2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
15 * The input and output are loaded in multiples of 8 bits. What this means is
16 * that if you hame numbits=12 and length=2 the first 12 bits will be
17 * retrieved from the first byte and half the second. The second 12 bits
18 * will come from the 3rd and half the 4th byte.
21 * Until Aug 1 2003 this function did not correctly implement CFB-r, so it
22 * will not be compatible with any encryption prior to that date. Ben.
24 void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
25 long length, DES_key_schedule *schedule,
26 DES_cblock *ivec, int enc)
28 register DES_LONG d0, d1, v0, v1;
29 register unsigned long l = length;
30 register int num = numbits / 8, n = (numbits + 7) / 8, i, rem =
35 unsigned char ovec[16];
38 unsigned char *ovec = (unsigned char *)sh;
40 /* I kind of count that compiler optimizes away this assertion, */
41 assert(sizeof(sh[0]) == 4); /* as this holds true for all, */
42 /* but 16-bit platforms... */
46 if (numbits <= 0 || numbits > 64)
52 while (l >= (unsigned long)n) {
56 DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
64 * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
70 } else if (numbits == 64) {
81 sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1;
84 memmove(ovec, ovec + num, 8);
86 for (i = 0; i < 8; ++i)
87 ovec[i] = ovec[i + num] << rem |
88 ovec[i + num + 1] >> (8 - rem);
90 v0 = sh[0], v1 = sh[1];
99 while (l >= (unsigned long)n) {
103 DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
107 * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
113 } else if (numbits == 64) {
124 sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1;
127 memmove(ovec, ovec + num, 8);
129 for (i = 0; i < 8; ++i)
130 ovec[i] = ovec[i + num] << rem |
131 ovec[i + num + 1] >> (8 - rem);
133 v0 = sh[0], v1 = sh[1];
142 l2cn(d0, d1, out, n);
149 v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0;