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 "e_os.h" 17 #include "des_local.h" 18 #include <assert.h> 19 20 /* 21 * The input and output are loaded in multiples of 8 bits. What this means is 22 * that if you hame numbits=12 and length=2 the first 12 bits will be 23 * retrieved from the first byte and half the second. The second 12 bits 24 * will come from the 3rd and half the 4th byte. 25 */ 26 /* 27 * Until Aug 1 2003 this function did not correctly implement CFB-r, so it 28 * will not be compatible with any encryption prior to that date. Ben. 29 */ 30 void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, 31 long length, DES_key_schedule *schedule, 32 DES_cblock *ivec, int enc) 33 { 34 register DES_LONG d0, d1, v0, v1; 35 register unsigned long l = length; 36 register int num = numbits / 8, n = (numbits + 7) / 8, i, rem = 37 numbits % 8; 38 DES_LONG ti[2]; 39 unsigned char *iv; 40 #ifndef L_ENDIAN 41 unsigned char ovec[16]; 42 #else 43 unsigned int sh[4]; 44 unsigned char *ovec = (unsigned char *)sh; 45 46 /* I kind of count that compiler optimizes away this assertion, */ 47 assert(sizeof(sh[0]) == 4); /* as this holds true for all, */ 48 /* but 16-bit platforms... */ 49 50 #endif 51 52 if (numbits <= 0 || numbits > 64) 53 return; 54 iv = &(*ivec)[0]; 55 c2l(iv, v0); 56 c2l(iv, v1); 57 if (enc) { 58 while (l >= (unsigned long)n) { 59 l -= n; 60 ti[0] = v0; 61 ti[1] = v1; 62 DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 63 c2ln(in, d0, d1, n); 64 in += n; 65 d0 ^= ti[0]; 66 d1 ^= ti[1]; 67 l2cn(d0, d1, out, n); 68 out += n; 69 /* 70 * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 71 * gcc :-( 72 */ 73 if (numbits == 32) { 74 v0 = v1; 75 v1 = d0; 76 } else if (numbits == 64) { 77 v0 = d0; 78 v1 = d1; 79 } else { 80 #ifndef L_ENDIAN 81 iv = &ovec[0]; 82 l2c(v0, iv); 83 l2c(v1, iv); 84 l2c(d0, iv); 85 l2c(d1, iv); 86 #else 87 sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 88 #endif 89 if (rem == 0) 90 memmove(ovec, ovec + num, 8); 91 else 92 for (i = 0; i < 8; ++i) 93 ovec[i] = ovec[i + num] << rem | 94 ovec[i + num + 1] >> (8 - rem); 95 #ifdef L_ENDIAN 96 v0 = sh[0], v1 = sh[1]; 97 #else 98 iv = &ovec[0]; 99 c2l(iv, v0); 100 c2l(iv, v1); 101 #endif 102 } 103 } 104 } else { 105 while (l >= (unsigned long)n) { 106 l -= n; 107 ti[0] = v0; 108 ti[1] = v1; 109 DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 110 c2ln(in, d0, d1, n); 111 in += n; 112 /* 113 * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 114 * gcc :-( 115 */ 116 if (numbits == 32) { 117 v0 = v1; 118 v1 = d0; 119 } else if (numbits == 64) { 120 v0 = d0; 121 v1 = d1; 122 } else { 123 #ifndef L_ENDIAN 124 iv = &ovec[0]; 125 l2c(v0, iv); 126 l2c(v1, iv); 127 l2c(d0, iv); 128 l2c(d1, iv); 129 #else 130 sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 131 #endif 132 if (rem == 0) 133 memmove(ovec, ovec + num, 8); 134 else 135 for (i = 0; i < 8; ++i) 136 ovec[i] = ovec[i + num] << rem | 137 ovec[i + num + 1] >> (8 - rem); 138 #ifdef L_ENDIAN 139 v0 = sh[0], v1 = sh[1]; 140 #else 141 iv = &ovec[0]; 142 c2l(iv, v0); 143 c2l(iv, v1); 144 #endif 145 } 146 d0 ^= ti[0]; 147 d1 ^= ti[1]; 148 l2cn(d0, d1, out, n); 149 out += n; 150 } 151 } 152 iv = &(*ivec)[0]; 153 l2c(v0, iv); 154 l2c(v1, iv); 155 v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0; 156 } 157