/* * FBox * * Implementation of the DES FBox. * * Taken from RSAREF, and their copyrights must probably * also apply. * * 2000(c) Burton Rosenberg. All rights reserved. * * 1.2 : Tue Aug 31 22:54:26 EDT 2004 * 1.1 : Tue Sep 19 14:48:02 EDT 2000 * 1.0 : Tue Sep 19 11:50:12 EDT 2000 */ /* * Bit-selection table E. */ unsigned char E[] = { 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1 }; /* * Selection functions (S-boxes). [[These are 0-origin indexed.]] */ unsigned char S[8][64] = { 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7, 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8, 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0, 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13, 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10, 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5, 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15, 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9, 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8, 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1, 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7, 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12, 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15, 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9, 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4, 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14, 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9, 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6, 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14, 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3, 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11, 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8, 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6, 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13, 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1, 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6, 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2, 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12, 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7, 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2, 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8, 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 }; /* * Permutation P. */ unsigned char P[32] = { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; /* * utility routines */ void print2bits( char * a ) { int j ; j = (a[0]<<1) + a[1] ; printf("%x", j) ; } void print4bits( char * a ) { int j ; j = (a[0]<<3) + (a[1]<<2) + (a[2]<<1) + a[3] ; printf("%x", j) ; } void print8by4( char * a ) { int i ; for ( i=0; i<32; i+=4 ) { printf(" ") ; print4bits(a+i) ; printf(" ") ; } printf("\n") ; } void print8by6( char * a ) { int i, j ; for ( i=0; i<48; i+= 6 ) { print2bits( a+i ) ; print4bits( a+(i+2) ) ; printf(" ") ; } printf("\n") ; } void unpack( unsigned long v, char * o, int count ) { unsigned bit = 1 ; while ( count ) { count-- ; o[count] = (v & bit ) ? 1 : 0 ; bit <<= 1 ; } } unsigned long pack( char * a, int len ) { unsigned long r = 0L ; unsigned long bit = 1L ; int i ; for ( i=len-1; i>=0; i-- ) { if ( a[i] ) r |= bit ; bit <<= 1 ; } return r ; } /* * FBox */ static int verbose = 0 ; unsigned int fBox( unsigned int input, unsigned int keyhigh, unsigned int keylow ) { unsigned char sInput[48] ; unsigned char sOutput[32] ; unsigned char keyA[48] ; unsigned char eInput[32] ; unsigned char eOutput[48] ; unsigned char pOutput[32] ; unsigned char t ; unsigned int k ; unpack( (unsigned long) input, eInput, 32 ) ; unpack( (unsigned long) keyhigh, keyA, 24 ) ; unpack( (unsigned long) keylow, keyA+24, 24 ) ; for ( k=0; k<48; k++ ) eOutput[k] = eInput[E[k]-1] ; for ( k=0; k<48; k++ ) sInput[k] = eOutput[k] ^ keyA[k] ; /* * Apply eight S boxes. Index into S box k is formed from these * bits of sInput: * * 6*k 6*k+5 6*k+1 6*k+2 6*k+3 6*k+4 * * Value of S box k becomes these bits of sOutput: * * 4*k 4*k+1 4*k+2 4*k+3 */ for (k = 0; k < 8; k++) { t = S[k][(sInput[6*k] << 5) | (sInput[6*k + 5] << 4) | (sInput[6*k + 1] << 3) | (sInput[6*k + 2] << 2) | (sInput[6*k + 3] << 1) | (sInput[6*k + 4] << 0)]; sOutput[4*k] = (unsigned char)((t >> 3) & 1); sOutput[4*k + 1] = (unsigned char)((t >> 2) & 1); sOutput[4*k + 2] = (unsigned char)((t >> 1) & 1); sOutput[4*k + 3] = (unsigned char)(t & 1); } /* * Compute P(sOutput). */ for (k = 0; k < 32; k++) pOutput[k] = sOutput[P[k]-1]; if ( verbose ) { printf("\n") ; printf("======== Input ========\n") ; print8by4( eInput ) ; printf("---------- E ----------\n") ; print8by6( eOutput ) ; printf("---------- K ----------\n") ; print8by6( keyA ) ; printf("---------- + ----------\n") ; print8by6( sInput ) ; printf("---------- S ----------\n") ; printf("S1-S2-S3-S4-S5-S6-S7-S8\n") ; printf("---------- S ----------\n") ; print8by4( sOutput ) ; printf("---------- P ----------\n") ; print8by4( pOutput ) ; printf("======== Output =======\n") ; printf("\n") ; } return (int) pack( pOutput, 32 ) ; } /* * main */ void usage() { printf("fbox v h l\n") ; printf(" v: 32 bits of value, in hex\n") ; printf(" h: high 24 bits of key, in hex\n") ; printf(" l: low 24 bits of key, in hex\n") ; printf(" output: DES_{h|l}(v)\n") ; } int main( int argc, char * argv[] ) { unsigned int t ; unsigned int kl ; unsigned int kh ; unsigned int s ; if ( argc != 4 ) { usage() ; return 0 ; } verbose = 1 ; sscanf( argv[1], "%x", &t) ; sscanf( argv[2], "%x", &kh) ; sscanf( argv[3], "%x", &kl) ; s = fBox(t,kh,kl) ; printf("fbox(0x%08x)[0x%06x%06x] = 0x%08x\n", t, kh, kl, s ) ; return 0 ; }