xref: /linux/crypto/fcrypt.c (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18)
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 
53 struct 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)					\
59 do {								\
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)
74 static 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))
111 static 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)
148 static 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)
185 static 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)						\
224 do {									\
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  */
fcrypt_encrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)233 static 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  */
fcrypt_decrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)265 static 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  */
fcrypt_setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)300 static 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 
389 static 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 
fcrypt_mod_init(void)404 static int __init fcrypt_mod_init(void)
405 {
406 	return crypto_register_alg(&fcrypt_alg);
407 }
408 
fcrypt_mod_fini(void)409 static void __exit fcrypt_mod_fini(void)
410 {
411 	crypto_unregister_alg(&fcrypt_alg);
412 }
413 
414 subsys_initcall(fcrypt_mod_init);
415 module_exit(fcrypt_mod_fini);
416 
417 MODULE_LICENSE("Dual BSD/GPL");
418 MODULE_DESCRIPTION("FCrypt Cipher Algorithm");
419 MODULE_AUTHOR("David Howells <dhowells@redhat.com>");
420 MODULE_ALIAS_CRYPTO("fcrypt");
421