abort();
		    DES_set_odd_parity(&fbp->temp_feed);
		} while(DES_is_weak_key(&fbp->temp_feed));

		p = fbp->fb_feed + 3;
		*p++ = ENCRYPT_IS;
		p++;
		*p++ = FB64_IV;
		for (x = 0; x < sizeof(DES_cblock); ++x) {
			if ((*p++ = fbp->temp_feed[x]) == IAC)
				*p++ = IAC;
		}
		*p++ = IAC;
		*p++ = SE;
		printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
		telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
		break;
	default:
		return(FAILED);
	}
	return(fbp->state[dir-1] = state);
}