#include #include #include #include unsigned int CSStab0[11]={5,0,1,2,3,4,0,1,2,3,4}; unsigned char CSStab1[256]= { 0x33,0x73,0x3b,0x26,0x63,0x23,0x6b,0x76,0x3e,0x7e,0x36,0x2b,0x6e,0x2e,0x66,0x7b, 0xd3,0x93,0xdb,0x06,0x43,0x03,0x4b,0x96,0xde,0x9e,0xd6,0x0b,0x4e,0x0e,0x46,0x9b, 0x57,0x17,0x5f,0x82,0xc7,0x87,0xcf,0x12,0x5a,0x1a,0x52,0x8f,0xca,0x8a,0xc2,0x1f, 0xd9,0x99,0xd1,0x00,0x49,0x09,0x41,0x90,0xd8,0x98,0xd0,0x01,0x48,0x08,0x40,0x91, 0x3d,0x7d,0x35,0x24,0x6d,0x2d,0x65,0x74,0x3c,0x7c,0x34,0x25,0x6c,0x2c,0x64,0x75, 0xdd,0x9d,0xd5,0x04,0x4d,0x0d,0x45,0x94,0xdc,0x9c,0xd4,0x05,0x4c,0x0c,0x44,0x95, 0x59,0x19,0x51,0x80,0xc9,0x89,0xc1,0x10,0x58,0x18,0x50,0x81,0xc8,0x88,0xc0,0x11, 0xd7,0x97,0xdf,0x02,0x47,0x07,0x4f,0x92,0xda,0x9a,0xd2,0x0f,0x4a,0x0a,0x42,0x9f, 0x53,0x13,0x5b,0x86,0xc3,0x83,0xcb,0x16,0x5e,0x1e,0x56,0x8b,0xce,0x8e,0xc6,0x1b, 0xb3,0xf3,0xbb,0xa6,0xe3,0xa3,0xeb,0xf6,0xbe,0xfe,0xb6,0xab,0xee,0xae,0xe6,0xfb, 0x37,0x77,0x3f,0x22,0x67,0x27,0x6f,0x72,0x3a,0x7a,0x32,0x2f,0x6a,0x2a,0x62,0x7f, 0xb9,0xf9,0xb1,0xa0,0xe9,0xa9,0xe1,0xf0,0xb8,0xf8,0xb0,0xa1,0xe8,0xa8,0xe0,0xf1, 0x5d,0x1d,0x55,0x84,0xcd,0x8d,0xc5,0x14,0x5c,0x1c,0x54,0x85,0xcc,0x8c,0xc4,0x15, 0xbd,0xfd,0xb5,0xa4,0xed,0xad,0xe5,0xf4,0xbc,0xfc,0xb4,0xa5,0xec,0xac,0xe4,0xf5, 0x39,0x79,0x31,0x20,0x69,0x29,0x61,0x70,0x38,0x78,0x30,0x21,0x68,0x28,0x60,0x71, 0xb7,0xf7,0xbf,0xa2,0xe7,0xa7,0xef,0xf2,0xba,0xfa,0xb2,0xaf,0xea,0xaa,0xe2,0xff }; unsigned char CSStab2[256]= { 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x09,0x08,0x0b,0x0a,0x0d,0x0c,0x0f,0x0e, 0x12,0x13,0x10,0x11,0x16,0x17,0x14,0x15,0x1b,0x1a,0x19,0x18,0x1f,0x1e,0x1d,0x1c, 0x24,0x25,0x26,0x27,0x20,0x21,0x22,0x23,0x2d,0x2c,0x2f,0x2e,0x29,0x28,0x2b,0x2a, 0x36,0x37,0x34,0x35,0x32,0x33,0x30,0x31,0x3f,0x3e,0x3d,0x3c,0x3b,0x3a,0x39,0x38, 0x49,0x48,0x4b,0x4a,0x4d,0x4c,0x4f,0x4e,0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47, 0x5b,0x5a,0x59,0x58,0x5f,0x5e,0x5d,0x5c,0x52,0x53,0x50,0x51,0x56,0x57,0x54,0x55, 0x6d,0x6c,0x6f,0x6e,0x69,0x68,0x6b,0x6a,0x64,0x65,0x66,0x67,0x60,0x61,0x62,0x63, 0x7f,0x7e,0x7d,0x7c,0x7b,0x7a,0x79,0x78,0x76,0x77,0x74,0x75,0x72,0x73,0x70,0x71, 0x92,0x93,0x90,0x91,0x96,0x97,0x94,0x95,0x9b,0x9a,0x99,0x98,0x9f,0x9e,0x9d,0x9c, 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x89,0x88,0x8b,0x8a,0x8d,0x8c,0x8f,0x8e, 0xb6,0xb7,0xb4,0xb5,0xb2,0xb3,0xb0,0xb1,0xbf,0xbe,0xbd,0xbc,0xbb,0xba,0xb9,0xb8, 0xa4,0xa5,0xa6,0xa7,0xa0,0xa1,0xa2,0xa3,0xad,0xac,0xaf,0xae,0xa9,0xa8,0xab,0xaa, 0xdb,0xda,0xd9,0xd8,0xdf,0xde,0xdd,0xdc,0xd2,0xd3,0xd0,0xd1,0xd6,0xd7,0xd4,0xd5, 0xc9,0xc8,0xcb,0xca,0xcd,0xcc,0xcf,0xce,0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7, 0xff,0xfe,0xfd,0xfc,0xfb,0xfa,0xf9,0xf8,0xf6,0xf7,0xf4,0xf5,0xf2,0xf3,0xf0,0xf1, 0xed,0xec,0xef,0xee,0xe9,0xe8,0xeb,0xea,0xe4,0xe5,0xe6,0xe7,0xe0,0xe1,0xe2,0xe3 }; unsigned char CSStab3[512]= { 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff, 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff }; unsigned char CSStab4[256]= { 0x00,0x80,0x40,0xc0,0x20,0xa0,0x60,0xe0,0x10,0x90,0x50,0xd0,0x30,0xb0,0x70,0xf0, 0x08,0x88,0x48,0xc8,0x28,0xa8,0x68,0xe8,0x18,0x98,0x58,0xd8,0x38,0xb8,0x78,0xf8, 0x04,0x84,0x44,0xc4,0x24,0xa4,0x64,0xe4,0x14,0x94,0x54,0xd4,0x34,0xb4,0x74,0xf4, 0x0c,0x8c,0x4c,0xcc,0x2c,0xac,0x6c,0xec,0x1c,0x9c,0x5c,0xdc,0x3c,0xbc,0x7c,0xfc, 0x02,0x82,0x42,0xc2,0x22,0xa2,0x62,0xe2,0x12,0x92,0x52,0xd2,0x32,0xb2,0x72,0xf2, 0x0a,0x8a,0x4a,0xca,0x2a,0xaa,0x6a,0xea,0x1a,0x9a,0x5a,0xda,0x3a,0xba,0x7a,0xfa, 0x06,0x86,0x46,0xc6,0x26,0xa6,0x66,0xe6,0x16,0x96,0x56,0xd6,0x36,0xb6,0x76,0xf6, 0x0e,0x8e,0x4e,0xce,0x2e,0xae,0x6e,0xee,0x1e,0x9e,0x5e,0xde,0x3e,0xbe,0x7e,0xfe, 0x01,0x81,0x41,0xc1,0x21,0xa1,0x61,0xe1,0x11,0x91,0x51,0xd1,0x31,0xb1,0x71,0xf1, 0x09,0x89,0x49,0xc9,0x29,0xa9,0x69,0xe9,0x19,0x99,0x59,0xd9,0x39,0xb9,0x79,0xf9, 0x05,0x85,0x45,0xc5,0x25,0xa5,0x65,0xe5,0x15,0x95,0x55,0xd5,0x35,0xb5,0x75,0xf5, 0x0d,0x8d,0x4d,0xcd,0x2d,0xad,0x6d,0xed,0x1d,0x9d,0x5d,0xdd,0x3d,0xbd,0x7d,0xfd, 0x03,0x83,0x43,0xc3,0x23,0xa3,0x63,0xe3,0x13,0x93,0x53,0xd3,0x33,0xb3,0x73,0xf3, 0x0b,0x8b,0x4b,0xcb,0x2b,0xab,0x6b,0xeb,0x1b,0x9b,0x5b,0xdb,0x3b,0xbb,0x7b,0xfb, 0x07,0x87,0x47,0xc7,0x27,0xa7,0x67,0xe7,0x17,0x97,0x57,0xd7,0x37,0xb7,0x77,0xf7, 0x0f,0x8f,0x4f,0xcf,0x2f,0xaf,0x6f,0xef,0x1f,0x9f,0x5f,0xdf,0x3f,0xbf,0x7f,0xff }; unsigned char CSStab5[256]= { 0xff,0x7f,0xbf,0x3f,0xdf,0x5f,0x9f,0x1f,0xef,0x6f,0xaf,0x2f,0xcf,0x4f,0x8f,0x0f, 0xf7,0x77,0xb7,0x37,0xd7,0x57,0x97,0x17,0xe7,0x67,0xa7,0x27,0xc7,0x47,0x87,0x07, 0xfb,0x7b,0xbb,0x3b,0xdb,0x5b,0x9b,0x1b,0xeb,0x6b,0xab,0x2b,0xcb,0x4b,0x8b,0x0b, 0xf3,0x73,0xb3,0x33,0xd3,0x53,0x93,0x13,0xe3,0x63,0xa3,0x23,0xc3,0x43,0x83,0x03, 0xfd,0x7d,0xbd,0x3d,0xdd,0x5d,0x9d,0x1d,0xed,0x6d,0xad,0x2d,0xcd,0x4d,0x8d,0x0d, 0xf5,0x75,0xb5,0x35,0xd5,0x55,0x95,0x15,0xe5,0x65,0xa5,0x25,0xc5,0x45,0x85,0x05, 0xf9,0x79,0xb9,0x39,0xd9,0x59,0x99,0x19,0xe9,0x69,0xa9,0x29,0xc9,0x49,0x89,0x09, 0xf1,0x71,0xb1,0x31,0xd1,0x51,0x91,0x11,0xe1,0x61,0xa1,0x21,0xc1,0x41,0x81,0x01, 0xfe,0x7e,0xbe,0x3e,0xde,0x5e,0x9e,0x1e,0xee,0x6e,0xae,0x2e,0xce,0x4e,0x8e,0x0e, 0xf6,0x76,0xb6,0x36,0xd6,0x56,0x96,0x16,0xe6,0x66,0xa6,0x26,0xc6,0x46,0x86,0x06, 0xfa,0x7a,0xba,0x3a,0xda,0x5a,0x9a,0x1a,0xea,0x6a,0xaa,0x2a,0xca,0x4a,0x8a,0x0a, 0xf2,0x72,0xb2,0x32,0xd2,0x52,0x92,0x12,0xe2,0x62,0xa2,0x22,0xc2,0x42,0x82,0x02, 0xfc,0x7c,0xbc,0x3c,0xdc,0x5c,0x9c,0x1c,0xec,0x6c,0xac,0x2c,0xcc,0x4c,0x8c,0x0c, 0xf4,0x74,0xb4,0x34,0xd4,0x54,0x94,0x14,0xe4,0x64,0xa4,0x24,0xc4,0x44,0x84,0x04, 0xf8,0x78,0xb8,0x38,0xd8,0x58,0x98,0x18,0xe8,0x68,0xa8,0x28,0xc8,0x48,0x88,0x08, 0xf0,0x70,0xb0,0x30,0xd0,0x50,0x90,0x10,0xe0,0x60,0xa0,0x20,0xc0,0x40,0x80,0x00 }; /*********************************************** * * The basic CSS cipher code * * * With reduced mangling in the key setup * * ***********************************************/ void CSSdescramble( unsigned char *key ) { unsigned int t1,t2,t3,t4,t5,t6; unsigned int i; t1= key[0] ^ 0x100; t2= key[1]; t3=(*((unsigned int *)(key+2))); t4=t3&7; t3=t3*2+8-t4; t5=0; printf( "Keystate at start: %03x %02x %08x\n", t1, t2, t3 ); printf( "output: " ); for( i=0 ; i < 10 ; i++ ) { t4=CSStab2[t2]^CSStab3[t1]; t2=t1>>1; t1=((t1&1)<<8)^t4; t4=CSStab5[t4]; t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff; t3=(t3<<8)|t6; t6=CSStab4[t6]; t5+=t6+t4; printf( "%02x ",t5&0xff); t5>>=8; } printf( "\n" ); } /******************************************************** * * The Divide and conquer attack * * Deviced and written by Frank A. Stevenson 26 Oct 1999 * * ( frank@funcom.com ) * Released under the GPL license * ********************************************************/ #define KEYSTREAMBYTES 10 static unsigned char invtab4[256]; void CSScracker( unsigned char* pStream ) { unsigned int t1,t2,t3,t4,t5,t6; unsigned int nTry; unsigned int vCandidate; int i; unsigned int j; /* Test that CSStab4 is a permutation */ memset( invtab4, 0, 256 ); for( i = 0 ; i < 256 ; i++ ) invtab4[ CSStab4[i] ] = 1; for( i = 0 ; i < 256 ; i++ ) if( invtab4[ i ] != 1 ) { printf( "Permutation error\n" ); exit( -1 ); } /* initialize the inverse of table4 */ for( i = 0 ; i < 256 ; i++ ) invtab4[ CSStab4[i] ] = i; for( nTry = 0 ; nTry < 65536 ; nTry++ ) { t1 = nTry >> 8 | 0x100; t2 = nTry & 0xff; t3 = 0; /* not needed */ t5 = 0; /* iterate cipher 4 times to reconstruct LFSR2 */ for( i = 0 ; i < 4 ; i++ ) { /* advance LFSR1 normaly */ t4=CSStab2[t2]^CSStab3[t1]; t2=t1>>1; t1=((t1&1)<<8)^t4; t4=CSStab5[t4]; /* deduce t6 & t5 */ t6 = pStream[ i ]; if( t5 ) t6 = ( t6 + 0xff )&0x0ff; if( t6 < t4 ) t6 += 0x100; t6 -= t4; t5 += t6 + t4; t6 = invtab4[ t6 ]; /* printf( "%02x/%02x ", t4, t6 ); */ /* feed / advance t3 / t5 */ t3 = (t3 << 8) | t6; t5 >>= 8; } vCandidate = t3; /* iterate 6 more times to validate candidate key */ for( ; i < KEYSTREAMBYTES ; i++ ) { t4=CSStab2[t2]^CSStab3[t1]; t2=t1>>1; t1=((t1&1)<<8)^t4; t4=CSStab5[t4]; t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff; t3=(t3<<8)|t6; t6=CSStab4[t6]; t5+=t6+t4; if( (t5 & 0xff) != pStream[i] ) break; t5>>=8; } if( i == KEYSTREAMBYTES ) { /* Do 4 backwards steps of iterating t3 to deduce initial state */ t3 = vCandidate; for( i = 0 ; i < 4 ; i++ ) { t1 = t3 & 0xff; t3 = ( t3 >> 8 ); /* easy to code, and fast enough bruteforce search for byte shifted in */ for( j=0 ; j < 256 ; j++ ) { t3 = (t3 & 0x1ffff) | ( j << 17 ); t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff; if( t6 == t1 ) break; } } printf( "Candidate: %03x %02x %08x\n", 0x100|(nTry>>8),nTry&0x0ff, t3 ); } } } /* simple function to convert hex bytes to int */ /* note: will give random results if nonhex digits are input */ static char hexdigits[17] = "0123456789abcdef\0"; static int HexByteToInt( const char *pNumber ) { char ch; int r; ch = tolower( pNumber[0] ); r = 16 * (int)( strchr( hexdigits, ch ) - hexdigits ); ch = tolower( pNumber[1] ); r+= (int)( strchr( hexdigits, ch ) - hexdigits ); return r & 0x0ff; /* invalid input will have produce garbage */ } /* Main function */ int main( int argc, char* argv[] ) { int i; unsigned char data[ KEYSTREAMBYTES ]; memset( data, 0, KEYSTREAMBYTES ); if( argc > KEYSTREAMBYTES + 1 ) { printf( "To many arguments\n" ); return -1; } if( argc < 6 ) { printf( "Usage: %s xx xx ... ( 5 / %i hex bytes )\n", argv[0], KEYSTREAMBYTES ); return -1; } for( i = 1; i < argc ; i++ ) { data[i-1] = HexByteToInt( argv[i] ); } if( argc == KEYSTREAMBYTES + 1 ) { /* search for key */ printf( "Attempting crack\n" ); CSScracker( data ); } else { /* Produce sample keystream */ printf( "Doing encryption\n" ); CSSdescramble( data ); } return( 0 ); }