/* | |
* An implementation of the ARCFOUR algorithm | |
* | |
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved | |
* SPDX-License-Identifier: Apache-2.0 | |
* | |
* Licensed under the Apache License, Version 2.0 (the "License"); you may | |
* not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | |
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
* | |
* This file is part of mbed TLS (https://tls.mbed.org) | |
*/ | |
/* | |
* The ARCFOUR algorithm was publicly disclosed on 94/09. | |
* | |
* http://groups.google.com/group/sci.crypt/msg/10a300c9d21afca0 | |
*/ | |
#if !defined(MBEDTLS_CONFIG_FILE) | |
#include "mbedtls/config.h" | |
#else | |
#include MBEDTLS_CONFIG_FILE | |
#endif | |
#if defined(MBEDTLS_ARC4_C) | |
#include "mbedtls/arc4.h" | |
#include "mbedtls/platform_util.h" | |
#include <string.h> | |
#if defined(MBEDTLS_SELF_TEST) | |
#if defined(MBEDTLS_PLATFORM_C) | |
#include "mbedtls/platform.h" | |
#else | |
#include <stdio.h> | |
#define mbedtls_printf printf | |
#endif /* MBEDTLS_PLATFORM_C */ | |
#endif /* MBEDTLS_SELF_TEST */ | |
#if !defined(MBEDTLS_ARC4_ALT) | |
void mbedtls_arc4_init( mbedtls_arc4_context *ctx ) | |
{ | |
memset( ctx, 0, sizeof( mbedtls_arc4_context ) ); | |
} | |
void mbedtls_arc4_free( mbedtls_arc4_context *ctx ) | |
{ | |
if( ctx == NULL ) | |
return; | |
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_arc4_context ) ); | |
} | |
/* | |
* ARC4 key schedule | |
*/ | |
void mbedtls_arc4_setup( mbedtls_arc4_context *ctx, const unsigned char *key, | |
unsigned int keylen ) | |
{ | |
int i, j, a; | |
unsigned int k; | |
unsigned char *m; | |
ctx->x = 0; | |
ctx->y = 0; | |
m = ctx->m; | |
for( i = 0; i < 256; i++ ) | |
m[i] = (unsigned char) i; | |
j = k = 0; | |
for( i = 0; i < 256; i++, k++ ) | |
{ | |
if( k >= keylen ) k = 0; | |
a = m[i]; | |
j = ( j + a + key[k] ) & 0xFF; | |
m[i] = m[j]; | |
m[j] = (unsigned char) a; | |
} | |
} | |
/* | |
* ARC4 cipher function | |
*/ | |
int mbedtls_arc4_crypt( mbedtls_arc4_context *ctx, size_t length, const unsigned char *input, | |
unsigned char *output ) | |
{ | |
int x, y, a, b; | |
size_t i; | |
unsigned char *m; | |
x = ctx->x; | |
y = ctx->y; | |
m = ctx->m; | |
for( i = 0; i < length; i++ ) | |
{ | |
x = ( x + 1 ) & 0xFF; a = m[x]; | |
y = ( y + a ) & 0xFF; b = m[y]; | |
m[x] = (unsigned char) b; | |
m[y] = (unsigned char) a; | |
output[i] = (unsigned char) | |
( input[i] ^ m[(unsigned char)( a + b )] ); | |
} | |
ctx->x = x; | |
ctx->y = y; | |
return( 0 ); | |
} | |
#endif /* !MBEDTLS_ARC4_ALT */ | |
#if defined(MBEDTLS_SELF_TEST) | |
/* | |
* ARC4 tests vectors as posted by Eric Rescorla in sep. 1994: | |
* | |
* http://groups.google.com/group/comp.security.misc/msg/10a300c9d21afca0 | |
*/ | |
static const unsigned char arc4_test_key[3][8] = | |
{ | |
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF }, | |
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF }, | |
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } | |
}; | |
static const unsigned char arc4_test_pt[3][8] = | |
{ | |
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF }, | |
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, | |
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } | |
}; | |
static const unsigned char arc4_test_ct[3][8] = | |
{ | |
{ 0x75, 0xB7, 0x87, 0x80, 0x99, 0xE0, 0xC5, 0x96 }, | |
{ 0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79 }, | |
{ 0xDE, 0x18, 0x89, 0x41, 0xA3, 0x37, 0x5D, 0x3A } | |
}; | |
/* | |
* Checkup routine | |
*/ | |
int mbedtls_arc4_self_test( int verbose ) | |
{ | |
int i, ret = 0; | |
unsigned char ibuf[8]; | |
unsigned char obuf[8]; | |
mbedtls_arc4_context ctx; | |
mbedtls_arc4_init( &ctx ); | |
for( i = 0; i < 3; i++ ) | |
{ | |
if( verbose != 0 ) | |
mbedtls_printf( " ARC4 test #%d: ", i + 1 ); | |
memcpy( ibuf, arc4_test_pt[i], 8 ); | |
mbedtls_arc4_setup( &ctx, arc4_test_key[i], 8 ); | |
mbedtls_arc4_crypt( &ctx, 8, ibuf, obuf ); | |
if( memcmp( obuf, arc4_test_ct[i], 8 ) != 0 ) | |
{ | |
if( verbose != 0 ) | |
mbedtls_printf( "failed\n" ); | |
ret = 1; | |
goto exit; | |
} | |
if( verbose != 0 ) | |
mbedtls_printf( "passed\n" ); | |
} | |
if( verbose != 0 ) | |
mbedtls_printf( "\n" ); | |
exit: | |
mbedtls_arc4_free( &ctx ); | |
return( ret ); | |
} | |
#endif /* MBEDTLS_SELF_TEST */ | |
#endif /* MBEDTLS_ARC4_C */ |