Show HN: RSA Multi Attacks Tool
GitHub - RsaCtfTool/RsaCtfTool: RSA attack tool (mainly for ctf) - retrieve private key from weak public key and/or uncipher data


RsaCtfTool









This tool is an utility designed to decrypt data from weak public keys and attempt to recover the corresponding private key. Also this tool offers a comprehensive range of attack options, enabling users to apply various strategies to crack the encryption.
The RSA security, at its core, relies on the complexity of the integer factorization problem. This project serves as a valuable resource by combining multiple integer factorization algorithms, effectively enhancing the overall decryption capabilities.
Please note that this tool is primarily intended for educational purposes. It is essential to manage your expectations, as not every key can be broken within a reasonable timeframe. The complexity of the encryption algorithm may present significant challenges.
It is essential to highlight that the tool, exclusively supports the RSA textbook semiprime composite modulus rather than composite multiprimes. This constraint is embedded upstream in the pycrypto library (see TODO). While this limitation exists, the tool still offers a powerful set of features for attacking RSA keys with semiprime composite modulus.
For an advanced integer factorization tool please use msieve, yafu, or cado-nfs.
This tool is meant for educational purposes. For those participating in CTFs, please do the following first:

Learn the basics of RSA math and understand number theory, modular arithmetic, integer factorization and the fundamental theorem of arithmetic.
Read the code in this repository to understand what it does and how it works and suggest improvements by sending pull requests.
Avoid copy-pasting and running the tool without understanding the underlying math, as knowing the math is more valuable than knowing how to run the tool.

We hope this tool enhances your understanding of RSA encryption and serves as a valuable resource for exploring the intricacies of integer factorization. Use it responsibly and within the bounds of applicable laws and regulations.
Attacks provided:


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

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



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

Weak public key factorization
Small q (q < 100,000)
Fermat's factorization for close p and q
Gimmicky Primes method
Past CTF Primes method
Non-RSA key in the form b^x, where b is the prime
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
Londahl
Noveltyprimes
Qicheng
binary polynomial factoring
Euler method
Pollard Rho
Wolfram alpha
Z3 theorem prover
Primorial pm1 gcd
Mersenne Numbers pm1 gcd
Factorial pm1 gcd
Compositorial pm1 gcd
Fermat Numbers gcd
Fibonacci Numbers 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 where P prime > X^Y and Q prime > X^Z
High and Low Bits Equal
Williams p+1
Hart algorithm (similar to Fermat)
Lehmer machine (similar to Fermat)
2PN special form where P is prime > 2 and sqrt(2PN) is close to (Pp + 2q)/2
Kraitchik algorithm (an improvement over Fermat)
Lehman algorithm improvement over Fermat
Carmichael algorithm
Quadratic sieve
Classical part of Shor algorithm
Lucas Numbers gcd
Rapid7 gcd prime dataset



Usage
usage: RsaCtfTool.py [-h] [--publickey PUBLICKEY] [--output OUTPUT] [--timeout TIMEOUT] [--createpub] [--dumpkey] [--ext] [--decryptfile DECRYPTFILE] [--decrypt DECRYPT]
                     [--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,XYXZ,binary_polinomial_factoring,brent,comfact_cn,cube_root,ecm,ecm2,factordb,fermat_numbers_gcd,fibonacci_gcd,highandlowbitsequal,mersenne_pm1_gcd,mersenne_primes,neca,nonRSA,noveltyprimes,pastctfprimes,pisano_period,pollard_p_1,primorial_pm1_gcd,qicheng,roca,siqs,small_crt_exp,smallfraction,smallq,system_primes_gcd,wolframalpha,wiener,boneh_durfee,euler,pollard_rho,williams_pp1,partial_q,partial_d,londahl,z3_solver,dixon,lehmer,fermat,hart,common_factors,common_modulus,same_n_huge_e,hastads,lattice,lehman,carmichael,qs,classical_shor,all} [{SQUFOF,XYXZ,binary_polinomial_factoring,brent,comfact_cn,cube_root,ecm,ecm2,factordb,fermat_numbers_gcd,fibonacci_gcd,highandlowbitsequal,mersenne_pm1_gcd,mersenne_primes,neca,nonRSA,noveltyprimes,pastctfprimes,pisano_period,pollard_p_1,primorial_pm1_gcd,qicheng,roca,siqs,small_crt_exp,smallfraction,smallq,system_primes_gcd,wolframalpha,wiener,boneh_durfee,euler,pollard_rho,williams_pp1,partial_q,partial_d,londahl,z3_solver,dixon,lehmer,fermat,hart,common_factors,common_modulus,same_n_huge_e,hastads,lattice,lehman,carmichael,qs,classical_shor,factorial_pm1_gcd,lucas_gcd,all} ...]]
                     [--sendtofdb] [--isconspicuous] [--isroca] [--convert_idrsa_pub] [--check_publickey] [--partial]
Mode 1 : Attack RSA (specify --publickey or n and e)

publickey : public rsa key to crack. You can import multiple public keys with wildcards.
decrypt : 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

Decrypt file
./RsaCtfTool.py --publickey ./key.pub --decryptfile ./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
Optionally 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 the test.sh file
Attack private keys with partial bits of Q known
./RsaCtfTool.py --attack partial_q --key examples/masked.pem
Attack private keys with partial bits of D known
./RsaCtfTool.py --attack partial_d --key examples/partial_d.pem
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 build -t rsactftool/rsactftool .
docker run -it --rm -v $PWD:/data rsactftool/rsactftool <arguments>
Virtual environment run
Setup the venv
virtualenv venv
source venv/bin/activate
pip3 install -r requirements.txt
Run
source venv/bin/activate
./RsaCtfTool.py <arguments>
Requirements

python3.9
GMPY2
PyCrypto
Requests
Libnum
SageMath : optional but advisable
Sage binaries

Ubuntu 18.04 and Kali specific Instructions
git clone https://github.com/RsaCtfTool/RsaCtfTool.git
sudo apt-get install libgmp3-dev libmpc-dev
cd RsaCtfTool
pip3 install -r "requirements.txt"
./RsaCtfTool.py
Fedora (33 and above) specific Instructions
git clone https://github.com/RsaCtfTool/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"
./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 the environment, the following command may work.
easy_install `cat requirements.txt` 
If you installed gmpy2 with homebrew(brew install gmp), you might have to point clang towards the header files with this command:
CFLAGS=-I/opt/homebrew/include LDFLAGS=-L/opt/homebrew/lib pip3 install -r requirements.txt
Optional to factor roca keys upto 512 bits, Install neca:
You can follow the instructions at : https://www.mersenneforum.org/showthread.php?t=23087
TODO (aka. Help wanted !)

Implement a test method for each attack.
Assign the correct algorithm complexity in Big O notation for each attack.
Support multiprime RSA, the project currently supports textbook RSA.
Wanted feature: Ransomware decrypter.

Contributing

Please read the CONTRIBUTING.md guideline for the bare minimum acceptable PRs.
Also please read the CODE_OF_CONDUCT.md, any contribution of any user not honoring it will ignored and the user blocked, good manners are paramount.

Thanks to all our Contributors

  

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