1 /*
2 * Cryptographic API.
3 *
4 * Function for checking keys for the DES and Tripple DES Encryption
5 * algorithms.
6 *
7 * Originally released as descore by Dana L. How <how@isl.stanford.edu>.
8 * Modified by Raimar Falke <rf13@inf.tu-dresden.de> for the Linux-Kernel.
9 * Derived from Cryptoapi and Nettle implementations, adapted for in-place
10 * scatterlist interface. Changed LGPL to GPL per section 3 of the LGPL.
11 *
12 * s390 Version:
13 * Copyright IBM Corp. 2003
14 * Author(s): Thomas Spatzier
15 * Jan Glauber (jan.glauber@de.ibm.com)
16 *
17 * Derived from "crypto/des.c"
18 * Copyright (c) 1992 Dana L. How.
19 * Copyright (c) Raimar Falke <rf13@inf.tu-dresden.de>
20 * Copyright (c) Gisle Sflensminde <gisle@ii.uib.no>
21 * Copyright (C) 2001 Niels Mvller.
22 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2 of the License, or
27 * (at your option) any later version.
28 *
29 */
30 #include <linux/init.h>
31 #include <linux/module.h>
32 #include <linux/errno.h>
33 #include <linux/crypto.h>
34 #include "crypto_des.h"
35
36 #define ROR(d,c,o) ((d) = (d) >> (c) | (d) << (o))
37
38 static const u8 parity[] = {
39 8,1,0,8,0,8,8,0,0,8,8,0,8,0,2,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,3,
40 0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,
41 0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,
42 8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,
43 0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,
44 8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,
45 8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,
46 4,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,5,0,8,0,8,8,0,0,8,8,0,8,0,6,8,
47 };
48
49 /*
50 * RFC2451: Weak key checks SHOULD be performed.
51 */
52 int
crypto_des_check_key(const u8 * key,unsigned int keylen,u32 * flags)53 crypto_des_check_key(const u8 *key, unsigned int keylen, u32 *flags)
54 {
55 u32 n, w;
56
57 n = parity[key[0]]; n <<= 4;
58 n |= parity[key[1]]; n <<= 4;
59 n |= parity[key[2]]; n <<= 4;
60 n |= parity[key[3]]; n <<= 4;
61 n |= parity[key[4]]; n <<= 4;
62 n |= parity[key[5]]; n <<= 4;
63 n |= parity[key[6]]; n <<= 4;
64 n |= parity[key[7]];
65 w = 0x88888888L;
66
67 if ((*flags & CRYPTO_TFM_REQ_WEAK_KEY)
68 && !((n - (w >> 3)) & w)) { /* 1 in 10^10 keys passes this test */
69 if (n < 0x41415151) {
70 if (n < 0x31312121) {
71 if (n < 0x14141515) {
72 /* 01 01 01 01 01 01 01 01 */
73 if (n == 0x11111111) goto weak;
74 /* 01 1F 01 1F 01 0E 01 0E */
75 if (n == 0x13131212) goto weak;
76 } else {
77 /* 01 E0 01 E0 01 F1 01 F1 */
78 if (n == 0x14141515) goto weak;
79 /* 01 FE 01 FE 01 FE 01 FE */
80 if (n == 0x16161616) goto weak;
81 }
82 } else {
83 if (n < 0x34342525) {
84 /* 1F 01 1F 01 0E 01 0E 01 */
85 if (n == 0x31312121) goto weak;
86 /* 1F 1F 1F 1F 0E 0E 0E 0E (?) */
87 if (n == 0x33332222) goto weak;
88 } else {
89 /* 1F E0 1F E0 0E F1 0E F1 */
90 if (n == 0x34342525) goto weak;
91 /* 1F FE 1F FE 0E FE 0E FE */
92 if (n == 0x36362626) goto weak;
93 }
94 }
95 } else {
96 if (n < 0x61616161) {
97 if (n < 0x44445555) {
98 /* E0 01 E0 01 F1 01 F1 01 */
99 if (n == 0x41415151) goto weak;
100 /* E0 1F E0 1F F1 0E F1 0E */
101 if (n == 0x43435252) goto weak;
102 } else {
103 /* E0 E0 E0 E0 F1 F1 F1 F1 (?) */
104 if (n == 0x44445555) goto weak;
105 /* E0 FE E0 FE F1 FE F1 FE */
106 if (n == 0x46465656) goto weak;
107 }
108 } else {
109 if (n < 0x64646565) {
110 /* FE 01 FE 01 FE 01 FE 01 */
111 if (n == 0x61616161) goto weak;
112 /* FE 1F FE 1F FE 0E FE 0E */
113 if (n == 0x63636262) goto weak;
114 } else {
115 /* FE E0 FE E0 FE F1 FE F1 */
116 if (n == 0x64646565) goto weak;
117 /* FE FE FE FE FE FE FE FE */
118 if (n == 0x66666666) goto weak;
119 }
120 }
121 }
122 }
123 return 0;
124 weak:
125 *flags |= CRYPTO_TFM_RES_WEAK_KEY;
126 return -EINVAL;
127 }
128
129 EXPORT_SYMBOL(crypto_des_check_key);
130
131 MODULE_LICENSE("GPL");
132 MODULE_DESCRIPTION("Key Check function for DES & DES3 Cipher Algorithms");
133