| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame] | 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 | } |