crypto/des/cfb64ede.c

   1 /*
   2  * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * DES low level APIs are deprecated for public use, but still ok for internal
  12  * use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include "des_local.h"
  17
  18 /*
  19  * The input and output encrypted as though 64bit cfb mode is being used.
  20  * The extra state information to record how much of the 64bit block we have
  21  * used is contained in *num;
  22  */
  23
  24 void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
  25                             long length, DES_key_schedule *ks1,
  26                             DES_key_schedule *ks2, DES_key_schedule *ks3,
  27                             DES_cblock *ivec, int *num, int enc)
  28 {
  29     register DES_LONG v0, v1;
  30     register long l = length;
  31     register int n = *num;
  32     DES_LONG ti[2];
  33     unsigned char *iv, c, cc;
  34
  35     iv = &(*ivec)[0];
  36     if (enc) {
  37         while (l--) {
  38             if (n == 0) {
  39                 c2l(iv, v0);
  40                 c2l(iv, v1);
  41
  42                 ti[0] = v0;
  43                 ti[1] = v1;
  44                 DES_encrypt3(ti, ks1, ks2, ks3);
  45                 v0 = ti[0];
  46                 v1 = ti[1];
  47
  48                 iv = &(*ivec)[0];
  49                 l2c(v0, iv);
  50                 l2c(v1, iv);
  51                 iv = &(*ivec)[0];
  52             }
  53             c = *(in++) ^ iv[n];
  54             *(out++) = c;
  55             iv[n] = c;
  56             n = (n + 1) & 0x07;
  57         }
  58     } else {
  59         while (l--) {
  60             if (n == 0) {
  61                 c2l(iv, v0);
  62                 c2l(iv, v1);
  63
  64                 ti[0] = v0;
  65                 ti[1] = v1;
  66                 DES_encrypt3(ti, ks1, ks2, ks3);
  67                 v0 = ti[0];
  68                 v1 = ti[1];
  69
  70                 iv = &(*ivec)[0];
  71                 l2c(v0, iv);
  72                 l2c(v1, iv);
  73                 iv = &(*ivec)[0];
  74             }
  75             cc = *(in++);
  76             c = iv[n];
  77             iv[n] = cc;
  78             *(out++) = c ^ cc;
  79             n = (n + 1) & 0x07;
  80         }
  81     }
  82     v0 = v1 = ti[0] = ti[1] = c = cc = 0;
  83     *num = n;
  84 }
  85
  86 /*
  87  * This is compatible with the single key CFB-r for DES, even thought that's
  88  * not what EVP needs.
  89  */
  90
  91 void DES_ede3_cfb_encrypt(const unsigned char *in, unsigned char *out,
  92                           int numbits, long length, DES_key_schedule *ks1,
  93                           DES_key_schedule *ks2, DES_key_schedule *ks3,
  94                           DES_cblock *ivec, int enc)
  95 {
  96     register DES_LONG d0, d1, v0, v1;
  97     register unsigned long l = length, n = ((unsigned int)numbits + 7) / 8;
  98     register int num = numbits, i;
  99     DES_LONG ti[2];
 100     unsigned char *iv;
 101     unsigned char ovec[16];
 102
 103     if (num > 64)
 104         return;
 105     iv = &(*ivec)[0];
 106     c2l(iv, v0);
 107     c2l(iv, v1);
 108     if (enc) {
 109         while (l >= n) {
 110             l -= n;
 111             ti[0] = v0;
 112             ti[1] = v1;
 113             DES_encrypt3(ti, ks1, ks2, ks3);
 114             c2ln(in, d0, d1, n);
 115             in += n;
 116             d0 ^= ti[0];
 117             d1 ^= ti[1];
 118             l2cn(d0, d1, out, n);
 119             out += n;
 120             /*
 121              * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
 122              * gcc :-(
 123              */
 124             if (num == 32) {
 125                 v0 = v1;
 126                 v1 = d0;
 127             } else if (num == 64) {
 128                 v0 = d0;
 129                 v1 = d1;
 130             } else {
 131                 iv = &ovec[0];
 132                 l2c(v0, iv);
 133                 l2c(v1, iv);
 134                 l2c(d0, iv);
 135                 l2c(d1, iv);
 136                 /* shift ovec left most of the bits... */
 137                 memmove(ovec, ovec + num / 8, 8 + (num % 8 ? 1 : 0));
 138                 /* now the remaining bits */
 139                 if (num % 8 != 0)
 140                     for (i = 0; i < 8; ++i) {
 141                         ovec[i] <<= num % 8;
 142                         ovec[i] |= ovec[i + 1] >> (8 - num % 8);
 143                     }
 144                 iv = &ovec[0];
 145                 c2l(iv, v0);
 146                 c2l(iv, v1);
 147             }
 148         }
 149     } else {
 150         while (l >= n) {
 151             l -= n;
 152             ti[0] = v0;
 153             ti[1] = v1;
 154             DES_encrypt3(ti, ks1, ks2, ks3);
 155             c2ln(in, d0, d1, n);
 156             in += n;
 157             /*
 158              * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
 159              * gcc :-(
 160              */
 161             if (num == 32) {
 162                 v0 = v1;
 163                 v1 = d0;
 164             } else if (num == 64) {
 165                 v0 = d0;
 166                 v1 = d1;
 167             } else {
 168                 iv = &ovec[0];
 169                 l2c(v0, iv);
 170                 l2c(v1, iv);
 171                 l2c(d0, iv);
 172                 l2c(d1, iv);
 173                 /* shift ovec left most of the bits... */
 174                 memmove(ovec, ovec + num / 8, 8 + (num % 8 ? 1 : 0));
 175                 /* now the remaining bits */
 176                 if (num % 8 != 0)
 177                     for (i = 0; i < 8; ++i) {
 178                         ovec[i] <<= num % 8;
 179                         ovec[i] |= ovec[i + 1] >> (8 - num % 8);
 180                     }
 181                 iv = &ovec[0];
 182                 c2l(iv, v0);
 183                 c2l(iv, v1);
 184             }
 185             d0 ^= ti[0];
 186             d1 ^= ti[1];
 187             l2cn(d0, d1, out, n);
 188             out += n;
 189         }
 190     }
 191     iv = &(*ivec)[0];
 192     l2c(v0, iv);
 193     l2c(v1, iv);
 194     v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0;
 195 }