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/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
  50 static void
  51 str_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
  67 static int
  68 smbhash(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                 cifs_dbg(VFS, "could not allocate des crypto API\n");
  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                 cifs_dbg(VFS, "could not encrypt crypt key rc: %d\n", rc);
  95
  96         crypto_free_blkcipher(tfm_des);
  97 smbhash_err:
  98         return rc;
  99 }
 100
 101 static int
 102 E_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
 115 static int
 116 E_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 */
 131 int
 132 mdfour(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                 cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
 143                          __func__, rc);
 144                 return rc;
 145         }
 146         size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
 147         sdescmd4 = kmalloc(size, GFP_KERNEL);
 148         if (!sdescmd4) {
 149                 rc = -ENOMEM;
 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                 cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
 158                 goto mdfour_err;
 159         }
 160         rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
 161         if (rc) {
 162                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 163                 goto mdfour_err;
 164         }
 165         rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
 166         if (rc)
 167                 cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
 168
 169 mdfour_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 */
 181 int
 182 SMBencrypt(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
 206 int
 207 E_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. */
 229 int
 230 SMBNTencrypt(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                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 242                          __func__, rc);
 243                 return rc;
 244         }
 245         memcpy(p21, p16, 16);
 246         rc = E_P24(p21, c8, p24);
 247         return rc;
 248 }