fs/cifs/smbencrypt.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3    Unix SMB/Netbios implementation.
   4    Version 1.9.
   5    SMB parameters and setup
   6    Copyright (C) Andrew Tridgell 1992-2000
   7    Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   8    Modified by Jeremy Allison 1995.
   9    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
  10    Modified by Steve French (sfrench@us.ibm.com) 2002-2003
  11
  12 */
  13
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/fips.h>
  17 #include <linux/fs.h>
  18 #include <linux/string.h>
  19 #include <linux/kernel.h>
  20 #include <linux/random.h>
  21 #include <crypto/des.h>
  22 #include "cifs_fs_sb.h"
  23 #include "cifs_unicode.h"
  24 #include "cifspdu.h"
  25 #include "cifsglob.h"
  26 #include "cifs_debug.h"
  27 #include "cifsproto.h"
  28
  29 #ifndef false
  30 #define false 0
  31 #endif
  32 #ifndef true
  33 #define true 1
  34 #endif
  35
  36 /* following came from the other byteorder.h to avoid include conflicts */
  37 #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
  38 #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
  39 #define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))
  40
  41 static void
  42 str_to_key(unsigned char *str, unsigned char *key)
  43 {
  44         int i;
  45
  46         key[0] = str[0] >> 1;
  47         key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
  48         key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
  49         key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
  50         key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
  51         key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
  52         key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
  53         key[7] = str[6] & 0x7F;
  54         for (i = 0; i < 8; i++)
  55                 key[i] = (key[i] << 1);
  56 }
  57
  58 static int
  59 smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
  60 {
  61         unsigned char key2[8];
  62         struct des_ctx ctx;
  63
  64         str_to_key(key, key2);
  65
  66         if (fips_enabled) {
  67                 cifs_dbg(VFS, "FIPS compliance enabled: DES not permitted\n");
  68                 return -ENOENT;
  69         }
  70
  71         des_expand_key(&ctx, key2, DES_KEY_SIZE);
  72         des_encrypt(&ctx, out, in);
  73         memzero_explicit(&ctx, sizeof(ctx));
  74
  75         return 0;
  76 }
  77
  78 static int
  79 E_P16(unsigned char *p14, unsigned char *p16)
  80 {
  81         int rc;
  82         unsigned char sp8[8] =
  83             { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
  84
  85         rc = smbhash(p16, sp8, p14);
  86         if (rc)
  87                 return rc;
  88         rc = smbhash(p16 + 8, sp8, p14 + 7);
  89         return rc;
  90 }
  91
  92 static int
  93 E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
  94 {
  95         int rc;
  96
  97         rc = smbhash(p24, c8, p21);
  98         if (rc)
  99                 return rc;
 100         rc = smbhash(p24 + 8, c8, p21 + 7);
 101         if (rc)
 102                 return rc;
 103         rc = smbhash(p24 + 16, c8, p21 + 14);
 104         return rc;
 105 }
 106
 107 /* produce a md4 message digest from data of length n bytes */
 108 int
 109 mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
 110 {
 111         int rc;
 112         struct crypto_shash *md4 = NULL;
 113         struct sdesc *sdescmd4 = NULL;
 114
 115         rc = cifs_alloc_hash("md4", &md4, &sdescmd4);
 116         if (rc)
 117                 goto mdfour_err;
 118
 119         rc = crypto_shash_init(&sdescmd4->shash);
 120         if (rc) {
 121                 cifs_dbg(VFS, "%s: Could not init md4 shash\n", __func__);
 122                 goto mdfour_err;
 123         }
 124         rc = crypto_shash_update(&sdescmd4->shash, link_str, link_len);
 125         if (rc) {
 126                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 127                 goto mdfour_err;
 128         }
 129         rc = crypto_shash_final(&sdescmd4->shash, md4_hash);
 130         if (rc)
 131                 cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);
 132
 133 mdfour_err:
 134         cifs_free_hash(&md4, &sdescmd4);
 135         return rc;
 136 }
 137
 138 /*
 139    This implements the X/Open SMB password encryption
 140    It takes a password, a 8 byte "crypt key" and puts 24 bytes of
 141    encrypted password into p24 */
 142 /* Note that password must be uppercased and null terminated */
 143 int
 144 SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 145 {
 146         int rc;
 147         unsigned char p14[14], p16[16], p21[21];
 148
 149         memset(p14, '\0', 14);
 150         memset(p16, '\0', 16);
 151         memset(p21, '\0', 21);
 152
 153         memcpy(p14, passwd, 14);
 154         rc = E_P16(p14, p16);
 155         if (rc)
 156                 return rc;
 157
 158         memcpy(p21, p16, 16);
 159         rc = E_P24(p21, c8, p24);
 160
 161         return rc;
 162 }
 163
 164 /*
 165  * Creates the MD4 Hash of the users password in NT UNICODE.
 166  */
 167
 168 int
 169 E_md4hash(const unsigned char *passwd, unsigned char *p16,
 170         const struct nls_table *codepage)
 171 {
 172         int rc;
 173         int len;
 174         __le16 wpwd[129];
 175
 176         /* Password cannot be longer than 128 characters */
 177         if (passwd) /* Password must be converted to NT unicode */
 178                 len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
 179         else {
 180                 len = 0;
 181                 *wpwd = 0; /* Ensure string is null terminated */
 182         }
 183
 184         rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
 185         memzero_explicit(wpwd, sizeof(wpwd));
 186
 187         return rc;
 188 }
 189
 190 /* Does the NT MD4 hash then des encryption. */
 191 int
 192 SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
 193                 const struct nls_table *codepage)
 194 {
 195         int rc;
 196         unsigned char p16[16], p21[21];
 197
 198         memset(p16, '\0', 16);
 199         memset(p21, '\0', 21);
 200
 201         rc = E_md4hash(passwd, p16, codepage);
 202         if (rc) {
 203                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 204                          __func__, rc);
 205                 return rc;
 206         }
 207         memcpy(p21, p16, 16);
 208         rc = E_P24(p21, c8, p24);
 209         return rc;
 210 }