1/* FCrypt encryption algorithm
2 *
3 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Based on code:
12 *
13 * Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan
14 * (Royal Institute of Technology, Stockholm, Sweden).
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 *
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 *
24 * 2. Redistributions in binary form must reproduce the above copyright
25 * notice, this list of conditions and the following disclaimer in the
26 * documentation and/or other materials provided with the distribution.
27 *
28 * 3. Neither the name of the Institute nor the names of its contributors
29 * may be used to endorse or promote products derived from this software
30 * without specific prior written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * SUCH DAMAGE.
43 */
44
45#include <asm/byteorder.h>
46#include <crypto/algapi.h>
47#include <linux/bitops.h>
48#include <linux/init.h>
49#include <linux/module.h>
50
51#define ROUNDS 16
52
53struct fcrypt_ctx {
54 __be32 sched[ROUNDS];
55};
56
57/* Rotate right two 32 bit numbers as a 56 bit number */
58#define ror56(hi, lo, n) \
59do { \
60 u32 t = lo & ((1 << n) - 1); \
61 lo = (lo >> n) | ((hi & ((1 << n) - 1)) << (32 - n)); \
62 hi = (hi >> n) | (t << (24-n)); \
63} while (0)
64
65/* Rotate right one 64 bit number as a 56 bit number */
66#define ror56_64(k, n) (k = (k >> n) | ((k & ((1 << n) - 1)) << (56 - n)))
67
68/*
69 * Sboxes for Feistel network derived from
70 * /afs/transarc.com/public/afsps/afs.rel31b.export-src/rxkad/sboxes.h
71 */
72#undef Z
73#define Z(x) cpu_to_be32(x << 3)
74static const __be32 sbox0[256] = {
75 Z(0xea), Z(0x7f), Z(0xb2), Z(0x64), Z(0x9d), Z(0xb0), Z(0xd9), Z(0x11),
76 Z(0xcd), Z(0x86), Z(0x86), Z(0x91), Z(0x0a), Z(0xb2), Z(0x93), Z(0x06),
77 Z(0x0e), Z(0x06), Z(0xd2), Z(0x65), Z(0x73), Z(0xc5), Z(0x28), Z(0x60),
78 Z(0xf2), Z(0x20), Z(0xb5), Z(0x38), Z(0x7e), Z(0xda), Z(0x9f), Z(0xe3),
79 Z(0xd2), Z(0xcf), Z(0xc4), Z(0x3c), Z(0x61), Z(0xff), Z(0x4a), Z(0x4a),
80 Z(0x35), Z(0xac), Z(0xaa), Z(0x5f), Z(0x2b), Z(0xbb), Z(0xbc), Z(0x53),
81 Z(0x4e), Z(0x9d), Z(0x78), Z(0xa3), Z(0xdc), Z(0x09), Z(0x32), Z(0x10),
82 Z(0xc6), Z(0x6f), Z(0x66), Z(0xd6), Z(0xab), Z(0xa9), Z(0xaf), Z(0xfd),
83 Z(0x3b), Z(0x95), Z(0xe8), Z(0x34), Z(0x9a), Z(0x81), Z(0x72), Z(0x80),
84 Z(0x9c), Z(0xf3), Z(0xec), Z(0xda), Z(0x9f), Z(0x26), Z(0x76), Z(0x15),
85 Z(0x3e), Z(0x55), Z(0x4d), Z(0xde), Z(0x84), Z(0xee), Z(0xad), Z(0xc7),
86 Z(0xf1), Z(0x6b), Z(0x3d), Z(0xd3), Z(0x04), Z(0x49), Z(0xaa), Z(0x24),
87 Z(0x0b), Z(0x8a), Z(0x83), Z(0xba), Z(0xfa), Z(0x85), Z(0xa0), Z(0xa8),
88 Z(0xb1), Z(0xd4), Z(0x01), Z(0xd8), Z(0x70), Z(0x64), Z(0xf0), Z(0x51),
89 Z(0xd2), Z(0xc3), Z(0xa7), Z(0x75), Z(0x8c), Z(0xa5), Z(0x64), Z(0xef),
90 Z(0x10), Z(0x4e), Z(0xb7), Z(0xc6), Z(0x61), Z(0x03), Z(0xeb), Z(0x44),
91 Z(0x3d), Z(0xe5), Z(0xb3), Z(0x5b), Z(0xae), Z(0xd5), Z(0xad), Z(0x1d),
92 Z(0xfa), Z(0x5a), Z(0x1e), Z(0x33), Z(0xab), Z(0x93), Z(0xa2), Z(0xb7),
93 Z(0xe7), Z(0xa8), Z(0x45), Z(0xa4), Z(0xcd), Z(0x29), Z(0x63), Z(0x44),
94 Z(0xb6), Z(0x69), Z(0x7e), Z(0x2e), Z(0x62), Z(0x03), Z(0xc8), Z(0xe0),
95 Z(0x17), Z(0xbb), Z(0xc7), Z(0xf3), Z(0x3f), Z(0x36), Z(0xba), Z(0x71),
96 Z(0x8e), Z(0x97), Z(0x65), Z(0x60), Z(0x69), Z(0xb6), Z(0xf6), Z(0xe6),
97 Z(0x6e), Z(0xe0), Z(0x81), Z(0x59), Z(0xe8), Z(0xaf), Z(0xdd), Z(0x95),
98 Z(0x22), Z(0x99), Z(0xfd), Z(0x63), Z(0x19), Z(0x74), Z(0x61), Z(0xb1),
99 Z(0xb6), Z(0x5b), Z(0xae), Z(0x54), Z(0xb3), Z(0x70), Z(0xff), Z(0xc6),
100 Z(0x3b), Z(0x3e), Z(0xc1), Z(0xd7), Z(0xe1), Z(0x0e), Z(0x76), Z(0xe5),
101 Z(0x36), Z(0x4f), Z(0x59), Z(0xc7), Z(0x08), Z(0x6e), Z(0x82), Z(0xa6),
102 Z(0x93), Z(0xc4), Z(0xaa), Z(0x26), Z(0x49), Z(0xe0), Z(0x21), Z(0x64),
103 Z(0x07), Z(0x9f), Z(0x64), Z(0x81), Z(0x9c), Z(0xbf), Z(0xf9), Z(0xd1),
104 Z(0x43), Z(0xf8), Z(0xb6), Z(0xb9), Z(0xf1), Z(0x24), Z(0x75), Z(0x03),
105 Z(0xe4), Z(0xb0), Z(0x99), Z(0x46), Z(0x3d), Z(0xf5), Z(0xd1), Z(0x39),
106 Z(0x72), Z(0x12), Z(0xf6), Z(0xba), Z(0x0c), Z(0x0d), Z(0x42), Z(0x2e)
107};
108
109#undef Z
110#define Z(x) cpu_to_be32(((x & 0x1f) << 27) | (x >> 5))
111static const __be32 sbox1[256] = {
112 Z(0x77), Z(0x14), Z(0xa6), Z(0xfe), Z(0xb2), Z(0x5e), Z(0x8c), Z(0x3e),
113 Z(0x67), Z(0x6c), Z(0xa1), Z(0x0d), Z(0xc2), Z(0xa2), Z(0xc1), Z(0x85),
114 Z(0x6c), Z(0x7b), Z(0x67), Z(0xc6), Z(0x23), Z(0xe3), Z(0xf2), Z(0x89),
115 Z(0x50), Z(0x9c), Z(0x03), Z(0xb7), Z(0x73), Z(0xe6), Z(0xe1), Z(0x39),
116 Z(0x31), Z(0x2c), Z(0x27), Z(0x9f), Z(0xa5), Z(0x69), Z(0x44), Z(0xd6),
117 Z(0x23), Z(0x83), Z(0x98), Z(0x7d), Z(0x3c), Z(0xb4), Z(0x2d), Z(0x99),
118 Z(0x1c), Z(0x1f), Z(0x8c), Z(0x20), Z(0x03), Z(0x7c), Z(0x5f), Z(0xad),
119 Z(0xf4), Z(0xfa), Z(0x95), Z(0xca), Z(0x76), Z(0x44), Z(0xcd), Z(0xb6),
120 Z(0xb8), Z(0xa1), Z(0xa1), Z(0xbe), Z(0x9e), Z(0x54), Z(0x8f), Z(0x0b),
121 Z(0x16), Z(0x74), Z(0x31), Z(0x8a), Z(0x23), Z(0x17), Z(0x04), Z(0xfa),
122 Z(0x79), Z(0x84), Z(0xb1), Z(0xf5), Z(0x13), Z(0xab), Z(0xb5), Z(0x2e),
123 Z(0xaa), Z(0x0c), Z(0x60), Z(0x6b), Z(0x5b), Z(0xc4), Z(0x4b), Z(0xbc),
124 Z(0xe2), Z(0xaf), Z(0x45), Z(0x73), Z(0xfa), Z(0xc9), Z(0x49), Z(0xcd),
125 Z(0x00), Z(0x92), Z(0x7d), Z(0x97), Z(0x7a), Z(0x18), Z(0x60), Z(0x3d),
126 Z(0xcf), Z(0x5b), Z(0xde), Z(0xc6), Z(0xe2), Z(0xe6), Z(0xbb), Z(0x8b),
127 Z(0x06), Z(0xda), Z(0x08), Z(0x15), Z(0x1b), Z(0x88), Z(0x6a), Z(0x17),
128 Z(0x89), Z(0xd0), Z(0xa9), Z(0xc1), Z(0xc9), Z(0x70), Z(0x6b), Z(0xe5),
129 Z(0x43), Z(0xf4), Z(0x68), Z(0xc8), Z(0xd3), Z(0x84), Z(0x28), Z(0x0a),
130 Z(0x52), Z(0x66), Z(0xa3), Z(0xca), Z(0xf2), Z(0xe3), Z(0x7f), Z(0x7a),
131 Z(0x31), Z(0xf7), Z(0x88), Z(0x94), Z(0x5e), Z(0x9c), Z(0x63), Z(0xd5),
132 Z(0x24), Z(0x66), Z(0xfc), Z(0xb3), Z(0x57), Z(0x25), Z(0xbe), Z(0x89),
133 Z(0x44), Z(0xc4), Z(0xe0), Z(0x8f), Z(0x23), Z(0x3c), Z(0x12), Z(0x52),
134 Z(0xf5), Z(0x1e), Z(0xf4), Z(0xcb), Z(0x18), Z(0x33), Z(0x1f), Z(0xf8),
135 Z(0x69), Z(0x10), Z(0x9d), Z(0xd3), Z(0xf7), Z(0x28), Z(0xf8), Z(0x30),
136 Z(0x05), Z(0x5e), Z(0x32), Z(0xc0), Z(0xd5), Z(0x19), Z(0xbd), Z(0x45),
137 Z(0x8b), Z(0x5b), Z(0xfd), Z(0xbc), Z(0xe2), Z(0x5c), Z(0xa9), Z(0x96),
138 Z(0xef), Z(0x70), Z(0xcf), Z(0xc2), Z(0x2a), Z(0xb3), Z(0x61), Z(0xad),
139 Z(0x80), Z(0x48), Z(0x81), Z(0xb7), Z(0x1d), Z(0x43), Z(0xd9), Z(0xd7),
140 Z(0x45), Z(0xf0), Z(0xd8), Z(0x8a), Z(0x59), Z(0x7c), Z(0x57), Z(0xc1),
141 Z(0x79), Z(0xc7), Z(0x34), Z(0xd6), Z(0x43), Z(0xdf), Z(0xe4), Z(0x78),
142 Z(0x16), Z(0x06), Z(0xda), Z(0x92), Z(0x76), Z(0x51), Z(0xe1), Z(0xd4),
143 Z(0x70), Z(0x03), Z(0xe0), Z(0x2f), Z(0x96), Z(0x91), Z(0x82), Z(0x80)
144};
145
146#undef Z
147#define Z(x) cpu_to_be32(x << 11)
148static const __be32 sbox2[256] = {
149 Z(0xf0), Z(0x37), Z(0x24), Z(0x53), Z(0x2a), Z(0x03), Z(0x83), Z(0x86),
150 Z(0xd1), Z(0xec), Z(0x50), Z(0xf0), Z(0x42), Z(0x78), Z(0x2f), Z(0x6d),
151 Z(0xbf), Z(0x80), Z(0x87), Z(0x27), Z(0x95), Z(0xe2), Z(0xc5), Z(0x5d),
152 Z(0xf9), Z(0x6f), Z(0xdb), Z(0xb4), Z(0x65), Z(0x6e), Z(0xe7), Z(0x24),
153 Z(0xc8), Z(0x1a), Z(0xbb), Z(0x49), Z(0xb5), Z(0x0a), Z(0x7d), Z(0xb9),
154 Z(0xe8), Z(0xdc), Z(0xb7), Z(0xd9), Z(0x45), Z(0x20), Z(0x1b), Z(0xce),
155 Z(0x59), Z(0x9d), Z(0x6b), Z(0xbd), Z(0x0e), Z(0x8f), Z(0xa3), Z(0xa9),
156 Z(0xbc), Z(0x74), Z(0xa6), Z(0xf6), Z(0x7f), Z(0x5f), Z(0xb1), Z(0x68),
157 Z(0x84), Z(0xbc), Z(0xa9), Z(0xfd), Z(0x55), Z(0x50), Z(0xe9), Z(0xb6),
158 Z(0x13), Z(0x5e), Z(0x07), Z(0xb8), Z(0x95), Z(0x02), Z(0xc0), Z(0xd0),
159 Z(0x6a), Z(0x1a), Z(0x85), Z(0xbd), Z(0xb6), Z(0xfd), Z(0xfe), Z(0x17),
160 Z(0x3f), Z(0x09), Z(0xa3), Z(0x8d), Z(0xfb), Z(0xed), Z(0xda), Z(0x1d),
161 Z(0x6d), Z(0x1c), Z(0x6c), Z(0x01), Z(0x5a), Z(0xe5), Z(0x71), Z(0x3e),
162 Z(0x8b), Z(0x6b), Z(0xbe), Z(0x29), Z(0xeb), Z(0x12), Z(0x19), Z(0x34),
163 Z(0xcd), Z(0xb3), Z(0xbd), Z(0x35), Z(0xea), Z(0x4b), Z(0xd5), Z(0xae),
164 Z(0x2a), Z(0x79), Z(0x5a), Z(0xa5), Z(0x32), Z(0x12), Z(0x7b), Z(0xdc),
165 Z(0x2c), Z(0xd0), Z(0x22), Z(0x4b), Z(0xb1), Z(0x85), Z(0x59), Z(0x80),
166 Z(0xc0), Z(0x30), Z(0x9f), Z(0x73), Z(0xd3), Z(0x14), Z(0x48), Z(0x40),
167 Z(0x07), Z(0x2d), Z(0x8f), Z(0x80), Z(0x0f), Z(0xce), Z(0x0b), Z(0x5e),
168 Z(0xb7), Z(0x5e), Z(0xac), Z(0x24), Z(0x94), Z(0x4a), Z(0x18), Z(0x15),
169 Z(0x05), Z(0xe8), Z(0x02), Z(0x77), Z(0xa9), Z(0xc7), Z(0x40), Z(0x45),
170 Z(0x89), Z(0xd1), Z(0xea), Z(0xde), Z(0x0c), Z(0x79), Z(0x2a), Z(0x99),
171 Z(0x6c), Z(0x3e), Z(0x95), Z(0xdd), Z(0x8c), Z(0x7d), Z(0xad), Z(0x6f),
172 Z(0xdc), Z(0xff), Z(0xfd), Z(0x62), Z(0x47), Z(0xb3), Z(0x21), Z(0x8a),
173 Z(0xec), Z(0x8e), Z(0x19), Z(0x18), Z(0xb4), Z(0x6e), Z(0x3d), Z(0xfd),
174 Z(0x74), Z(0x54), Z(0x1e), Z(0x04), Z(0x85), Z(0xd8), Z(0xbc), Z(0x1f),
175 Z(0x56), Z(0xe7), Z(0x3a), Z(0x56), Z(0x67), Z(0xd6), Z(0xc8), Z(0xa5),
176 Z(0xf3), Z(0x8e), Z(0xde), Z(0xae), Z(0x37), Z(0x49), Z(0xb7), Z(0xfa),
177 Z(0xc8), Z(0xf4), Z(0x1f), Z(0xe0), Z(0x2a), Z(0x9b), Z(0x15), Z(0xd1),
178 Z(0x34), Z(0x0e), Z(0xb5), Z(0xe0), Z(0x44), Z(0x78), Z(0x84), Z(0x59),
179 Z(0x56), Z(0x68), Z(0x77), Z(0xa5), Z(0x14), Z(0x06), Z(0xf5), Z(0x2f),
180 Z(0x8c), Z(0x8a), Z(0x73), Z(0x80), Z(0x76), Z(0xb4), Z(0x10), Z(0x86)
181};
182
183#undef Z
184#define Z(x) cpu_to_be32(x << 19)
185static const __be32 sbox3[256] = {
186 Z(0xa9), Z(0x2a), Z(0x48), Z(0x51), Z(0x84), Z(0x7e), Z(0x49), Z(0xe2),
187 Z(0xb5), Z(0xb7), Z(0x42), Z(0x33), Z(0x7d), Z(0x5d), Z(0xa6), Z(0x12),
188 Z(0x44), Z(0x48), Z(0x6d), Z(0x28), Z(0xaa), Z(0x20), Z(0x6d), Z(0x57),
189 Z(0xd6), Z(0x6b), Z(0x5d), Z(0x72), Z(0xf0), Z(0x92), Z(0x5a), Z(0x1b),
190 Z(0x53), Z(0x80), Z(0x24), Z(0x70), Z(0x9a), Z(0xcc), Z(0xa7), Z(0x66),
191 Z(0xa1), Z(0x01), Z(0xa5), Z(0x41), Z(0x97), Z(0x41), Z(0x31), Z(0x82),
192 Z(0xf1), Z(0x14), Z(0xcf), Z(0x53), Z(0x0d), Z(0xa0), Z(0x10), Z(0xcc),
193 Z(0x2a), Z(0x7d), Z(0xd2), Z(0xbf), Z(0x4b), Z(0x1a), Z(0xdb), Z(0x16),
194 Z(0x47), Z(0xf6), Z(0x51), Z(0x36), Z(0xed), Z(0xf3), Z(0xb9), Z(0x1a),
195 Z(0xa7), Z(0xdf), Z(0x29), Z(0x43), Z(0x01), Z(0x54), Z(0x70), Z(0xa4),
196 Z(0xbf), Z(0xd4), Z(0x0b), Z(0x53), Z(0x44), Z(0x60), Z(0x9e), Z(0x23),
197 Z(0xa1), Z(0x18), Z(0x68), Z(0x4f), Z(0xf0), Z(0x2f), Z(0x82), Z(0xc2),
198 Z(0x2a), Z(0x41), Z(0xb2), Z(0x42), Z(0x0c), Z(0xed), Z(0x0c), Z(0x1d),
199 Z(0x13), Z(0x3a), Z(0x3c), Z(0x6e), Z(0x35), Z(0xdc), Z(0x60), Z(0x65),
200 Z(0x85), Z(0xe9), Z(0x64), Z(0x02), Z(0x9a), Z(0x3f), Z(0x9f), Z(0x87),
201 Z(0x96), Z(0xdf), Z(0xbe), Z(0xf2), Z(0xcb), Z(0xe5), Z(0x6c), Z(0xd4),
202 Z(0x5a), Z(0x83), Z(0xbf), Z(0x92), Z(0x1b), Z(0x94), Z(0x00), Z(0x42),
203 Z(0xcf), Z(0x4b), Z(0x00), Z(0x75), Z(0xba), Z(0x8f), Z(0x76), Z(0x5f),
204 Z(0x5d), Z(0x3a), Z(0x4d), Z(0x09), Z(0x12), Z(0x08), Z(0x38), Z(0x95),
205 Z(0x17), Z(0xe4), Z(0x01), Z(0x1d), Z(0x4c), Z(0xa9), Z(0xcc), Z(0x85),
206 Z(0x82), Z(0x4c), Z(0x9d), Z(0x2f), Z(0x3b), Z(0x66), Z(0xa1), Z(0x34),
207 Z(0x10), Z(0xcd), Z(0x59), Z(0x89), Z(0xa5), Z(0x31), Z(0xcf), Z(0x05),
208 Z(0xc8), Z(0x84), Z(0xfa), Z(0xc7), Z(0xba), Z(0x4e), Z(0x8b), Z(0x1a),
209 Z(0x19), Z(0xf1), Z(0xa1), Z(0x3b), Z(0x18), Z(0x12), Z(0x17), Z(0xb0),
210 Z(0x98), Z(0x8d), Z(0x0b), Z(0x23), Z(0xc3), Z(0x3a), Z(0x2d), Z(0x20),
211 Z(0xdf), Z(0x13), Z(0xa0), Z(0xa8), Z(0x4c), Z(0x0d), Z(0x6c), Z(0x2f),
212 Z(0x47), Z(0x13), Z(0x13), Z(0x52), Z(0x1f), Z(0x2d), Z(0xf5), Z(0x79),
213 Z(0x3d), Z(0xa2), Z(0x54), Z(0xbd), Z(0x69), Z(0xc8), Z(0x6b), Z(0xf3),
214 Z(0x05), Z(0x28), Z(0xf1), Z(0x16), Z(0x46), Z(0x40), Z(0xb0), Z(0x11),
215 Z(0xd3), Z(0xb7), Z(0x95), Z(0x49), Z(0xcf), Z(0xc3), Z(0x1d), Z(0x8f),
216 Z(0xd8), Z(0xe1), Z(0x73), Z(0xdb), Z(0xad), Z(0xc8), Z(0xc9), Z(0xa9),
217 Z(0xa1), Z(0xc2), Z(0xc5), Z(0xe3), Z(0xba), Z(0xfc), Z(0x0e), Z(0x25)
218};
219
220/*
221 * This is a 16 round Feistel network with permutation F_ENCRYPT
222 */
223#define F_ENCRYPT(R, L, sched) \
224do { \
225 union lc4 { __be32 l; u8 c[4]; } u; \
226 u.l = sched ^ R; \
227 L ^= sbox0[u.c[0]] ^ sbox1[u.c[1]] ^ sbox2[u.c[2]] ^ sbox3[u.c[3]]; \
228} while (0)
229
230/*
231 * encryptor
232 */
233static void fcrypt_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
234{
235 const struct fcrypt_ctx *ctx = crypto_tfm_ctx(tfm);
236 struct {
237 __be32 l, r;
238 } X;
239
240 memcpy(&X, src, sizeof(X));
241
242 F_ENCRYPT(X.r, X.l, ctx->sched[0x0]);
243 F_ENCRYPT(X.l, X.r, ctx->sched[0x1]);
244 F_ENCRYPT(X.r, X.l, ctx->sched[0x2]);
245 F_ENCRYPT(X.l, X.r, ctx->sched[0x3]);
246 F_ENCRYPT(X.r, X.l, ctx->sched[0x4]);
247 F_ENCRYPT(X.l, X.r, ctx->sched[0x5]);
248 F_ENCRYPT(X.r, X.l, ctx->sched[0x6]);
249 F_ENCRYPT(X.l, X.r, ctx->sched[0x7]);
250 F_ENCRYPT(X.r, X.l, ctx->sched[0x8]);
251 F_ENCRYPT(X.l, X.r, ctx->sched[0x9]);
252 F_ENCRYPT(X.r, X.l, ctx->sched[0xa]);
253 F_ENCRYPT(X.l, X.r, ctx->sched[0xb]);
254 F_ENCRYPT(X.r, X.l, ctx->sched[0xc]);
255 F_ENCRYPT(X.l, X.r, ctx->sched[0xd]);
256 F_ENCRYPT(X.r, X.l, ctx->sched[0xe]);
257 F_ENCRYPT(X.l, X.r, ctx->sched[0xf]);
258
259 memcpy(dst, &X, sizeof(X));
260}
261
262/*
263 * decryptor
264 */
265static void fcrypt_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
266{
267 const struct fcrypt_ctx *ctx = crypto_tfm_ctx(tfm);
268 struct {
269 __be32 l, r;
270 } X;
271
272 memcpy(&X, src, sizeof(X));
273
274 F_ENCRYPT(X.l, X.r, ctx->sched[0xf]);
275 F_ENCRYPT(X.r, X.l, ctx->sched[0xe]);
276 F_ENCRYPT(X.l, X.r, ctx->sched[0xd]);
277 F_ENCRYPT(X.r, X.l, ctx->sched[0xc]);
278 F_ENCRYPT(X.l, X.r, ctx->sched[0xb]);
279 F_ENCRYPT(X.r, X.l, ctx->sched[0xa]);
280 F_ENCRYPT(X.l, X.r, ctx->sched[0x9]);
281 F_ENCRYPT(X.r, X.l, ctx->sched[0x8]);
282 F_ENCRYPT(X.l, X.r, ctx->sched[0x7]);
283 F_ENCRYPT(X.r, X.l, ctx->sched[0x6]);
284 F_ENCRYPT(X.l, X.r, ctx->sched[0x5]);
285 F_ENCRYPT(X.r, X.l, ctx->sched[0x4]);
286 F_ENCRYPT(X.l, X.r, ctx->sched[0x3]);
287 F_ENCRYPT(X.r, X.l, ctx->sched[0x2]);
288 F_ENCRYPT(X.l, X.r, ctx->sched[0x1]);
289 F_ENCRYPT(X.r, X.l, ctx->sched[0x0]);
290
291 memcpy(dst, &X, sizeof(X));
292}
293
294/*
295 * Generate a key schedule from key, the least significant bit in each key byte
296 * is parity and shall be ignored. This leaves 56 significant bits in the key
297 * to scatter over the 16 key schedules. For each schedule extract the low
298 * order 32 bits and use as schedule, then rotate right by 11 bits.
299 */
300static int fcrypt_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
301{
302 struct fcrypt_ctx *ctx = crypto_tfm_ctx(tfm);
303
304#if BITS_PER_LONG == 64 /* the 64-bit version can also be used for 32-bit
305 * kernels - it seems to be faster but the code is
306 * larger */
307
308 u64 k; /* k holds all 56 non-parity bits */
309
310 /* discard the parity bits */
311 k = (*key++) >> 1;
312 k <<= 7;
313 k |= (*key++) >> 1;
314 k <<= 7;
315 k |= (*key++) >> 1;
316 k <<= 7;
317 k |= (*key++) >> 1;
318 k <<= 7;
319 k |= (*key++) >> 1;
320 k <<= 7;
321 k |= (*key++) >> 1;
322 k <<= 7;
323 k |= (*key++) >> 1;
324 k <<= 7;
325 k |= (*key) >> 1;
326
327 /* Use lower 32 bits for schedule, rotate by 11 each round (16 times) */
328 ctx->sched[0x0] = cpu_to_be32(k); ror56_64(k, 11);
329 ctx->sched[0x1] = cpu_to_be32(k); ror56_64(k, 11);
330 ctx->sched[0x2] = cpu_to_be32(k); ror56_64(k, 11);
331 ctx->sched[0x3] = cpu_to_be32(k); ror56_64(k, 11);
332 ctx->sched[0x4] = cpu_to_be32(k); ror56_64(k, 11);
333 ctx->sched[0x5] = cpu_to_be32(k); ror56_64(k, 11);
334 ctx->sched[0x6] = cpu_to_be32(k); ror56_64(k, 11);
335 ctx->sched[0x7] = cpu_to_be32(k); ror56_64(k, 11);
336 ctx->sched[0x8] = cpu_to_be32(k); ror56_64(k, 11);
337 ctx->sched[0x9] = cpu_to_be32(k); ror56_64(k, 11);
338 ctx->sched[0xa] = cpu_to_be32(k); ror56_64(k, 11);
339 ctx->sched[0xb] = cpu_to_be32(k); ror56_64(k, 11);
340 ctx->sched[0xc] = cpu_to_be32(k); ror56_64(k, 11);
341 ctx->sched[0xd] = cpu_to_be32(k); ror56_64(k, 11);
342 ctx->sched[0xe] = cpu_to_be32(k); ror56_64(k, 11);
343 ctx->sched[0xf] = cpu_to_be32(k);
344
345 return 0;
346#else
347 u32 hi, lo; /* hi is upper 24 bits and lo lower 32, total 56 */
348
349 /* discard the parity bits */
350 lo = (*key++) >> 1;
351 lo <<= 7;
352 lo |= (*key++) >> 1;
353 lo <<= 7;
354 lo |= (*key++) >> 1;
355 lo <<= 7;
356 lo |= (*key++) >> 1;
357 hi = lo >> 4;
358 lo &= 0xf;
359 lo <<= 7;
360 lo |= (*key++) >> 1;
361 lo <<= 7;
362 lo |= (*key++) >> 1;
363 lo <<= 7;
364 lo |= (*key++) >> 1;
365 lo <<= 7;
366 lo |= (*key) >> 1;
367
368 /* Use lower 32 bits for schedule, rotate by 11 each round (16 times) */
369 ctx->sched[0x0] = cpu_to_be32(lo); ror56(hi, lo, 11);
370 ctx->sched[0x1] = cpu_to_be32(lo); ror56(hi, lo, 11);
371 ctx->sched[0x2] = cpu_to_be32(lo); ror56(hi, lo, 11);
372 ctx->sched[0x3] = cpu_to_be32(lo); ror56(hi, lo, 11);
373 ctx->sched[0x4] = cpu_to_be32(lo); ror56(hi, lo, 11);
374 ctx->sched[0x5] = cpu_to_be32(lo); ror56(hi, lo, 11);
375 ctx->sched[0x6] = cpu_to_be32(lo); ror56(hi, lo, 11);
376 ctx->sched[0x7] = cpu_to_be32(lo); ror56(hi, lo, 11);
377 ctx->sched[0x8] = cpu_to_be32(lo); ror56(hi, lo, 11);
378 ctx->sched[0x9] = cpu_to_be32(lo); ror56(hi, lo, 11);
379 ctx->sched[0xa] = cpu_to_be32(lo); ror56(hi, lo, 11);
380 ctx->sched[0xb] = cpu_to_be32(lo); ror56(hi, lo, 11);
381 ctx->sched[0xc] = cpu_to_be32(lo); ror56(hi, lo, 11);
382 ctx->sched[0xd] = cpu_to_be32(lo); ror56(hi, lo, 11);
383 ctx->sched[0xe] = cpu_to_be32(lo); ror56(hi, lo, 11);
384 ctx->sched[0xf] = cpu_to_be32(lo);
385 return 0;
386#endif
387}
388
389static struct crypto_alg fcrypt_alg = {
390 .cra_name = "fcrypt",
391 .cra_driver_name = "fcrypt-generic",
392 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
393 .cra_blocksize = 8,
394 .cra_ctxsize = sizeof(struct fcrypt_ctx),
395 .cra_module = THIS_MODULE,
396 .cra_u = { .cipher = {
397 .cia_min_keysize = 8,
398 .cia_max_keysize = 8,
399 .cia_setkey = fcrypt_setkey,
400 .cia_encrypt = fcrypt_encrypt,
401 .cia_decrypt = fcrypt_decrypt } }
402};
403
404static int __init fcrypt_mod_init(void)
405{
406 return crypto_register_alg(alg: &fcrypt_alg);
407}
408
409static void __exit fcrypt_mod_fini(void)
410{
411 crypto_unregister_alg(alg: &fcrypt_alg);
412}
413
414subsys_initcall(fcrypt_mod_init);
415module_exit(fcrypt_mod_fini);
416
417MODULE_LICENSE("Dual BSD/GPL");
418MODULE_DESCRIPTION("FCrypt Cipher Algorithm");
419MODULE_AUTHOR("David Howells <dhowells@redhat.com>");
420MODULE_ALIAS_CRYPTO("fcrypt");
421

source code of linux/crypto/fcrypt.c