keep current position in card dump in $pos

diff --git a/mifare-mad.pl b/mifare-mad.pl
index 44c3af8..dd28516 100755 (executable)
--- a/mifare-mad.pl
+++ b/mifare-mad.pl
@@ -52,15 +52,16 @@ foreach my $i ( 0 .. 15 ) {
                , $mad_id->{$full_id} || "FIXME: add $full_id from MAD_overview.pdf to __DATA__ at end of $0"
                ;
 
+       my $pos = 0x40 * $i;
        foreach my $j ( 0 .. 3 ) {
-               my $offset = 0x40 * $i + $j * 0x10;
+               my $offset = $pos + $j * 0x10;
                my $block = substr($card, $offset, 0x10);
                printf "%04x %s\n", $offset, unpack('H*',$block);
        }
 
        if ( $v == 0x0004 ) {
                # RLE encoded card holder information
-               my $data = substr( $card, 0x40 * $i, 0x30);
+               my $data = substr( $card, $pos, 0x30);
                my $o = 0;
                my $types = {
                        0b00 => 'surname',