From f2df25ca202300fe04672703ea7fb30d8431b302 Mon Sep 17 00:00:00 2001
From: Dirk Engling <erdgeist@erdgeist.org>
Date: Sun, 12 Jan 2014 22:07:32 +0100
Subject: Make extract code for old phone books much more generic and detect
necessary values automatically
---
src/extractblocks_new.c | 121 ++++++++++++++++++++++++++++++++----------------
1 file changed, 80 insertions(+), 41 deletions(-)
diff --git a/src/extractblocks_new.c b/src/extractblocks_new.c
index 94ab0b7..53c16f2 100644
--- a/src/extractblocks_new.c
+++ b/src/extractblocks_new.c
@@ -5,76 +5,115 @@
#include <stdint.h>
#include <unistd.h>
+/* lha header:
+
+00 Header length
+01 Header checksum [02-length]
+02 0x2d ('-')
+03 0x6c ('l')
+04 0x68 ('h')
+05 0x?? ('0' or '5') unsure
+06 0x2d ('-')
+07 0x?? LSB of compressed size
+08 0x?? ..
+09 0x00 ..
+10 0x00 MSB of compressed size, i.e. 0
+..
+21 Length of path name
+
+
+*/
+
+static uint8_t mantra_in[] = { 0x68, 0x00, 0x2d, 0x6c };
+
int main( int args, char **argv )
{
- int filenum = 0;
- size_t offset = 0, oldoffset = -1;
- uint8_t *mappedfile;
+ int filenum = 0, run = 1;
+ size_t offset = 0, oldoffset = -1, enc_len = 32;
+ uint8_t mantra[4], id0, id5, *mappedfile;
MAP map;
- uint8_t mantra0 = 0x1b, mantra1 = 0x35, mantra2 = 0x2d, mantra3 = 0x6c; /* clean*/
-// unsigned char mantra0 = 0x08, mantra1 = 0x57, mantra2 = 0x64, mantra3 = 0x69; /* 98 H */
-// unsigned char mantra0 = 0x13, mantra1 = 0xe4, mantra2 = 0x55, mantra3 = 0x05; /* 99 F */
-// unsigned char mantra0 = 0x12, mantra1 = 0x08, mantra2 = 0x23, mantra3 = 0x01; /* 99 H */
+ /* For streets we do have a enc_len of 34 */
+ while( run ) {
+ switch( getopt( args, argv, ":e:" ) ) {
+ case -1 : run = 0; break;
+ case 'e':
+ enc_len = atol( optarg );
+ break;
+ default:
+ fputs( "Syntax: %s [-e encrypted_length (default: 32, for streets 34 or 0)] path-to-teiln.dat", stderr ); exit( 1 );
+ break;
+ }
+ }
+ run = 1;
- if( args != 2 )
- { fputs( "Missing filenames.", stderr ); exit( 1 ); }
+ if( optind == args )
+ { fputs( "Missing filename.", stderr ); exit( 1 ); }
- map = map_file( argv[1], 1 );
+ map = map_file( argv[optind], 1 );
mappedfile = map->addr;
- mantra0 ^= mappedfile[0];
- mantra1 ^= mappedfile[5];
- mantra2 ^= mappedfile[2];
- mantra3 ^= mappedfile[3];
+ mantra[0] = mantra_in[0] ^ mappedfile[4];
+ mantra[1] = mantra_in[1] ^ mappedfile[9];
+ mantra[2] = mantra_in[2] ^ mappedfile[2];
+ mantra[3] = mantra_in[3] ^ mappedfile[3];
+
+ id0 = mappedfile[0];
+ id5 = mappedfile[5];
- while( 1 )
+ while( run )
{
while( ( offset < map->size ) && (
- ( mappedfile[ offset + 0 ] != ( 0x1b^ mantra0 )) ||
- ( mappedfile[ offset + 2 ] != ( '-' ^ mantra2 )) ||
- ( mappedfile[ offset + 3 ] != ( 'l' ^ mantra3 )) ||
- ( mappedfile[ offset + 4 ] != ( 'h' ^ mantra0 )) ||
- ( mappedfile[ offset + 5 ] != ( '5' ^ mantra1 )) ||
- ( mappedfile[ offset + 6 ] != ( '-' ^ mantra2 ))
+ ( mappedfile[ offset + 0 ] != id0 ) ||
+ ( mappedfile[ offset + 2 ] != ( '-' ^ mantra[2] )) ||
+ ( mappedfile[ offset + 3 ] != ( 'l' ^ mantra[3] )) ||
+ ( mappedfile[ offset + 4 ] != ( 'h' ^ mantra[0] )) ||
+ ( mappedfile[ offset + 5 ] != id5 ) ||
+ ( mappedfile[ offset + 6 ] != ( '-' ^ mantra[2] ))
) ) offset++;
- printf( "Found an appropriate offset at: %zd\n", oldoffset );
+ printf( "Found an appropriate offset at: %zd\n", offset );
if( offset == map->size )
- {
- unmap_file( &map );
- exit(0);
- }
+ run = 0;
if( oldoffset != -1 )
{
- uint8_t cs = 0, *mf = mappedfile + oldoffset, df[32];
- char filename[20];
+ uint8_t *mf = mappedfile + oldoffset, df[128];
+ size_t filename_len, header_len;
+ char filename_template[32], filename[32];
int i;
- for( i=0; i<8; ++i)
- {
- df[4*i+0] = mf[4*i+0] ^ mantra0;
- df[4*i+1] = mf[4*i+1] ^ mantra1;
- df[4*i+2] = mf[4*i+2] ^ mantra2;
- df[4*i+3] = mf[4*i+3] ^ mantra3;
- }
+ /* De-"crypt" obfuscation to our header copy */
+ for( i=0; i<enc_len; ++i)
+ df[i] = mf[i] ^ mantra[i%4];
+
+ /* Get values from LHA header */
+ header_len = df[0];
+ filename_len = df[21];
+
+ /* Copy rest of header, so we can checksum */
+ for( i=enc_len; i<header_len+2; ++i)
+ df[i] = mf[i];
- snprintf( filename, sizeof( filename ), "%05d.lha", filenum++ );
- memcpy( ((uint8_t*)df) + 22, filename, 5);
+ /* Make up new sequental file name */
+ snprintf( filename_template, sizeof(filename_template), "%%0%dd.lha", (int)filename_len );
+ snprintf( filename, sizeof( filename ), filename_template, filenum++ );
+ memcpy( ((uint8_t*)df) + 22, filename, filename_len);
- for( i=2; i<29; ++i) cs += ((uint8_t*)df)[i];
- ((uint8_t*)df)[1] = cs;
+ /* Recalculate checksum with new file name */
+ df[1] = 0; for( i=2; i<header_len+2; ++i) df[1] += df[i];
+ /* Open file and dump our de-"crypted" header and then rest of file */
i = open( filename, O_CREAT | O_TRUNC | O_WRONLY, 0644 );
- write( i, df, 32 );
- write( i, mf + 32, offset - oldoffset - 32 );
+ write( i, df, enc_len );
+ write( i, mf + enc_len, offset - oldoffset - enc_len );
close( i );
}
oldoffset = offset;
offset++;
}
+ unmap_file( &map );
return 0;
}
--
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