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 * RC2 low level APIs are deprecated for public use, but still ok for internal
12 * use.
13 */
14#include "internal/deprecated.h"
15
16#include <openssl/rc2.h>
17#include "rc2_local.h"
18
19void RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
20                     RC2_KEY *ks, unsigned char *iv, int encrypt)
21{
22    register unsigned long tin0, tin1;
23    register unsigned long tout0, tout1, xor0, xor1;
24    register long l = length;
25    unsigned long tin[2];
26
27    if (encrypt) {
28        c2l(iv, tout0);
29        c2l(iv, tout1);
30        iv -= 8;
31        for (l -= 8; l >= 0; l -= 8) {
32            c2l(in, tin0);
33            c2l(in, tin1);
34            tin0 ^= tout0;
35            tin1 ^= tout1;
36            tin[0] = tin0;
37            tin[1] = tin1;
38            RC2_encrypt(tin, ks);
39            tout0 = tin[0];
40            l2c(tout0, out);
41            tout1 = tin[1];
42            l2c(tout1, out);
43        }
44        if (l != -8) {
45            c2ln(in, tin0, tin1, l + 8);
46            tin0 ^= tout0;
47            tin1 ^= tout1;
48            tin[0] = tin0;
49            tin[1] = tin1;
50            RC2_encrypt(tin, ks);
51            tout0 = tin[0];
52            l2c(tout0, out);
53            tout1 = tin[1];
54            l2c(tout1, out);
55        }
56        l2c(tout0, iv);
57        l2c(tout1, iv);
58    } else {
59        c2l(iv, xor0);
60        c2l(iv, xor1);
61        iv -= 8;
62        for (l -= 8; l >= 0; l -= 8) {
63            c2l(in, tin0);
64            tin[0] = tin0;
65            c2l(in, tin1);
66            tin[1] = tin1;
67            RC2_decrypt(tin, ks);
68            tout0 = tin[0] ^ xor0;
69            tout1 = tin[1] ^ xor1;
70            l2c(tout0, out);
71            l2c(tout1, out);
72            xor0 = tin0;
73            xor1 = tin1;
74        }
75        if (l != -8) {
76            c2l(in, tin0);
77            tin[0] = tin0;
78            c2l(in, tin1);
79            tin[1] = tin1;
80            RC2_decrypt(tin, ks);
81            tout0 = tin[0] ^ xor0;
82            tout1 = tin[1] ^ xor1;
83            l2cn(tout0, tout1, out, l + 8);
84            xor0 = tin0;
85            xor1 = tin1;
86        }
87        l2c(xor0, iv);
88        l2c(xor1, iv);
89    }
90    tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
91    tin[0] = tin[1] = 0;
92}
93
94void RC2_encrypt(unsigned long *d, RC2_KEY *key)
95{
96    int i, n;
97    register RC2_INT *p0, *p1;
98    register RC2_INT x0, x1, x2, x3, t;
99    unsigned long l;
100
101    l = d[0];
102    x0 = (RC2_INT) l & 0xffff;
103    x1 = (RC2_INT) (l >> 16L);
104    l = d[1];
105    x2 = (RC2_INT) l & 0xffff;
106    x3 = (RC2_INT) (l >> 16L);
107
108    n = 3;
109    i = 5;
110
111    p0 = p1 = &(key->data[0]);
112    for (;;) {
113        t = (x0 + (x1 & ~x3) + (x2 & x3) + *(p0++)) & 0xffff;
114        x0 = (t << 1) | (t >> 15);
115        t = (x1 + (x2 & ~x0) + (x3 & x0) + *(p0++)) & 0xffff;
116        x1 = (t << 2) | (t >> 14);
117        t = (x2 + (x3 & ~x1) + (x0 & x1) + *(p0++)) & 0xffff;
118        x2 = (t << 3) | (t >> 13);
119        t = (x3 + (x0 & ~x2) + (x1 & x2) + *(p0++)) & 0xffff;
120        x3 = (t << 5) | (t >> 11);
121
122        if (--i == 0) {
123            if (--n == 0)
124                break;
125            i = (n == 2) ? 6 : 5;
126
127            x0 += p1[x3 & 0x3f];
128            x1 += p1[x0 & 0x3f];
129            x2 += p1[x1 & 0x3f];
130            x3 += p1[x2 & 0x3f];
131        }
132    }
133
134    d[0] =
135        (unsigned long)(x0 & 0xffff) | ((unsigned long)(x1 & 0xffff) << 16L);
136    d[1] =
137        (unsigned long)(x2 & 0xffff) | ((unsigned long)(x3 & 0xffff) << 16L);
138}
139
140void RC2_decrypt(unsigned long *d, RC2_KEY *key)
141{
142    int i, n;
143    register RC2_INT *p0, *p1;
144    register RC2_INT x0, x1, x2, x3, t;
145    unsigned long l;
146
147    l = d[0];
148    x0 = (RC2_INT) l & 0xffff;
149    x1 = (RC2_INT) (l >> 16L);
150    l = d[1];
151    x2 = (RC2_INT) l & 0xffff;
152    x3 = (RC2_INT) (l >> 16L);
153
154    n = 3;
155    i = 5;
156
157    p0 = &(key->data[63]);
158    p1 = &(key->data[0]);
159    for (;;) {
160        t = ((x3 << 11) | (x3 >> 5)) & 0xffff;
161        x3 = (t - (x0 & ~x2) - (x1 & x2) - *(p0--)) & 0xffff;
162        t = ((x2 << 13) | (x2 >> 3)) & 0xffff;
163        x2 = (t - (x3 & ~x1) - (x0 & x1) - *(p0--)) & 0xffff;
164        t = ((x1 << 14) | (x1 >> 2)) & 0xffff;
165        x1 = (t - (x2 & ~x0) - (x3 & x0) - *(p0--)) & 0xffff;
166        t = ((x0 << 15) | (x0 >> 1)) & 0xffff;
167        x0 = (t - (x1 & ~x3) - (x2 & x3) - *(p0--)) & 0xffff;
168
169        if (--i == 0) {
170            if (--n == 0)
171                break;
172            i = (n == 2) ? 6 : 5;
173
174            x3 = (x3 - p1[x2 & 0x3f]) & 0xffff;
175            x2 = (x2 - p1[x1 & 0x3f]) & 0xffff;
176            x1 = (x1 - p1[x0 & 0x3f]) & 0xffff;
177            x0 = (x0 - p1[x3 & 0x3f]) & 0xffff;
178        }
179    }
180
181    d[0] =
182        (unsigned long)(x0 & 0xffff) | ((unsigned long)(x1 & 0xffff) << 16L);
183    d[1] =
184        (unsigned long)(x2 & 0xffff) | ((unsigned long)(x3 & 0xffff) << 16L);
185}
186