1 /* 2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <openssl/idea.h> 11 #include "idea_local.h" 12 13 static IDEA_INT inverse(unsigned int xin); 14 void IDEA_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks) 15 { 16 int i; 17 register IDEA_INT *kt, *kf, r0, r1, r2; 18 19 kt = &(ks->data[0][0]); 20 n2s(key, kt[0]); 21 n2s(key, kt[1]); 22 n2s(key, kt[2]); 23 n2s(key, kt[3]); 24 n2s(key, kt[4]); 25 n2s(key, kt[5]); 26 n2s(key, kt[6]); 27 n2s(key, kt[7]); 28 29 kf = kt; 30 kt += 8; 31 for (i = 0; i < 6; i++) { 32 r2 = kf[1]; 33 r1 = kf[2]; 34 *(kt++) = ((r2 << 9) | (r1 >> 7)) & 0xffff; 35 r0 = kf[3]; 36 *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff; 37 r1 = kf[4]; 38 *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff; 39 r0 = kf[5]; 40 *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff; 41 r1 = kf[6]; 42 *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff; 43 r0 = kf[7]; 44 *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff; 45 r1 = kf[0]; 46 if (i >= 5) 47 break; 48 *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff; 49 *(kt++) = ((r1 << 9) | (r2 >> 7)) & 0xffff; 50 kf += 8; 51 } 52 } 53 54 void IDEA_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk) 55 { 56 int r; 57 register IDEA_INT *fp, *tp, t; 58 59 tp = &(dk->data[0][0]); 60 fp = &(ek->data[8][0]); 61 for (r = 0; r < 9; r++) { 62 *(tp++) = inverse(fp[0]); 63 *(tp++) = ((int)(0x10000L - fp[2]) & 0xffff); 64 *(tp++) = ((int)(0x10000L - fp[1]) & 0xffff); 65 *(tp++) = inverse(fp[3]); 66 if (r == 8) 67 break; 68 fp -= 6; 69 *(tp++) = fp[4]; 70 *(tp++) = fp[5]; 71 } 72 73 tp = &(dk->data[0][0]); 74 t = tp[1]; 75 tp[1] = tp[2]; 76 tp[2] = t; 77 78 t = tp[49]; 79 tp[49] = tp[50]; 80 tp[50] = t; 81 } 82 83 /* taken directly from the 'paper' I'll have a look at it later */ 84 static IDEA_INT inverse(unsigned int xin) 85 { 86 long n1, n2, q, r, b1, b2, t; 87 88 if (xin == 0) 89 b2 = 0; 90 else { 91 n1 = 0x10001; 92 n2 = xin; 93 b2 = 1; 94 b1 = 0; 95 96 do { 97 r = (n1 % n2); 98 q = (n1 - r) / n2; 99 if (r == 0) { 100 if (b2 < 0) 101 b2 = 0x10001 + b2; 102 } else { 103 n1 = n2; 104 n2 = r; 105 t = b2; 106 b2 = b1 - q * b2; 107 b1 = t; 108 } 109 } while (r != 0); 110 } 111 return (IDEA_INT)b2; 112 } 113