crypto/des/pcbc_enc.c

   1 /*
   2  * Copyright 1995-2016 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 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
  19                       long length, DES_key_schedule *schedule,
  20                       DES_cblock *ivec, int enc)
  21 {
  22     register DES_LONG sin0, sin1, xor0, xor1, tout0, tout1;
  23     DES_LONG tin[2];
  24     const unsigned char *in;
  25     unsigned char *out, *iv;
  26
  27     in = input;
  28     out = output;
  29     iv = &(*ivec)[0];
  30
  31     if (enc) {
  32         c2l(iv, xor0);
  33         c2l(iv, xor1);
  34         for (; length > 0; length -= 8) {
  35             if (length >= 8) {
  36                 c2l(in, sin0);
  37                 c2l(in, sin1);
  38             } else
  39                 c2ln(in, sin0, sin1, length);
  40             tin[0] = sin0 ^ xor0;
  41             tin[1] = sin1 ^ xor1;
  42             DES_encrypt1((DES_LONG *)tin, schedule, DES_ENCRYPT);
  43             tout0 = tin[0];
  44             tout1 = tin[1];
  45             xor0 = sin0 ^ tout0;
  46             xor1 = sin1 ^ tout1;
  47             l2c(tout0, out);
  48             l2c(tout1, out);
  49         }
  50     } else {
  51         c2l(iv, xor0);
  52         c2l(iv, xor1);
  53         for (; length > 0; length -= 8) {
  54             c2l(in, sin0);
  55             c2l(in, sin1);
  56             tin[0] = sin0;
  57             tin[1] = sin1;
  58             DES_encrypt1((DES_LONG *)tin, schedule, DES_DECRYPT);
  59             tout0 = tin[0] ^ xor0;
  60             tout1 = tin[1] ^ xor1;
  61             if (length >= 8) {
  62                 l2c(tout0, out);
  63                 l2c(tout1, out);
  64             } else
  65                 l2cn(tout0, tout1, out, length);
  66             xor0 = tout0 ^ sin0;
  67             xor1 = tout1 ^ sin1;
  68         }
  69     }
  70     tin[0] = tin[1] = 0;
  71     sin0 = sin1 = xor0 = xor1 = tout0 = tout1 = 0;
  72 }