Initial revision
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@38 ec53bebd-3082-4978-b11e-865c3cabbd6b
This commit is contained in:
Unknown User d91-jda
741
appl/telnet/libtelnet/enc_des.c
Normal file
741
appl/telnet/libtelnet/enc_des.c
Normal file
@@ -0,0 +1,741 @@
|
||||
/*-
|
||||
* Copyright (c) 1991, 1993
|
||||
* 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 8.3 (Berkeley) 5/30/95";
|
||||
#endif /* not lint */
|
||||
|
||||
#ifndef lint
|
||||
static char orig_sccsid[] = "@(#)enc_des.c 5.1 (Berkeley) 3/22/91";
|
||||
#endif /* not lint */
|
||||
|
||||
#if defined(AUTHENTICATION) && defined(ENCRYPTION) && defined(DES_ENCRYPTION)
|
||||
#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;
|
||||
{
|
||||
memset((void *)fbp,0, 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.
|
||||
*/
|
||||
#if OLD
|
||||
des_new_random_key(fbp->temp_feed);
|
||||
#else
|
||||
/*
|
||||
* From des_cryp.man "If the des_check_key flag is non-zero,
|
||||
* des_set_key will check that the key passed is
|
||||
* of odd parity and is not a week or semi-weak key."
|
||||
*/
|
||||
do {
|
||||
des_random_key(fbp->temp_feed);
|
||||
des_set_odd_parity(fbp->temp_feed);
|
||||
} while (des_is_weak_key(fbp->temp_feed));
|
||||
#endif
|
||||
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:
|
||||
memset(fbp->temp_feed, 0, 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;
|
||||
}
|
||||
memcpy((void *)fbp->krbdes_key, (void *)key->data, 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) {
|
||||
#if OLD
|
||||
des_set_random_generator_seed(fbp->krbdes_key);
|
||||
#endif
|
||||
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;
|
||||
{
|
||||
|
||||
memcpy((void *)stp->str_iv, (void *)seed,sizeof(Block));
|
||||
memcpy((void *)stp->str_output, (void *)seed, 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;
|
||||
{
|
||||
memcpy((void *)stp->str_ikey, (void *)key, sizeof(Block));
|
||||
des_key_sched(key, stp->str_sched);
|
||||
|
||||
memcpy((void *)stp->str_output, (void *)stp->str_iv, 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);
|
||||
memcpy((void *)stp->str_feed, (void *)b, 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);
|
||||
memcpy((void *)stp->str_feed, (void *)b, 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);
|
||||
memcpy((void *)stp->str_feed, (void *)b, 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);
|
||||
memcpy((void *)stp->str_feed, (void *)b, sizeof(Block));
|
||||
stp->str_index = 1; /* Next time will be 1 */
|
||||
index = 0; /* But now use 0 */
|
||||
}
|
||||
|
||||
return(data ^ stp->str_feed[index]);
|
||||
}
|
||||
#endif
|
||||
|
||||
Reference in New Issue
Block a user