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|
/***************************************************************************
* Copyright (c) 2024 Microsoft Corporation
* Copyright (c) 2025-present Eclipse ThreadX Contributors
*
* This program and the accompanying materials are made available under the
* terms of the MIT License which is available at
* https://opensource.org/licenses/MIT.
*
* SPDX-License-Identifier: MIT
**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Component */
/** */
/** DES Encryption Standard (DES) */
/** */
/**************************************************************************/
/**************************************************************************/
#include "nx_api.h"
#include "nx_des.h"
/* Define macros for the DES transform function. */
/* Define the eight S-box data structures used in the permutation. Keep them static, since there is no
reason to have these symbols referenced outside this file. */
static ULONG sb1[64] =
{
0x01010400UL, 0x00000000UL, 0x00010000UL, 0x01010404UL, 0x01010004UL, 0x00010404UL, 0x00000004UL, 0x00010000UL,
0x00000400UL, 0x01010400UL, 0x01010404UL, 0x00000400UL, 0x01000404UL, 0x01010004UL, 0x01000000UL, 0x00000004UL,
0x00000404UL, 0x01000400UL, 0x01000400UL, 0x00010400UL, 0x00010400UL, 0x01010000UL, 0x01010000UL, 0x01000404UL,
0x00010004UL, 0x01000004UL, 0x01000004UL, 0x00010004UL, 0x00000000UL, 0x00000404UL, 0x00010404UL, 0x01000000UL,
0x00010000UL, 0x01010404UL, 0x00000004UL, 0x01010000UL, 0x01010400UL, 0x01000000UL, 0x01000000UL, 0x00000400UL,
0x01010004UL, 0x00010000UL, 0x00010400UL, 0x01000004UL, 0x00000400UL, 0x00000004UL, 0x01000404UL, 0x00010404UL,
0x01010404UL, 0x00010004UL, 0x01010000UL, 0x01000404UL, 0x01000004UL, 0x00000404UL, 0x00010404UL, 0x01010400UL,
0x00000404UL, 0x01000400UL, 0x01000400UL, 0x00000000UL, 0x00010004UL, 0x00010400UL, 0x00000000UL, 0x01010004UL
};
static ULONG sb2[64] =
{
0x80108020UL, 0x80008000UL, 0x00008000UL, 0x00108020UL, 0x00100000UL, 0x00000020UL, 0x80100020UL, 0x80008020UL,
0x80000020UL, 0x80108020UL, 0x80108000UL, 0x80000000UL, 0x80008000UL, 0x00100000UL, 0x00000020UL, 0x80100020UL,
0x00108000UL, 0x00100020UL, 0x80008020UL, 0x00000000UL, 0x80000000UL, 0x00008000UL, 0x00108020UL, 0x80100000UL,
0x00100020UL, 0x80000020UL, 0x00000000UL, 0x00108000UL, 0x00008020UL, 0x80108000UL, 0x80100000UL, 0x00008020UL,
0x00000000UL, 0x00108020UL, 0x80100020UL, 0x00100000UL, 0x80008020UL, 0x80100000UL, 0x80108000UL, 0x00008000UL,
0x80100000UL, 0x80008000UL, 0x00000020UL, 0x80108020UL, 0x00108020UL, 0x00000020UL, 0x00008000UL, 0x80000000UL,
0x00008020UL, 0x80108000UL, 0x00100000UL, 0x80000020UL, 0x00100020UL, 0x80008020UL, 0x80000020UL, 0x00100020UL,
0x00108000UL, 0x00000000UL, 0x80008000UL, 0x00008020UL, 0x80000000UL, 0x80100020UL, 0x80108020UL, 0x00108000UL
};
static ULONG sb3[64] =
{
0x00000208UL, 0x08020200UL, 0x00000000UL, 0x08020008UL, 0x08000200UL, 0x00000000UL, 0x00020208UL, 0x08000200UL,
0x00020008UL, 0x08000008UL, 0x08000008UL, 0x00020000UL, 0x08020208UL, 0x00020008UL, 0x08020000UL, 0x00000208UL,
0x08000000UL, 0x00000008UL, 0x08020200UL, 0x00000200UL, 0x00020200UL, 0x08020000UL, 0x08020008UL, 0x00020208UL,
0x08000208UL, 0x00020200UL, 0x00020000UL, 0x08000208UL, 0x00000008UL, 0x08020208UL, 0x00000200UL, 0x08000000UL,
0x08020200UL, 0x08000000UL, 0x00020008UL, 0x00000208UL, 0x00020000UL, 0x08020200UL, 0x08000200UL, 0x00000000UL,
0x00000200UL, 0x00020008UL, 0x08020208UL, 0x08000200UL, 0x08000008UL, 0x00000200UL, 0x00000000UL, 0x08020008UL,
0x08000208UL, 0x00020000UL, 0x08000000UL, 0x08020208UL, 0x00000008UL, 0x00020208UL, 0x00020200UL, 0x08000008UL,
0x08020000UL, 0x08000208UL, 0x00000208UL, 0x08020000UL, 0x00020208UL, 0x00000008UL, 0x08020008UL, 0x00020200UL
};
static ULONG sb4[64] =
{
0x00802001UL, 0x00002081UL, 0x00002081UL, 0x00000080UL, 0x00802080UL, 0x00800081UL, 0x00800001UL, 0x00002001UL,
0x00000000UL, 0x00802000UL, 0x00802000UL, 0x00802081UL, 0x00000081UL, 0x00000000UL, 0x00800080UL, 0x00800001UL,
0x00000001UL, 0x00002000UL, 0x00800000UL, 0x00802001UL, 0x00000080UL, 0x00800000UL, 0x00002001UL, 0x00002080UL,
0x00800081UL, 0x00000001UL, 0x00002080UL, 0x00800080UL, 0x00002000UL, 0x00802080UL, 0x00802081UL, 0x00000081UL,
0x00800080UL, 0x00800001UL, 0x00802000UL, 0x00802081UL, 0x00000081UL, 0x00000000UL, 0x00000000UL, 0x00802000UL,
0x00002080UL, 0x00800080UL, 0x00800081UL, 0x00000001UL, 0x00802001UL, 0x00002081UL, 0x00002081UL, 0x00000080UL,
0x00802081UL, 0x00000081UL, 0x00000001UL, 0x00002000UL, 0x00800001UL, 0x00002001UL, 0x00802080UL, 0x00800081UL,
0x00002001UL, 0x00002080UL, 0x00800000UL, 0x00802001UL, 0x00000080UL, 0x00800000UL, 0x00002000UL, 0x00802080UL
};
static ULONG sb5[64] =
{
0x00000100UL, 0x02080100UL, 0x02080000UL, 0x42000100UL, 0x00080000UL, 0x00000100UL, 0x40000000UL, 0x02080000UL,
0x40080100UL, 0x00080000UL, 0x02000100UL, 0x40080100UL, 0x42000100UL, 0x42080000UL, 0x00080100UL, 0x40000000UL,
0x02000000UL, 0x40080000UL, 0x40080000UL, 0x00000000UL, 0x40000100UL, 0x42080100UL, 0x42080100UL, 0x02000100UL,
0x42080000UL, 0x40000100UL, 0x00000000UL, 0x42000000UL, 0x02080100UL, 0x02000000UL, 0x42000000UL, 0x00080100UL,
0x00080000UL, 0x42000100UL, 0x00000100UL, 0x02000000UL, 0x40000000UL, 0x02080000UL, 0x42000100UL, 0x40080100UL,
0x02000100UL, 0x40000000UL, 0x42080000UL, 0x02080100UL, 0x40080100UL, 0x00000100UL, 0x02000000UL, 0x42080000UL,
0x42080100UL, 0x00080100UL, 0x42000000UL, 0x42080100UL, 0x02080000UL, 0x00000000UL, 0x40080000UL, 0x42000000UL,
0x00080100UL, 0x02000100UL, 0x40000100UL, 0x00080000UL, 0x00000000UL, 0x40080000UL, 0x02080100UL, 0x40000100UL
};
static ULONG sb6[64] =
{
0x20000010UL, 0x20400000UL, 0x00004000UL, 0x20404010UL, 0x20400000UL, 0x00000010UL, 0x20404010UL, 0x00400000UL,
0x20004000UL, 0x00404010UL, 0x00400000UL, 0x20000010UL, 0x00400010UL, 0x20004000UL, 0x20000000UL, 0x00004010UL,
0x00000000UL, 0x00400010UL, 0x20004010UL, 0x00004000UL, 0x00404000UL, 0x20004010UL, 0x00000010UL, 0x20400010UL,
0x20400010UL, 0x00000000UL, 0x00404010UL, 0x20404000UL, 0x00004010UL, 0x00404000UL, 0x20404000UL, 0x20000000UL,
0x20004000UL, 0x00000010UL, 0x20400010UL, 0x00404000UL, 0x20404010UL, 0x00400000UL, 0x00004010UL, 0x20000010UL,
0x00400000UL, 0x20004000UL, 0x20000000UL, 0x00004010UL, 0x20000010UL, 0x20404010UL, 0x00404000UL, 0x20400000UL,
0x00404010UL, 0x20404000UL, 0x00000000UL, 0x20400010UL, 0x00000010UL, 0x00004000UL, 0x20400000UL, 0x00404010UL,
0x00004000UL, 0x00400010UL, 0x20004010UL, 0x00000000UL, 0x20404000UL, 0x20000000UL, 0x00400010UL, 0x20004010UL
};
static ULONG sb7[64] =
{
0x00200000UL, 0x04200002UL, 0x04000802UL, 0x00000000UL, 0x00000800UL, 0x04000802UL, 0x00200802UL, 0x04200800UL,
0x04200802UL, 0x00200000UL, 0x00000000UL, 0x04000002UL, 0x00000002UL, 0x04000000UL, 0x04200002UL, 0x00000802UL,
0x04000800UL, 0x00200802UL, 0x00200002UL, 0x04000800UL, 0x04000002UL, 0x04200000UL, 0x04200800UL, 0x00200002UL,
0x04200000UL, 0x00000800UL, 0x00000802UL, 0x04200802UL, 0x00200800UL, 0x00000002UL, 0x04000000UL, 0x00200800UL,
0x04000000UL, 0x00200800UL, 0x00200000UL, 0x04000802UL, 0x04000802UL, 0x04200002UL, 0x04200002UL, 0x00000002UL,
0x00200002UL, 0x04000000UL, 0x04000800UL, 0x00200000UL, 0x04200800UL, 0x00000802UL, 0x00200802UL, 0x04200800UL,
0x00000802UL, 0x04000002UL, 0x04200802UL, 0x04200000UL, 0x00200800UL, 0x00000000UL, 0x00000002UL, 0x04200802UL,
0x00000000UL, 0x00200802UL, 0x04200000UL, 0x00000800UL, 0x04000002UL, 0x04000800UL, 0x00000800UL, 0x00200002UL
};
static ULONG sb8[64] =
{
0x10001040UL, 0x00001000UL, 0x00040000UL, 0x10041040UL, 0x10000000UL, 0x10001040UL, 0x00000040UL, 0x10000000UL,
0x00040040UL, 0x10040000UL, 0x10041040UL, 0x00041000UL, 0x10041000UL, 0x00041040UL, 0x00001000UL, 0x00000040UL,
0x10040000UL, 0x10000040UL, 0x10001000UL, 0x00001040UL, 0x00041000UL, 0x00040040UL, 0x10040040UL, 0x10041000UL,
0x00001040UL, 0x00000000UL, 0x00000000UL, 0x10040040UL, 0x10000040UL, 0x10001000UL, 0x00041040UL, 0x00040000UL,
0x00041040UL, 0x00040000UL, 0x10041000UL, 0x00001000UL, 0x00000040UL, 0x10040040UL, 0x00001000UL, 0x00041040UL,
0x10001000UL, 0x00000040UL, 0x10000040UL, 0x10040000UL, 0x10040040UL, 0x10000000UL, 0x00040000UL, 0x10001040UL,
0x00000000UL, 0x10041040UL, 0x00040040UL, 0x10000040UL, 0x10040000UL, 0x10001000UL, 0x10001040UL, 0x00000000UL,
0x10041040UL, 0x00041000UL, 0x00041000UL, 0x00001040UL, 0x00001040UL, 0x00040040UL, 0x10000000UL, 0x10041000UL
};
/* Define the left half bit swap table. */
static ULONG left_half_bit_swap[16] =
{
0x00000000UL, 0x00000001UL, 0x00000100UL, 0x00000101UL,
0x00010000UL, 0x00010001UL, 0x00010100UL, 0x00010101UL,
0x01000000UL, 0x01000001UL, 0x01000100UL, 0x01000101UL,
0x01010000UL, 0x01010001UL, 0x01010100UL, 0x01010101UL
};
/* Define the right half bit swap table. */
static ULONG right_half_bit_swap[16] =
{
0x00000000UL, 0x01000000UL, 0x00010000UL, 0x01010000UL,
0x00000100UL, 0x01000100UL, 0x00010100UL, 0x01010100UL,
0x00000001UL, 0x01000001UL, 0x00010001UL, 0x01010001UL,
0x00000101UL, 0x01000101UL, 0x00010101UL, 0x01010101UL
};
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_des_key_set PORTABLE C */
/* 6.4.3 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function sets up the 32 encryption keys as well as the 32 */
/* decryption keys for the DES algorithm. It must be called before */
/* either _nx_des_encrypt or _nx_des_decrypt can be called. */
/* destination. */
/* */
/* INPUT */
/* */
/* context DES context pointer */
/* key 8-byte (64-bit) key */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* None */
/* */
/* CALLED BY */
/* */
/* NetX Applications */
/* */
/**************************************************************************/
UINT _nx_des_key_set(NX_DES *context, UCHAR key[8])
{
ULONG left, right, temp;
ULONG *encrypt_keys_ptr;
ULONG *decrypt_keys_ptr;
UINT round;
/* Determine if the context is non-null. */
if (context == NX_NULL)
return(NX_PTR_ERROR);
/* First, convert the 8-byte raw key into two ULONG halves, in an endian neutral fashion. */
left = (((ULONG) key[0]) << 24) | (((ULONG) key[1]) << 16) | (((ULONG) key[2]) << 8) | ((ULONG) key[3]);
right = (((ULONG) key[4]) << 24) | (((ULONG) key[5]) << 16) | (((ULONG) key[6]) << 8) | ((ULONG) key[7]);
/* Perform permutation on the key halves. */
temp = ((right >> 4) ^ left) & 0x0F0F0F0FUL;
left = left ^ temp;
right = right ^ (temp << 4);
temp = (right ^ left) & 0x10101010;
left = left ^ temp;
right = right ^ temp;
left = (left_half_bit_swap[(left) & 0xf] << 3) | (left_half_bit_swap[(left >> 8) & 0xf] << 2) |
(left_half_bit_swap[(left >> 16) & 0xf] << 1) | (left_half_bit_swap[(left >> 24) & 0xf]) |
(left_half_bit_swap[(left >> 5) & 0xf] << 7) | (left_half_bit_swap[(left >> 13) & 0xf] << 6) |
(left_half_bit_swap[(left >> 21) & 0xf] << 5) | (left_half_bit_swap[(left >> 29) & 0xf] << 4);
left = left & 0x0fffffff;
right = (right_half_bit_swap[(right >> 1) & 0xf] << 3) | (right_half_bit_swap[(right >> 9) & 0xf] << 2) |
(right_half_bit_swap[(right >> 17) & 0xf] << 1) | (right_half_bit_swap[(right >> 25) & 0xf]) |
(right_half_bit_swap[(right >> 4) & 0xf] << 7) | (right_half_bit_swap[(right >> 12) & 0xf] << 6) |
(right_half_bit_swap[(right >> 20) & 0xf] << 5) | (right_half_bit_swap[(right >> 28) & 0xf] << 4);
right = right & 0x0fffffff;
/* Setup encryption keys pointer. */
encrypt_keys_ptr = context -> nx_des_encryption_keys;
/* Calculate the encryption keys. */
for (round = 0; round < 16; round++)
{
/* Modify the left and right portions of the keys. */
if ((round < 2) || (round == 8) || (round == 15))
{
left = ((left << 1) | (left >> 27)) & 0x0FFFFFFFUL;
right = ((right << 1) | (right >> 27)) & 0x0FFFFFFFUL;
}
else
{
left = ((left << 2) | (left >> 26)) & 0x0FFFFFFFUL;
right = ((right << 2) | (right >> 26)) & 0x0FFFFFFFUL;
}
/* Setup the key. */
*encrypt_keys_ptr++ = ((left << 4) & 0x24000000UL) | ((left << 28) & 0x10000000UL) |
((left << 14) & 0x08000000UL) | ((left << 18) & 0x02080000UL) |
((left << 6) & 0x01000000UL) | ((left << 9) & 0x00200000UL) |
((left >> 1) & 0x00100000UL) | ((left << 10) & 0x00040000UL) |
((left << 2) & 0x00020000UL) | ((left >> 10) & 0x00010000UL) |
((right >> 13) & 0x00002000UL) | ((right >> 4) & 0x00001000UL) |
((right << 6) & 0x00000800UL) | ((right >> 1) & 0x00000400UL) |
((right >> 14) & 0x00000200UL) | (right & 0x00000100UL) |
((right >> 5) & 0x00000020UL) | ((right >> 10) & 0x00000010UL) |
((right >> 3) & 0x00000008UL) | ((right >> 18) & 0x00000004UL) |
((right >> 26) & 0x00000002UL) | ((right >> 24) & 0x00000001UL);
/* Setup the next key. */
*encrypt_keys_ptr++ = ((left << 15) & 0x20000000UL) | ((left << 17) & 0x10000000UL) |
((left << 10) & 0x08000000UL) | ((left << 22) & 0x04000000UL) |
((left >> 2) & 0x02000000UL) | ((left << 1) & 0x01000000UL) |
((left << 16) & 0x00200000UL) | ((left << 11) & 0x00100000UL) |
((left << 3) & 0x00080000UL) | ((left >> 6) & 0x00040000UL) |
((left << 15) & 0x00020000UL) | ((left >> 4) & 0x00010000UL) |
((right >> 2) & 0x00002000UL) | ((right << 8) & 0x00001000UL) |
((right >> 14) & 0x00000808UL) | ((right >> 9) & 0x00000400UL) |
((right) & 0x00000200UL) | ((right << 7) & 0x00000100UL) |
((right >> 7) & 0x00000020UL) | ((right >> 3) & 0x00000011UL) |
((right << 2) & 0x00000004UL) | ((right >> 21) & 0x00000002UL);
}
/* Reposition the encryption key pointer. */
encrypt_keys_ptr = encrypt_keys_ptr - 2;
/* Setup decryption pointer. */
decrypt_keys_ptr = context -> nx_des_decryption_keys;
/* Now setup decryption keys. */
for (round = 0; round < 16; round++)
{
/* Copy the reverse of the encryption keys. */
*decrypt_keys_ptr++ = *encrypt_keys_ptr;
*decrypt_keys_ptr++ = *(encrypt_keys_ptr + 1);
/* Adjust the encryption keys pointer. */
encrypt_keys_ptr = encrypt_keys_ptr - 2;
}
/* Return successful completion. */
return(NX_SUCCESS);
}
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_des_encrypt PORTABLE C */
/* 6.4.3 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function uses the DES algorithm to encrypt 8-bytes (64-bits). */
/* The result is 8 encrypted bytes. Note that the caller must make */
/* sure the source and destination are 8-bytes in size! */
/* */
/* INPUT */
/* */
/* context DES context pointer */
/* source 8-byte source */
/* destination 8-byte destination */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _nx_des_process_block Encrypt 8-bytes of source */
/* */
/* CALLED BY */
/* */
/* NetX Applications */
/* */
/**************************************************************************/
UINT _nx_des_encrypt(NX_DES *context, UCHAR source[8], UCHAR destination[8])
{
/* Determine if the context is non-null. */
if (context == NX_NULL)
return(NX_PTR_ERROR);
/* Encrypt the block by supplying the encryption key set. */
_nx_des_process_block(source, destination, context -> nx_des_encryption_keys);
/* Return successful completion. */
return(NX_SUCCESS);
}
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_des_decrypt PORTABLE C */
/* 6.4.3 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function uses the DES algorithm to decrypt 8-bytes (64-bits). */
/* The result is 8 original source bytes. Note that the caller must */
/* make sure the source and destination are 8-bytes in size! */
/* */
/* INPUT */
/* */
/* context DES context pointer */
/* source 8-byte source */
/* destination 8-byte destination */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _nx_des_process_block Decrypt 8-bytes of source */
/* */
/* CALLED BY */
/* */
/* NetX Applications */
/* */
/**************************************************************************/
UINT _nx_des_decrypt(NX_DES *context, UCHAR source[8], UCHAR destination[8])
{
/* Determine if the context is non-null. */
if (context == NX_NULL)
return(NX_PTR_ERROR);
/* Decrypt the block by supplying the decryption key set. */
_nx_des_process_block(source, destination, context -> nx_des_decryption_keys);
/* Return successful completion. */
return(NX_SUCCESS);
}
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_des_process_block PORTABLE C */
/* 6.4.3 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function uses the DES algorithm to decrypt 8-bytes (64-bits). */
/* The result is 8 original source bytes. Note that the caller must */
/* make sure the source and destination are 8-bytes in size! */
/* */
/* INPUT */
/* */
/* source 8-byte source */
/* destination 8-byte destination */
/* keys Pointer to either the encrypt */
/* or decrypt keys */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* None */
/* */
/* CALLED BY */
/* */
/* NetX Applications */
/* */
/**************************************************************************/
VOID _nx_des_process_block(UCHAR source[8], UCHAR destination[8], ULONG keys[32])
{
ULONG left, right, temp;
ULONG *key_ptr;
UINT round;
/* First, convert the 8-byte source into two ULONG halves, in an endian neutral fashion. */
left = (((ULONG) source[0]) << 24) | (((ULONG) source[1]) << 16) | (((ULONG) source[2]) << 8) | ((ULONG) source[3]);
right = (((ULONG) source[4]) << 24) | (((ULONG) source[5]) << 16) | (((ULONG) source[6]) << 8) | ((ULONG) source[7]);
/* Compute the initial permutation. */
temp = ((left >> 4) ^ right) & 0x0F0F0F0FUL;
right = right ^ temp;
left = left ^ (temp << 4);
temp = ((left >> 16) ^ right) & 0x0000FFFFUL;
right = right ^ temp;
left = left ^ (temp << 16);
temp = ((right >> 2) ^ left) & 0x33333333UL;
left = left ^ temp;
right = right ^ (temp << 2);
temp = ((right >> 8) ^ left) & 0x00FF00FFUL;
left = left ^ temp;
right = right ^ (temp << 8);
right = ((right << 1) | (right >> 31)) & 0xFFFFFFFFUL;
temp = (left ^ right) & 0xAAAAAAAAUL;
right = right ^ temp;
left = left ^ temp;
left = ((left << 1) | (left >> 31)) & 0xFFFFFFFFUL;
/* Setup pointer to input keys. */
key_ptr = keys;
/* Now process the 16 rounds of the DES computation. There are two rounds per
loop. */
for (round = 0; round < 8; round++)
{
/* Calculate the left half. */
temp = *key_ptr++ ^ right;
left = left ^ sb8[temp & 0x3F] ^ sb6[(temp >> 8) & 0x3F] ^ sb4[(temp >> 16) & 0x3F] ^ sb2[(temp >> 24) & 0x3F];
temp = *key_ptr++ ^ ((right << 28) | (right >> 4));
left = left ^ sb7[temp & 0x3F] ^ sb5[(temp >> 8) & 0x3F] ^ sb3[(temp >> 16) & 0x3F] ^ sb1[(temp >> 24) & 0x3F];
/* Calculate the right half. */
temp = *key_ptr++ ^ left;
right = right ^ sb8[temp & 0x3F] ^ sb6[(temp >> 8) & 0x3F] ^ sb4[(temp >> 16) & 0x3F] ^ sb2[(temp >> 24) & 0x3F];
temp = *key_ptr++ ^ ((left << 28) | (left >> 4));
right = right ^ sb7[temp & 0x3F] ^ sb5[(temp >> 8) & 0x3F] ^ sb3[(temp >> 16) & 0x3F] ^ sb1[(temp >> 24) & 0x3F];
}
/* Now compute the final permutation. */
right = ((right << 31) | (right >> 1)) & 0xFFFFFFFFUL;
temp = (right ^ left) & 0xAAAAAAAAUL;
right = right ^ temp;
left = left ^ temp;
left = ((left << 31) | (left >> 1)) & 0xFFFFFFFFUL;
temp = ((left >> 8) ^ right) & 0x00FF00FFUL;
right = right ^ temp;
left = left ^ (temp << 8);
temp = ((left >> 2) ^ right) & 0x33333333UL;
right = right ^ temp;
left = left ^ (temp << 2);
temp = ((right >> 16) ^ left) & 0x0000FFFFUL;
left = left ^ temp;
right = right ^ (temp << 16);
temp = ((right >> 4) ^ left) & 0x0F0F0F0FUL;
left = left ^ temp;
right = right ^ (temp << 4);
/* Finally, build the output. */
destination[0] = (UCHAR) (right >> 24);
destination[1] = (UCHAR) (right >> 16);
destination[2] = (UCHAR) (right >> 8);
destination[3] = (UCHAR) (right);
destination[4] = (UCHAR) (left >> 24);
destination[5] = (UCHAR) (left >> 16);
destination[6] = (UCHAR) (left >> 8);
destination[7] = (UCHAR) (left);
}
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