743 lines
28 KiB
C
743 lines
28 KiB
C
#include "lmhash.h"
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
/* ========================================================================== **
|
|
*
|
|
* LMhash.h
|
|
*
|
|
* Copyright:
|
|
* Copyright (C) 2004 by Christopher R. Hertel
|
|
*
|
|
* Email: crh@ubiqx.mn.org
|
|
*
|
|
* $Id: LMhash.h,v 0.1 2004/05/30 02:26:31 crh Exp $
|
|
*
|
|
* -------------------------------------------------------------------------- **
|
|
*
|
|
* Description:
|
|
*
|
|
* Implemention of the LAN Manager hash (LM hash) and LM response
|
|
* algorithms.
|
|
*
|
|
* -------------------------------------------------------------------------- **
|
|
*
|
|
* License:
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
* -------------------------------------------------------------------------- **
|
|
*
|
|
* Notes:
|
|
*
|
|
* This module implements the LM hash. The NT hash is simply the MD4() of
|
|
* the password, so we don't need a separate implementation of that. This
|
|
* module also implements the LM response, which can be combined with the
|
|
* NT hash to produce the NTLM response.
|
|
*
|
|
* This implementation was created based on the description in my own book.
|
|
* The book description was, in turn, written after studying many existing
|
|
* examples in various documentation. Jeremy Allison and Andrew Tridgell
|
|
* deserve lots of credit for having figured out the secrets of Lan Manager
|
|
* authentication many years ago.
|
|
*
|
|
* See:
|
|
* Implementing CIFS - the Common Internet File System
|
|
* by your truly. ISBN 0-13-047116-X, Prentice Hall PTR., August 2003
|
|
* Section 15.3, in particular.
|
|
* (Online at: http://ubiqx.org/cifs/SMB.html#SMB.8.3)
|
|
*
|
|
* ========================================================================== **
|
|
*/
|
|
|
|
|
|
/* Initial permutation map.
|
|
* In the first step of DES, the bits of the initial plaintext are rearranged
|
|
* according to the map given below. This map and those like it are read by
|
|
* the Permute() function (below) which uses the maps as a guide when moving
|
|
* bits from one place to another.
|
|
*
|
|
* Note that the values here are all one less than those shown in Schneier.
|
|
* That's because C likes to start counting from 0, not 1.
|
|
*
|
|
* According to Schneier (Ch12, pg 271), the purpose of the initial
|
|
* permutation was to make it easier to load plaintext and ciphertext into
|
|
* a DES ecryption chip. I have no idea why that would be the case.
|
|
*/
|
|
static const uint8_t InitialPermuteMap[64] =
|
|
{
|
|
57, 49, 41, 33, 25, 17, 9, 1,
|
|
59, 51, 43, 35, 27, 19, 11, 3,
|
|
61, 53, 45, 37, 29, 21, 13, 5,
|
|
63, 55, 47, 39, 31, 23, 15, 7,
|
|
56, 48, 40, 32, 24, 16, 8, 0,
|
|
58, 50, 42, 34, 26, 18, 10, 2,
|
|
60, 52, 44, 36, 28, 20, 12, 4,
|
|
62, 54, 46, 38, 30, 22, 14, 6
|
|
};
|
|
|
|
|
|
/* Key permutation map.
|
|
* Like the input data and encryption result, the key is permuted before
|
|
* the algorithm really gets going. The original algorithm called for an
|
|
* eight-byte key in which each byte contained a parity bit. During the
|
|
* key permutiation, the parity bits were discarded. The DES algorithm,
|
|
* as used with SMB, does not make use of the parity bits. Instead, SMB
|
|
* passes 7-byte keys to DES. For DES implementations that expect parity,
|
|
* the parity bits must be added. In this case, however, we're just going
|
|
* to start with a 7-byte (56 bit) key. KeyPermuteMap, below, is adjusted
|
|
* accordingly and, of course, each entry in the map is reduced by 1 with
|
|
* respect to the documented values because C likes to start counting from
|
|
* 0, not 1.
|
|
*/
|
|
static const uint8_t KeyPermuteMap[56] =
|
|
{
|
|
49, 42, 35, 28, 21, 14, 7, 0,
|
|
50, 43, 36, 29, 22, 15, 8, 1,
|
|
51, 44, 37, 30, 23, 16, 9, 2,
|
|
52, 45, 38, 31, 55, 48, 41, 34,
|
|
27, 20, 13, 6, 54, 47, 40, 33,
|
|
26, 19, 12, 5, 53, 46, 39, 32,
|
|
25, 18, 11, 4, 24, 17, 10, 3,
|
|
};
|
|
|
|
|
|
/* Key rotation table.
|
|
* At the start of each round of encryption, the key is split and each
|
|
* 28-bit half is rotated left. The number of bits of rotation per round
|
|
* is given in the table below.
|
|
*/
|
|
static const uint8_t KeyRotation[16] =
|
|
{ 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };
|
|
|
|
|
|
/* Key compression table.
|
|
* This table is used to select 48 of the 56 bits of the key.
|
|
* The left and right halves of the source text are each 32 bits,
|
|
* but they are expanded to 48 bits and the results are XOR'd
|
|
* against the compressed (48-bit) key.
|
|
*/
|
|
static const uint8_t KeyCompression[48] =
|
|
{
|
|
13, 16, 10, 23, 0, 4, 2, 27,
|
|
14, 5, 20, 9, 22, 18, 11, 3,
|
|
25, 7, 15, 6, 26, 19, 12, 1,
|
|
40, 51, 30, 36, 46, 54, 29, 39,
|
|
50, 44, 32, 47, 43, 48, 38, 55,
|
|
33, 52, 45, 41, 49, 35, 28, 31
|
|
};
|
|
|
|
|
|
/* Data expansion table.
|
|
* This table is used after the data block (64-bits) has been split
|
|
* into two 32-bit (4-byte) halves (generally denoted L and R).
|
|
* Each 32-bit half is "expanded", using this table, to a 48 bit
|
|
* data block, which is then XOR'd with the 48 bit subkey for the
|
|
* round.
|
|
*/
|
|
static const uint8_t DataExpansion[48] =
|
|
{
|
|
31, 0, 1, 2, 3, 4, 3, 4,
|
|
5, 6, 7, 8, 7, 8, 9, 10,
|
|
11, 12, 11, 12, 13, 14, 15, 16,
|
|
15, 16, 17, 18, 19, 20, 19, 20,
|
|
21, 22, 23, 24, 23, 24, 25, 26,
|
|
27, 28, 27, 28, 29, 30, 31, 0
|
|
};
|
|
|
|
|
|
/* The (in)famous S-boxes.
|
|
* These are used to perform substitutions.
|
|
* Six bits worth of input will return four bits of output.
|
|
* The four bit values are stored in these tables. Each table has
|
|
* 64 entries...and 6 bits provides a number between 0 and 63.
|
|
* There are eight S-boxes, one per 6 bits of a 48-bit value.
|
|
* Thus, 48 bits are reduced to 32 bits. Obviously, this step
|
|
* follows the DataExpansion step.
|
|
*
|
|
* Note that the literature generally shows this as 8 arrays each
|
|
* with four rows and 16 colums. There is a complex formula for
|
|
* mapping the 6 bit input values to the correct row and column.
|
|
* I've pre-computed that mapping, and the tables below provide
|
|
* direct 6-bit input to 4-bit output. See pp 274-274 in Schneier.
|
|
*/
|
|
static const uint8_t SBox[8][64] =
|
|
{
|
|
{ /* S0 */
|
|
14, 0, 4, 15, 13, 7, 1, 4, 2, 14, 15, 2, 11, 13, 8, 1,
|
|
3, 10, 10, 6, 6, 12, 12, 11, 5, 9, 9, 5, 0, 3, 7, 8,
|
|
4, 15, 1, 12, 14, 8, 8, 2, 13, 4, 6, 9, 2, 1, 11, 7,
|
|
15, 5, 12, 11, 9, 3, 7, 14, 3, 10, 10, 0, 5, 6, 0, 13
|
|
},
|
|
{ /* S1 */
|
|
15, 3, 1, 13, 8, 4, 14, 7, 6, 15, 11, 2, 3, 8, 4, 14,
|
|
9, 12, 7, 0, 2, 1, 13, 10, 12, 6, 0, 9, 5, 11, 10, 5,
|
|
0, 13, 14, 8, 7, 10, 11, 1, 10, 3, 4, 15, 13, 4, 1, 2,
|
|
5, 11, 8, 6, 12, 7, 6, 12, 9, 0, 3, 5, 2, 14, 15, 9
|
|
},
|
|
{ /* S2 */
|
|
10, 13, 0, 7, 9, 0, 14, 9, 6, 3, 3, 4, 15, 6, 5, 10,
|
|
1, 2, 13, 8, 12, 5, 7, 14, 11, 12, 4, 11, 2, 15, 8, 1,
|
|
13, 1, 6, 10, 4, 13, 9, 0, 8, 6, 15, 9, 3, 8, 0, 7,
|
|
11, 4, 1, 15, 2, 14, 12, 3, 5, 11, 10, 5, 14, 2, 7, 12
|
|
},
|
|
{ /* S3 */
|
|
7, 13, 13, 8, 14, 11, 3, 5, 0, 6, 6, 15, 9, 0, 10, 3,
|
|
1, 4, 2, 7, 8, 2, 5, 12, 11, 1, 12, 10, 4, 14, 15, 9,
|
|
10, 3, 6, 15, 9, 0, 0, 6, 12, 10, 11, 1, 7, 13, 13, 8,
|
|
15, 9, 1, 4, 3, 5, 14, 11, 5, 12, 2, 7, 8, 2, 4, 14
|
|
},
|
|
{ /* S4 */
|
|
2, 14, 12, 11, 4, 2, 1, 12, 7, 4, 10, 7, 11, 13, 6, 1,
|
|
8, 5, 5, 0, 3, 15, 15, 10, 13, 3, 0, 9, 14, 8, 9, 6,
|
|
4, 11, 2, 8, 1, 12, 11, 7, 10, 1, 13, 14, 7, 2, 8, 13,
|
|
15, 6, 9, 15, 12, 0, 5, 9, 6, 10, 3, 4, 0, 5, 14, 3
|
|
},
|
|
{ /* S5 */
|
|
12, 10, 1, 15, 10, 4, 15, 2, 9, 7, 2, 12, 6, 9, 8, 5,
|
|
0, 6, 13, 1, 3, 13, 4, 14, 14, 0, 7, 11, 5, 3, 11, 8,
|
|
9, 4, 14, 3, 15, 2, 5, 12, 2, 9, 8, 5, 12, 15, 3, 10,
|
|
7, 11, 0, 14, 4, 1, 10, 7, 1, 6, 13, 0, 11, 8, 6, 13
|
|
},
|
|
{ /* S6 */
|
|
4, 13, 11, 0, 2, 11, 14, 7, 15, 4, 0, 9, 8, 1, 13, 10,
|
|
3, 14, 12, 3, 9, 5, 7, 12, 5, 2, 10, 15, 6, 8, 1, 6,
|
|
1, 6, 4, 11, 11, 13, 13, 8, 12, 1, 3, 4, 7, 10, 14, 7,
|
|
10, 9, 15, 5, 6, 0, 8, 15, 0, 14, 5, 2, 9, 3, 2, 12
|
|
},
|
|
{ /* S7 */
|
|
13, 1, 2, 15, 8, 13, 4, 8, 6, 10, 15, 3, 11, 7, 1, 4,
|
|
10, 12, 9, 5, 3, 6, 14, 11, 5, 0, 0, 14, 12, 9, 7, 2,
|
|
7, 2, 11, 1, 4, 14, 1, 7, 9, 4, 12, 10, 14, 8, 2, 13,
|
|
0, 15, 6, 12, 10, 9, 13, 0, 15, 3, 3, 5, 5, 6, 8, 11
|
|
}
|
|
};
|
|
|
|
|
|
/* P-Box permutation.
|
|
* This permutation is applied to the result of the S-Box Substitutions.
|
|
* It's a straight-forward re-arrangement of the bits.
|
|
*/
|
|
static const uint8_t PBox[32] =
|
|
{
|
|
15, 6, 19, 20, 28, 11, 27, 16,
|
|
0, 14, 22, 25, 4, 17, 30, 9,
|
|
1, 7, 23, 13, 31, 26, 2, 8,
|
|
18, 12, 29, 5, 21, 10, 3, 24
|
|
};
|
|
|
|
|
|
/* Final permutation map.
|
|
* This is supposed to be the inverse of the Initial Permutation,
|
|
* but there's been a bit of fiddling done.
|
|
* As always, the values given are one less than those in the literature
|
|
* (because C starts counting from 0, not 1). In addition, the penultimate
|
|
* step in DES is to swap the left and right hand sides of the ciphertext.
|
|
* The inverse of the Initial Permutation is then applied to produce the
|
|
* final result.
|
|
* To save a step, the map below does the left/right swap as well as the
|
|
* inverse permutation.
|
|
*/
|
|
static const uint8_t FinalPermuteMap[64] =
|
|
{
|
|
7, 39, 15, 47, 23, 55, 31, 63,
|
|
6, 38, 14, 46, 22, 54, 30, 62,
|
|
5, 37, 13, 45, 21, 53, 29, 61,
|
|
4, 36, 12, 44, 20, 52, 28, 60,
|
|
3, 35, 11, 43, 19, 51, 27, 59,
|
|
2, 34, 10, 42, 18, 50, 26, 58,
|
|
1, 33, 9, 41, 17, 49, 25, 57,
|
|
0, 32, 8, 40, 16, 48, 24, 56
|
|
};
|
|
|
|
|
|
/* -------------------------------------------------------------------------- **
|
|
* Macros:
|
|
*
|
|
* CLRBIT( STR, IDX )
|
|
* Input: STR - (uchar *) pointer to an array of 8-bit bytes.
|
|
* IDX - (int) bitwise index of a bit within the STR array
|
|
* that is to be cleared (that is, given a value of 0).
|
|
* Notes: This macro clears a bit within an array of bits (which is
|
|
* built within an array of bytes).
|
|
* - The macro converts to an assignment of the form A &= B.
|
|
* - The string of bytes is viewed as an array of bits, read from
|
|
* highest order bit first. The highest order bit of a byte
|
|
* would, therefore, be bit 0 (within that byte).
|
|
*
|
|
* SETBIT( STR, IDX )
|
|
* Input: STR - (uchar *) pointer to an array of 8-bit bytes.
|
|
* IDX - (int) bitwise index of a bit within the STR array
|
|
* that is to be set (that is, given a value of 1).
|
|
* Notes: This macro sets a bit within an array of bits (which is
|
|
* built within an array of bytes).
|
|
* - The macro converts to an assignment of the form A |= B.
|
|
* - The string of bytes is viewed as an array of bits, read from
|
|
* highest order bit first. The highest order bit of a byte
|
|
* would, therefore, be bit 0 (within that byte).
|
|
*
|
|
* GETBIT( STR, IDX )
|
|
* Input: STR - (uchar *) pointer to an array of 8-bit bytes.
|
|
* IDX - (int) bit-wise index of a bit within the STR array
|
|
* that is to be read.
|
|
* Output: True (1) if the indexed bit was set, else false (0).
|
|
*
|
|
* -------------------------------------------------------------------------- **
|
|
*/
|
|
|
|
#define CLRBIT( STR, IDX ) ( (STR)[(IDX)/8] &= ~(0x01 << (7 - ((IDX)%8))) )
|
|
|
|
#define SETBIT( STR, IDX ) ( (STR)[(IDX)/8] |= (0x01 << (7 - ((IDX)%8))) )
|
|
|
|
#define GETBIT( STR, IDX ) (( ((STR)[(IDX)/8]) >> (7 - ((IDX)%8)) ) & 0x01)
|
|
|
|
|
|
/* -------------------------------------------------------------------------- **
|
|
* Static Functions:
|
|
*/
|
|
|
|
static void Permute( uchar *dst,
|
|
const uchar *src,
|
|
const uint8_t *map,
|
|
const int mapsize )
|
|
/* ------------------------------------------------------------------------ **
|
|
* Performs a DES permutation, which re-arranges the bits in an array of
|
|
* bytes.
|
|
*
|
|
* Input: dst - Destination into which to put the re-arranged bits.
|
|
* src - Source from which to read the bits.
|
|
* map - Permutation map.
|
|
* mapsize - Number of bytes represented by the <map>. This also
|
|
* represents the number of bytes to be copied to <dst>.
|
|
*
|
|
* Output: none.
|
|
*
|
|
* Notes: <src> and <dst> must not point to the same location.
|
|
*
|
|
* - No checks are done to ensure that there is enough room
|
|
* in <dst>, or that the bit numbers in <map> do not exceed
|
|
* the bits available in <src>. A good reason to make this
|
|
* function static (private).
|
|
*
|
|
* - The <mapsize> value is in bytes. All permutations in DES
|
|
* use tables that are a multiple of 8 bits, so there is no
|
|
* need to handle partial bytes. (Yes, I know that there
|
|
* are some machines out there that still use bytes of a size
|
|
* other than 8 bits. For our purposes we'll stick with 8-bit
|
|
* bytes.)
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int bitcount;
|
|
int i;
|
|
|
|
/* Clear all bits in the destination.
|
|
*/
|
|
for( i = 0; i < mapsize; i++ )
|
|
dst[i] = 0;
|
|
|
|
/* Set destination bit if the mapped source bit it set. */
|
|
bitcount = mapsize * 8;
|
|
for( i = 0; i < bitcount; i++ )
|
|
{
|
|
if( GETBIT( src, map[i] ) )
|
|
SETBIT( dst, i );
|
|
}
|
|
} /* Permute */
|
|
|
|
|
|
static void KeyShift( uchar *key, const int numbits )
|
|
/* ------------------------------------------------------------------------ **
|
|
* Split the 56-bit key in half & left rotate each half by <numbits> bits.
|
|
*
|
|
* Input: key - The 56-bit key to be split-rotated.
|
|
* numbits - The number of bits by which to rotate the key.
|
|
*
|
|
* Output: none.
|
|
*
|
|
* Notes: There are probably several better ways to implement this.
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int i;
|
|
uchar keep = key[0]; /* Copy the highest order bits of the key. */
|
|
|
|
/* Repeat the shift process <numbits> times.
|
|
*/
|
|
for( i = 0; i < numbits; i++ )
|
|
{
|
|
int j;
|
|
|
|
/* Shift the entire thing, byte by byte.
|
|
*/
|
|
for( j = 0; j < 7; j++ )
|
|
{
|
|
if( j && (key[j] & 0x80) ) /* If the top bit of this byte is set. */
|
|
key[j-1] |= 0x01; /* ...shift it to last byte's low bit. */
|
|
key[j] <<= 1; /* Then left-shift the whole byte. */
|
|
}
|
|
|
|
/* Now move the high-order bits of each 28-bit half-key to their
|
|
* correct locations.
|
|
* Bit 27 is the lowest order bit of the first half-key.
|
|
* Before the shift, it was the highest order bit of the 2nd half-key.
|
|
*/
|
|
if( GETBIT( key, 27 ) ) /* If bit 27 is set... */
|
|
{
|
|
CLRBIT( key, 27 ); /* ...clear bit 27. */
|
|
SETBIT( key, 55 ); /* ...set lowest order bit of 2nd half-key. */
|
|
}
|
|
|
|
/* We kept the highest order bit of the first half-key in <keep>.
|
|
* If it's set, copy it to bit 27.
|
|
*/
|
|
if( keep & 0x80 )
|
|
SETBIT( key, 27 );
|
|
|
|
/* Rotate the <keep> byte too, in case <numbits> is 2 and there's
|
|
* a second round coming.
|
|
*/
|
|
keep <<= 1;
|
|
}
|
|
} /* KeyShift */
|
|
|
|
|
|
static void sbox( uchar *dst, const uchar *src )
|
|
/* ------------------------------------------------------------------------ **
|
|
* Perform S-Box substitutions.
|
|
*
|
|
* Input: dst - Destination byte array into which the S-Box substituted
|
|
* bitmap will be written.
|
|
* src - Source byte array.
|
|
*
|
|
* Output: none.
|
|
*
|
|
* Notes: It's really not possible (for me, anyway) to understand how
|
|
* this works without reading one or more detailed explanations.
|
|
* Quick overview, though:
|
|
*
|
|
* After the DataExpansion step (in which a 32-bit bit array is
|
|
* expanded to a 48-bit bit array) the expanded data block is
|
|
* XOR'd with 48-bits worth of key. That 48 bits then needs to
|
|
* be condensed back into 32 bits.
|
|
*
|
|
* The S-Box substitution handles the data reduction by breaking
|
|
* the 48-bit value into eight 6-bit values. For each of these
|
|
* 6-bit values there is a table (an S-Box table). The table
|
|
* contains 64 possible values. Conveniently, a 6-bit integer
|
|
* can represent a value between 0 and 63.
|
|
*
|
|
* So, if you think of the 48-bit bit array as an array of 6-bit
|
|
* integers, you use S-Box table 0 with the 0th 6-bit value.
|
|
* Table 1 is used with the 6-bit value #1, and so on until #7.
|
|
* Within each table, the correct substitution is found based
|
|
* simply on the value of the 6-bit integer.
|
|
*
|
|
* Well, the original algorithm (and most documentation) don't
|
|
* make it so simple. There's a complex formula for mapping
|
|
* the 6-bit values to the correct substitution. Fortunately,
|
|
* those lookups can be precomputed (and have been for this
|
|
* implementation). See pp 274-274 in Schneier.
|
|
*
|
|
* Oh, and the substitute values are all 4-bit values, so each
|
|
* 6-bits gets reduced to 4-bits resulting in a 32-bit bit array.
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int i;
|
|
|
|
/* Clear the destination array.
|
|
*/
|
|
for( i = 0; i < 4; i++ )
|
|
dst[i] = 0;
|
|
|
|
/* For each set of six input bits...
|
|
*/
|
|
for( i = 0; i < 8; i++ )
|
|
{
|
|
int j;
|
|
int Snum;
|
|
int bitnum;
|
|
|
|
/* Extract the 6-bit integer from the source.
|
|
* This will be the lookup key within the SBox[i] array.
|
|
*/
|
|
for( Snum = j = 0, bitnum = (i * 6); j < 6; j++, bitnum++ )
|
|
{
|
|
Snum <<= 1;
|
|
Snum |= GETBIT( src, bitnum );
|
|
}
|
|
|
|
/* Find the correct value in the correct SBox[]
|
|
* and copy it into the destination.
|
|
* Left shift the nibble four bytes for even values of <i>.
|
|
*/
|
|
if( 0 == (i%2) )
|
|
dst[i/2] |= ((SBox[i][Snum]) << 4);
|
|
else
|
|
dst[i/2] |= SBox[i][Snum];
|
|
}
|
|
} /* sbox */
|
|
|
|
|
|
static void xor( uchar *dst, const uchar *a, const uchar *b, const int count )
|
|
/* ------------------------------------------------------------------------ **
|
|
* Perform an XOR operation on two byte arrays.
|
|
*
|
|
* Input: dst - Destination array to which the result will be written.
|
|
* a - The first string of bytes.
|
|
* b - The second string of bytes.
|
|
* count - Number of bytes to XOR against one another.
|
|
*
|
|
* Output: none.
|
|
*
|
|
* Notes: This function operates on whole byte chunks. There's no need
|
|
* to XOR partial bytes so no need to write code to handle it.
|
|
*
|
|
* - This function essentially implements dst = a ^ b; for byte
|
|
* arrays.
|
|
*
|
|
* - <dst> may safely point to the same location as <a> or <b>.
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int i;
|
|
|
|
for( i = 0; i < count; i++ )
|
|
dst[i] = a[i] ^ b[i];
|
|
} /* xor */
|
|
|
|
|
|
/* -------------------------------------------------------------------------- **
|
|
* Functions:
|
|
*/
|
|
|
|
uchar *auth_DESkey8to7( uchar *dst, const uchar *key )
|
|
/* ------------------------------------------------------------------------ **
|
|
* Compress an 8-byte DES key to its 7-byte form.
|
|
*
|
|
* Input: dst - Pointer to a memory location (minimum 7 bytes) to accept
|
|
* the compressed key.
|
|
* key - Pointer to an 8-byte DES key. See the notes below.
|
|
*
|
|
* Output: A pointer to the compressed key (same as <dst>) or NULL if
|
|
* either <src> or <dst> were NULL.
|
|
*
|
|
* Notes: There are no checks done to ensure that <dst> and <key> point
|
|
* to sufficient space. Please be carefull.
|
|
*
|
|
* The two pointers, <dst> and <key> may point to the same
|
|
* memory location. Internally, a temporary buffer is used and
|
|
* the results are copied back to <dst>.
|
|
*
|
|
* The DES algorithm uses 8 byte keys by definition. The first
|
|
* step in the algorithm, however, involves removing every eigth
|
|
* bit to produce a 56-bit key (seven bytes). SMB authentication
|
|
* skips this step and uses 7-byte keys. The <auth_DEShash()>
|
|
* algorithm in this module expects 7-byte keys. This function
|
|
* is used to convert an 8-byte DES key into a 7-byte SMB DES key.
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int i;
|
|
uchar tmp[7];
|
|
static const uint8_t map8to7[56] =
|
|
{
|
|
0, 1, 2, 3, 4, 5, 6,
|
|
8, 9, 10, 11, 12, 13, 14,
|
|
16, 17, 18, 19, 20, 21, 22,
|
|
24, 25, 26, 27, 28, 29, 30,
|
|
32, 33, 34, 35, 36, 37, 38,
|
|
40, 41, 42, 43, 44, 45, 46,
|
|
48, 49, 50, 51, 52, 53, 54,
|
|
56, 57, 58, 59, 60, 61, 62
|
|
};
|
|
|
|
if( (NULL == dst) || (NULL == key) )
|
|
return( NULL );
|
|
|
|
Permute( tmp, key, map8to7, 7 );
|
|
for( i = 0; i < 7; i++ )
|
|
dst[i] = tmp[i];
|
|
|
|
return( dst );
|
|
} /* auth_DESkey8to7 */
|
|
|
|
|
|
uchar *auth_DEShash( uchar *dst, const uchar *key, const uchar *src )
|
|
/* ------------------------------------------------------------------------ **
|
|
* DES encryption of the input data using the input key.
|
|
*
|
|
* Input: dst - Destination buffer. It *must* be at least eight bytes
|
|
* in length, to receive the encrypted result.
|
|
* key - Encryption key. Exactly seven bytes will be used.
|
|
* If your key is shorter, ensure that you pad it to seven
|
|
* bytes.
|
|
* src - Source data to be encrypted. Exactly eight bytes will
|
|
* be used. If your source data is shorter, ensure that
|
|
* you pad it to eight bytes.
|
|
*
|
|
* Output: A pointer to the encrpyted data (same as <dst>).
|
|
*
|
|
* Notes: In SMB, the DES function is used as a hashing function rather
|
|
* than an encryption/decryption tool. When used for generating
|
|
* the LM hash the <src> input is the known value "KGS!@#$%" and
|
|
* the key is derived from the password entered by the user.
|
|
* When used to generate the LM or NTLM response, the <key> is
|
|
* derived from the LM or NTLM hash, and the challenge is used
|
|
* as the <src> input.
|
|
* See: http://ubiqx.org/cifs/SMB.html#SMB.8.3
|
|
*
|
|
* - This function is called "DEShash" rather than just "DES"
|
|
* because it is only used for creating LM hashes and the
|
|
* LM/NTLM responses. For all practical purposes, however, it
|
|
* is a full DES encryption implementation.
|
|
*
|
|
* - This DES implementation does not need to be fast, nor is a
|
|
* DES decryption function needed. The goal is to keep the
|
|
* code small, simple, and well documented.
|
|
*
|
|
* - The input values are copied and refiddled within the module
|
|
* and the result is not written to <dst> until the very last
|
|
* step, so it's okay if <dst> points to the same memory as
|
|
* <key> or <src>.
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int i; /* Loop counter. */
|
|
uchar K[7]; /* Holds the key, as we manipulate it. */
|
|
uchar D[8]; /* The data block, as we manipulate it. */
|
|
|
|
/* Create the permutations of the key and the source.
|
|
*/
|
|
Permute( K, key, KeyPermuteMap, 7 );
|
|
Permute( D, src, InitialPermuteMap, 8 );
|
|
|
|
/* DES encryption proceeds in 16 rounds.
|
|
* The stuff inside the loop is known in the literature as "function f".
|
|
*/
|
|
for( i = 0; i < 16; i++ )
|
|
{
|
|
int j;
|
|
uchar *L = D; /* The left 4 bytes (half) of the data block. */
|
|
uchar *R = &(D[4]); /* The right half of the ciphertext block. */
|
|
uchar Rexp[6]; /* Expanded right half. */
|
|
uchar Rn[4]; /* New value of R, as we manipulate it. */
|
|
uchar SubK[6]; /* The 48-bit subkey. */
|
|
|
|
/* Generate the subkey for this round.
|
|
*/
|
|
KeyShift( K, KeyRotation[i] );
|
|
Permute( SubK, K, KeyCompression, 6 );
|
|
|
|
/* Expand the right half (R) of the data block to 48 bytes,
|
|
* then XOR the result with the Subkey for this round.
|
|
*/
|
|
Permute( Rexp, R, DataExpansion, 6 );
|
|
xor( Rexp, Rexp, SubK, 6 );
|
|
|
|
/* S-Box substitutions, P-Box permutation, and final XOR.
|
|
* The S-Box substitutions return a 32-bit value, which is then
|
|
* run through the 32-bit to 32-bit P-Box permutation. The P-Box
|
|
* result is then XOR'd with the left-hand half of the key.
|
|
* (Rexp is used as a temporary variable between the P-Box & XOR).
|
|
*/
|
|
sbox( Rn, Rexp );
|
|
Permute( Rexp, Rn, PBox, 4 );
|
|
xor( Rn, L, Rexp, 4 );
|
|
|
|
/* The previous R becomes the new L,
|
|
* and Rn is moved into R ready for the next round.
|
|
*/
|
|
for( j = 0; j < 4; j++ )
|
|
{
|
|
L[j] = R[j];
|
|
R[j] = Rn[j];
|
|
}
|
|
}
|
|
|
|
/* The encryption is complete.
|
|
* Now reverse-permute the ciphertext to produce the final result.
|
|
* We actually combine two steps here. The penultimate step is to
|
|
* swap the positions of L and R in the result of the 16 rounds,
|
|
* after which the reverse of the Initial Permutation is applied.
|
|
* To save a step, the FinalPermuteMap applies both the L/R swap
|
|
* and the inverse of the Initial Permutation.
|
|
*/
|
|
Permute( dst, D, FinalPermuteMap, 8 );
|
|
return( dst );
|
|
} /* auth_DEShash */
|
|
|
|
|
|
static const uchar SMB_LMhash_Magic[8] =
|
|
{ 'K', 'G', 'S', '!', '@', '#', '$', '%' };
|
|
|
|
uchar *auth_LMhash( uchar *dst, const uchar *pwd, const int pwdlen )
|
|
/* ------------------------------------------------------------------------ **
|
|
* Generate an LM Hash from the input password.
|
|
*
|
|
* Input: dst - Pointer to a location to which to write the LM Hash.
|
|
* Requires 16 bytes minimum.
|
|
* pwd - Source password. Should be in OEM charset (extended
|
|
* ASCII) format in all upper-case, but this
|
|
* implementation doesn't really care. See the notes
|
|
* below.
|
|
* pwdlen - Length, in bytes, of the password. Normally, this
|
|
* will be strlen( pwd ).
|
|
*
|
|
* Output: Pointer to the resulting LM hash (same as <dst>).
|
|
*
|
|
* Notes: This function does not convert the input password to upper
|
|
* case. The upper-case conversion should be done before the
|
|
* password gets this far. DOS codepage handling and such
|
|
* should be taken into consideration. Rather than attempt to
|
|
* work out all those details here, the function assumes that
|
|
* the password is in the correct form before it reaches this
|
|
* point.
|
|
*
|
|
* ------------------------------------------------------------------------ **
|
|
*/
|
|
{
|
|
int i,
|
|
max14;
|
|
uint8_t tmp_pwd[14] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
|
|
|
|
/* Copy at most 14 bytes of <pwd> into <tmp_pwd>.
|
|
* If the password is less than 14 bytes long
|
|
* the rest will be nul padded.
|
|
*/
|
|
max14 = pwdlen > 14 ? 14 : pwdlen;
|
|
for( i = 0; i < max14; i++ )
|
|
tmp_pwd[i] = pwd[i];
|
|
|
|
/* The password is split into two 7-byte keys, each of which
|
|
* are used to DES-encrypt the magic string. The results are
|
|
* concatonated to produce the 16-byte LM Hash.
|
|
*/
|
|
(void)auth_DEShash( dst, tmp_pwd, SMB_LMhash_Magic );
|
|
(void)auth_DEShash( &dst[8], &tmp_pwd[7], SMB_LMhash_Magic );
|
|
|
|
/* Return a pointer to the result.
|
|
*/
|
|
return( dst );
|
|
} /* auth_LMhash */
|