dldkey is a tool that shipped with a relatively obscure Linux distribution in 1993/1994 called Deutsche Linux Distribution (DLD). The utility was used by the install script to install commercial software. The software was encrypted and dldkey was used to decrypt the contents of the encrypted tar.gz file as it installed.

The purpose of this repo is to reverse engineer dldkey and determine the install key used or write a replacement dldkey utility that doesn't need a key. The code in this repo may not necessarily be very high quality since we are attempting to match the original binary (where it makes sense) using reverse engineering techniques. Since the tool was staticly linked with the C library at the time, the tool developed here will not be byte for byte compatible with the original binary.

Use gdb, set a breakpoint at 0x564 (main)

b *0x564
disassemble 0x564 0x570
info registers

ndisasm may also work but you may need to subtract 0x400 from all calls/addresses.

ndisasm -b 32 -k 0x400,0 dldkey