#!/usr/bin/perl
use strict;
use FileHandle;

my $fn = 'td.elf';
my $fh = FileHandle->new($fn, '+< :raw') or die "$fn: $!";
$fh->binmode(':raw');
my $o1 = 0x21fc73c;
my $inb;
$fh->seek($o1, 0);
$fh->read($inb, 2);
if ($inb eq "\x7e\x0d") {
  print("Chunk#1: patched\n");
  $fh->seek($o1, 0);
  $fh->write("\x90\x90", 2);
} elsif ($inb eq "\x90\x90") {
  print("Chunk#1: already patched\n");
} else {
  printf("Chunk#1: unknown sequence: %02x.%02x\n", unpack("C2", $inb));
}
my $o2 = 0x21fc744;
$fh->seek($o2, 0);
$fh->read($inb, 2);
if ($inb eq "\x75\xb4") {
  print("Chunk#2: patched\n");
  $fh->seek($o2, 0);
  $fh->write("\xEB", 1);
} elsif ($inb eq "\xEB\xb4") {
  print("Chunk#2: already patched\n");
} else {
  printf("Chunk#2: unknown sequence: %02x.%02x\n", unpack("C2", $inb));
}
$fh->close();
__END__
.text:00000000021FC736 loc_21FC736:   ; CODE XREF: ValidateLicense(std::string const&,char *)+B88j
.text:00000000021FC736                 mov     edx, [rcx+10h]
.text:00000000021FC739                 cmp     r12d, edx
.text:00000000021FC73C                 jle     short l_21FC74B_lic_expired
.text:00000000021FC73E                 add     edx, 1
.text:00000000021FC741                 cmp     r12d, edx
.text:00000000021FC744                 jnz     short lc_21FC6FA_lic_ok
.text:00000000021FC746                 cmp     esi, [rcx+0Ch]
.text:00000000021FC749                 jge     short lc_21FC6FA_lic_ok