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/cast.h>
11#include "cast_local.h"
12
13void CAST_encrypt(CAST_LONG *data, const CAST_KEY *key)
14{
15    CAST_LONG l, r, t;
16    const CAST_LONG *k;
17
18    k = &(key->data[0]);
19    l = data[0];
20    r = data[1];
21
22    E_CAST(0, k, l, r, +, ^, -);
23    E_CAST(1, k, r, l, ^, -, +);
24    E_CAST(2, k, l, r, -, +, ^);
25    E_CAST(3, k, r, l, +, ^, -);
26    E_CAST(4, k, l, r, ^, -, +);
27    E_CAST(5, k, r, l, -, +, ^);
28    E_CAST(6, k, l, r, +, ^, -);
29    E_CAST(7, k, r, l, ^, -, +);
30    E_CAST(8, k, l, r, -, +, ^);
31    E_CAST(9, k, r, l, +, ^, -);
32    E_CAST(10, k, l, r, ^, -, +);
33    E_CAST(11, k, r, l, -, +, ^);
34    if (!key->short_key) {
35        E_CAST(12, k, l, r, +, ^, -);
36        E_CAST(13, k, r, l, ^, -, +);
37        E_CAST(14, k, l, r, -, +, ^);
38        E_CAST(15, k, r, l, +, ^, -);
39    }
40
41    data[1] = l & 0xffffffffL;
42    data[0] = r & 0xffffffffL;
43}
44
45void CAST_decrypt(CAST_LONG *data, const CAST_KEY *key)
46{
47    CAST_LONG l, r, t;
48    const CAST_LONG *k;
49
50    k = &(key->data[0]);
51    l = data[0];
52    r = data[1];
53
54    if (!key->short_key) {
55        E_CAST(15, k, l, r, +, ^, -);
56        E_CAST(14, k, r, l, -, +, ^);
57        E_CAST(13, k, l, r, ^, -, +);
58        E_CAST(12, k, r, l, +, ^, -);
59    }
60    E_CAST(11, k, l, r, -, +, ^);
61    E_CAST(10, k, r, l, ^, -, +);
62    E_CAST(9, k, l, r, +, ^, -);
63    E_CAST(8, k, r, l, -, +, ^);
64    E_CAST(7, k, l, r, ^, -, +);
65    E_CAST(6, k, r, l, +, ^, -);
66    E_CAST(5, k, l, r, -, +, ^);
67    E_CAST(4, k, r, l, ^, -, +);
68    E_CAST(3, k, l, r, +, ^, -);
69    E_CAST(2, k, r, l, -, +, ^);
70    E_CAST(1, k, l, r, ^, -, +);
71    E_CAST(0, k, r, l, +, ^, -);
72
73    data[1] = l & 0xffffffffL;
74    data[0] = r & 0xffffffffL;
75}
76
77void CAST_cbc_encrypt(const unsigned char *in, unsigned char *out,
78                      long length, const CAST_KEY *ks, unsigned char *iv,
79                      int enc)
80{
81    register CAST_LONG tin0, tin1;
82    register CAST_LONG tout0, tout1, xor0, xor1;
83    register long l = length;
84    CAST_LONG tin[2];
85
86    if (enc) {
87        n2l(iv, tout0);
88        n2l(iv, tout1);
89        iv -= 8;
90        for (l -= 8; l >= 0; l -= 8) {
91            n2l(in, tin0);
92            n2l(in, tin1);
93            tin0 ^= tout0;
94            tin1 ^= tout1;
95            tin[0] = tin0;
96            tin[1] = tin1;
97            CAST_encrypt(tin, ks);
98            tout0 = tin[0];
99            tout1 = tin[1];
100            l2n(tout0, out);
101            l2n(tout1, out);
102        }
103        if (l != -8) {
104            n2ln(in, tin0, tin1, l + 8);
105            tin0 ^= tout0;
106            tin1 ^= tout1;
107            tin[0] = tin0;
108            tin[1] = tin1;
109            CAST_encrypt(tin, ks);
110            tout0 = tin[0];
111            tout1 = tin[1];
112            l2n(tout0, out);
113            l2n(tout1, out);
114        }
115        l2n(tout0, iv);
116        l2n(tout1, iv);
117    } else {
118        n2l(iv, xor0);
119        n2l(iv, xor1);
120        iv -= 8;
121        for (l -= 8; l >= 0; l -= 8) {
122            n2l(in, tin0);
123            n2l(in, tin1);
124            tin[0] = tin0;
125            tin[1] = tin1;
126            CAST_decrypt(tin, ks);
127            tout0 = tin[0] ^ xor0;
128            tout1 = tin[1] ^ xor1;
129            l2n(tout0, out);
130            l2n(tout1, out);
131            xor0 = tin0;
132            xor1 = tin1;
133        }
134        if (l != -8) {
135            n2l(in, tin0);
136            n2l(in, tin1);
137            tin[0] = tin0;
138            tin[1] = tin1;
139            CAST_decrypt(tin, ks);
140            tout0 = tin[0] ^ xor0;
141            tout1 = tin[1] ^ xor1;
142            l2nn(tout0, tout1, out, l + 8);
143            xor0 = tin0;
144            xor1 = tin1;
145        }
146        l2n(xor0, iv);
147        l2n(xor1, iv);
148    }
149    tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
150    tin[0] = tin[1] = 0;
151}
152