155714Skris/* crypto/des/ofb_enc.c */ 255714Skris/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 355714Skris * All rights reserved. 455714Skris * 555714Skris * This package is an SSL implementation written 655714Skris * by Eric Young (eay@cryptsoft.com). 755714Skris * The implementation was written so as to conform with Netscapes SSL. 8296341Sdelphij * 955714Skris * This library is free for commercial and non-commercial use as long as 1055714Skris * the following conditions are aheared to. The following conditions 1155714Skris * apply to all code found in this distribution, be it the RC4, RSA, 1255714Skris * lhash, DES, etc., code; not just the SSL code. The SSL documentation 1355714Skris * included with this distribution is covered by the same copyright terms 1455714Skris * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15296341Sdelphij * 1655714Skris * Copyright remains Eric Young's, and as such any Copyright notices in 1755714Skris * the code are not to be removed. 1855714Skris * If this package is used in a product, Eric Young should be given attribution 1955714Skris * as the author of the parts of the library used. 2055714Skris * This can be in the form of a textual message at program startup or 2155714Skris * in documentation (online or textual) provided with the package. 22296341Sdelphij * 2355714Skris * Redistribution and use in source and binary forms, with or without 2455714Skris * modification, are permitted provided that the following conditions 2555714Skris * are met: 2655714Skris * 1. Redistributions of source code must retain the copyright 2755714Skris * notice, this list of conditions and the following disclaimer. 2855714Skris * 2. Redistributions in binary form must reproduce the above copyright 2955714Skris * notice, this list of conditions and the following disclaimer in the 3055714Skris * documentation and/or other materials provided with the distribution. 3155714Skris * 3. All advertising materials mentioning features or use of this software 3255714Skris * must display the following acknowledgement: 3355714Skris * "This product includes cryptographic software written by 3455714Skris * Eric Young (eay@cryptsoft.com)" 3555714Skris * The word 'cryptographic' can be left out if the rouines from the library 3655714Skris * being used are not cryptographic related :-). 37296341Sdelphij * 4. If you include any Windows specific code (or a derivative thereof) from 3855714Skris * the apps directory (application code) you must include an acknowledgement: 3955714Skris * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40296341Sdelphij * 4155714Skris * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 4255714Skris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 4355714Skris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 4455714Skris * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 4555714Skris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 4655714Skris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 4755714Skris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 4855714Skris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 4955714Skris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 5055714Skris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 5155714Skris * SUCH DAMAGE. 52296341Sdelphij * 5355714Skris * The licence and distribution terms for any publically available version or 5455714Skris * derivative of this code cannot be changed. i.e. this code cannot simply be 5555714Skris * copied and put under another distribution licence 5655714Skris * [including the GNU Public Licence.] 5755714Skris */ 5855714Skris 5955714Skris#include "des_locl.h" 6055714Skris 61296341Sdelphij/* 62296341Sdelphij * The input and output are loaded in multiples of 8 bits. What this means is 63296341Sdelphij * that if you hame numbits=12 and length=2 the first 12 bits will be 64296341Sdelphij * retrieved from the first byte and half the second. The second 12 bits 65296341Sdelphij * will come from the 3rd and half the 4th byte. 6655714Skris */ 67109998Smarkmvoid DES_ofb_encrypt(const unsigned char *in, unsigned char *out, int numbits, 68296341Sdelphij long length, DES_key_schedule *schedule, 69296341Sdelphij DES_cblock *ivec) 70296341Sdelphij{ 71296341Sdelphij register DES_LONG d0, d1, vv0, vv1, v0, v1, n = (numbits + 7) / 8; 72296341Sdelphij register DES_LONG mask0, mask1; 73296341Sdelphij register long l = length; 74296341Sdelphij register int num = numbits; 75296341Sdelphij DES_LONG ti[2]; 76296341Sdelphij unsigned char *iv; 7755714Skris 78296341Sdelphij if (num > 64) 79296341Sdelphij return; 80296341Sdelphij if (num > 32) { 81296341Sdelphij mask0 = 0xffffffffL; 82296341Sdelphij if (num >= 64) 83296341Sdelphij mask1 = mask0; 84296341Sdelphij else 85296341Sdelphij mask1 = (1L << (num - 32)) - 1; 86296341Sdelphij } else { 87296341Sdelphij if (num == 32) 88296341Sdelphij mask0 = 0xffffffffL; 89296341Sdelphij else 90296341Sdelphij mask0 = (1L << num) - 1; 91296341Sdelphij mask1 = 0x00000000L; 92296341Sdelphij } 9355714Skris 94296341Sdelphij iv = &(*ivec)[0]; 95296341Sdelphij c2l(iv, v0); 96296341Sdelphij c2l(iv, v1); 97296341Sdelphij ti[0] = v0; 98296341Sdelphij ti[1] = v1; 99296341Sdelphij while (l-- > 0) { 100296341Sdelphij ti[0] = v0; 101296341Sdelphij ti[1] = v1; 102296341Sdelphij DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 103296341Sdelphij vv0 = ti[0]; 104296341Sdelphij vv1 = ti[1]; 105296341Sdelphij c2ln(in, d0, d1, n); 106296341Sdelphij in += n; 107296341Sdelphij d0 = (d0 ^ vv0) & mask0; 108296341Sdelphij d1 = (d1 ^ vv1) & mask1; 109296341Sdelphij l2cn(d0, d1, out, n); 110296341Sdelphij out += n; 11155714Skris 112296341Sdelphij if (num == 32) { 113296341Sdelphij v0 = v1; 114296341Sdelphij v1 = vv0; 115296341Sdelphij } else if (num == 64) { 116296341Sdelphij v0 = vv0; 117296341Sdelphij v1 = vv1; 118296341Sdelphij } else if (num > 32) { /* && num != 64 */ 119296341Sdelphij v0 = ((v1 >> (num - 32)) | (vv0 << (64 - num))) & 0xffffffffL; 120296341Sdelphij v1 = ((vv0 >> (num - 32)) | (vv1 << (64 - num))) & 0xffffffffL; 121296341Sdelphij } else { /* num < 32 */ 12255714Skris 123296341Sdelphij v0 = ((v0 >> num) | (v1 << (32 - num))) & 0xffffffffL; 124296341Sdelphij v1 = ((v1 >> num) | (vv0 << (32 - num))) & 0xffffffffL; 125296341Sdelphij } 126296341Sdelphij } 127296341Sdelphij iv = &(*ivec)[0]; 128296341Sdelphij l2c(v0, iv); 129296341Sdelphij l2c(v1, iv); 130296341Sdelphij v0 = v1 = d0 = d1 = ti[0] = ti[1] = vv0 = vv1 = 0; 131296341Sdelphij} 132