1 /*
2 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 /*
11 * IDEA low level APIs are deprecated for public use, but still ok for internal
12 * use where we're using them to implement the higher level EVP interface, as is
13 * the case here.
14 */
15 #include "internal/deprecated.h"
16
17 #include <openssl/idea.h>
18 #include "idea_local.h"
19
20 static IDEA_INT inverse(unsigned int xin);
IDEA_set_encrypt_key(const unsigned char * key,IDEA_KEY_SCHEDULE * ks)21 void IDEA_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks)
22 {
23 int i;
24 register IDEA_INT *kt, *kf, r0, r1, r2;
25
26 kt = &(ks->data[0][0]);
27 n2s(key, kt[0]);
28 n2s(key, kt[1]);
29 n2s(key, kt[2]);
30 n2s(key, kt[3]);
31 n2s(key, kt[4]);
32 n2s(key, kt[5]);
33 n2s(key, kt[6]);
34 n2s(key, kt[7]);
35
36 kf = kt;
37 kt += 8;
38 for (i = 0; i < 6; i++) {
39 r2 = kf[1];
40 r1 = kf[2];
41 *(kt++) = ((r2 << 9) | (r1 >> 7)) & 0xffff;
42 r0 = kf[3];
43 *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
44 r1 = kf[4];
45 *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
46 r0 = kf[5];
47 *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
48 r1 = kf[6];
49 *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
50 r0 = kf[7];
51 *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
52 r1 = kf[0];
53 if (i >= 5)
54 break;
55 *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
56 *(kt++) = ((r1 << 9) | (r2 >> 7)) & 0xffff;
57 kf += 8;
58 }
59 }
60
IDEA_set_decrypt_key(IDEA_KEY_SCHEDULE * ek,IDEA_KEY_SCHEDULE * dk)61 void IDEA_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)
62 {
63 int r;
64 register IDEA_INT *fp, *tp, t;
65
66 tp = &(dk->data[0][0]);
67 fp = &(ek->data[8][0]);
68 for (r = 0; r < 9; r++) {
69 *(tp++) = inverse(fp[0]);
70 *(tp++) = ((int)(0x10000L - fp[2]) & 0xffff);
71 *(tp++) = ((int)(0x10000L - fp[1]) & 0xffff);
72 *(tp++) = inverse(fp[3]);
73 if (r == 8)
74 break;
75 fp -= 6;
76 *(tp++) = fp[4];
77 *(tp++) = fp[5];
78 }
79
80 tp = &(dk->data[0][0]);
81 t = tp[1];
82 tp[1] = tp[2];
83 tp[2] = t;
84
85 t = tp[49];
86 tp[49] = tp[50];
87 tp[50] = t;
88 }
89
90 /* taken directly from the 'paper' I'll have a look at it later */
inverse(unsigned int xin)91 static IDEA_INT inverse(unsigned int xin)
92 {
93 long n1, n2, q, r, b1, b2, t;
94
95 if (xin == 0)
96 b2 = 0;
97 else {
98 n1 = 0x10001;
99 n2 = xin;
100 b2 = 1;
101 b1 = 0;
102
103 do {
104 r = (n1 % n2);
105 q = (n1 - r) / n2;
106 if (r == 0) {
107 if (b2 < 0)
108 b2 = 0x10001 + b2;
109 } else {
110 n1 = n2;
111 n2 = r;
112 t = b2;
113 b2 = b1 - q * b2;
114 b1 = t;
115 }
116 } while (r != 0);
117 }
118 return (IDEA_INT)b2;
119 }
120