c_ofb64.c revision 296341
1273515Sbryanv/* crypto/cast/c_ofb64.c */ 2273515Sbryanv/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3273515Sbryanv * All rights reserved. 4273515Sbryanv * 5273515Sbryanv * This package is an SSL implementation written 6273515Sbryanv * by Eric Young (eay@cryptsoft.com). 7273515Sbryanv * The implementation was written so as to conform with Netscapes SSL. 8273515Sbryanv * 9273515Sbryanv * This library is free for commercial and non-commercial use as long as 10273515Sbryanv * the following conditions are aheared to. The following conditions 11273515Sbryanv * apply to all code found in this distribution, be it the RC4, RSA, 12273515Sbryanv * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13273515Sbryanv * included with this distribution is covered by the same copyright terms 14273515Sbryanv * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15273515Sbryanv * 16273515Sbryanv * Copyright remains Eric Young's, and as such any Copyright notices in 17273515Sbryanv * the code are not to be removed. 18273515Sbryanv * If this package is used in a product, Eric Young should be given attribution 19273515Sbryanv * as the author of the parts of the library used. 20273515Sbryanv * This can be in the form of a textual message at program startup or 21273515Sbryanv * in documentation (online or textual) provided with the package. 22273515Sbryanv * 23273515Sbryanv * Redistribution and use in source and binary forms, with or without 24273515Sbryanv * modification, are permitted provided that the following conditions 25273515Sbryanv * are met: 26273515Sbryanv * 1. Redistributions of source code must retain the copyright 27273515Sbryanv * notice, this list of conditions and the following disclaimer. 28273515Sbryanv * 2. Redistributions in binary form must reproduce the above copyright 29273515Sbryanv * notice, this list of conditions and the following disclaimer in the 30273515Sbryanv * documentation and/or other materials provided with the distribution. 31273515Sbryanv * 3. All advertising materials mentioning features or use of this software 32273515Sbryanv * must display the following acknowledgement: 33273515Sbryanv * "This product includes cryptographic software written by 34273515Sbryanv * Eric Young (eay@cryptsoft.com)" 35273515Sbryanv * The word 'cryptographic' can be left out if the rouines from the library 36273515Sbryanv * being used are not cryptographic related :-). 37273515Sbryanv * 4. If you include any Windows specific code (or a derivative thereof) from 38273515Sbryanv * the apps directory (application code) you must include an acknowledgement: 39273515Sbryanv * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40273515Sbryanv * 41273515Sbryanv * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42273515Sbryanv * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43273515Sbryanv * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44273515Sbryanv * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45273515Sbryanv * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46273515Sbryanv * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47273515Sbryanv * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48273515Sbryanv * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49273515Sbryanv * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50273515Sbryanv * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51273515Sbryanv * SUCH DAMAGE. 52273515Sbryanv * 53273515Sbryanv * The licence and distribution terms for any publically available version or 54273515Sbryanv * derivative of this code cannot be changed. i.e. this code cannot simply be 55273515Sbryanv * copied and put under another distribution licence 56273515Sbryanv * [including the GNU Public Licence.] 57273515Sbryanv */ 58273515Sbryanv 59275273Sbryanv#include <openssl/cast.h> 60273515Sbryanv#include "cast_lcl.h" 61273515Sbryanv 62273515Sbryanv/* 63273515Sbryanv * The input and output encrypted as though 64bit ofb mode is being used. 64273515Sbryanv * The extra state information to record how much of the 64bit block we have 65273515Sbryanv * used is contained in *num; 66273515Sbryanv */ 67273515Sbryanvvoid CAST_ofb64_encrypt(const unsigned char *in, unsigned char *out, 68 long length, const CAST_KEY *schedule, 69 unsigned char *ivec, int *num) 70{ 71 register CAST_LONG v0, v1, t; 72 register int n = *num; 73 register long l = length; 74 unsigned char d[8]; 75 register char *dp; 76 CAST_LONG ti[2]; 77 unsigned char *iv; 78 int save = 0; 79 80 iv = ivec; 81 n2l(iv, v0); 82 n2l(iv, v1); 83 ti[0] = v0; 84 ti[1] = v1; 85 dp = (char *)d; 86 l2n(v0, dp); 87 l2n(v1, dp); 88 while (l--) { 89 if (n == 0) { 90 CAST_encrypt((CAST_LONG *)ti, schedule); 91 dp = (char *)d; 92 t = ti[0]; 93 l2n(t, dp); 94 t = ti[1]; 95 l2n(t, dp); 96 save++; 97 } 98 *(out++) = *(in++) ^ d[n]; 99 n = (n + 1) & 0x07; 100 } 101 if (save) { 102 v0 = ti[0]; 103 v1 = ti[1]; 104 iv = ivec; 105 l2n(v0, iv); 106 l2n(v1, iv); 107 } 108 t = v0 = v1 = ti[0] = ti[1] = 0; 109 *num = n; 110} 111