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00029 #include "polarssl/config.h"
00030
00031 #if defined(POLARSSL_ARC4_C)
00032
00033 #include "polarssl/arc4.h"
00034
00035
00036
00037
00038 void arc4_setup( arc4_context *ctx, unsigned char *key, int keylen )
00039 {
00040 int i, j, k, a;
00041 unsigned char *m;
00042
00043 ctx->x = 0;
00044 ctx->y = 0;
00045 m = ctx->m;
00046
00047 for( i = 0; i < 256; i++ )
00048 m[i] = (unsigned char) i;
00049
00050 j = k = 0;
00051
00052 for( i = 0; i < 256; i++, k++ )
00053 {
00054 if( k >= keylen ) k = 0;
00055
00056 a = m[i];
00057 j = ( j + a + key[k] ) & 0xFF;
00058 m[i] = m[j];
00059 m[j] = (unsigned char) a;
00060 }
00061 }
00062
00063
00064
00065
00066 void arc4_crypt( arc4_context *ctx, unsigned char *buf, int buflen )
00067 {
00068 int i, x, y, a, b;
00069 unsigned char *m;
00070
00071 x = ctx->x;
00072 y = ctx->y;
00073 m = ctx->m;
00074
00075 for( i = 0; i < buflen; i++ )
00076 {
00077 x = ( x + 1 ) & 0xFF; a = m[x];
00078 y = ( y + a ) & 0xFF; b = m[y];
00079
00080 m[x] = (unsigned char) b;
00081 m[y] = (unsigned char) a;
00082
00083 buf[i] = (unsigned char)
00084 ( buf[i] ^ m[(unsigned char)( a + b )] );
00085 }
00086
00087 ctx->x = x;
00088 ctx->y = y;
00089 }
00090
00091 #if defined(POLARSSL_SELF_TEST)
00092
00093 #include <string.h>
00094 #include <stdio.h>
00095
00096
00097
00098
00099
00100
00101 static const unsigned char arc4_test_key[3][8] =
00102 {
00103 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
00104 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
00105 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
00106 };
00107
00108 static const unsigned char arc4_test_pt[3][8] =
00109 {
00110 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
00111 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
00112 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
00113 };
00114
00115 static const unsigned char arc4_test_ct[3][8] =
00116 {
00117 { 0x75, 0xB7, 0x87, 0x80, 0x99, 0xE0, 0xC5, 0x96 },
00118 { 0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79 },
00119 { 0xDE, 0x18, 0x89, 0x41, 0xA3, 0x37, 0x5D, 0x3A }
00120 };
00121
00122
00123
00124
00125 int arc4_self_test( int verbose )
00126 {
00127 int i;
00128 unsigned char buf[8];
00129 arc4_context ctx;
00130
00131 for( i = 0; i < 3; i++ )
00132 {
00133 if( verbose != 0 )
00134 printf( " ARC4 test #%d: ", i + 1 );
00135
00136 memcpy( buf, arc4_test_pt[i], 8 );
00137
00138 arc4_setup( &ctx, (unsigned char *) arc4_test_key[i], 8 );
00139 arc4_crypt( &ctx, buf, 8 );
00140
00141 if( memcmp( buf, arc4_test_ct[i], 8 ) != 0 )
00142 {
00143 if( verbose != 0 )
00144 printf( "failed\n" );
00145
00146 return( 1 );
00147 }
00148
00149 if( verbose != 0 )
00150 printf( "passed\n" );
00151 }
00152
00153 if( verbose != 0 )
00154 printf( "\n" );
00155
00156 return( 0 );
00157 }
00158
00159 #endif
00160
00161 #endif