1 /* crypto/idea/i_skey.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/idea.h> 60 #include "idea_lcl.h" 61 62 static IDEA_INT inverse(unsigned int xin); 63 void idea_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks) 64 { 65 int i; 66 register IDEA_INT *kt,*kf,r0,r1,r2; 67 68 kt= &(ks->data[0][0]); 69 n2s(key,kt[0]); n2s(key,kt[1]); n2s(key,kt[2]); n2s(key,kt[3]); 70 n2s(key,kt[4]); n2s(key,kt[5]); n2s(key,kt[6]); n2s(key,kt[7]); 71 72 kf=kt; 73 kt+=8; 74 for (i=0; i<6; i++) 75 { 76 r2= kf[1]; 77 r1= kf[2]; 78 *(kt++)= ((r2<<9) | (r1>>7))&0xffff; 79 r0= kf[3]; 80 *(kt++)= ((r1<<9) | (r0>>7))&0xffff; 81 r1= kf[4]; 82 *(kt++)= ((r0<<9) | (r1>>7))&0xffff; 83 r0= kf[5]; 84 *(kt++)= ((r1<<9) | (r0>>7))&0xffff; 85 r1= kf[6]; 86 *(kt++)= ((r0<<9) | (r1>>7))&0xffff; 87 r0= kf[7]; 88 *(kt++)= ((r1<<9) | (r0>>7))&0xffff; 89 r1= kf[0]; 90 if (i >= 5) break; 91 *(kt++)= ((r0<<9) | (r1>>7))&0xffff; 92 *(kt++)= ((r1<<9) | (r2>>7))&0xffff; 93 kf+=8; 94 } 95 } 96 97 void idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk) 98 { 99 int r; 100 register IDEA_INT *fp,*tp,t; 101 102 tp= &(dk->data[0][0]); 103 fp= &(ek->data[8][0]); 104 for (r=0; r<9; r++) 105 { 106 *(tp++)=inverse(fp[0]); 107 *(tp++)=((int)(0x10000L-fp[2])&0xffff); 108 *(tp++)=((int)(0x10000L-fp[1])&0xffff); 109 *(tp++)=inverse(fp[3]); 110 if (r == 8) break; 111 fp-=6; 112 *(tp++)=fp[4]; 113 *(tp++)=fp[5]; 114 } 115 116 tp= &(dk->data[0][0]); 117 t=tp[1]; 118 tp[1]=tp[2]; 119 tp[2]=t; 120 121 t=tp[49]; 122 tp[49]=tp[50]; 123 tp[50]=t; 124 } 125 126 /* taken directly from the 'paper' I'll have a look at it later */ 127 static IDEA_INT inverse(unsigned int xin) 128 { 129 int32_t n1,n2,q,r,b1,b2,t; 130 131 if (xin == 0) 132 b2=0; 133 else 134 { 135 n1=0x10001; 136 n2=xin; 137 b2=1; 138 b1=0; 139 140 do { 141 r=(n1%n2); 142 q=(n1-r)/n2; 143 if (r == 0) 144 { if (b2 < 0) b2=0x10001+b2; } 145 else 146 { 147 n1=n2; 148 n2=r; 149 t=b2; 150 b2=b1-q*b2; 151 b1=t; 152 } 153 } while (r != 0); 154 } 155 return((IDEA_INT)b2); 156 } 157