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112 lines
2.7 KiB
C
112 lines
2.7 KiB
C
/*
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* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the OpenSSL license (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include <openssl/idea.h>
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#include "idea_lcl.h"
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static IDEA_INT inverse(unsigned int xin);
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void IDEA_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks)
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{
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int i;
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register IDEA_INT *kt, *kf, r0, r1, r2;
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kt = &(ks->data[0][0]);
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n2s(key, kt[0]);
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n2s(key, kt[1]);
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n2s(key, kt[2]);
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n2s(key, kt[3]);
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n2s(key, kt[4]);
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n2s(key, kt[5]);
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n2s(key, kt[6]);
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n2s(key, kt[7]);
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kf = kt;
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kt += 8;
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for (i = 0; i < 6; i++) {
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r2 = kf[1];
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r1 = kf[2];
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*(kt++) = ((r2 << 9) | (r1 >> 7)) & 0xffff;
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r0 = kf[3];
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*(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
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r1 = kf[4];
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*(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
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r0 = kf[5];
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*(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
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r1 = kf[6];
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*(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
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r0 = kf[7];
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*(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
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r1 = kf[0];
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if (i >= 5)
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break;
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*(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
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*(kt++) = ((r1 << 9) | (r2 >> 7)) & 0xffff;
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kf += 8;
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}
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}
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void IDEA_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)
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{
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int r;
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register IDEA_INT *fp, *tp, t;
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tp = &(dk->data[0][0]);
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fp = &(ek->data[8][0]);
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for (r = 0; r < 9; r++) {
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*(tp++) = inverse(fp[0]);
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*(tp++) = ((int)(0x10000L - fp[2]) & 0xffff);
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*(tp++) = ((int)(0x10000L - fp[1]) & 0xffff);
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*(tp++) = inverse(fp[3]);
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if (r == 8)
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break;
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fp -= 6;
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*(tp++) = fp[4];
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*(tp++) = fp[5];
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}
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tp = &(dk->data[0][0]);
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t = tp[1];
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tp[1] = tp[2];
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tp[2] = t;
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t = tp[49];
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tp[49] = tp[50];
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tp[50] = t;
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}
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/* taken directly from the 'paper' I'll have a look at it later */
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static IDEA_INT inverse(unsigned int xin)
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{
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long n1, n2, q, r, b1, b2, t;
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if (xin == 0)
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b2 = 0;
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else {
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n1 = 0x10001;
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n2 = xin;
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b2 = 1;
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b1 = 0;
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do {
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r = (n1 % n2);
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q = (n1 - r) / n2;
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if (r == 0) {
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if (b2 < 0)
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b2 = 0x10001 + b2;
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} else {
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n1 = n2;
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n2 = r;
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t = b2;
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b2 = b1 - q * b2;
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b1 = t;
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}
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} while (r != 0);
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}
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return (IDEA_INT)b2;
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}
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