linux/fs/cifs/smbencrypt.c
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   1/*
   2   Unix SMB/Netbios implementation.
   3   Version 1.9.
   4   SMB parameters and setup
   5   Copyright (C) Andrew Tridgell 1992-2000
   6   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   7   Modified by Jeremy Allison 1995.
   8   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
   9   Modified by Steve French (sfrench@us.ibm.com) 2002-2003
  10
  11   This program is free software; you can redistribute it and/or modify
  12   it under the terms of the GNU General Public License as published by
  13   the Free Software Foundation; either version 2 of the License, or
  14   (at your option) any later version.
  15
  16   This program is distributed in the hope that it will be useful,
  17   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19   GNU General Public License for more details.
  20
  21   You should have received a copy of the GNU General Public License
  22   along with this program; if not, write to the Free Software
  23   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24*/
  25
  26#include <linux/module.h>
  27#include <linux/slab.h>
  28#include <linux/fs.h>
  29#include <linux/string.h>
  30#include <linux/kernel.h>
  31#include <linux/random.h>
  32#include "cifs_unicode.h"
  33#include "cifspdu.h"
  34#include "cifsglob.h"
  35#include "cifs_debug.h"
  36#include "cifsproto.h"
  37
  38#ifndef false
  39#define false 0
  40#endif
  41#ifndef true
  42#define true 1
  43#endif
  44
  45/* following came from the other byteorder.h to avoid include conflicts */
  46#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
  47#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
  48#define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))
  49
  50static void
  51str_to_key(unsigned char *str, unsigned char *key)
  52{
  53        int i;
  54
  55        key[0] = str[0] >> 1;
  56        key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
  57        key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
  58        key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
  59        key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
  60        key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
  61        key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
  62        key[7] = str[6] & 0x7F;
  63        for (i = 0; i < 8; i++)
  64                key[i] = (key[i] << 1);
  65}
  66
  67static int
  68smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
  69{
  70        int rc;
  71        unsigned char key2[8];
  72        struct crypto_blkcipher *tfm_des;
  73        struct scatterlist sgin, sgout;
  74        struct blkcipher_desc desc;
  75
  76        str_to_key(key, key2);
  77
  78        tfm_des = crypto_alloc_blkcipher("ecb(des)", 0, CRYPTO_ALG_ASYNC);
  79        if (IS_ERR(tfm_des)) {
  80                rc = PTR_ERR(tfm_des);
  81                cERROR(1, "could not allocate des crypto API");
  82                goto smbhash_err;
  83        }
  84
  85        desc.tfm = tfm_des;
  86
  87        crypto_blkcipher_setkey(tfm_des, key2, 8);
  88
  89        sg_init_one(&sgin, in, 8);
  90        sg_init_one(&sgout, out, 8);
  91
  92        rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, 8);
  93        if (rc)
  94                cERROR(1, "could not encrypt crypt key rc: %d", rc);
  95
  96        crypto_free_blkcipher(tfm_des);
  97smbhash_err:
  98        return rc;
  99}
 100
 101static int
 102E_P16(unsigned char *p14, unsigned char *p16)
 103{
 104        int rc;
 105        unsigned char sp8[8] =
 106            { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
 107
 108        rc = smbhash(p16, sp8, p14);
 109        if (rc)
 110                return rc;
 111        rc = smbhash(p16 + 8, sp8, p14 + 7);
 112        return rc;
 113}
 114
 115static int
 116E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
 117{
 118        int rc;
 119
 120        rc = smbhash(p24, c8, p21);
 121        if (rc)
 122                return rc;
 123        rc = smbhash(p24 + 8, c8, p21 + 7);
 124        if (rc)
 125                return rc;
 126        rc = smbhash(p24 + 16, c8, p21 + 14);
 127        return rc;
 128}
 129
 130/* produce a md4 message digest from data of length n bytes */
 131int
 132mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
 133{
 134        int rc;
 135        unsigned int size;
 136        struct crypto_shash *md4;
 137        struct sdesc *sdescmd4;
 138
 139        md4 = crypto_alloc_shash("md4", 0, 0);
 140        if (IS_ERR(md4)) {
 141                rc = PTR_ERR(md4);
 142                cERROR(1, "%s: Crypto md4 allocation error %d", __func__, rc);
 143                return rc;
 144        }
 145        size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
 146        sdescmd4 = kmalloc(size, GFP_KERNEL);
 147        if (!sdescmd4) {
 148                rc = -ENOMEM;
 149                cERROR(1, "%s: Memory allocation failure", __func__);
 150                goto mdfour_err;
 151        }
 152        sdescmd4->shash.tfm = md4;
 153        sdescmd4->shash.flags = 0x0;
 154
 155        rc = crypto_shash_init(&sdescmd4->shash);
 156        if (rc) {
 157                cERROR(1, "%s: Could not init md4 shash", __func__);
 158                goto mdfour_err;
 159        }
 160        rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
 161        if (rc) {
 162                cERROR(1, "%s: Could not update with link_str", __func__);
 163                goto mdfour_err;
 164        }
 165        rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
 166        if (rc)
 167                cERROR(1, "%s: Could not genereate md4 hash", __func__);
 168
 169mdfour_err:
 170        crypto_free_shash(md4);
 171        kfree(sdescmd4);
 172
 173        return rc;
 174}
 175
 176/*
 177   This implements the X/Open SMB password encryption
 178   It takes a password, a 8 byte "crypt key" and puts 24 bytes of
 179   encrypted password into p24 */
 180/* Note that password must be uppercased and null terminated */
 181int
 182SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 183{
 184        int rc;
 185        unsigned char p14[14], p16[16], p21[21];
 186
 187        memset(p14, '\0', 14);
 188        memset(p16, '\0', 16);
 189        memset(p21, '\0', 21);
 190
 191        memcpy(p14, passwd, 14);
 192        rc = E_P16(p14, p16);
 193        if (rc)
 194                return rc;
 195
 196        memcpy(p21, p16, 16);
 197        rc = E_P24(p21, c8, p24);
 198
 199        return rc;
 200}
 201
 202/*
 203 * Creates the MD4 Hash of the users password in NT UNICODE.
 204 */
 205
 206int
 207E_md4hash(const unsigned char *passwd, unsigned char *p16,
 208        const struct nls_table *codepage)
 209{
 210        int rc;
 211        int len;
 212        __le16 wpwd[129];
 213
 214        /* Password cannot be longer than 128 characters */
 215        if (passwd) /* Password must be converted to NT unicode */
 216                len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
 217        else {
 218                len = 0;
 219                *wpwd = 0; /* Ensure string is null terminated */
 220        }
 221
 222        rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
 223        memset(wpwd, 0, 129 * sizeof(__le16));
 224
 225        return rc;
 226}
 227
 228/* Does the NT MD4 hash then des encryption. */
 229int
 230SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
 231                const struct nls_table *codepage)
 232{
 233        int rc;
 234        unsigned char p16[16], p21[21];
 235
 236        memset(p16, '\0', 16);
 237        memset(p21, '\0', 21);
 238
 239        rc = E_md4hash(passwd, p16, codepage);
 240        if (rc) {
 241                cFYI(1, "%s Can't generate NT hash, error: %d", __func__, rc);
 242                return rc;
 243        }
 244        memcpy(p21, p16, 16);
 245        rc = E_P24(p21, c8, p24);
 246        return rc;
 247}
 248
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