JtR_cheatsheet.md

John the Ripper Cheatsheet

John the Ripper, often called "John," is an open-source and highly flexible password-cracking tool. It supports multiple algorithms and is available on both Windows and Linux.

Table of Contents

• Dictionary Attacks
• Brute Force Attacks
• Tips & Additional Commands

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Dictionary Attacks

Basic Dictionary Attack

john --wordlist=dictionary.txt hashfile

• wordlist: This option specifies the dictionary file you'd like to use.

Example:

john --wordlist=passwords.txt hashes.txt

With Rules

john --wordlist=dictionary.txt --rules hashfile

• -rules: This enables John's wordlist rules. You can also specify your own rules.

Example:

john --wordlist=words.txt --rules=best64.rule hashes.txt

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Brute Force Attacks

Basic Brute Force

john --incremental hashfile 

Example:

john --incremental hashes.txt

Specify Charset

john --incremental=Digits hashfile

• Here, you can define custom charsets like Digits, Alpha, AlphaNum, etc.

Brute Force with Custom Charset

john --incremental=Custom --mask='?a?a?a?a' hashfile

Example:

john --incremental=Custom --mask='?a?a?a?a?a' hashes.txt

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Tips & Additional Commands

• Resume Cracking: Use john --restore to resume cracking.
• Show Cracked Passwords: Run john --show hashfile to display cracked passwords.
• List Supported Formats: Use john --list=formats to see all supported hash formats.
• Performance Tuning: Use -fork=N to distribute the task over multiple processes.
• Verbose Mode: Add vv for a detailed output.
• GPU Acceleration: Versions like John the Ripper Pro support GPU acceleration with -device=opencl.
• Manual Page: Check man john for a complete list of options.

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