adding GNU dc ("desk calculator")

[unix-history] / lib / libtelnet / enc_des.c

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*/

#ifndef lint
static char sccsid[] = "@(#)enc_des.c   5.1 (Berkeley) 3/22/91";
#endif /* not lint */

#if     defined(AUTHENTICATE) && defined(ENCRYPT) && defined(DES_ENCRYPT)
#include <arpa/telnet.h>
#include <stdio.h>
#ifdef  __STDC__
#include <stdlib.h>
#endif

#include "encrypt.h"
#include "key-proto.h"
#include "misc-proto.h"

extern encrypt_debug_mode;

#define CFB     0
#define OFB     1

#define NO_SEND_IV      1
#define NO_RECV_IV      2
#define NO_KEYID        4
#define IN_PROGRESS     (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
#define SUCCESS         0
#define FAILED          -1


struct fb {
       Block krbdes_key;
       Schedule krbdes_sched;
       Block temp_feed;
       unsigned char fb_feed[64];
       int need_start;
       int state[2];
       int keyid[2];
       int once;
       struct stinfo {
               Block           str_output;
               Block           str_feed;
               Block           str_iv;
               Block           str_ikey;
               Schedule        str_sched;
               int             str_index;
               int             str_flagshift;
       } streams[2];
};

static struct fb fb[2];

struct keyidlist {
       char    *keyid;
       int     keyidlen;
       char    *key;
       int     keylen;
       int     flags;
} keyidlist [] = {
       { "\0", 1, 0, 0, 0 },           /* default key of zero */
       { 0, 0, 0, 0, 0 }
};

#define KEYFLAG_MASK    03

#define KEYFLAG_NOINIT  00
#define KEYFLAG_INIT    01
#define KEYFLAG_OK      02
#define KEYFLAG_BAD     03

#define KEYFLAG_SHIFT   2

#define SHIFT_VAL(a,b)  (KEYFLAG_SHIFT*((a)+((b)*2)))

#define FB64_IV         1
#define FB64_IV_OK      2
#define FB64_IV_BAD     3


void fb64_stream_iv P((Block, struct stinfo *));
void fb64_init P((struct fb *));
int fb64_start P((struct fb *, int, int));
int fb64_is P((unsigned char *, int, struct fb *));
int fb64_reply P((unsigned char *, int, struct fb *));
void fb64_session P((Session_Key *, int, struct fb *));
void fb64_stream_key P((Block, struct stinfo *));
int fb64_keyid P((int, unsigned char *, int *, struct fb *));

       void
cfb64_init(server)
       int server;
{
       fb64_init(&fb[CFB]);
       fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
       fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
       fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
}

       void
ofb64_init(server)
       int server;
{
       fb64_init(&fb[OFB]);
       fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
       fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
       fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
}

       void
fb64_init(fbp)
       register struct fb *fbp;
{
       bzero((void *)fbp, sizeof(*fbp));
       fbp->state[0] = fbp->state[1] = FAILED;
       fbp->fb_feed[0] = IAC;
       fbp->fb_feed[1] = SB;
       fbp->fb_feed[2] = TELOPT_ENCRYPT;
       fbp->fb_feed[3] = ENCRYPT_IS;
}

/*
* Returns:
*      -1: some error.  Negotiation is done, encryption not ready.
*       0: Successful, initial negotiation all done.
*       1: successful, negotiation not done yet.
*       2: Not yet.  Other things (like getting the key from
*          Kerberos) have to happen before we can continue.
*/
       int
cfb64_start(dir, server)
       int dir;
       int server;
{
       return(fb64_start(&fb[CFB], dir, server));
}
       int
ofb64_start(dir, server)
       int dir;
       int server;
{
       return(fb64_start(&fb[OFB], dir, server));
}

       static int
fb64_start(fbp, dir, server)
       struct fb *fbp;
       int dir;
       int server;
{
       Block b;
       int x;
       unsigned char *p;
       register 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_new_random_key(fbp->temp_feed);
               des_ecb_encrypt(fbp->temp_feed, 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);
}

/*
* Returns:
*      -1: some error.  Negotiation is done, encryption not ready.
*       0: Successful, initial negotiation all done.
*       1: successful, negotiation not done yet.
*/
       int
cfb64_is(data, cnt)
       unsigned char *data;
       int cnt;
{
       return(fb64_is(data, cnt, &fb[CFB]));
}
       int
ofb64_is(data, cnt)
       unsigned char *data;
       int cnt;
{
       return(fb64_is(data, cnt, &fb[OFB]));
}

       int
fb64_is(data, cnt, fbp)
       unsigned char *data;
       int cnt;
       struct fb *fbp;
{
       int x;
       unsigned char *p;
       Block b;
       register int state = fbp->state[DIR_DECRYPT-1];

       if (cnt-- < 1)
               goto failure;

       switch (*data++) {
       case FB64_IV:
               if (cnt != sizeof(Block)) {
                       if (encrypt_debug_mode)
                               printf("CFB64: initial vector failed on size\r\n");
                       state = FAILED;
                       goto failure;
               }

               if (encrypt_debug_mode)
                       printf("CFB64: initial vector received\r\n");

               if (encrypt_debug_mode)
                       printf("Initializing Decrypt stream\r\n");

               fb64_stream_iv((void *)data, &fbp->streams[DIR_DECRYPT-1]);

               p = fbp->fb_feed + 3;
               *p++ = ENCRYPT_REPLY;
               p++;
               *p++ = FB64_IV_OK;
               *p++ = IAC;
               *p++ = SE;
               printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
               net_write(fbp->fb_feed, p - fbp->fb_feed);

               state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
               break;

       default:
               if (encrypt_debug_mode) {
                       printf("Unknown option type: %d\r\n", *(data-1));
                       printd(data, cnt);
                       printf("\r\n");
               }
               /* FALL THROUGH */
       failure:
               /*
                * We failed.  Send an FB64_IV_BAD option
                * to the other side so it will know that
                * things failed.
                */
               p = fbp->fb_feed + 3;
               *p++ = ENCRYPT_REPLY;
               p++;
               *p++ = FB64_IV_BAD;
               *p++ = IAC;
               *p++ = SE;
               printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
               net_write(fbp->fb_feed, p - fbp->fb_feed);

               break;
       }
       return(fbp->state[DIR_DECRYPT-1] = state);
}

/*
* Returns:
*      -1: some error.  Negotiation is done, encryption not ready.
*       0: Successful, initial negotiation all done.
*       1: successful, negotiation not done yet.
*/
       int
cfb64_reply(data, cnt)
       unsigned char *data;
       int cnt;
{
       return(fb64_reply(data, cnt, &fb[CFB]));
}
       int
ofb64_reply(data, cnt)
       unsigned char *data;
       int cnt;
{
       return(fb64_reply(data, cnt, &fb[OFB]));
}


       int
fb64_reply(data, cnt, fbp)
       unsigned char *data;
       int cnt;
       struct fb *fbp;
{
       int x;
       unsigned char *p;
       Block b;
       register int state = fbp->state[DIR_ENCRYPT-1];

       if (cnt-- < 1)
               goto failure;

       switch (*data++) {
       case FB64_IV_OK:
               fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
               if (state == FAILED)
                       state = IN_PROGRESS;
               state &= ~NO_RECV_IV;
               encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
               break;

       case FB64_IV_BAD:
               bzero(fbp->temp_feed, sizeof(Block));
               fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
               state = FAILED;
               break;

       default:
               if (encrypt_debug_mode) {
                       printf("Unknown option type: %d\r\n", data[-1]);
                       printd(data, cnt);
                       printf("\r\n");
               }
               /* FALL THROUGH */
       failure:
               state = FAILED;
               break;
       }
       return(fbp->state[DIR_ENCRYPT-1] = state);
}

       void
cfb64_session(key, server)
       Session_Key *key;
       int server;
{
       fb64_session(key, server, &fb[CFB]);
}

       void
ofb64_session(key, server)
       Session_Key *key;
       int server;
{
       fb64_session(key, server, &fb[OFB]);
}

       static void
fb64_session(key, server, fbp)
       Session_Key *key;
       int server;
       struct fb *fbp;
{

       if (!key || key->type != SK_DES) {
               if (encrypt_debug_mode)
                       printf("Can't set krbdes's session key (%d != %d)\r\n",
                               key ? key->type : -1, SK_DES);
               return;
       }
       bcopy((void *)key->data, (void *)fbp->krbdes_key, sizeof(Block));

       fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
       fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);

       if (fbp->once == 0) {
               des_set_random_generator_seed(fbp->krbdes_key);
               fbp->once = 1;
       }
       des_key_sched(fbp->krbdes_key, fbp->krbdes_sched);
       /*
        * Now look to see if krbdes_start() was was waiting for
        * the key to show up.  If so, go ahead an call it now
        * that we have the key.
        */
       if (fbp->need_start) {
               fbp->need_start = 0;
               fb64_start(fbp, DIR_ENCRYPT, server);
       }
}

/*
* We only accept a keyid of 0.  If we get a keyid of
* 0, then mark the state as SUCCESS.
*/
       int
cfb64_keyid(dir, kp, lenp)
       int dir, *lenp;
       unsigned char *kp;
{
       return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
}

       int
ofb64_keyid(dir, kp, lenp)
       int dir, *lenp;
       unsigned char *kp;
{
       return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
}

       int
fb64_keyid(dir, kp, lenp, fbp)
       int dir, *lenp;
       unsigned char *kp;
       struct fb *fbp;
{
       register int state = fbp->state[dir-1];

       if (*lenp != 1 || (*kp != '\0')) {
               *lenp = 0;
               return(state);
       }

       if (state == FAILED)
               state = IN_PROGRESS;

       state &= ~NO_KEYID;

       return(fbp->state[dir-1] = state);
}

       void
fb64_printsub(data, cnt, buf, buflen, type)
       unsigned char *data, *buf, *type;
       int cnt, buflen;
{
       char lbuf[32];
       register int i;
       char *cp;

       buf[buflen-1] = '\0';           /* make sure it's NULL terminated */
       buflen -= 1;

       switch(data[2]) {
       case FB64_IV:
               sprintf(lbuf, "%s_IV", type);
               cp = lbuf;
               goto common;

       case FB64_IV_OK:
               sprintf(lbuf, "%s_IV_OK", type);
               cp = lbuf;
               goto common;

       case FB64_IV_BAD:
               sprintf(lbuf, "%s_IV_BAD", type);
               cp = lbuf;
               goto common;

       default:
               sprintf(lbuf, " %d (unknown)", data[2]);
               cp = lbuf;
       common:
               for (; (buflen > 0) && (*buf = *cp++); buf++)
                       buflen--;
               for (i = 3; i < cnt; i++) {
                       sprintf(lbuf, " %d", data[i]);
                       for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
                               buflen--;
               }
               break;
       }
}

       void
cfb64_printsub(data, cnt, buf, buflen)
       unsigned char *data, *buf;
       int cnt, buflen;
{
       fb64_printsub(data, cnt, buf, buflen, "CFB64");
}

       void
ofb64_printsub(data, cnt, buf, buflen)
       unsigned char *data, *buf;
       int cnt, buflen;
{
       fb64_printsub(data, cnt, buf, buflen, "OFB64");
}

       void
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