1 /* crypto/rc2/rc2cfb64.c */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59 #include <openssl/rc2.h> 60 #include "rc2_locl.h" 61 62 /* 63 * The input and output encrypted as though 64bit cfb mode is being used. 64 * The extra state information to record how much of the 64bit block we have 65 * used is contained in *num; 66 */ 67 68 void RC2_cfb64_encrypt(const unsigned char *in, unsigned char *out, 69 long length, RC2_KEY *schedule, unsigned char *ivec, 70 int *num, int encrypt) 71 { 72 register unsigned long v0, v1, t; 73 register int n = *num; 74 register long l = length; 75 unsigned long ti[2]; 76 unsigned char *iv, c, cc; 77 78 iv = (unsigned char *)ivec; 79 if (encrypt) { 80 while (l--) { 81 if (n == 0) { 82 c2l(iv, v0); 83 ti[0] = v0; 84 c2l(iv, v1); 85 ti[1] = v1; 86 RC2_encrypt((unsigned long *)ti, schedule); 87 iv = (unsigned char *)ivec; 88 t = ti[0]; 89 l2c(t, iv); 90 t = ti[1]; 91 l2c(t, iv); 92 iv = (unsigned char *)ivec; 93 } 94 c = *(in++) ^ iv[n]; 95 *(out++) = c; 96 iv[n] = c; 97 n = (n + 1) & 0x07; 98 } 99 } else { 100 while (l--) { 101 if (n == 0) { 102 c2l(iv, v0); 103 ti[0] = v0; 104 c2l(iv, v1); 105 ti[1] = v1; 106 RC2_encrypt((unsigned long *)ti, schedule); 107 iv = (unsigned char *)ivec; 108 t = ti[0]; 109 l2c(t, iv); 110 t = ti[1]; 111 l2c(t, iv); 112 iv = (unsigned char *)ivec; 113 } 114 cc = *(in++); 115 c = iv[n]; 116 iv[n] = cc; 117 *(out++) = c ^ cc; 118 n = (n + 1) & 0x07; 119 } 120 } 121 v0 = v1 = ti[0] = ti[1] = t = c = cc = 0; 122 *num = n; 123 } 124