[331] | 1 | /*
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| 2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
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| 3 | *
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| 4 | * Licensed under the OpenSSL license (the "License"). You may not use
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| 5 | * this file except in compliance with the License. You can obtain a copy
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| 6 | * in the file LICENSE in the source distribution or at
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| 7 | * https://www.openssl.org/source/license.html
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| 8 | */
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| 9 |
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| 10 | #include "e_os.h"
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| 11 | #include "des_locl.h"
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| 12 | #include <assert.h>
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| 13 |
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| 14 | /*
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| 15 | * The input and output are loaded in multiples of 8 bits. What this means is
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| 16 | * that if you hame numbits=12 and length=2 the first 12 bits will be
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| 17 | * retrieved from the first byte and half the second. The second 12 bits
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| 18 | * will come from the 3rd and half the 4th byte.
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| 19 | */
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| 20 | /*
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| 21 | * Until Aug 1 2003 this function did not correctly implement CFB-r, so it
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| 22 | * will not be compatible with any encryption prior to that date. Ben.
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| 23 | */
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| 24 | void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
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| 25 | long length, DES_key_schedule *schedule,
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| 26 | DES_cblock *ivec, int enc)
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| 27 | {
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| 28 | register DES_LONG d0, d1, v0, v1;
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| 29 | register unsigned long l = length;
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| 30 | register int num = numbits / 8, n = (numbits + 7) / 8, i, rem =
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| 31 | numbits % 8;
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| 32 | DES_LONG ti[2];
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| 33 | unsigned char *iv;
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| 34 | #ifndef L_ENDIAN
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| 35 | unsigned char ovec[16];
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| 36 | #else
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| 37 | unsigned int sh[4];
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| 38 | unsigned char *ovec = (unsigned char *)sh;
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| 39 |
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| 40 | /* I kind of count that compiler optimizes away this assertioni, */
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| 41 | assert(sizeof(sh[0]) == 4); /* as this holds true for all, */
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| 42 | /* but 16-bit platforms... */
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| 43 |
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| 44 | #endif
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| 45 |
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| 46 | if (numbits <= 0 || numbits > 64)
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| 47 | return;
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| 48 | iv = &(*ivec)[0];
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| 49 | c2l(iv, v0);
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| 50 | c2l(iv, v1);
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| 51 | if (enc) {
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| 52 | while (l >= (unsigned long)n) {
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| 53 | l -= n;
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| 54 | ti[0] = v0;
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| 55 | ti[1] = v1;
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| 56 | DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
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| 57 | c2ln(in, d0, d1, n);
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| 58 | in += n;
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| 59 | d0 ^= ti[0];
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| 60 | d1 ^= ti[1];
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| 61 | l2cn(d0, d1, out, n);
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| 62 | out += n;
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| 63 | /*
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| 64 | * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
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| 65 | * gcc :-(
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| 66 | */
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| 67 | if (numbits == 32) {
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| 68 | v0 = v1;
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| 69 | v1 = d0;
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| 70 | } else if (numbits == 64) {
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| 71 | v0 = d0;
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| 72 | v1 = d1;
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| 73 | } else {
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| 74 | #ifndef L_ENDIAN
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| 75 | iv = &ovec[0];
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| 76 | l2c(v0, iv);
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| 77 | l2c(v1, iv);
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| 78 | l2c(d0, iv);
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| 79 | l2c(d1, iv);
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| 80 | #else
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| 81 | sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1;
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| 82 | #endif
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| 83 | if (rem == 0)
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| 84 | memmove(ovec, ovec + num, 8);
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| 85 | else
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| 86 | for (i = 0; i < 8; ++i)
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| 87 | ovec[i] = ovec[i + num] << rem |
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| 88 | ovec[i + num + 1] >> (8 - rem);
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| 89 | #ifdef L_ENDIAN
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| 90 | v0 = sh[0], v1 = sh[1];
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| 91 | #else
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| 92 | iv = &ovec[0];
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| 93 | c2l(iv, v0);
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| 94 | c2l(iv, v1);
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| 95 | #endif
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| 96 | }
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| 97 | }
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| 98 | } else {
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| 99 | while (l >= (unsigned long)n) {
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| 100 | l -= n;
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| 101 | ti[0] = v0;
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| 102 | ti[1] = v1;
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| 103 | DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
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| 104 | c2ln(in, d0, d1, n);
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| 105 | in += n;
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| 106 | /*
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| 107 | * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
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| 108 | * gcc :-(
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| 109 | */
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| 110 | if (numbits == 32) {
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| 111 | v0 = v1;
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| 112 | v1 = d0;
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| 113 | } else if (numbits == 64) {
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| 114 | v0 = d0;
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| 115 | v1 = d1;
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| 116 | } else {
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| 117 | #ifndef L_ENDIAN
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| 118 | iv = &ovec[0];
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| 119 | l2c(v0, iv);
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| 120 | l2c(v1, iv);
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| 121 | l2c(d0, iv);
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| 122 | l2c(d1, iv);
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| 123 | #else
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| 124 | sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1;
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| 125 | #endif
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| 126 | if (rem == 0)
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| 127 | memmove(ovec, ovec + num, 8);
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| 128 | else
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| 129 | for (i = 0; i < 8; ++i)
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| 130 | ovec[i] = ovec[i + num] << rem |
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| 131 | ovec[i + num + 1] >> (8 - rem);
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| 132 | #ifdef L_ENDIAN
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| 133 | v0 = sh[0], v1 = sh[1];
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| 134 | #else
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| 135 | iv = &ovec[0];
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| 136 | c2l(iv, v0);
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| 137 | c2l(iv, v1);
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| 138 | #endif
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| 139 | }
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| 140 | d0 ^= ti[0];
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| 141 | d1 ^= ti[1];
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| 142 | l2cn(d0, d1, out, n);
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| 143 | out += n;
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| 144 | }
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| 145 | }
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| 146 | iv = &(*ivec)[0];
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| 147 | l2c(v0, iv);
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| 148 | l2c(v1, iv);
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| 149 | v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0;
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| 150 | }
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