4 * Function for checking keys for the DES and Tripple DES Encryption
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.
13 * Copyright (C) 2003 IBM Deutschland GmbH, IBM Corporation
14 * Author(s): Thomas Spatzier (tspat@de.ibm.com)
16 * Derived from "crypto/des.c"
17 * Copyright (c) 1992 Dana L. How.
18 * Copyright (c) Raimar Falke <rf13@inf.tu-dresden.de>
19 * Copyright (c) Gisle Sflensminde <gisle@ii.uib.no>
20 * Copyright (C) 2001 Niels Mvller.
21 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
29 #include <linux/init.h>
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/crypto.h>
33 #include "crypto_des.h"
35 #define ROR(d,c,o) ((d) = (d) >> (c) | (d) << (o))
37 static const u8 parity
[] = {
38 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,
39 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,
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 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,
42 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,
43 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,
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 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,
49 * RFC2451: Weak key checks SHOULD be performed.
52 crypto_des_check_key(const u8
*key
, unsigned int keylen
, u32
*flags
)
56 n
= parity
[key
[0]]; n
<<= 4;
57 n
|= parity
[key
[1]]; n
<<= 4;
58 n
|= parity
[key
[2]]; n
<<= 4;
59 n
|= parity
[key
[3]]; n
<<= 4;
60 n
|= parity
[key
[4]]; n
<<= 4;
61 n
|= parity
[key
[5]]; n
<<= 4;
62 n
|= parity
[key
[6]]; n
<<= 4;
66 if ((*flags
& CRYPTO_TFM_REQ_WEAK_KEY
)
67 && !((n
- (w
>> 3)) & w
)) { /* 1 in 10^10 keys passes this test */
71 /* 01 01 01 01 01 01 01 01 */
72 if (n
== 0x11111111) goto weak
;
73 /* 01 1F 01 1F 01 0E 01 0E */
74 if (n
== 0x13131212) goto weak
;
76 /* 01 E0 01 E0 01 F1 01 F1 */
77 if (n
== 0x14141515) goto weak
;
78 /* 01 FE 01 FE 01 FE 01 FE */
79 if (n
== 0x16161616) goto weak
;
83 /* 1F 01 1F 01 0E 01 0E 01 */
84 if (n
== 0x31312121) goto weak
;
85 /* 1F 1F 1F 1F 0E 0E 0E 0E (?) */
86 if (n
== 0x33332222) goto weak
;
88 /* 1F E0 1F E0 0E F1 0E F1 */
89 if (n
== 0x34342525) goto weak
;
90 /* 1F FE 1F FE 0E FE 0E FE */
91 if (n
== 0x36362626) goto weak
;
97 /* E0 01 E0 01 F1 01 F1 01 */
98 if (n
== 0x41415151) goto weak
;
99 /* E0 1F E0 1F F1 0E F1 0E */
100 if (n
== 0x43435252) goto weak
;
102 /* E0 E0 E0 E0 F1 F1 F1 F1 (?) */
103 if (n
== 0x44445555) goto weak
;
104 /* E0 FE E0 FE F1 FE F1 FE */
105 if (n
== 0x46465656) goto weak
;
108 if (n
< 0x64646565) {
109 /* FE 01 FE 01 FE 01 FE 01 */
110 if (n
== 0x61616161) goto weak
;
111 /* FE 1F FE 1F FE 0E FE 0E */
112 if (n
== 0x63636262) goto weak
;
114 /* FE E0 FE E0 FE F1 FE F1 */
115 if (n
== 0x64646565) goto weak
;
116 /* FE FE FE FE FE FE FE FE */
117 if (n
== 0x66666666) goto weak
;
124 *flags
|= CRYPTO_TFM_RES_WEAK_KEY
;
128 EXPORT_SYMBOL(crypto_des_check_key
);
130 MODULE_LICENSE("GPL");
131 MODULE_DESCRIPTION("Key Check function for DES & DES3 Cipher Algorithms");