linux/fs/cifs/smbencrypt.c
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   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
  41static void
  42str_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
  58static int
  59smbhash(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
  78static int
  79E_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
  92static int
  93E_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 */
 108int
 109mdfour(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
 133mdfour_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 */
 143int
 144SMBencrypt(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
 168int
 169E_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. */
 191int
 192SMBNTencrypt(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}
 211