From 046857dfb88f05e6b310fe9ef07b9f2d3ac5922d Mon Sep 17 00:00:00 2001
From: Dirk Engling <erdgeist@erdgeist.org>
Date: Thu, 20 Feb 2014 22:42:56 +0100
Subject: Restructure project, make names more clear

---
 src/export/extract_version_2.c | 131 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100644 src/export/extract_version_2.c

(limited to 'src/export/extract_version_2.c')

diff --git a/src/export/extract_version_2.c b/src/export/extract_version_2.c
new file mode 100644
index 0000000..fe85252
--- /dev/null
+++ b/src/export/extract_version_2.c
@@ -0,0 +1,131 @@
+#include <fcntl.h>
+#include "mystdlib.h"
+#include <stdlib.h>
+#include <string.h>
+#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, 0x35, 0x2d, 0x6c };
+
+int main( int args, char **argv )
+{
+  int      filenum = 0, run = 1;
+  size_t   offset = 0, oldoffset = -1, reported = 0, enc_len = 32;
+  uint8_t  mantra[4], id0, id5, *mappedfile;
+  MAP      map;
+
+  /* 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( optind == args  )
+    { fputs( "Missing filename.", stderr ); exit( 1 ); }
+
+  map = map_file( argv[optind], 1 );
+  mappedfile = map->addr;
+
+  mantra[0] = mantra_in[0] ^ mappedfile[4];
+  mantra[1] = mantra_in[1] ^ mappedfile[5];
+  mantra[2] = mantra_in[2] ^ mappedfile[2];
+  mantra[3] = mantra_in[3] ^ mappedfile[3];
+
+  id0 = mappedfile[0];
+  id5 = mappedfile[5];
+
+  while( run )
+  {
+    while( ( offset < map->size ) && (
+           ( 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", offset );
+
+    if( reported < ( offset * 10 ) / map->size )
+    {
+      reported++;
+      printf( "%zd%% ", 10 * reported );
+      fflush( stdout );
+    }
+
+    if( offset == map->size )
+        run = 0;
+
+    if( oldoffset != -1 )
+    {
+        uint8_t *mf = mappedfile + oldoffset, df[128];
+        size_t filename_len, header_len;
+        char filename_template[32], filename[32];
+        int i;
+
+        /* 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] + 2;
+        filename_len = df[21];
+
+        /* Copy rest of header, so we can checksum */
+        for( i=enc_len; i<header_len; ++i)
+           df[i] = mf[i];
+
+        /* 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);
+
+        /* Recalculate checksum with new file name */
+        df[1] = 0; for( i=2; i<header_len; ++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 );
+        if( enc_len > header_len ) {
+            write( i, df, enc_len );
+            write( i, mf + enc_len, offset - oldoffset - enc_len );
+        } else {
+            write( i, df, header_len );
+            write( i, mf + header_len, offset - oldoffset - header_len );
+        }
+        close( i );
+    }
+    oldoffset = offset;
+    offset++;
+  }
+
+  unmap_file( &map );
+  return 0;
+}
-- 
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