725 lines
15 KiB
C
725 lines
15 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)enc_des.c 8.2 (Berkeley) 12/15/93";
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#endif /* not lint */
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#ifdef ENCRYPTION
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# ifdef AUTHENTICATION
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# ifdef DES_ENCRYPTION
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#include <arpa/telnet.h>
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#include <stdio.h>
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#ifdef __STDC__
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#include <stdlib.h>
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#endif
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#include "encrypt.h"
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#include "key-proto.h"
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#include "misc-proto.h"
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extern encrypt_debug_mode;
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#define CFB 0
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#define OFB 1
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#define NO_SEND_IV 1
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#define NO_RECV_IV 2
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#define NO_KEYID 4
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#define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
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#define SUCCESS 0
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#define FAILED -1
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struct fb {
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Block krbdes_key;
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Schedule krbdes_sched;
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Block temp_feed;
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unsigned char fb_feed[64];
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int need_start;
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int state[2];
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int keyid[2];
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int once;
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struct stinfo {
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Block str_output;
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Block str_feed;
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Block str_iv;
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Block str_ikey;
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Schedule str_sched;
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int str_index;
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int str_flagshift;
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} streams[2];
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};
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static struct fb fb[2];
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struct keyidlist {
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char *keyid;
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int keyidlen;
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char *key;
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int keylen;
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int flags;
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} keyidlist [] = {
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{ "\0", 1, 0, 0, 0 }, /* default key of zero */
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{ 0, 0, 0, 0, 0 }
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};
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#define KEYFLAG_MASK 03
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#define KEYFLAG_NOINIT 00
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#define KEYFLAG_INIT 01
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#define KEYFLAG_OK 02
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#define KEYFLAG_BAD 03
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#define KEYFLAG_SHIFT 2
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#define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
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#define FB64_IV 1
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#define FB64_IV_OK 2
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#define FB64_IV_BAD 3
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void fb64_stream_iv P((Block, struct stinfo *));
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void fb64_init P((struct fb *));
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static int fb64_start P((struct fb *, int, int));
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int fb64_is P((unsigned char *, int, struct fb *));
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int fb64_reply P((unsigned char *, int, struct fb *));
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static void fb64_session P((Session_Key *, int, struct fb *));
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void fb64_stream_key P((Block, struct stinfo *));
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int fb64_keyid P((int, unsigned char *, int *, struct fb *));
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void
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cfb64_init(server)
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int server;
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{
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fb64_init(&fb[CFB]);
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fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
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fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
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fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
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}
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void
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ofb64_init(server)
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int server;
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{
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fb64_init(&fb[OFB]);
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fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
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fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
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fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
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}
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void
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fb64_init(fbp)
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register struct fb *fbp;
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{
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bzero((void *)fbp, sizeof(*fbp));
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fbp->state[0] = fbp->state[1] = FAILED;
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fbp->fb_feed[0] = IAC;
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fbp->fb_feed[1] = SB;
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fbp->fb_feed[2] = TELOPT_ENCRYPT;
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fbp->fb_feed[3] = ENCRYPT_IS;
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}
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/*
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* Returns:
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* -1: some error. Negotiation is done, encryption not ready.
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* 0: Successful, initial negotiation all done.
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* 1: successful, negotiation not done yet.
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* 2: Not yet. Other things (like getting the key from
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* Kerberos) have to happen before we can continue.
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*/
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int
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cfb64_start(dir, server)
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int dir;
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int server;
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{
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return(fb64_start(&fb[CFB], dir, server));
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}
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int
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ofb64_start(dir, server)
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int dir;
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int server;
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{
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return(fb64_start(&fb[OFB], dir, server));
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}
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static int
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fb64_start(fbp, dir, server)
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struct fb *fbp;
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int dir;
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int server;
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{
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Block b;
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int x;
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unsigned char *p;
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register int state;
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switch (dir) {
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case DIR_DECRYPT:
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/*
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* This is simply a request to have the other side
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* start output (our input). He will negotiate an
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* IV so we need not look for it.
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*/
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state = fbp->state[dir-1];
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if (state == FAILED)
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state = IN_PROGRESS;
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break;
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case DIR_ENCRYPT:
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state = fbp->state[dir-1];
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if (state == FAILED)
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state = IN_PROGRESS;
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else if ((state & NO_SEND_IV) == 0)
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break;
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if (!VALIDKEY(fbp->krbdes_key)) {
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fbp->need_start = 1;
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break;
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}
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state &= ~NO_SEND_IV;
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state |= NO_RECV_IV;
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if (encrypt_debug_mode)
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printf("Creating new feed\r\n");
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/*
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* Create a random feed and send it over.
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*/
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des_new_random_key(fbp->temp_feed);
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des_ecb_encrypt(fbp->temp_feed, fbp->temp_feed,
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fbp->krbdes_sched, 1);
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p = fbp->fb_feed + 3;
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*p++ = ENCRYPT_IS;
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p++;
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*p++ = FB64_IV;
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for (x = 0; x < sizeof(Block); ++x) {
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if ((*p++ = fbp->temp_feed[x]) == IAC)
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*p++ = IAC;
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}
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*p++ = IAC;
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*p++ = SE;
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printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
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net_write(fbp->fb_feed, p - fbp->fb_feed);
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break;
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default:
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return(FAILED);
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}
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return(fbp->state[dir-1] = state);
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}
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/*
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* Returns:
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* -1: some error. Negotiation is done, encryption not ready.
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* 0: Successful, initial negotiation all done.
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* 1: successful, negotiation not done yet.
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*/
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int
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cfb64_is(data, cnt)
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unsigned char *data;
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int cnt;
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{
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return(fb64_is(data, cnt, &fb[CFB]));
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}
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int
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ofb64_is(data, cnt)
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unsigned char *data;
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int cnt;
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{
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return(fb64_is(data, cnt, &fb[OFB]));
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}
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int
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fb64_is(data, cnt, fbp)
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unsigned char *data;
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int cnt;
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struct fb *fbp;
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{
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int x;
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unsigned char *p;
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Block b;
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register int state = fbp->state[DIR_DECRYPT-1];
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if (cnt-- < 1)
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goto failure;
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switch (*data++) {
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case FB64_IV:
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if (cnt != sizeof(Block)) {
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if (encrypt_debug_mode)
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printf("CFB64: initial vector failed on size\r\n");
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state = FAILED;
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goto failure;
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}
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if (encrypt_debug_mode)
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printf("CFB64: initial vector received\r\n");
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if (encrypt_debug_mode)
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printf("Initializing Decrypt stream\r\n");
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fb64_stream_iv((void *)data, &fbp->streams[DIR_DECRYPT-1]);
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p = fbp->fb_feed + 3;
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*p++ = ENCRYPT_REPLY;
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p++;
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*p++ = FB64_IV_OK;
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*p++ = IAC;
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*p++ = SE;
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printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
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net_write(fbp->fb_feed, p - fbp->fb_feed);
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state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
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break;
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default:
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if (encrypt_debug_mode) {
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printf("Unknown option type: %d\r\n", *(data-1));
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printd(data, cnt);
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printf("\r\n");
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}
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/* FALL THROUGH */
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failure:
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/*
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* We failed. Send an FB64_IV_BAD option
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* to the other side so it will know that
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* things failed.
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*/
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p = fbp->fb_feed + 3;
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*p++ = ENCRYPT_REPLY;
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p++;
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*p++ = FB64_IV_BAD;
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*p++ = IAC;
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*p++ = SE;
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printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
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net_write(fbp->fb_feed, p - fbp->fb_feed);
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break;
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}
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return(fbp->state[DIR_DECRYPT-1] = state);
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}
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/*
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* Returns:
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* -1: some error. Negotiation is done, encryption not ready.
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* 0: Successful, initial negotiation all done.
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* 1: successful, negotiation not done yet.
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*/
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int
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cfb64_reply(data, cnt)
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unsigned char *data;
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int cnt;
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{
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return(fb64_reply(data, cnt, &fb[CFB]));
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}
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int
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ofb64_reply(data, cnt)
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unsigned char *data;
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int cnt;
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{
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return(fb64_reply(data, cnt, &fb[OFB]));
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}
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int
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fb64_reply(data, cnt, fbp)
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unsigned char *data;
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int cnt;
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struct fb *fbp;
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{
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int x;
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unsigned char *p;
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Block b;
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register int state = fbp->state[DIR_ENCRYPT-1];
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if (cnt-- < 1)
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goto failure;
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switch (*data++) {
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case FB64_IV_OK:
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fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
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if (state == FAILED)
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state = IN_PROGRESS;
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state &= ~NO_RECV_IV;
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encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
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break;
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case FB64_IV_BAD:
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bzero(fbp->temp_feed, sizeof(Block));
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fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
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state = FAILED;
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break;
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default:
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if (encrypt_debug_mode) {
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printf("Unknown option type: %d\r\n", data[-1]);
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printd(data, cnt);
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printf("\r\n");
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}
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/* FALL THROUGH */
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failure:
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state = FAILED;
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break;
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}
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return(fbp->state[DIR_ENCRYPT-1] = state);
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}
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void
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cfb64_session(key, server)
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Session_Key *key;
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int server;
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{
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fb64_session(key, server, &fb[CFB]);
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}
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void
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ofb64_session(key, server)
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Session_Key *key;
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int server;
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{
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fb64_session(key, server, &fb[OFB]);
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}
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static void
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fb64_session(key, server, fbp)
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Session_Key *key;
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int server;
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struct fb *fbp;
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{
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if (!key || key->type != SK_DES) {
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if (encrypt_debug_mode)
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printf("Can't set krbdes's session key (%d != %d)\r\n",
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key ? key->type : -1, SK_DES);
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return;
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}
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bcopy((void *)key->data, (void *)fbp->krbdes_key, sizeof(Block));
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fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
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fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
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if (fbp->once == 0) {
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des_set_random_generator_seed(fbp->krbdes_key);
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fbp->once = 1;
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}
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des_key_sched(fbp->krbdes_key, fbp->krbdes_sched);
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/*
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* Now look to see if krbdes_start() was was waiting for
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* the key to show up. If so, go ahead an call it now
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* that we have the key.
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*/
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if (fbp->need_start) {
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fbp->need_start = 0;
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fb64_start(fbp, DIR_ENCRYPT, server);
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}
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}
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/*
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* We only accept a keyid of 0. If we get a keyid of
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* 0, then mark the state as SUCCESS.
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*/
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int
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cfb64_keyid(dir, kp, lenp)
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int dir, *lenp;
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unsigned char *kp;
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{
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return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
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}
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int
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ofb64_keyid(dir, kp, lenp)
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int dir, *lenp;
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unsigned char *kp;
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{
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return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
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}
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int
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fb64_keyid(dir, kp, lenp, fbp)
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int dir, *lenp;
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unsigned char *kp;
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struct fb *fbp;
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{
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register int state = fbp->state[dir-1];
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if (*lenp != 1 || (*kp != '\0')) {
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*lenp = 0;
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return(state);
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}
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if (state == FAILED)
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state = IN_PROGRESS;
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state &= ~NO_KEYID;
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return(fbp->state[dir-1] = state);
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}
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void
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fb64_printsub(data, cnt, buf, buflen, type)
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unsigned char *data, *buf, *type;
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int cnt, buflen;
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{
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char lbuf[32];
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register int i;
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char *cp;
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buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
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buflen -= 1;
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switch(data[2]) {
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case FB64_IV:
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sprintf(lbuf, "%s_IV", type);
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cp = lbuf;
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goto common;
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case FB64_IV_OK:
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sprintf(lbuf, "%s_IV_OK", type);
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cp = lbuf;
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goto common;
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case FB64_IV_BAD:
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sprintf(lbuf, "%s_IV_BAD", type);
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cp = lbuf;
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goto common;
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default:
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sprintf(lbuf, " %d (unknown)", data[2]);
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cp = lbuf;
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common:
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for (; (buflen > 0) && (*buf = *cp++); buf++)
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buflen--;
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for (i = 3; i < cnt; i++) {
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sprintf(lbuf, " %d", data[i]);
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for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
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buflen--;
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}
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break;
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}
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}
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void
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cfb64_printsub(data, cnt, buf, buflen)
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unsigned char *data, *buf;
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int cnt, buflen;
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{
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fb64_printsub(data, cnt, buf, buflen, "CFB64");
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}
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void
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ofb64_printsub(data, cnt, buf, buflen)
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unsigned char *data, *buf;
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int cnt, buflen;
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{
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fb64_printsub(data, cnt, buf, buflen, "OFB64");
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}
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void
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fb64_stream_iv(seed, stp)
|
|
Block seed;
|
|
register struct stinfo *stp;
|
|
{
|
|
|
|
bcopy((void *)seed, (void *)stp->str_iv, sizeof(Block));
|
|
bcopy((void *)seed, (void *)stp->str_output, sizeof(Block));
|
|
|
|
des_key_sched(stp->str_ikey, stp->str_sched);
|
|
|
|
stp->str_index = sizeof(Block);
|
|
}
|
|
|
|
void
|
|
fb64_stream_key(key, stp)
|
|
Block key;
|
|
register struct stinfo *stp;
|
|
{
|
|
bcopy((void *)key, (void *)stp->str_ikey, sizeof(Block));
|
|
des_key_sched(key, stp->str_sched);
|
|
|
|
bcopy((void *)stp->str_iv, (void *)stp->str_output, sizeof(Block));
|
|
|
|
stp->str_index = sizeof(Block);
|
|
}
|
|
|
|
/*
|
|
* DES 64 bit Cipher Feedback
|
|
*
|
|
* key --->+-----+
|
|
* +->| DES |--+
|
|
* | +-----+ |
|
|
* | v
|
|
* INPUT --(--------->(+)+---> DATA
|
|
* | |
|
|
* +-------------+
|
|
*
|
|
*
|
|
* Given:
|
|
* iV: Initial vector, 64 bits (8 bytes) long.
|
|
* Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
|
|
* On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
|
|
*
|
|
* V0 = DES(iV, key)
|
|
* On = Dn ^ Vn
|
|
* V(n+1) = DES(On, key)
|
|
*/
|
|
|
|
void
|
|
cfb64_encrypt(s, c)
|
|
register unsigned char *s;
|
|
int c;
|
|
{
|
|
register struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
|
|
register int index;
|
|
|
|
index = stp->str_index;
|
|
while (c-- > 0) {
|
|
if (index == sizeof(Block)) {
|
|
Block b;
|
|
des_ecb_encrypt(stp->str_output, b, stp->str_sched, 1);
|
|
bcopy((void *)b, (void *)stp->str_feed, sizeof(Block));
|
|
index = 0;
|
|
}
|
|
|
|
/* On encryption, we store (feed ^ data) which is cypher */
|
|
*s = stp->str_output[index] = (stp->str_feed[index] ^ *s);
|
|
s++;
|
|
index++;
|
|
}
|
|
stp->str_index = index;
|
|
}
|
|
|
|
int
|
|
cfb64_decrypt(data)
|
|
int data;
|
|
{
|
|
register struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
|
|
int index;
|
|
|
|
if (data == -1) {
|
|
/*
|
|
* Back up one byte. It is assumed that we will
|
|
* never back up more than one byte. If we do, this
|
|
* may or may not work.
|
|
*/
|
|
if (stp->str_index)
|
|
--stp->str_index;
|
|
return(0);
|
|
}
|
|
|
|
index = stp->str_index++;
|
|
if (index == sizeof(Block)) {
|
|
Block b;
|
|
des_ecb_encrypt(stp->str_output, b, stp->str_sched, 1);
|
|
bcopy((void *)b, (void *)stp->str_feed, sizeof(Block));
|
|
stp->str_index = 1; /* Next time will be 1 */
|
|
index = 0; /* But now use 0 */
|
|
}
|
|
|
|
/* On decryption we store (data) which is cypher. */
|
|
stp->str_output[index] = data;
|
|
return(data ^ stp->str_feed[index]);
|
|
}
|
|
|
|
/*
|
|
* DES 64 bit Output Feedback
|
|
*
|
|
* key --->+-----+
|
|
* +->| DES |--+
|
|
* | +-----+ |
|
|
* +-----------+
|
|
* v
|
|
* INPUT -------->(+) ----> DATA
|
|
*
|
|
* Given:
|
|
* iV: Initial vector, 64 bits (8 bytes) long.
|
|
* Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
|
|
* On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
|
|
*
|
|
* V0 = DES(iV, key)
|
|
* V(n+1) = DES(Vn, key)
|
|
* On = Dn ^ Vn
|
|
*/
|
|
void
|
|
ofb64_encrypt(s, c)
|
|
register unsigned char *s;
|
|
int c;
|
|
{
|
|
register struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
|
|
register int index;
|
|
|
|
index = stp->str_index;
|
|
while (c-- > 0) {
|
|
if (index == sizeof(Block)) {
|
|
Block b;
|
|
des_ecb_encrypt(stp->str_feed, b, stp->str_sched, 1);
|
|
bcopy((void *)b, (void *)stp->str_feed, sizeof(Block));
|
|
index = 0;
|
|
}
|
|
*s++ ^= stp->str_feed[index];
|
|
index++;
|
|
}
|
|
stp->str_index = index;
|
|
}
|
|
|
|
int
|
|
ofb64_decrypt(data)
|
|
int data;
|
|
{
|
|
register struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
|
|
int index;
|
|
|
|
if (data == -1) {
|
|
/*
|
|
* Back up one byte. It is assumed that we will
|
|
* never back up more than one byte. If we do, this
|
|
* may or may not work.
|
|
*/
|
|
if (stp->str_index)
|
|
--stp->str_index;
|
|
return(0);
|
|
}
|
|
|
|
index = stp->str_index++;
|
|
if (index == sizeof(Block)) {
|
|
Block b;
|
|
des_ecb_encrypt(stp->str_feed, b, stp->str_sched, 1);
|
|
bcopy((void *)b, (void *)stp->str_feed, sizeof(Block));
|
|
stp->str_index = 1; /* Next time will be 1 */
|
|
index = 0; /* But now use 0 */
|
|
}
|
|
|
|
return(data ^ stp->str_feed[index]);
|
|
}
|
|
# endif /* DES_ENCRYPTION */
|
|
# endif /* AUTHENTICATION */
|
|
#endif /* ENCRYPTION */
|