Page MenuHome GnuPG
Files F22067864

des.c
No OneTemporary
Actions

des.c
View Options

/* des.c - DES and Triple-DES encryption/decryption Algorithm
* Copyright (C) 1998 Free Software Foundation, Inc.
*
* Please see below for more legal information!
*
* According to the definition of DES in FIPS PUB 46-2 from December 1993.
* For a description of triple encryption, see:
* Bruce Schneier: Applied Cryptography. Second Edition.
* John Wiley & Sons, 1996. ISBN 0-471-12845-7. Pages 358 ff.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
/*
* Written by Michael Roth <mroth@nessie.de>, September 1998
*/
/*
* U S A G E
* ===========
*
* For DES or Triple-DES encryption/decryption you must initialize a proper
* encryption context with a key.
*
* A DES key is 64bit wide but only 56bits of the key are used. The remaining
* bits are parity bits and they will _not_ checked in this implementation, but
* simply ignored.
*
* For Tripple-DES you could use either two 64bit keys or three 64bit keys.
* The parity bits will _not_ checked, too.
*
* After initializing a context with a key you could use this context to
* encrypt or decrypt data in 64bit blocks in Electronic Codebook Mode.
*
* (In the examples below the slashes at the beginning and ending of comments
* are omited.)
*
* DES Example
* -----------
* unsigned char key[8];
* unsigned char plaintext[8];
* unsigned char ciphertext[8];
* unsigned char recoverd[8];
* des_ctx context;
*
* * Fill 'key' and 'plaintext' with some data *
* ....
*
* * Set up the DES encryption context *
* des_setkey(context, key);
*
* * Encrypt the plaintext *
* des_ecb_encrypt(context, plaintext, ciphertext);
*
* * To recover the orginal plaintext from ciphertext use: *
* des_ecb_decrypt(context, ciphertext, recoverd);
*
*
* Triple-DES Example
* ------------------
* unsigned char key1[8];
* unsigned char key2[8];
* unsigned char key3[8];
* unsigned char plaintext[8];
* unsigned char ciphertext[8];
* unsigned char recoverd[8];
* tripledes_ctx context;
*
* * If you would like to use two 64bit keys, fill 'key1' and'key2'
* then setup the encryption context: *
* tripledes_set2keys(context, key1, key2);
*
* * To use three 64bit keys with Triple-DES use: *
* tripledes_set3keys(context, key1, key2, key3);
*
* * Encrypting plaintext with Triple-DES *
* tripledes_ecb_encrypt(context, plaintext, ciphertext);
*
* * Decrypting ciphertext to recover the plaintext with Triple-DES *
* tripledes_ecb_decrypt(context, ciphertext, recoverd);
*
*
* Selftest
* --------
* char *error_msg;
*
* * To perform a selftest of this DES/Triple-DES implementation use the
* function selftest(). It will return an error string if their are
* some problems with this library. *
*
* if ( (error_msg = selftest()) )
* {
* fprintf(stderr, "An error in the DES/Tripple-DES implementation occured: %s\n", error_msg);
* abort();
* }
*/
#include <config.h>
#include <stdio.h>
#include <string.h> /* memcpy, memcmp */
#include "types.h" /* for byte and u32 typedefs */
#include "errors.h"
#include "des.h"
#if defined(__GNUC__) && defined(__GNU_LIBRARY__)
#define working_memcmp memcmp
#else
/*
* According to the SunOS man page, memcmp returns indeterminate sign
* depending on whether characters are signed or not.
*/
int
working_memcmp( const char *a, const char *b, size_t n )
{
for( ; n; n--, a++, b++ )
if( *a != *b )
return (int)(*(byte*)a) - (int)(*(byte*)b);
return 0;
}
#endif
/* Some defines/checks to support standalone modules */
#ifndef CIPHER_ALGO_3DES
#define CIPHER_ALGO_3DES 2
#elif CIPHER_ALGO_3DES != 2
#error CIPHER_ALGO_3DES is defined to a wrong value.
#endif
/* Macros used by the info function. */
#define FNCCAST_SETKEY(f) ((int(*)(void*, byte*, unsigned))(f))
#define FNCCAST_CRYPT(f) ((void(*)(void*, byte*, byte*))(f))
/*
* Encryption/Decryption context of DES
*/
typedef struct _des_ctx
{
u32 encrypt_subkeys[32];
u32 decrypt_subkeys[32];
}
des_ctx[1];
/*
* Encryption/Decryption context of Triple-DES
*/
typedef struct _tripledes_ctx
{
u32 encrypt_subkeys[96];
u32 decrypt_subkeys[96];
}
tripledes_ctx[1];
static const char *selftest_failed;
static void des_key_schedule (const byte *, u32 *);
static int des_setkey (struct _des_ctx *, const byte *);
static int des_ecb_crypt (struct _des_ctx *, const byte *, byte *, int);
static int tripledes_set2keys (struct _tripledes_ctx *, const byte *, const byte *);
static int tripledes_set3keys (struct _tripledes_ctx *, const byte *, const byte *, const byte *);
static int tripledes_ecb_crypt (struct _tripledes_ctx *, const byte *, byte *, int);
static int is_weak_key ( const byte *key );
static const char *selftest (void);
/*
* The s-box values are permuted according to the 'primitive function P'
*/
static u32 sbox1[64] =
{
0x00808200, 0x00000000, 0x00008000, 0x00808202, 0x00808002, 0x00008202, 0x00000002, 0x00008000,
0x00000200, 0x00808200, 0x00808202, 0x00000200, 0x00800202, 0x00808002, 0x00800000, 0x00000002,
0x00000202, 0x00800200, 0x00800200, 0x00008200, 0x00008200, 0x00808000, 0x00808000, 0x00800202,
0x00008002, 0x00800002, 0x00800002, 0x00008002, 0x00000000, 0x00000202, 0x00008202, 0x00800000,
0x00008000, 0x00808202, 0x00000002, 0x00808000, 0x00808200, 0x00800000, 0x00800000, 0x00000200,
0x00808002, 0x00008000, 0x00008200, 0x00800002, 0x00000200, 0x00000002, 0x00800202, 0x00008202,
0x00808202, 0x00008002, 0x00808000, 0x00800202, 0x00800002, 0x00000202, 0x00008202, 0x00808200,
0x00000202, 0x00800200, 0x00800200, 0x00000000, 0x00008002, 0x00008200, 0x00000000, 0x00808002
};
static u32 sbox2[64] =
{
0x40084010, 0x40004000, 0x00004000, 0x00084010, 0x00080000, 0x00000010, 0x40080010, 0x40004010,
0x40000010, 0x40084010, 0x40084000, 0x40000000, 0x40004000, 0x00080000, 0x00000010, 0x40080010,
0x00084000, 0x00080010, 0x40004010, 0x00000000, 0x40000000, 0x00004000, 0x00084010, 0x40080000,
0x00080010, 0x40000010, 0x00000000, 0x00084000, 0x00004010, 0x40084000, 0x40080000, 0x00004010,
0x00000000, 0x00084010, 0x40080010, 0x00080000, 0x40004010, 0x40080000, 0x40084000, 0x00004000,
0x40080000, 0x40004000, 0x00000010, 0x40084010, 0x00084010, 0x00000010, 0x00004000, 0x40000000,
0x00004010, 0x40084000, 0x00080000, 0x40000010, 0x00080010, 0x40004010, 0x40000010, 0x00080010,
0x00084000, 0x00000000, 0x40004000, 0x00004010, 0x40000000, 0x40080010, 0x40084010, 0x00084000
};
static u32 sbox3[64] =
{
0x00000104, 0x04010100, 0x00000000, 0x04010004, 0x04000100, 0x00000000, 0x00010104, 0x04000100,
0x00010004, 0x04000004, 0x04000004, 0x00010000, 0x04010104, 0x00010004, 0x04010000, 0x00000104,
0x04000000, 0x00000004, 0x04010100, 0x00000100, 0x00010100, 0x04010000, 0x04010004, 0x00010104,
0x04000104, 0x00010100, 0x00010000, 0x04000104, 0x00000004, 0x04010104, 0x00000100, 0x04000000,
0x04010100, 0x04000000, 0x00010004, 0x00000104, 0x00010000, 0x04010100, 0x04000100, 0x00000000,
0x00000100, 0x00010004, 0x04010104, 0x04000100, 0x04000004, 0x00000100, 0x00000000, 0x04010004,
0x04000104, 0x00010000, 0x04000000, 0x04010104, 0x00000004, 0x00010104, 0x00010100, 0x04000004,
0x04010000, 0x04000104, 0x00000104, 0x04010000, 0x00010104, 0x00000004, 0x04010004, 0x00010100
};
static u32 sbox4[64] =
{
0x80401000, 0x80001040, 0x80001040, 0x00000040, 0x00401040, 0x80400040, 0x80400000, 0x80001000,
0x00000000, 0x00401000, 0x00401000, 0x80401040, 0x80000040, 0x00000000, 0x00400040, 0x80400000,
0x80000000, 0x00001000, 0x00400000, 0x80401000, 0x00000040, 0x00400000, 0x80001000, 0x00001040,
0x80400040, 0x80000000, 0x00001040, 0x00400040, 0x00001000, 0x00401040, 0x80401040, 0x80000040,
0x00400040, 0x80400000, 0x00401000, 0x80401040, 0x80000040, 0x00000000, 0x00000000, 0x00401000,
0x00001040, 0x00400040, 0x80400040, 0x80000000, 0x80401000, 0x80001040, 0x80001040, 0x00000040,
0x80401040, 0x80000040, 0x80000000, 0x00001000, 0x80400000, 0x80001000, 0x00401040, 0x80400040,
0x80001000, 0x00001040, 0x00400000, 0x80401000, 0x00000040, 0x00400000, 0x00001000, 0x00401040
};
static u32 sbox5[64] =
{
0x00000080, 0x01040080, 0x01040000, 0x21000080, 0x00040000, 0x00000080, 0x20000000, 0x01040000,
0x20040080, 0x00040000, 0x01000080, 0x20040080, 0x21000080, 0x21040000, 0x00040080, 0x20000000,
0x01000000, 0x20040000, 0x20040000, 0x00000000, 0x20000080, 0x21040080, 0x21040080, 0x01000080,
0x21040000, 0x20000080, 0x00000000, 0x21000000, 0x01040080, 0x01000000, 0x21000000, 0x00040080,
0x00040000, 0x21000080, 0x00000080, 0x01000000, 0x20000000, 0x01040000, 0x21000080, 0x20040080,
0x01000080, 0x20000000, 0x21040000, 0x01040080, 0x20040080, 0x00000080, 0x01000000, 0x21040000,
0x21040080, 0x00040080, 0x21000000, 0x21040080, 0x01040000, 0x00000000, 0x20040000, 0x21000000,
0x00040080, 0x01000080, 0x20000080, 0x00040000, 0x00000000, 0x20040000, 0x01040080, 0x20000080
};
static u32 sbox6[64] =
{
0x10000008, 0x10200000, 0x00002000, 0x10202008, 0x10200000, 0x00000008, 0x10202008, 0x00200000,
0x10002000, 0x00202008, 0x00200000, 0x10000008, 0x00200008, 0x10002000, 0x10000000, 0x00002008,
0x00000000, 0x00200008, 0x10002008, 0x00002000, 0x00202000, 0x10002008, 0x00000008, 0x10200008,
0x10200008, 0x00000000, 0x00202008, 0x10202000, 0x00002008, 0x00202000, 0x10202000, 0x10000000,
0x10002000, 0x00000008, 0x10200008, 0x00202000, 0x10202008, 0x00200000, 0x00002008, 0x10000008,
0x00200000, 0x10002000, 0x10000000, 0x00002008, 0x10000008, 0x10202008, 0x00202000, 0x10200000,
0x00202008, 0x10202000, 0x00000000, 0x10200008, 0x00000008, 0x00002000, 0x10200000, 0x00202008,
0x00002000, 0x00200008, 0x10002008, 0x00000000, 0x10202000, 0x10000000, 0x00200008, 0x10002008
};
static u32 sbox7[64] =
{
0x00100000, 0x02100001, 0x02000401, 0x00000000, 0x00000400, 0x02000401, 0x00100401, 0x02100400,
0x02100401, 0x00100000, 0x00000000, 0x02000001, 0x00000001, 0x02000000, 0x02100001, 0x00000401,
0x02000400, 0x00100401, 0x00100001, 0x02000400, 0x02000001, 0x02100000, 0x02100400, 0x00100001,
0x02100000, 0x00000400, 0x00000401, 0x02100401, 0x00100400, 0x00000001, 0x02000000, 0x00100400,
0x02000000, 0x00100400, 0x00100000, 0x02000401, 0x02000401, 0x02100001, 0x02100001, 0x00000001,
0x00100001, 0x02000000, 0x02000400, 0x00100000, 0x02100400, 0x00000401, 0x00100401, 0x02100400,
0x00000401, 0x02000001, 0x02100401, 0x02100000, 0x00100400, 0x00000000, 0x00000001, 0x02100401,
0x00000000, 0x00100401, 0x02100000, 0x00000400, 0x02000001, 0x02000400, 0x00000400, 0x00100001
};
static u32 sbox8[64] =
{
0x08000820, 0x00000800, 0x00020000, 0x08020820, 0x08000000, 0x08000820, 0x00000020, 0x08000000,
0x00020020, 0x08020000, 0x08020820, 0x00020800, 0x08020800, 0x00020820, 0x00000800, 0x00000020,
0x08020000, 0x08000020, 0x08000800, 0x00000820, 0x00020800, 0x00020020, 0x08020020, 0x08020800,
0x00000820, 0x00000000, 0x00000000, 0x08020020, 0x08000020, 0x08000800, 0x00020820, 0x00020000,
0x00020820, 0x00020000, 0x08020800, 0x00000800, 0x00000020, 0x08020020, 0x00000800, 0x00020820,
0x08000800, 0x00000020, 0x08000020, 0x08020000, 0x08020020, 0x08000000, 0x00020000, 0x08000820,
0x00000000, 0x08020820, 0x00020020, 0x08000020, 0x08020000, 0x08000800, 0x08000820, 0x00000000,
0x08020820, 0x00020800, 0x00020800, 0x00000820, 0x00000820, 0x00020020, 0x08000000, 0x08020800
};
/*
* These two tables are part of the 'permuted choice 1' function.
* In this implementation several speed improvements are done.
*/
u32 leftkey_swap[16] =
{
0x00000000, 0x00000001, 0x00000100, 0x00000101,
0x00010000, 0x00010001, 0x00010100, 0x00010101,
0x01000000, 0x01000001, 0x01000100, 0x01000101,
0x01010000, 0x01010001, 0x01010100, 0x01010101
};
u32 rightkey_swap[16] =
{
0x00000000, 0x01000000, 0x00010000, 0x01010000,
0x00000100, 0x01000100, 0x00010100, 0x01010100,
0x00000001, 0x01000001, 0x00010001, 0x01010001,
0x00000101, 0x01000101, 0x00010101, 0x01010101,
};
/*
* Numbers of left shifts per round for encryption subkey schedule
* To calculate the decryption key scheduling we just reverse the
* ordering of the subkeys so we can omit the table for decryption
* subkey schedule.
*/
static byte encrypt_rotate_tab[16] =
{
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
/*
* Table with weak DES keys sorted in ascending order.
* In DES their are 64 known keys wich are weak. They are weak
* because they produce only one, two or four different
* subkeys in the subkey scheduling process.
* The keys in this table have all their parity bits cleared.
*/
static byte weak_keys[64][8] =
{
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x00, 0x00, 0x1e, 0x1e, 0x00, 0x00, 0x0e, 0x0e },
{ 0x00, 0x00, 0xe0, 0xe0, 0x00, 0x00, 0xf0, 0xf0 }, { 0x00, 0x00, 0xfe, 0xfe, 0x00, 0x00, 0xfe, 0xfe },
{ 0x00, 0x1e, 0x00, 0x1e, 0x00, 0x0e, 0x00, 0x0e }, { 0x00, 0x1e, 0x1e, 0x00, 0x00, 0x0e, 0x0e, 0x00 },
{ 0x00, 0x1e, 0xe0, 0xfe, 0x00, 0x0e, 0xf0, 0xfe }, { 0x00, 0x1e, 0xfe, 0xe0, 0x00, 0x0e, 0xfe, 0xf0 },
{ 0x00, 0xe0, 0x00, 0xe0, 0x00, 0xf0, 0x00, 0xf0 }, { 0x00, 0xe0, 0x1e, 0xfe, 0x00, 0xf0, 0x0e, 0xfe },
{ 0x00, 0xe0, 0xe0, 0x00, 0x00, 0xf0, 0xf0, 0x00 }, { 0x00, 0xe0, 0xfe, 0x1e, 0x00, 0xf0, 0xfe, 0x0e },
{ 0x00, 0xfe, 0x00, 0xfe, 0x00, 0xfe, 0x00, 0xfe }, { 0x00, 0xfe, 0x1e, 0xe0, 0x00, 0xfe, 0x0e, 0xf0 },
{ 0x00, 0xfe, 0xe0, 0x1e, 0x00, 0xfe, 0xf0, 0x0e }, { 0x00, 0xfe, 0xfe, 0x00, 0x00, 0xfe, 0xfe, 0x00 },
{ 0x0e, 0x0e, 0x0e, 0x0e, 0xf0, 0xf0, 0xf0, 0xf0 }, { 0x1e, 0x00, 0x00, 0x1e, 0x0e, 0x00, 0x00, 0x0e },
{ 0x1e, 0x00, 0x1e, 0x00, 0x0e, 0x00, 0x0e, 0x00 }, { 0x1e, 0x00, 0xe0, 0xfe, 0x0e, 0x00, 0xf0, 0xfe },
{ 0x1e, 0x00, 0xfe, 0xe0, 0x0e, 0x00, 0xfe, 0xf0 }, { 0x1e, 0x1e, 0x00, 0x00, 0x0e, 0x0e, 0x00, 0x00 },
{ 0x1e, 0x1e, 0x1e, 0x1e, 0x0e, 0x0e, 0x0e, 0x0e }, { 0x1e, 0x1e, 0xe0, 0xe0, 0x0e, 0x0e, 0xf0, 0xf0 },
{ 0x1e, 0x1e, 0xfe, 0xfe, 0x0e, 0x0e, 0xfe, 0xfe }, { 0x1e, 0xe0, 0x00, 0xfe, 0x0e, 0xf0, 0x00, 0xfe },
{ 0x1e, 0xe0, 0x1e, 0xe0, 0x0e, 0xf0, 0x0e, 0xf0 }, { 0x1e, 0xe0, 0xe0, 0x1e, 0x0e, 0xf0, 0xf0, 0x0e },
{ 0x1e, 0xe0, 0xfe, 0x00, 0x0e, 0xf0, 0xfe, 0x00 }, { 0x1e, 0xfe, 0x00, 0xe0, 0x0e, 0xfe, 0x00, 0xf0 },
{ 0x1e, 0xfe, 0x1e, 0xfe, 0x0e, 0xfe, 0x0e, 0xfe }, { 0x1e, 0xfe, 0xe0, 0x00, 0x0e, 0xfe, 0xf0, 0x00 },
{ 0x1e, 0xfe, 0xfe, 0x1e, 0x0e, 0xfe, 0xfe, 0x0e }, { 0xe0, 0x00, 0x00, 0xe0, 0xf0, 0x00, 0x00, 0xf0 },
{ 0xe0, 0x00, 0x1e, 0xfe, 0xf0, 0x00, 0x0e, 0xfe }, { 0xe0, 0x00, 0xe0, 0x00, 0xf0, 0x00, 0xf0, 0x00 },
{ 0xe0, 0x00, 0xfe, 0x1e, 0xf0, 0x00, 0xfe, 0x0e }, { 0xe0, 0x1e, 0x00, 0xfe, 0xf0, 0x0e, 0x00, 0xfe },
{ 0xe0, 0x1e, 0x1e, 0xe0, 0xf0, 0x0e, 0x0e, 0xf0 }, { 0xe0, 0x1e, 0xe0, 0x1e, 0xf0, 0x0e, 0xf0, 0x0e },
{ 0xe0, 0x1e, 0xfe, 0x00, 0xf0, 0x0e, 0xfe, 0x00 }, { 0xe0, 0xe0, 0x00, 0x00, 0xf0, 0xf0, 0x00, 0x00 },
{ 0xe0, 0xe0, 0x1e, 0x1e, 0xf0, 0xf0, 0x0e, 0x0e }, { 0xe0, 0xe0, 0xfe, 0xfe, 0xf0, 0xf0, 0xfe, 0xfe },
{ 0xe0, 0xfe, 0x00, 0x1e, 0xf0, 0xfe, 0x00, 0x0e }, { 0xe0, 0xfe, 0x1e, 0x00, 0xf0, 0xfe, 0x0e, 0x00 },
{ 0xe0, 0xfe, 0xe0, 0xfe, 0xf0, 0xfe, 0xf0, 0xfe }, { 0xe0, 0xfe, 0xfe, 0xe0, 0xf0, 0xfe, 0xfe, 0xf0 },
{ 0xfe, 0x00, 0x00, 0xfe, 0xfe, 0x00, 0x00, 0xfe }, { 0xfe, 0x00, 0x1e, 0xe0, 0xfe, 0x00, 0x0e, 0xf0 },
{ 0xfe, 0x00, 0xe0, 0x1e, 0xfe, 0x00, 0xf0, 0x0e }, { 0xfe, 0x00, 0xfe, 0x00, 0xfe, 0x00, 0xfe, 0x00 },
{ 0xfe, 0x1e, 0x00, 0xe0, 0xfe, 0x0e, 0x00, 0xf0 }, { 0xfe, 0x1e, 0x1e, 0xfe, 0xfe, 0x0e, 0x0e, 0xfe },
{ 0xfe, 0x1e, 0xe0, 0x00, 0xfe, 0x0e, 0xf0, 0x00 }, { 0xfe, 0x1e, 0xfe, 0x1e, 0xfe, 0x0e, 0xfe, 0x0e },
{ 0xfe, 0xe0, 0x00, 0x1e, 0xfe, 0xf0, 0x00, 0x0e }, { 0xfe, 0xe0, 0x1e, 0x00, 0xfe, 0xf0, 0x0e, 0x00 },
{ 0xfe, 0xe0, 0xe0, 0xfe, 0xfe, 0xf0, 0xf0, 0xfe }, { 0xfe, 0xe0, 0xfe, 0xe0, 0xfe, 0xf0, 0xfe, 0xf0 },
{ 0xfe, 0xfe, 0x00, 0x00, 0xfe, 0xfe, 0x00, 0x00 }, { 0xfe, 0xfe, 0x1e, 0x1e, 0xfe, 0xfe, 0x0e, 0x0e },
{ 0xfe, 0xfe, 0xe0, 0xe0, 0xfe, 0xfe, 0xf0, 0xf0 }, { 0xfe, 0xfe, 0xfe, 0xfe, 0xfe, 0xfe, 0xfe, 0xfe }
};
/*
* Macro to swap bits across two words
*/
#define DO_PERMUTATION(a, temp, b, offset, mask) \
temp = ((a>>offset) ^ b) & mask; \
b ^= temp; \
a ^= temp<<offset;
/*
* This performs the 'initial permutation' for the data to be encrypted or decrypted
*/
#define INITIAL_PERMUTATION(left, temp, right) \
DO_PERMUTATION(left, temp, right, 4, 0x0f0f0f0f) \
DO_PERMUTATION(left, temp, right, 16, 0x0000ffff) \
DO_PERMUTATION(right, temp, left, 2, 0x33333333) \
DO_PERMUTATION(right, temp, left, 8, 0x00ff00ff) \
DO_PERMUTATION(left, temp, right, 1, 0x55555555)
/*
* The 'inverse initial permutation'
*/
#define FINAL_PERMUTATION(left, temp, right) \
DO_PERMUTATION(left, temp, right, 1, 0x55555555) \
DO_PERMUTATION(right, temp, left, 8, 0x00ff00ff) \
DO_PERMUTATION(right, temp, left, 2, 0x33333333) \
DO_PERMUTATION(left, temp, right, 16, 0x0000ffff) \
DO_PERMUTATION(left, temp, right, 4, 0x0f0f0f0f)
/*
* A full DES round including 'expansion function', 'sbox substitution'
* and 'primitive function P' but without swapping the left and right word.
*/
#define DES_ROUND(from, to, work, subkey) \
work = ((from<<1) | (from>>31)) ^ *subkey++; \
to ^= sbox8[ work & 0x3f ]; \
to ^= sbox6[ (work>>8) & 0x3f ]; \
to ^= sbox4[ (work>>16) & 0x3f ]; \
to ^= sbox2[ (work>>24) & 0x3f ]; \
work = ((from>>3) | (from<<29)) ^ *subkey++; \
to ^= sbox7[ work & 0x3f ]; \
to ^= sbox5[ (work>>8) & 0x3f ]; \
to ^= sbox3[ (work>>16) & 0x3f ]; \
to ^= sbox1[ (work>>24) & 0x3f ];
/*
* Macros to convert 8 bytes from/to 32bit words
*/
#define READ_64BIT_DATA(data, left, right) \
left = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3]; \
right = (data[4] << 24) | (data[5] << 16) | (data[6] << 8) | data[7];
#define WRITE_64BIT_DATA(data, left, right) \
data[0] = (left >> 24) &0xff; data[1] = (left >> 16) &0xff; \
data[2] = (left >> 8) &0xff; data[3] = left &0xff; \
data[4] = (right >> 24) &0xff; data[5] = (right >> 16) &0xff; \
data[6] = (right >> 8) &0xff; data[7] = right &0xff;
/*
* Handy macros for encryption and decryption of data
*/
#define des_ecb_encrypt(ctx, from, to) des_ecb_crypt(ctx, from, to, 0)
#define des_ecb_decrypt(ctx, from, to) des_ecb_crypt(ctx, from, to, 1)
#define tripledes_ecb_encrypt(ctx, from, to) tripledes_ecb_crypt(ctx, from, to, 0)
#define tripledes_ecb_decrypt(ctx, from, to) tripledes_ecb_crypt(ctx, from, to, 1)
/*
* des_key_schedule(): Calculate 16 subkeys pairs (even/odd) for
* 16 encryption rounds.
* To calculate subkeys for decryption the caller
* have to reorder the generated subkeys.
*
* rawkey: 8 Bytes of key data
* subkey: Array of at least 32 u32s. Will be filled
* with calculated subkeys.
*
*/
static void
des_key_schedule (const byte * rawkey, u32 * subkey)
{
u32 left, right, work;
int round;
READ_64BIT_DATA (rawkey, left, right)
DO_PERMUTATION (right, work, left, 4, 0x0f0f0f0f)
DO_PERMUTATION (right, work, left, 0, 0x10101010)
left = (leftkey_swap[(left >> 0) & 0xf] << 3) | (leftkey_swap[(left >> 8) & 0xf] << 2)
| (leftkey_swap[(left >> 16) & 0xf] << 1) | (leftkey_swap[(left >> 24) & 0xf])
| (leftkey_swap[(left >> 5) & 0xf] << 7) | (leftkey_swap[(left >> 13) & 0xf] << 6)
| (leftkey_swap[(left >> 21) & 0xf] << 5) | (leftkey_swap[(left >> 29) & 0xf] << 4);
left &= 0x0fffffff;
right = (rightkey_swap[(right >> 1) & 0xf] << 3) | (rightkey_swap[(right >> 9) & 0xf] << 2)
| (rightkey_swap[(right >> 17) & 0xf] << 1) | (rightkey_swap[(right >> 25) & 0xf])
| (rightkey_swap[(right >> 4) & 0xf] << 7) | (rightkey_swap[(right >> 12) & 0xf] << 6)
| (rightkey_swap[(right >> 20) & 0xf] << 5) | (rightkey_swap[(right >> 28) & 0xf] << 4);
right &= 0x0fffffff;
for (round = 0; round < 16; ++round)
{
left = ((left << encrypt_rotate_tab[round]) | (left >> (28 - encrypt_rotate_tab[round]))) & 0x0fffffff;
right = ((right << encrypt_rotate_tab[round]) | (right >> (28 - encrypt_rotate_tab[round]))) & 0x0fffffff;
*subkey++ = ((left << 4) & 0x24000000)
| ((left << 28) & 0x10000000)
| ((left << 14) & 0x08000000)
| ((left << 18) & 0x02080000)
| ((left << 6) & 0x01000000)
| ((left << 9) & 0x00200000)
| ((left >> 1) & 0x00100000)
| ((left << 10) & 0x00040000)
| ((left << 2) & 0x00020000)
| ((left >> 10) & 0x00010000)
| ((right >> 13) & 0x00002000)
| ((right >> 4) & 0x00001000)
| ((right << 6) & 0x00000800)
| ((right >> 1) & 0x00000400)
| ((right >> 14) & 0x00000200)
| (right & 0x00000100)
| ((right >> 5) & 0x00000020)
| ((right >> 10) & 0x00000010)
| ((right >> 3) & 0x00000008)
| ((right >> 18) & 0x00000004)
| ((right >> 26) & 0x00000002)
| ((right >> 24) & 0x00000001);
*subkey++ = ((left << 15) & 0x20000000)
| ((left << 17) & 0x10000000)
| ((left << 10) & 0x08000000)
| ((left << 22) & 0x04000000)
| ((left >> 2) & 0x02000000)
| ((left << 1) & 0x01000000)
| ((left << 16) & 0x00200000)
| ((left << 11) & 0x00100000)
| ((left << 3) & 0x00080000)
| ((left >> 6) & 0x00040000)
| ((left << 15) & 0x00020000)
| ((left >> 4) & 0x00010000)
| ((right >> 2) & 0x00002000)
| ((right << 8) & 0x00001000)
| ((right >> 14) & 0x00000808)
| ((right >> 9) & 0x00000400)
| ((right) & 0x00000200)
| ((right << 7) & 0x00000100)
| ((right >> 7) & 0x00000020)
| ((right >> 3) & 0x00000011)
| ((right << 2) & 0x00000004)
| ((right >> 21) & 0x00000002);
}
}
/*
* Fill a DES context with subkeys calculated from a 64bit key.
* Does not check parity bits, but simply ignore them.
* Does not check for weak keys.
*/
static int
des_setkey (struct _des_ctx *ctx, const byte * key)
{
int i;
if( selftest_failed )
return G10ERR_SELFTEST_FAILED;
des_key_schedule (key, ctx->encrypt_subkeys);
for(i=0; i<32; i+=2)
{
ctx->decrypt_subkeys[i] = ctx->encrypt_subkeys[30-i];
ctx->decrypt_subkeys[i+1] = ctx->encrypt_subkeys[31-i];
}
return 0;
}
/*
* Electronic Codebook Mode DES encryption/decryption of data according
* to 'mode'.
*/
static int
des_ecb_crypt (struct _des_ctx *ctx, const byte * from, byte * to, int mode)
{
u32 left, right, work;
u32 *keys;
keys = mode ? ctx->decrypt_subkeys : ctx->encrypt_subkeys;
READ_64BIT_DATA (from, left, right)
INITIAL_PERMUTATION (left, work, right)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
FINAL_PERMUTATION (right, work, left)
WRITE_64BIT_DATA (to, right, left)
return 0;
}
/*
* Fill a Triple-DES context with subkeys calculated from two 64bit keys.
* Does not check the parity bits of the keys, but simply ignore them.
* Does not check for weak keys.
*/
static int
tripledes_set2keys (struct _tripledes_ctx *ctx,
const byte * key1,
const byte * key2)
{
int i;
des_key_schedule (key1, ctx->encrypt_subkeys);
des_key_schedule (key2, &(ctx->decrypt_subkeys[32]));
for(i=0; i<32; i+=2)
{
ctx->decrypt_subkeys[i] = ctx->encrypt_subkeys[30-i];
ctx->decrypt_subkeys[i+1] = ctx->encrypt_subkeys[31-i];
ctx->encrypt_subkeys[i+32] = ctx->decrypt_subkeys[62-i];
ctx->encrypt_subkeys[i+33] = ctx->decrypt_subkeys[63-i];
ctx->encrypt_subkeys[i+64] = ctx->encrypt_subkeys[i];
ctx->encrypt_subkeys[i+65] = ctx->encrypt_subkeys[i+1];
ctx->decrypt_subkeys[i+64] = ctx->decrypt_subkeys[i];
ctx->decrypt_subkeys[i+65] = ctx->decrypt_subkeys[i+1];
}
return 0;
}
/*
* Fill a Triple-DES context with subkeys calculated from three 64bit keys.
* Does not check the parity bits of the keys, but simply ignore them.
* Does not check for weak keys.
*/
static int
tripledes_set3keys (struct _tripledes_ctx *ctx,
const byte * key1,
const byte * key2,
const byte * key3)
{
int i;
des_key_schedule (key1, ctx->encrypt_subkeys);
des_key_schedule (key2, &(ctx->decrypt_subkeys[32]));
des_key_schedule (key3, &(ctx->encrypt_subkeys[64]));
for(i=0; i<32; i+=2)
{
ctx->decrypt_subkeys[i] = ctx->encrypt_subkeys[94-i];
ctx->decrypt_subkeys[i+1] = ctx->encrypt_subkeys[95-i];
ctx->encrypt_subkeys[i+32] = ctx->decrypt_subkeys[62-i];
ctx->encrypt_subkeys[i+33] = ctx->decrypt_subkeys[63-i];
ctx->decrypt_subkeys[i+64] = ctx->encrypt_subkeys[30-i];
ctx->decrypt_subkeys[i+65] = ctx->encrypt_subkeys[31-i];
}
return 0;
}
/*
* Electronic Codebook Mode Triple-DES encryption/decryption of data according to 'mode'.
* Sometimes this mode is named 'EDE' mode (Encryption-Decryption-Encryption).
*/
static int
tripledes_ecb_crypt (struct _tripledes_ctx *ctx, const byte * from, byte * to, int mode)
{
u32 left, right, work;
u32 *keys;
keys = mode ? ctx->decrypt_subkeys : ctx->encrypt_subkeys;
READ_64BIT_DATA (from, left, right)
INITIAL_PERMUTATION (left, work, right)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (left, right, work, keys) DES_ROUND (right, left, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
DES_ROUND (right, left, work, keys) DES_ROUND (left, right, work, keys)
FINAL_PERMUTATION (right, work, left)
WRITE_64BIT_DATA (to, right, left)
return 0;
}
/*
* Check whether the 8 byte key is weak.
* Dose not check the parity bits of the key but simple ignore them.
*/
static int
is_weak_key ( const byte *key )
{
byte work[8];
int i, left, right, middle, cmp_result;
/* clear parity bits */
for(i=0; i<8; ++i)
work[i] = key[i] & 0xfe;
/* binary search in the weak key table */
left = 0;
right = 63;
while(left <= right)
{
middle = (left + right) / 2;
if ( !(cmp_result=working_memcmp(work, weak_keys[middle], 8)) )
return -1;
if ( cmp_result > 0 )
left = middle + 1;
else
right = middle - 1;
}
return 0;
}
/*
* Performs a selftest of this DES/Triple-DES implementation.
* Returns an string with the error text on failure.
* Returns NULL if all is ok.
*/
static const char *
selftest (void)
{
/*
* Check if 'u32' is really 32 bits wide. This DES / 3DES implementation
* need this.
*/
if (sizeof (u32) != 4)
return "Wrong word size for DES configured.";
/*
* DES Maintenance Test
*/
{
int i;
byte key[8] =
{0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55};
byte input[8] =
{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
byte result[8] =
{0x24, 0x6e, 0x9d, 0xb9, 0xc5, 0x50, 0x38, 0x1a};
byte temp1[8], temp2[8], temp3[8];
des_ctx des;
for (i = 0; i < 64; ++i)
{
des_setkey (des, key);
des_ecb_encrypt (des, input, temp1);
des_ecb_encrypt (des, temp1, temp2);
des_setkey (des, temp2);
des_ecb_decrypt (des, temp1, temp3);
memcpy (key, temp3, 8);
memcpy (input, temp1, 8);
}
if (memcmp (temp3, result, 8))
return "DES maintenance test failed.";
}
/*
* Triple-DES test (Do somebody known on official test?)
*
* Note: This test doesn't use tripledes_set3keys() !
*/
{
int i;
byte input[8] =
{0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10};
byte key1[8] =
{0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0};
byte key2[8] =
{0x11, 0x22, 0x33, 0x44, 0xff, 0xaa, 0xcc, 0xdd};
byte result[8] =
{0x7b, 0x38, 0x3b, 0x23, 0xa2, 0x7d, 0x26, 0xd3};
tripledes_ctx des3;
for (i = 0; i < 16; ++i)
{
tripledes_set2keys (des3, key1, key2);
tripledes_ecb_encrypt (des3, input, key1);
tripledes_ecb_decrypt (des3, input, key2);
tripledes_set3keys (des3, key1, input, key2);
tripledes_ecb_encrypt (des3, input, input);
}
if (memcmp (input, result, 8))
return "TRIPLE-DES test failed.";
}
/*
* Check the weak key detection. We simply assume the table with
* weak keys is ok and check every key in the table if it is
* detected... (This test is a little bit stupid)
*/
{
int i;
for (i = 0; i < 64; ++i)
if (!is_weak_key(weak_keys[i]))
return "DES weak key detection failed";
}
return 0;
}
static int
do_tripledes_setkey ( struct _tripledes_ctx *ctx, byte *key, unsigned keylen )
{
if( selftest_failed )
return G10ERR_SELFTEST_FAILED;
if( keylen != 24 )
return G10ERR_WRONG_KEYLEN;
tripledes_set3keys ( ctx, key, key+8, key+16);
if( is_weak_key( key ) || is_weak_key( key+8 ) || is_weak_key( key+16 ) )
return G10ERR_WEAK_KEY;
return 0;
}
static void
do_tripledes_encrypt( struct _tripledes_ctx *ctx, byte *outbuf, byte *inbuf )
{
tripledes_ecb_encrypt ( ctx, inbuf, outbuf );
}
static void
do_tripledes_decrypt( struct _tripledes_ctx *ctx, byte *outbuf, byte *inbuf )
{
tripledes_ecb_decrypt ( ctx, inbuf, outbuf );
}
/****************
* Return some information about the algorithm. We need algo here to
* distinguish different flavors of the algorithm.
* Returns: A pointer to string describing the algorithm or NULL if
* the ALGO is invalid.
*/
const char *
des_get_info( int algo, size_t *keylen,
size_t *blocksize, size_t *contextsize,
int (**r_setkey)( void *c, byte *key, unsigned keylen ),
void (**r_encrypt)( void *c, byte *outbuf, byte *inbuf ),
void (**r_decrypt)( void *c, byte *outbuf, byte *inbuf )
)
{
static int did_selftest = 0;
if( !did_selftest ) {
const char *s = selftest();
did_selftest = 1;
if( s ) {
fprintf(stderr,"%s\n", s );
selftest_failed = s;
return NULL;
}
}
if( algo == CIPHER_ALGO_3DES ) {
*keylen = 192;
*blocksize = 8;
*contextsize = sizeof(struct _tripledes_ctx);
*r_setkey = FNCCAST_SETKEY(do_tripledes_setkey);
*r_encrypt= FNCCAST_CRYPT(do_tripledes_encrypt);
*r_decrypt= FNCCAST_CRYPT(do_tripledes_decrypt);
return "3DES";
}
return NULL;
}

File Metadata

Mime Type
text/x-c
Expires
Tue, Apr 22, 3:59 AM (4 h, 16 m)
Storage Engine
local-disk
Storage Format
Raw Data
Storage Handle
26/16/06a0190baffd925e6d8e8d715aaa

Event Timeline