Cytro - 解决CTF加密挑战的工具。

项目说明

Crypto Tools For CTF

![GitHub]()

In this project, I integrate some source code made by myself and collected from other great write-ups, blogs, and projects, also reimplementing to keep the project structure neat.

I always use those methods to sol problem and put new attack or method after the CTF, hoping this project will bring help for other CTF players.

It's still incomplete for now. Pull requests are always welcome.

cytro.RSA

Here provides some factorize formula to factor large RSA modulus and some common RSA attacks.

Redundant Work

* RSAKey((n, e, d)) - Same as Crypto.PublicKey.RSA added some lazy functions. d is optional, determine is pubkey or privkey
* encrypt(m) - return the encryption of message
* decrypt(c) - return the decryption of cipher
* load_pem(pem) - Read Key by String
* load_file(key.pem) - Read Key by file path
* cal_private(e, p, q) - return the decrypt exponent

* sol(remainders, modules) - sol Remainder Theoreme
* factordb(n) - API for getting well-known prime in FactorDB

Factorization Method

* gcd_multiple_keys(keys) - GCD for Multiple keys
* factordb(n) - Check the prime is factorize in FactorDB or not
* fermat_factorization(n) - Fermat Factorization
* wiener(n, e) - Wiener Attack
* boneh_durfee(n, e) - Boneh Durfee Attack
* williams_pp1(n) - Williams p+1 Attack
* pollard_rho(n) - Pollards-Rho
* pollard_pm1(n) - Pollards P-1 (Go through every primes)
* pollard_brute(n) - Pollards P-1 (Go through every integer)

RSA Specific Methods

* Partial Key Recovery for n/2 bits of the private key
* Chinese Remainder Theorem full private key recovery

Decoding despite invalid Public Exponent

Low Public Exponent

* hastad_broadcast(c, N) - Hastad's Broadcast Attack
* common_modular(set1, set2) - Common Modulus, Common public Exponent [set:(N, e, c)]
* franklin_reiter(n, e, c1, c2, r, a=1) - Franklin Reiter Related Message Attack :

Information LOSS : (TODO)

* coppersmith - Coppersmith Attack
* coppersmith_shortpad - Coppersmith Shortpad Attack
* partial_m() - Known Partial bits of m, recover.
* partial_p() - Known Partial bits of p, recover.
* partial_d() - Known Partial bits of d, recover.
* reco() - Known Partial bits of d, recover.

Forge Signature

* bleichenbacher_06 - Attack on (e=3) python-rsa signature.

Others

* no(n)
* smallq(n)
* smallfraction(n)
* mersenne_primes(n)

cytro.DSA

* Biased-K Attack

cytro.CBC

* Bit-flipping attack
* Padding Oracle
* POODLE Attack

项目信息

开发语言：Python

Star 数：101

技术要点

该项目属于CTF思路方向的开源资源，代码结构清晰，适合安全研究人员学习参考。项目围绕Tools to solve CTF crypto challenge.展开，提供了可运行的实现，对理解相关安全机制、工具原理与攻防技术具有较高的研究价值。

从技术实现角度看，此类项目的核心在于对底层原理的深入理解与工程化落地。开发者在研究过程中可以结合官方文档与社区讨论，梳理项目的初始化流程、核心模块职责与数据流转，逐步掌握其中的技术细节与设计思路。

使用与学习建议

1. 下载源码压缩包，解压到本地环境。

2. 根据项目类型准备对应的运行环境与依赖。

3. 按照 README 中的步骤完成配置与部署。

4. 在隔离的测试环境中运行验证，避免影响生产系统。

免责声明

本资源来源于开源社区，仅供安全研究、技术学习与合法授权范围内的攻防演练使用，请勿用于任何非法或侵害他人权益的用途。使用本项目产生的一切后果由使用者自行承担。