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 <crypto/skcipher.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         int rc;
  73         unsigned char key2[8];
  74         struct crypto_skcipher *tfm_des;
  75         struct scatterlist sgin, sgout;
  76         struct skcipher_request *req;
  77
  78         str_to_key(key, key2);
  79
  80         tfm_des = crypto_alloc_skcipher("ecb(des)", 0, CRYPTO_ALG_ASYNC);
  81         if (IS_ERR(tfm_des)) {
  82                 rc = PTR_ERR(tfm_des);
  83                 cifs_dbg(VFS, "could not allocate des crypto API\n");
  84                 goto smbhash_err;
  85         }
  86
  87         req = skcipher_request_alloc(tfm_des, GFP_KERNEL);
  88         if (!req) {
  89                 rc = -ENOMEM;
  90                 cifs_dbg(VFS, "could not allocate des crypto API\n");
  91                 goto smbhash_free_skcipher;
  92         }
  93
  94         crypto_skcipher_setkey(tfm_des, key2, 8);
  95
  96         sg_init_one(&sgin, in, 8);
  97         sg_init_one(&sgout, out, 8);
  98
  99         skcipher_request_set_callback(req, 0, NULL, NULL);
 100         skcipher_request_set_crypt(req, &sgin, &sgout, 8, NULL);
 101
 102         rc = crypto_skcipher_encrypt(req);
 103         if (rc)
 104                 cifs_dbg(VFS, "could not encrypt crypt key rc: %d\n", rc);
 105
 106         skcipher_request_free(req);
 107
 108 smbhash_free_skcipher:
 109         crypto_free_skcipher(tfm_des);
 110 smbhash_err:
 111         return rc;
 112 }
 113
 114 static int
 115 E_P16(unsigned char *p14, unsigned char *p16)
 116 {
 117         int rc;
 118         unsigned char sp8[8] =
 119             { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
 120
 121         rc = smbhash(p16, sp8, p14);
 122         if (rc)
 123                 return rc;
 124         rc = smbhash(p16 + 8, sp8, p14 + 7);
 125         return rc;
 126 }
 127
 128 static int
 129 E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
 130 {
 131         int rc;
 132
 133         rc = smbhash(p24, c8, p21);
 134         if (rc)
 135                 return rc;
 136         rc = smbhash(p24 + 8, c8, p21 + 7);
 137         if (rc)
 138                 return rc;
 139         rc = smbhash(p24 + 16, c8, p21 + 14);
 140         return rc;
 141 }
 142
 143 /* produce a md4 message digest from data of length n bytes */
 144 int
 145 mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
 146 {
 147         int rc;
 148         unsigned int size;
 149         struct crypto_shash *md4;
 150         struct sdesc *sdescmd4;
 151
 152         md4 = crypto_alloc_shash("md4", 0, 0);
 153         if (IS_ERR(md4)) {
 154                 rc = PTR_ERR(md4);
 155                 cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
 156                          __func__, rc);
 157                 return rc;
 158         }
 159         size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
 160         sdescmd4 = kmalloc(size, GFP_KERNEL);
 161         if (!sdescmd4) {
 162                 rc = -ENOMEM;
 163                 goto mdfour_err;
 164         }
 165         sdescmd4->shash.tfm = md4;
 166         sdescmd4->shash.flags = 0x0;
 167
 168         rc = crypto_shash_init(&sdescmd4->shash);
 169         if (rc) {
 170                 cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
 171                 goto mdfour_err;
 172         }
 173         rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
 174         if (rc) {
 175                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 176                 goto mdfour_err;
 177         }
 178         rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
 179         if (rc)
 180                 cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
 181
 182 mdfour_err:
 183         crypto_free_shash(md4);
 184         kfree(sdescmd4);
 185
 186         return rc;
 187 }
 188
 189 /*
 190    This implements the X/Open SMB password encryption
 191    It takes a password, a 8 byte "crypt key" and puts 24 bytes of
 192    encrypted password into p24 */
 193 /* Note that password must be uppercased and null terminated */
 194 int
 195 SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 196 {
 197         int rc;
 198         unsigned char p14[14], p16[16], p21[21];
 199
 200         memset(p14, '\0', 14);
 201         memset(p16, '\0', 16);
 202         memset(p21, '\0', 21);
 203
 204         memcpy(p14, passwd, 14);
 205         rc = E_P16(p14, p16);
 206         if (rc)
 207                 return rc;
 208
 209         memcpy(p21, p16, 16);
 210         rc = E_P24(p21, c8, p24);
 211
 212         return rc;
 213 }
 214
 215 /*
 216  * Creates the MD4 Hash of the users password in NT UNICODE.
 217  */
 218
 219 int
 220 E_md4hash(const unsigned char *passwd, unsigned char *p16,
 221         const struct nls_table *codepage)
 222 {
 223         int rc;
 224         int len;
 225         __le16 wpwd[129];
 226
 227         /* Password cannot be longer than 128 characters */
 228         if (passwd) /* Password must be converted to NT unicode */
 229                 len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
 230         else {
 231                 len = 0;
 232                 *wpwd = 0; /* Ensure string is null terminated */
 233         }
 234
 235         rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
 236         memzero_explicit(wpwd, sizeof(wpwd));
 237
 238         return rc;
 239 }
 240
 241 /* Does the NT MD4 hash then des encryption. */
 242 int
 243 SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
 244                 const struct nls_table *codepage)
 245 {
 246         int rc;
 247         unsigned char p16[16], p21[21];
 248
 249         memset(p16, '\0', 16);
 250         memset(p21, '\0', 21);
 251
 252         rc = E_md4hash(passwd, p16, codepage);
 253         if (rc) {
 254                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 255                          __func__, rc);
 256                 return rc;
 257         }
 258         memcpy(p21, p16, 16);
 259         rc = E_P24(p21, c8, p24);
 260         return rc;
 261 }