fs/cifs/smbencrypt.c

   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/crypto.h>
  27 #include <linux/module.h>
  28 #include <linux/slab.h>
  29 #include <linux/fs.h>
  30 #include <linux/string.h>
  31 #include <linux/kernel.h>
  32 #include <linux/random.h>
  33 #include "cifs_fs_sb.h"
  34 #include "cifs_unicode.h"
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifs_debug.h"
  38 #include "cifsproto.h"
  39
  40 #ifndef false
  41 #define false 0
  42 #endif
  43 #ifndef true
  44 #define true 1
  45 #endif
  46
  47 /* following came from the other byteorder.h to avoid include conflicts */
  48 #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
  49 #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
  50 #define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))
  51
  52 static void
  53 str_to_key(unsigned char *str, unsigned char *key)
  54 {
  55         int i;
  56
  57         key[0] = str[0] >> 1;
  58         key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
  59         key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
  60         key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
  61         key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
  62         key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
  63         key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
  64         key[7] = str[6] & 0x7F;
  65         for (i = 0; i < 8; i++)
  66                 key[i] = (key[i] << 1);
  67 }
  68
  69 static int
  70 smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
  71 {
  72         unsigned char key2[8];
  73         struct crypto_cipher *tfm_des;
  74
  75         str_to_key(key, key2);
  76
  77         tfm_des = crypto_alloc_cipher("des", 0, 0);
  78         if (IS_ERR(tfm_des)) {
  79                 cifs_dbg(VFS, "could not allocate des crypto API\n");
  80                 return PTR_ERR(tfm_des);
  81         }
  82
  83         crypto_cipher_setkey(tfm_des, key2, 8);
  84         crypto_cipher_encrypt_one(tfm_des, out, in);
  85         crypto_free_cipher(tfm_des);
  86
  87         return 0;
  88 }
  89
  90 static int
  91 E_P16(unsigned char *p14, unsigned char *p16)
  92 {
  93         int rc;
  94         unsigned char sp8[8] =
  95             { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
  96
  97         rc = smbhash(p16, sp8, p14);
  98         if (rc)
  99                 return rc;
 100         rc = smbhash(p16 + 8, sp8, p14 + 7);
 101         return rc;
 102 }
 103
 104 static int
 105 E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
 106 {
 107         int rc;
 108
 109         rc = smbhash(p24, c8, p21);
 110         if (rc)
 111                 return rc;
 112         rc = smbhash(p24 + 8, c8, p21 + 7);
 113         if (rc)
 114                 return rc;
 115         rc = smbhash(p24 + 16, c8, p21 + 14);
 116         return rc;
 117 }
 118
 119 /* produce a md4 message digest from data of length n bytes */
 120 int
 121 mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
 122 {
 123         int rc;
 124         unsigned int size;
 125         struct crypto_shash *md4;
 126         struct sdesc *sdescmd4;
 127
 128         md4 = crypto_alloc_shash("md4", 0, 0);
 129         if (IS_ERR(md4)) {
 130                 rc = PTR_ERR(md4);
 131                 cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
 132                          __func__, rc);
 133                 return rc;
 134         }
 135         size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
 136         sdescmd4 = kmalloc(size, GFP_KERNEL);
 137         if (!sdescmd4) {
 138                 rc = -ENOMEM;
 139                 goto mdfour_err;
 140         }
 141         sdescmd4->shash.tfm = md4;
 142         sdescmd4->shash.flags = 0x0;
 143
 144         rc = crypto_shash_init(&sdescmd4->shash);
 145         if (rc) {
 146                 cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
 147                 goto mdfour_err;
 148         }
 149         rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
 150         if (rc) {
 151                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 152                 goto mdfour_err;
 153         }
 154         rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
 155         if (rc)
 156                 cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
 157
 158 mdfour_err:
 159         crypto_free_shash(md4);
 160         kfree(sdescmd4);
 161
 162         return rc;
 163 }
 164
 165 /*
 166    This implements the X/Open SMB password encryption
 167    It takes a password, a 8 byte "crypt key" and puts 24 bytes of
 168    encrypted password into p24 */
 169 /* Note that password must be uppercased and null terminated */
 170 int
 171 SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 172 {
 173         int rc;
 174         unsigned char p14[14], p16[16], p21[21];
 175
 176         memset(p14, '\0', 14);
 177         memset(p16, '\0', 16);
 178         memset(p21, '\0', 21);
 179
 180         memcpy(p14, passwd, 14);
 181         rc = E_P16(p14, p16);
 182         if (rc)
 183                 return rc;
 184
 185         memcpy(p21, p16, 16);
 186         rc = E_P24(p21, c8, p24);
 187
 188         return rc;
 189 }
 190
 191 /*
 192  * Creates the MD4 Hash of the users password in NT UNICODE.
 193  */
 194
 195 int
 196 E_md4hash(const unsigned char *passwd, unsigned char *p16,
 197         const struct nls_table *codepage)
 198 {
 199         int rc;
 200         int len;
 201         __le16 wpwd[129];
 202
 203         /* Password cannot be longer than 128 characters */
 204         if (passwd) /* Password must be converted to NT unicode */
 205                 len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
 206         else {
 207                 len = 0;
 208                 *wpwd = 0; /* Ensure string is null terminated */
 209         }
 210
 211         rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
 212         memzero_explicit(wpwd, sizeof(wpwd));
 213
 214         return rc;
 215 }
 216
 217 /* Does the NT MD4 hash then des encryption. */
 218 int
 219 SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
 220                 const struct nls_table *codepage)
 221 {
 222         int rc;
 223         unsigned char p16[16], p21[21];
 224
 225         memset(p16, '\0', 16);
 226         memset(p21, '\0', 21);
 227
 228         rc = E_md4hash(passwd, p16, codepage);
 229         if (rc) {
 230                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 231                          __func__, rc);
 232                 return rc;
 233         }
 234         memcpy(p21, p16, 16);
 235         rc = E_P24(p21, c8, p24);
 236         return rc;
 237 }