flare-on-dudelocker-decryptor

This repo contains the decryptor for the Flare-On 2016 challenge 2 "Dudelocker". Important note must be read in dec.cpp to adjust code in case the decryptor doesn't work for your file.
There's also an encryptor just for fun (:

compiling

using g++:

g++ -fpermissive -Wwrite-strings .\dec.cpp -o .\dec.exe -w

example usage:

.\dec.exe ".\SampleFiles\BusinessPapers.doc" "output.jpg" "businesspapers.doc"

where

• ".\SampleFiles\BusinessPapers.doc" is path of the encrypted source file
• "output.jpg" is the path of the result of the decryption
• "businesspapers.doc" is the plaintext initialization vector used in the MD5 hashing. For this challenge, it's always the filename + extension in lowercase.