/***************************************************************************** * nscdec.c: NSC decoder 1.0 ***************************************************************************** * Copyright (C) 2005 Jon Lech Johansen * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ #include #include #include #include #include static const unsigned char inverse[ 128 ] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0xFF, 0x3F, 0xFF, 0xFF }; static int load_byte( unsigned char encoding_type, unsigned char *output, char **input, unsigned char *j, unsigned char *k ) { *output = 0; if( encoding_type == 1 ) { if( isxdigit( **input ) == 0 ) return -1; if( isdigit( **input ) == 0 ) *output = (toupper( **input ) - 7) * 16; else *output = **input * 16; (*input)++; if( isxdigit( **input ) == 0 ) return -1; if( isdigit( **input ) == 0 ) *output |= toupper( **input ) - 0x37; else *output |= **input - 0x30; (*input)++; } else if( encoding_type == 2 ) { unsigned char **uinput = (unsigned char **)input; if( **uinput > 127 || inverse[ **uinput ] == 0xFF ) return -1; if( *k == 0 ) { if( (*uinput)[ 1 ] > 127 || inverse[ (*uinput)[ 1 ] ] == 0xFF ) return -1; *output = (inverse[ (*uinput)[ 0 ] ] * 4) | (inverse[ (*uinput)[ 1 ] ] / 16); *j = inverse[ (*uinput)[ 1 ] ] * 16; *k = 4; (*uinput) += 2; } else if( *k == 2 ) { *output = *j | inverse[ **uinput ]; *j = 0; *k = 0; (*uinput)++; } else if( *k == 4 ) { *output = (inverse[ **uinput ] / 4) | *j; *j = inverse[ **uinput ] * 64; *k = 2; (*uinput)++; } } return 0; } int main( int argc, char **argv ) { int ret = 0; unsigned int i; unsigned char tmp; unsigned char j, k; unsigned int length; unsigned char encoding_type; unsigned char *buffer; if( argc != 2 ) { fprintf( stderr, "Usage: nscdec string\n" ); return 1; } char *p_input = &argv[ 1 ][ 0 ]; if( strlen( p_input ) < 15 ) { fprintf( stderr, "Input string less than 15 characters\n" ); return 1; } if( load_byte( 1, &encoding_type, &p_input, NULL, NULL ) ) { fprintf( stderr, "Unable to get encoding type\n" ); return 1; } if( encoding_type != 1 && encoding_type != 2 ) { fprintf( stderr, "Encoding type %d is not supported\n", encoding_type ); return 1; } printf( "Encoding type: %d\n", encoding_type ); j = k = 0; if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) ) { fprintf( stderr, "load_byte failed\n" ); return 1; } for( i = 0; i < 4; i++ ) { if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) ) { fprintf( stderr, "load_byte failed\n" ); return 1; } } length = 0; for( i = 4; i; i-- ) { if( load_byte( encoding_type, &tmp, &p_input, &j, &k ) ) { fprintf( stderr, "load_byte failed\n" ); return 1; } length |= tmp << ((i - 1) * 8); } if( length == 0 ) { fprintf( stderr, "Length is 0\n" ); return 1; } buffer = (unsigned char *)malloc( length ); if( buffer == NULL ) { fprintf( stderr, "Out of memory\n" ); return 1; } for( i = 0; i < length; i++ ) { if( load_byte( encoding_type, &buffer[ i ], &p_input, &j, &k ) ) { fprintf( stderr, "load_byte failed\n" ); free( (void *)buffer ); return 1; } } if( buffer[ length - 1 ] != 0 && buffer[ length - 2 ] != 0 ) { printf( "Decoded data:\n" ); for( i = 0; i < length; i++ ) { printf( "0x%02X, ", buffer[ i ] ); if( ((i + 1) % 12) == 0 ) printf( "\n" ); } printf( "\n" ); } else { iconv_t conv; char *buf8; char *p_buf8; char *p_buffer; size_t buffer_size = length; size_t buf8_size = length; buf8 = (char *)malloc( buf8_size + 1 ); if( buf8 == NULL ) { fprintf( stderr, "Out of memory\n" ); free( (void *)buffer ); return 1; } conv = iconv_open( "UTF-8", "UTF-16LE" ); if( conv == (iconv_t)-1 ) { fprintf( stderr, "iconv_open failed\n" ); free( (void *)buffer ); free( (void *)buf8 ); return 1; } p_buf8 = &buf8[ 0 ]; p_buffer = (char *)&buffer[ 0 ]; if( iconv( conv, &p_buffer, &buffer_size, &p_buf8, &buf8_size ) == -1 ) { fprintf( stderr, "iconv failed\n" ); ret = 1; } else { buf8[ length - buf8_size ] = 0; printf( "Decoded string: [%s]\n", buf8 ); } iconv_close( conv ); free( (void *)buf8 ); } free( (void *)buffer ); return ret; }