150 lines
4.4 KiB
C
150 lines
4.4 KiB
C
/*
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* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the OpenSSL license (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include "e_os.h"
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#include "des_locl.h"
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#include <assert.h>
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/*
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* The input and output are loaded in multiples of 8 bits. What this means is
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* that if you hame numbits=12 and length=2 the first 12 bits will be
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* retrieved from the first byte and half the second. The second 12 bits
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* will come from the 3rd and half the 4th byte.
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*/
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/*
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* Until Aug 1 2003 this function did not correctly implement CFB-r, so it
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* will not be compatible with any encryption prior to that date. Ben.
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*/
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void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
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long length, DES_key_schedule *schedule,
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DES_cblock *ivec, int enc)
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{
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register DES_LONG d0, d1, v0, v1;
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register unsigned long l = length;
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register int num = numbits / 8, n = (numbits + 7) / 8, i, rem =
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numbits % 8;
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DES_LONG ti[2];
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unsigned char *iv;
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#ifndef L_ENDIAN
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unsigned char ovec[16];
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#else
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unsigned int sh[4];
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unsigned char *ovec = (unsigned char *)sh;
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/* I kind of count that compiler optimizes away this assertioni, */
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assert(sizeof(sh[0]) == 4); /* as this holds true for all, */
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/* but 16-bit platforms... */
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#endif
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if (numbits <= 0 || numbits > 64)
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return;
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iv = &(*ivec)[0];
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c2l(iv, v0);
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c2l(iv, v1);
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if (enc) {
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while (l >= (unsigned long)n) {
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l -= n;
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ti[0] = v0;
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ti[1] = v1;
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DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
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c2ln(in, d0, d1, n);
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in += n;
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d0 ^= ti[0];
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d1 ^= ti[1];
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l2cn(d0, d1, out, n);
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out += n;
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/*
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* 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
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* gcc :-(
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*/
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if (numbits == 32) {
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v0 = v1;
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v1 = d0;
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} else if (numbits == 64) {
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v0 = d0;
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v1 = d1;
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} else {
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#ifndef L_ENDIAN
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iv = &ovec[0];
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l2c(v0, iv);
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l2c(v1, iv);
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l2c(d0, iv);
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l2c(d1, iv);
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#else
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sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1;
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#endif
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if (rem == 0)
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memmove(ovec, ovec + num, 8);
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else
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for (i = 0; i < 8; ++i)
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ovec[i] = ovec[i + num] << rem |
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ovec[i + num + 1] >> (8 - rem);
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#ifdef L_ENDIAN
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v0 = sh[0], v1 = sh[1];
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#else
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iv = &ovec[0];
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c2l(iv, v0);
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c2l(iv, v1);
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#endif
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}
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}
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} else {
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while (l >= (unsigned long)n) {
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l -= n;
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ti[0] = v0;
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ti[1] = v1;
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DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
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c2ln(in, d0, d1, n);
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in += n;
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/*
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* 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
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* gcc :-(
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*/
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if (numbits == 32) {
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v0 = v1;
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v1 = d0;
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} else if (numbits == 64) {
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v0 = d0;
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v1 = d1;
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} else {
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#ifndef L_ENDIAN
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iv = &ovec[0];
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l2c(v0, iv);
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l2c(v1, iv);
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l2c(d0, iv);
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l2c(d1, iv);
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#else
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sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1;
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#endif
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if (rem == 0)
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memmove(ovec, ovec + num, 8);
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else
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for (i = 0; i < 8; ++i)
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ovec[i] = ovec[i + num] << rem |
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ovec[i + num + 1] >> (8 - rem);
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#ifdef L_ENDIAN
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v0 = sh[0], v1 = sh[1];
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#else
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iv = &ovec[0];
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c2l(iv, v0);
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c2l(iv, v1);
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#endif
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}
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d0 ^= ti[0];
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d1 ^= ti[1];
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l2cn(d0, d1, out, n);
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out += n;
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}
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}
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iv = &(*ivec)[0];
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l2c(v0, iv);
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l2c(v1, iv);
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v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0;
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}
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