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 * CAST low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <openssl/cast.h>
17 #include "cast_local.h"
18 #include "cast_s.h"
19
20 #define CAST_exp(l,A,a,n) \
21 A[n/4]=l; \
22 a[n+3]=(l )&0xff; \
23 a[n+2]=(l>> 8)&0xff; \
24 a[n+1]=(l>>16)&0xff; \
25 a[n+0]=(l>>24)&0xff;
26
27 #define S4 CAST_S_table4
28 #define S5 CAST_S_table5
29 #define S6 CAST_S_table6
30 #define S7 CAST_S_table7
31
CAST_set_key(CAST_KEY * key,int len,const unsigned char * data)32 void CAST_set_key(CAST_KEY *key, int len, const unsigned char *data)
33 {
34 CAST_LONG x[16];
35 CAST_LONG z[16];
36 CAST_LONG k[32];
37 CAST_LONG X[4], Z[4];
38 CAST_LONG l, *K;
39 int i;
40
41 for (i = 0; i < 16; i++)
42 x[i] = 0;
43 if (len > 16)
44 len = 16;
45 for (i = 0; i < len; i++)
46 x[i] = data[i];
47 if (len <= 10)
48 key->short_key = 1;
49 else
50 key->short_key = 0;
51
52 K = &k[0];
53 X[0] = ((x[0] << 24) | (x[1] << 16) | (x[2] << 8) | x[3]) & 0xffffffffL;
54 X[1] = ((x[4] << 24) | (x[5] << 16) | (x[6] << 8) | x[7]) & 0xffffffffL;
55 X[2] = ((x[8] << 24) | (x[9] << 16) | (x[10] << 8) | x[11]) & 0xffffffffL;
56 X[3] =
57 ((x[12] << 24) | (x[13] << 16) | (x[14] << 8) | x[15]) & 0xffffffffL;
58
59 for (;;) {
60 l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
61 CAST_exp(l, Z, z, 0);
62 l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
63 CAST_exp(l, Z, z, 4);
64 l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
65 CAST_exp(l, Z, z, 8);
66 l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
67 CAST_exp(l, Z, z, 12);
68
69 K[0] = S4[z[8]] ^ S5[z[9]] ^ S6[z[7]] ^ S7[z[6]] ^ S4[z[2]];
70 K[1] = S4[z[10]] ^ S5[z[11]] ^ S6[z[5]] ^ S7[z[4]] ^ S5[z[6]];
71 K[2] = S4[z[12]] ^ S5[z[13]] ^ S6[z[3]] ^ S7[z[2]] ^ S6[z[9]];
72 K[3] = S4[z[14]] ^ S5[z[15]] ^ S6[z[1]] ^ S7[z[0]] ^ S7[z[12]];
73
74 l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
75 CAST_exp(l, X, x, 0);
76 l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
77 CAST_exp(l, X, x, 4);
78 l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
79 CAST_exp(l, X, x, 8);
80 l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
81 CAST_exp(l, X, x, 12);
82
83 K[4] = S4[x[3]] ^ S5[x[2]] ^ S6[x[12]] ^ S7[x[13]] ^ S4[x[8]];
84 K[5] = S4[x[1]] ^ S5[x[0]] ^ S6[x[14]] ^ S7[x[15]] ^ S5[x[13]];
85 K[6] = S4[x[7]] ^ S5[x[6]] ^ S6[x[8]] ^ S7[x[9]] ^ S6[x[3]];
86 K[7] = S4[x[5]] ^ S5[x[4]] ^ S6[x[10]] ^ S7[x[11]] ^ S7[x[7]];
87
88 l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
89 CAST_exp(l, Z, z, 0);
90 l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
91 CAST_exp(l, Z, z, 4);
92 l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
93 CAST_exp(l, Z, z, 8);
94 l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
95 CAST_exp(l, Z, z, 12);
96
97 K[8] = S4[z[3]] ^ S5[z[2]] ^ S6[z[12]] ^ S7[z[13]] ^ S4[z[9]];
98 K[9] = S4[z[1]] ^ S5[z[0]] ^ S6[z[14]] ^ S7[z[15]] ^ S5[z[12]];
99 K[10] = S4[z[7]] ^ S5[z[6]] ^ S6[z[8]] ^ S7[z[9]] ^ S6[z[2]];
100 K[11] = S4[z[5]] ^ S5[z[4]] ^ S6[z[10]] ^ S7[z[11]] ^ S7[z[6]];
101
102 l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
103 CAST_exp(l, X, x, 0);
104 l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
105 CAST_exp(l, X, x, 4);
106 l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
107 CAST_exp(l, X, x, 8);
108 l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
109 CAST_exp(l, X, x, 12);
110
111 K[12] = S4[x[8]] ^ S5[x[9]] ^ S6[x[7]] ^ S7[x[6]] ^ S4[x[3]];
112 K[13] = S4[x[10]] ^ S5[x[11]] ^ S6[x[5]] ^ S7[x[4]] ^ S5[x[7]];
113 K[14] = S4[x[12]] ^ S5[x[13]] ^ S6[x[3]] ^ S7[x[2]] ^ S6[x[8]];
114 K[15] = S4[x[14]] ^ S5[x[15]] ^ S6[x[1]] ^ S7[x[0]] ^ S7[x[13]];
115 if (K != k)
116 break;
117 K += 16;
118 }
119
120 for (i = 0; i < 16; i++) {
121 key->data[i * 2] = k[i];
122 key->data[i * 2 + 1] = ((k[i + 16]) + 16) & 0x1f;
123 }
124 }
125