matteverson/rsactftool

RSA tool for ctf - retreive private key from weak public key and/or uncipher data

RsaCtfTool

RSA tool for ctf - uncipher data from weak public key and try to recover private key Automatic selection of best attack for the given public key

Attacks :

• Weak public key factorization
• Wiener's attack
• Hastad's attack (Small exponent attack)

Usage:

usage: RsaCtfTool.py [-h] --publickey ./pub.pem [--uncipher ./cipher [--verbose]] [--private]

• publickey : public rsa key to crack
• uncipher : cipher message to decrypt
• private : display private rsa key if recovered

Uncipher file :

./RsaCtfTool.py --publickey ./key.pub --uncipher ./ciphered_file

Print private key :

./RsaCtfTool.py --publickey ./key.pub --private

Examples :

• weak_public.pub, weak_public.cipher : weak public key
• wiener.pub, wiener.cipher : key vulnerable to Wiener's attack
• small\exponent.pub, small_exponent.cipher : key with e=3, vulnerable to Hastad's attack

Requirements:

• GMPY
• libnum (https://github.com/hellman/libnum.git)