251 lines
6.6 KiB
C
251 lines
6.6 KiB
C
/*
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* An 32-bit implementation of the XTEA algorithm
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*
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* Copyright (C) 2006-2013, Brainspark B.V.
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*
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* This file is part of PolarSSL (http://www.polarssl.org)
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* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "polarssl/config.h"
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#if defined(POLARSSL_XTEA_C)
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#include "polarssl/xtea.h"
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#if !defined(POLARSSL_XTEA_ALT)
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/*
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* 32-bit integer manipulation macros (big endian)
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*/
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#ifndef GET_UINT32_BE
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#define GET_UINT32_BE(n,b,i) \
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{ \
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(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
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| ( (uint32_t) (b)[(i) + 1] << 16 ) \
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| ( (uint32_t) (b)[(i) + 2] << 8 ) \
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| ( (uint32_t) (b)[(i) + 3] ); \
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}
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#endif
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#ifndef PUT_UINT32_BE
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#define PUT_UINT32_BE(n,b,i) \
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{ \
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(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
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(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
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(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
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(b)[(i) + 3] = (unsigned char) ( (n) ); \
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}
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#endif
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/*
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* XTEA key schedule
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*/
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void xtea_setup( xtea_context *ctx, const unsigned char key[16] )
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{
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int i;
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memset(ctx, 0, sizeof(xtea_context));
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for( i = 0; i < 4; i++ )
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{
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GET_UINT32_BE( ctx->k[i], key, i << 2 );
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}
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}
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/*
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* XTEA encrypt function
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*/
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int xtea_crypt_ecb( xtea_context *ctx, int mode,
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const unsigned char input[8], unsigned char output[8])
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{
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uint32_t *k, v0, v1, i;
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k = ctx->k;
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GET_UINT32_BE( v0, input, 0 );
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GET_UINT32_BE( v1, input, 4 );
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if( mode == XTEA_ENCRYPT )
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{
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uint32_t sum = 0, delta = 0x9E3779B9;
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for( i = 0; i < 32; i++ )
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{
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v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
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sum += delta;
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v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
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}
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}
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else /* XTEA_DECRYPT */
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{
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uint32_t delta = 0x9E3779B9, sum = delta * 32;
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for( i = 0; i < 32; i++ )
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{
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v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
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sum -= delta;
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v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
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}
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}
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PUT_UINT32_BE( v0, output, 0 );
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PUT_UINT32_BE( v1, output, 4 );
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return( 0 );
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}
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#if defined(POLARSSL_CIPHER_MODE_CBC)
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/*
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* XTEA-CBC buffer encryption/decryption
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*/
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int xtea_crypt_cbc( xtea_context *ctx, int mode, size_t length,
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unsigned char iv[8], const unsigned char *input,
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unsigned char *output)
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{
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int i;
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unsigned char temp[8];
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if( length % 8 )
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return( POLARSSL_ERR_XTEA_INVALID_INPUT_LENGTH );
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if( mode == XTEA_DECRYPT )
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{
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while( length > 0 )
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{
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memcpy( temp, input, 8 );
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xtea_crypt_ecb( ctx, mode, input, output );
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for(i = 0; i < 8; i++)
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output[i] = (unsigned char)( output[i] ^ iv[i] );
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memcpy( iv, temp, 8 );
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input += 8;
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output += 8;
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length -= 8;
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}
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}
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else
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{
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while( length > 0 )
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{
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for( i = 0; i < 8; i++ )
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output[i] = (unsigned char)( input[i] ^ iv[i] );
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xtea_crypt_ecb( ctx, mode, output, output );
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memcpy( iv, output, 8 );
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input += 8;
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output += 8;
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length -= 8;
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}
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}
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return( 0 );
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}
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#endif /* POLARSSL_CIPHER_MODE_CBC */
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#endif /* !POLARSSL_XTEA_ALT */
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#if defined(POLARSSL_SELF_TEST)
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#include <string.h>
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#include <stdio.h>
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/*
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* XTEA tests vectors (non-official)
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*/
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static const unsigned char xtea_test_key[6][16] =
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{
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{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
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0x0c, 0x0d, 0x0e, 0x0f },
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{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
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0x0c, 0x0d, 0x0e, 0x0f },
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{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
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0x0c, 0x0d, 0x0e, 0x0f },
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{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 },
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{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 },
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{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 }
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};
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static const unsigned char xtea_test_pt[6][8] =
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{
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{ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
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{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
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{ 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
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{ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
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{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
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{ 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }
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};
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static const unsigned char xtea_test_ct[6][8] =
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{
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{ 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 },
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{ 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 },
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{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
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{ 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 },
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{ 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d },
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{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
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};
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/*
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* Checkup routine
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*/
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int xtea_self_test( int verbose )
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{
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int i;
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unsigned char buf[8];
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xtea_context ctx;
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for( i = 0; i < 6; i++ )
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{
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if( verbose != 0 )
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printf( " XTEA test #%d: ", i + 1 );
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memcpy( buf, xtea_test_pt[i], 8 );
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xtea_setup( &ctx, xtea_test_key[i] );
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xtea_crypt_ecb( &ctx, XTEA_ENCRYPT, buf, buf );
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if( memcmp( buf, xtea_test_ct[i], 8 ) != 0 )
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{
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if( verbose != 0 )
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printf( "failed\n" );
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return( 1 );
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}
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if( verbose != 0 )
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printf( "passed\n" );
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}
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if( verbose != 0 )
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printf( "\n" );
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return( 0 );
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}
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#endif
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#endif
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