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 38static 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 */ 52int 53crypto_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; 124weak: 125 *flags |= CRYPTO_TFM_RES_WEAK_KEY; 126 return -EINVAL; 127} 128 129EXPORT_SYMBOL(crypto_des_check_key); 130 131MODULE_LICENSE("GPL"); 132MODULE_DESCRIPTION("Key Check function for DES & DES3 Cipher Algorithms"); 133