RsaCtfTool

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

Attacks :

• Attacks that doesn't depend on the factorization of integers (may depend on knowing n,e,cyphertext,etc...):

  • Wiener's attack
  • Hastad's attack (Small public exponent attack)
  • Boneh Durfee Method when the private exponent d is too small compared to the modulus (i.e d < n^0.292)
  • Londahl
  • Same n, huge e
  • Small crt exponent
  • Common factor between ciphertext and modulus attack
  • Partial q

• Strict Integer factorization methods (only depends on knowing n):

  • Weak public key factorization
  • Small q (q < 100,000)
  • Fermat's factorisation for close p and q
  • Gimmicky Primes method
  • Past CTF Primes method
  • Non RSA key in the form b^x, where b is prime
  • Self-Initializing Quadratic Sieve (SIQS) using Yafu (https://github.com/DarkenCode/yafu.git)
  • Common factor attacks across multiple keys
  • Small fractions method when p/q is close to a small fraction
  • Elliptic Curve Method
  • Pollards p-1 for relatively smooth numbers
  • Mersenne primes factorization
  • Factordb
  • Noveltyprimes
  • Primefac
  • Qicheng
  • binary polynomial factoring
  • Euler method
  • Pollard Rho
  • Wolfram alpha
  • cm-factor
  • z3 theorem prover
  • Primorial pm1 gcd
  • Mersenne pm1 gcd
  • Fermat Numbers gcd
  • Fibonacci gcd
  • System primes gcd
  • Shanks's square forms factorization (SQUFOF)
  • Return of Coppersmith's attack (ROCA) with NECA variant
  • Dixon
  • brent (Pollard rho variant)
  • Pisano Period
  • XYXZ form integer factorization
  • High and Low Bits Equal attack

Usage

usage: RsaCtfTool.py [-h] [--publickey PUBLICKEY] [--output OUTPUT] [--timeout TIMEOUT] [--createpub] [--dumpkey] [--ext] [--uncipherfile UNCIPHERFILE] [--uncipher UNCIPHER]
                     [--verbosity {CRITICAL,ERROR,WARNING,DEBUG,INFO}] [--private] [--tests] [--ecmdigits ECMDIGITS] [-n N] [-p P] [-q Q] [-e E] [--key KEY]
                     [--password PASSWORD] [--show-factors SHOW_FACTORS]
                     [--attack {SQUFOF,binary_polinomial_factoring,boneh_durfee,brent,cm_factor,comfact_cn,cube_root,dixon,ecm,ecm2,euler,factordb,fermat,fermat_numbers_gcd,fibonacci_gcd,londahl,mersenne_pm1_gcd,mersenne_primes,neca,nonRSA,noveltyprimes,partial_q,pastctfprimes,pisano_period,pollard_p_1,pollard_rho,primorial_pm1_gcd,qicheng,roca,siqs,small_crt_exp,smallfraction,smallq,system_primes_gcd,wiener,wolframalpha,z3_solver,XYXZ,highandlowbitsequal,common_factors,common_modulus,hastads,same_n_huge_e,all} [{SQUFOF,binary_polinomial_factoring,boneh_durfee,brent,cm_factor,comfact_cn,cube_root,dixon,ecm,ecm2,euler,factordb,fermat,fermat_numbers_gcd,fibonacci_gcd,londahl,mersenne_pm1_gcd,mersenne_primes,neca,nonRSA,noveltyprimes,partial_q,pastctfprimes,pisano_period,pollard_p_1,pollard_rho,primorial_pm1_gcd,qicheng,roca,siqs,small_crt_exp,smallfraction,smallq,system_primes_gcd,wiener,wolframalpha,z3_solver,XYXZ,highandlowbitsequal,common_factors,common_modulus,hastads,same_n_huge_e,all} ...]]
                     [--sendtofdb] [--isconspicuous] [--isroca] [--convert_idrsa_pub] [--check_publickey]

Mode 1 : Attack RSA (specify --publickey or n and e)

• publickey : public rsa key to crack. You can import multiple public keys with wildcards.
• uncipher : cipher message to decrypt
• private : display private rsa key if recovered

Mode 2 : Create a Public Key File Given n and e (specify --createpub)

• n : modulus
• e : public exponent

Mode 3 : Dump the public and/or private numbers (optionally including CRT parameters in extended mode) from a PEM/DER format public or private key (specify --dumpkey)

• key : the public or private key in PEM or DER format

Uncipher file

./RsaCtfTool.py --publickey ./key.pub --uncipherfile ./ciphered\_file

Print private key

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

Attempt to break multiple public keys with common factor attacks or individually- use quotes around wildcards to stop bash expansion

./RsaCtfTool.py --publickey "*.pub" --private

Optionaly send the results back to factordb

./RsaCtfTool.py --publickey "*.pub" --private --sendtofdb

Generate a public key

./RsaCtfTool.py --createpub -n 7828374823761928712873129873981723...12837182 -e 65537

Dump the parameters from a key

./RsaCtfTool.py --dumpkey --key ./key.pub

Check a given private key for conspicuousness

./RsaCtfTool.py --key examples/conspicuous.priv --isconspicuous

Factor with ECM when you know the approximate length in digits of a prime

./RsaCtfTool.py --publickey key.pub --ecmdigits 25 --verbose --private

For more examples, look at test.sh file

Convert idrsa.pub to pem format

./RsaCtfTool.py --convert_idrsa_pub --publickey $HOME/.ssh/id_rsa.pub

Check if a given key or keys are roca

./RsaCtfTool.py --isroca --publickey "examples/*.pub"

Docker run

docker pull ganapati/rsactftool docker run -it --rm -v $PWD:/data ganapati/rsactftool <arguments>

Requirements

• GMPY2
• SymPy
• PyCrypto
• Requests
• Libnum
• SageMath : optional but advisable
• Sage binaries

Ubuntu 18.04 and Kali specific Instructions

git clone https://github.com/Ganapati/RsaCtfTool.git
sudo apt-get install libgmp3-dev libmpc-dev
cd RsaCtfTool
pip3 install -r "requirements.txt"
python3 RsaCtfTool.py

Fedora (33 and above) specific Instructions

git clone https://github.com/Ganapati/RsaCtfTool.git
sudo dnf install gcc python3-devel python3-pip python3-wheel gmp-devel mpfr-devel libmpc-devel
cd RsaCtfTool
pip3 install -r "requirements.txt"
python3 RsaCtfTool.py

If you also want the optional SageMath you need to do

sudo dnf install sagemath
pip3 install -r "optional-requirements.txt"

MacOS-specific Instructions

If pip3 install -r "requirements.txt" fails to install requirements accessible within environment, the following command may work.

easy_install `cat requirements.txt`

Optional to factor roca keys upto 512 bits, Install neca:

You can follow instructions from : https://www.mersenneforum.org/showthread.php?t=23087

Todo (aka. Help wanted !)

• Implement test method in each attack.
• Assign the correct algorithm complexity in Big O notation for each attack.
• Support multiprime RSA, the project currently supports textbook RSA.

Contributing

• Please read the CONTRIBUTING.md guideline for the bare minimum aceptable PRs.