/* crypto/idea/i_skey.c */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #include <openssl/idea.h> #include "idea_lcl.h" static IDEA_INT inverse(unsigned int xin); void idea_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks) { int i; register IDEA_INT *kt,*kf,r0,r1,r2; kt= &(ks->data[0][0]); n2s(key,kt[0]); n2s(key,kt[1]); n2s(key,kt[2]); n2s(key,kt[3]); n2s(key,kt[4]); n2s(key,kt[5]); n2s(key,kt[6]); n2s(key,kt[7]); kf=kt; kt+=8; for (i=0; i<6; i++) { r2= kf[1]; r1= kf[2]; *(kt++)= ((r2<<9) | (r1>>7))&0xffff; r0= kf[3]; *(kt++)= ((r1<<9) | (r0>>7))&0xffff; r1= kf[4]; *(kt++)= ((r0<<9) | (r1>>7))&0xffff; r0= kf[5]; *(kt++)= ((r1<<9) | (r0>>7))&0xffff; r1= kf[6]; *(kt++)= ((r0<<9) | (r1>>7))&0xffff; r0= kf[7]; *(kt++)= ((r1<<9) | (r0>>7))&0xffff; r1= kf[0]; if (i >= 5) break; *(kt++)= ((r0<<9) | (r1>>7))&0xffff; *(kt++)= ((r1<<9) | (r2>>7))&0xffff; kf+=8; } } void idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk) { int r; register IDEA_INT *fp,*tp,t; tp= &(dk->data[0][0]); fp= &(ek->data[8][0]); for (r=0; r<9; r++) { *(tp++)=inverse(fp[0]); *(tp++)=((int)(0x10000L-fp[2])&0xffff); *(tp++)=((int)(0x10000L-fp[1])&0xffff); *(tp++)=inverse(fp[3]); if (r == 8) break; fp-=6; *(tp++)=fp[4]; *(tp++)=fp[5]; } tp= &(dk->data[0][0]); t=tp[1]; tp[1]=tp[2]; tp[2]=t; t=tp[49]; tp[49]=tp[50]; tp[50]=t; } /* taken directly from the 'paper' I'll have a look at it later */ static IDEA_INT inverse(unsigned int xin) { long n1,n2,q,r,b1,b2,t; if (xin == 0) b2=0; else { n1=0x10001; n2=xin; b2=1; b1=0; do { r=(n1%n2); q=(n1-r)/n2; if (r == 0) { if (b2 < 0) b2=0x10001+b2; } else { n1=n2; n2=r; t=b2; b2=b1-q*b2; b1=t; } } while (r != 0); } return((IDEA_INT)b2); }

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