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_fs_sb.h"
  33 #include "cifs_unicode.h"
  34 #include "cifspdu.h"
  35 #include "cifsglob.h"
  36 #include "cifs_debug.h"
  37 #include "cifsproto.h"
  38
  39 #ifndef false
  40 #define false 0
  41 #endif
  42 #ifndef true
  43 #define true 1
  44 #endif
  45
  46 /* following came from the other byteorder.h to avoid include conflicts */
  47 #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
  48 #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
  49 #define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))
  50
  51 static void
  52 str_to_key(unsigned char *str, unsigned char *key)
  53 {
  54         int i;
  55
  56         key[0] = str[0] >> 1;
  57         key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
  58         key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
  59         key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
  60         key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
  61         key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
  62         key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
  63         key[7] = str[6] & 0x7F;
  64         for (i = 0; i < 8; i++)
  65                 key[i] = (key[i] << 1);
  66 }
  67
  68 static int
  69 smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
  70 {
  71         int rc;
  72         unsigned char key2[8];
  73         struct crypto_blkcipher *tfm_des;
  74         struct scatterlist sgin, sgout;
  75         struct blkcipher_desc desc;
  76
  77         str_to_key(key, key2);
  78
  79         tfm_des = crypto_alloc_blkcipher("ecb(des)", 0, CRYPTO_ALG_ASYNC);
  80         if (IS_ERR(tfm_des)) {
  81                 rc = PTR_ERR(tfm_des);
  82                 cifs_dbg(VFS, "could not allocate des crypto API\n");
  83                 goto smbhash_err;
  84         }
  85
  86         desc.tfm = tfm_des;
  87
  88         crypto_blkcipher_setkey(tfm_des, key2, 8);
  89
  90         sg_init_one(&sgin, in, 8);
  91         sg_init_one(&sgout, out, 8);
  92
  93         rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, 8);
  94         if (rc)
  95                 cifs_dbg(VFS, "could not encrypt crypt key rc: %d\n", rc);
  96
  97         crypto_free_blkcipher(tfm_des);
  98 smbhash_err:
  99         return rc;
 100 }
 101
 102 static int
 103 E_P16(unsigned char *p14, unsigned char *p16)
 104 {
 105         int rc;
 106         unsigned char sp8[8] =
 107             { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
 108
 109         rc = smbhash(p16, sp8, p14);
 110         if (rc)
 111                 return rc;
 112         rc = smbhash(p16 + 8, sp8, p14 + 7);
 113         return rc;
 114 }
 115
 116 static int
 117 E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
 118 {
 119         int rc;
 120
 121         rc = smbhash(p24, c8, p21);
 122         if (rc)
 123                 return rc;
 124         rc = smbhash(p24 + 8, c8, p21 + 7);
 125         if (rc)
 126                 return rc;
 127         rc = smbhash(p24 + 16, c8, p21 + 14);
 128         return rc;
 129 }
 130
 131 /* produce a md4 message digest from data of length n bytes */
 132 int
 133 mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
 134 {
 135         int rc;
 136         unsigned int size;
 137         struct crypto_shash *md4;
 138         struct sdesc *sdescmd4;
 139
 140         md4 = crypto_alloc_shash("md4", 0, 0);
 141         if (IS_ERR(md4)) {
 142                 rc = PTR_ERR(md4);
 143                 cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
 144                          __func__, rc);
 145                 return rc;
 146         }
 147         size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
 148         sdescmd4 = kmalloc(size, GFP_KERNEL);
 149         if (!sdescmd4) {
 150                 rc = -ENOMEM;
 151                 goto mdfour_err;
 152         }
 153         sdescmd4->shash.tfm = md4;
 154         sdescmd4->shash.flags = 0x0;
 155
 156         rc = crypto_shash_init(&sdescmd4->shash);
 157         if (rc) {
 158                 cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
 159                 goto mdfour_err;
 160         }
 161         rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
 162         if (rc) {
 163                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 164                 goto mdfour_err;
 165         }
 166         rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
 167         if (rc)
 168                 cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
 169
 170 mdfour_err:
 171         crypto_free_shash(md4);
 172         kfree(sdescmd4);
 173
 174         return rc;
 175 }
 176
 177 /*
 178    This implements the X/Open SMB password encryption
 179    It takes a password, a 8 byte "crypt key" and puts 24 bytes of
 180    encrypted password into p24 */
 181 /* Note that password must be uppercased and null terminated */
 182 int
 183 SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 184 {
 185         int rc;
 186         unsigned char p14[14], p16[16], p21[21];
 187
 188         memset(p14, '\0', 14);
 189         memset(p16, '\0', 16);
 190         memset(p21, '\0', 21);
 191
 192         memcpy(p14, passwd, 14);
 193         rc = E_P16(p14, p16);
 194         if (rc)
 195                 return rc;
 196
 197         memcpy(p21, p16, 16);
 198         rc = E_P24(p21, c8, p24);
 199
 200         return rc;
 201 }
 202
 203 /*
 204  * Creates the MD4 Hash of the users password in NT UNICODE.
 205  */
 206
 207 int
 208 E_md4hash(const unsigned char *passwd, unsigned char *p16,
 209         const struct nls_table *codepage)
 210 {
 211         int rc;
 212         int len;
 213         __le16 wpwd[129];
 214
 215         /* Password cannot be longer than 128 characters */
 216         if (passwd) /* Password must be converted to NT unicode */
 217                 len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
 218         else {
 219                 len = 0;
 220                 *wpwd = 0; /* Ensure string is null terminated */
 221         }
 222
 223         rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
 224         memzero_explicit(wpwd, sizeof(wpwd));
 225
 226         return rc;
 227 }
 228
 229 /* Does the NT MD4 hash then des encryption. */
 230 int
 231 SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
 232                 const struct nls_table *codepage)
 233 {
 234         int rc;
 235         unsigned char p16[16], p21[21];
 236
 237         memset(p16, '\0', 16);
 238         memset(p21, '\0', 21);
 239
 240         rc = E_md4hash(passwd, p16, codepage);
 241         if (rc) {
 242                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 243                          __func__, rc);
 244                 return rc;
 245         }
 246         memcpy(p21, p16, 16);
 247         rc = E_P24(p21, c8, p24);
 248         return rc;
 249 }