LXR linux/arch/s390/crypto/des_check

   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