iagox86/hash_extender

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

1211 stars · 194 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

A C command-line tool that automates hash length extension attacks against algorithms like MD4, MD5, SHA-1, SHA-256, SHA-512, RIPEMD-160, and WHIRLPOOL. It lets an attacker forge valid hashes for data appended to a string whose hash uses an unknown secret prefix.

Use cases

• perform a hash length extension attack
• forge a signature when a secret is prepended to hashed data
• test whether an application is vulnerable to length extension attacks
• solve CTF challenges involving hash extension
• generate valid hashes for appended data without knowing the secret key
• demonstrate weaknesses in MD5/SHA1-based MAC schemes

When to choose

• you need a ready-made, multi-algorithm tool for length extension attacks
• you're doing security research, penetration testing, or CTF challenges
• you want a small, dependency-free C tool

When to avoid

• you need to hash data normally rather than forge extension hashes
• the target uses HMAC or length-extension-resistant algorithms like SHA-224/384 or SHA-3
• you need a library API rather than a command-line tool

Facets

cli-tool · maturity maintenance

security cryptography cli developer-tools security penetration-testing windows cli cpp hash-length-extension-attack md5 sha1 sha256 sha512 ctf offensive-security c cryptography linux macos

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