hashcat-reverse-rules-js

The library is used to reverse the password based on hashcat rules. Given a final password and one or more Hashcat rules, the library generates candidate inputs that - when the rules are applied - produce that final password.

Password123 ---- > Password, $1$2$3

This is useful for improving wordlists, narrowing down candidate inputs, and for research into rule-based password transformations. For background on rules and rule syntax, see the Hashcat wiki.

Installation

npm install hashcat-reverse-rules-js

Compiles and minifies for production

npm run build

Usage

applyReverseRule

function applyReverseRule(password, rule, memlimit=65000, limit=10)

Generate possible input candidates that would become a password after applying the rule.

The applyReverseRule function takes the following options:

• password (required): The password to which the rules will be applied.
• rule (required): Rules compatible with the Hashcat rules engine.
• memlimit (optional): Maximum memory (or total candidates) to allow while generating results. Defaults to 65000.
• limit(optional): Max candidates produced by a single part of a multi-part rule. Defaults to 10.

The reverseRule function returns an array of strings (candidates) that will generate the initial password with specific rules. If no candidates could be generated, the empty[] array will be returned.

import reverse from 'hashcat-reverse-rules-js';

console.log(reverse.applyReverseRule('password', 'l'));
/*
[
  'PASSWORD', 'Password',
  'pASSWORD', 'PAssword',
  'PASSWOrd', 'PASSWord',
  'PASsword', 'PASSWORd',
  'PASSword'
]
*/

reversePassword

Try to deduce likely candidate inputs and the rules that could produce the given password.

function reversePassword(string, withRules=false)

The reversePassword function takes the following options:

• string (required): The password to which the rules will be applied.
• withRules (required): output the rules for the candidate

An array of candidate strings, or an array of objects when withRules is true (each object contains the candidate and the rule(s) that produced it). If no candidates are found, returns an empty array [].

console.log(hashcat.reversePassword("P@assword123"));

[
  'P@assword12',
  'P@assword1',
  'P@assword',
  'p@assword123',
  'p@assword12',
  'p@assword1',
  'p@assword'
]

Supported rules

Name	Function	Description	Example Rule	Input Word	Output Word
Nothing	:	Do nothing (passthrough)	:	p@ssW0rd	p@ssW0rd
Lowercase	l	Lowercase all letters	l	p@ssW0rd	p@ssw0rd
Uppercase	u	Uppercase all letters	u	p@ssW0rd	P@SSW0RD
Capitalize	c	Capitalize the first letter and lower the rest	c	p@ssW0rd	P@ssw0rd
Invert Capitalize	C	Lowercase first found character, uppercase the rest	C	p@ssW0rd	p@SSW0RD
Toggle Case	t	Toggle the case of all characters in word.	t	p@ssW0rd	P@SSw0RD
Toggle @	TN	Toggle the case of characters at position N	T3	p@ssW0rd	p@sSW0rd
Reverse	r	Reverse the entire word	r	p@ssW0rd	dr0Wss@p
Duplicate	d	Duplicate entire word	d	p@ssW0rd	p@ssW0rdp@ssW0rd
Duplicate N	pN	Append duplicated word N times	p2	p@ssW0rd	p@ssW0rdp@ssW0rdp@ssW0rd
Reflect	f	Duplicate word reversed	f	p@ssW0rd	p@ssW0rddr0Wss@p
Rotate Left	{	Rotate the word left.	{	p@ssW0rd	@ssW0rdp
Rotate Right	}	Rotate the word right	}	p@ssW0rd	dp@ssW0r
Append Character	$X	Append character X to end	$1	p@ssW0rd	p@ssW0rd1
Prepend Character	^X	Prepend character X to front	^1	p@ssW0rd	1p@ssW0rd
Truncate left	[	Delete first character	[	p@ssW0rd	@ssW0rd
Trucate right	]	Delete last character	]	p@ssW0rd	p@assW0r
Delete @ N	DN	Delete character at position N	D3	p@ssW0rd	p@sW0rd
Extract range	xNM	Extract M characters, starting at position N	x04	p@ssW0rd	p@ss
Omit range	ONM	Delete M characters, starting at position N	O12	p@ssW0rd	psW0rd
Insert @ N	iNX	Insert character X at position N	i4!	p@ssW0rd	p@ss!W0rd
Overwrite @ N	oNX	Overwrite character at position N with X	o3$	p@ssW0rd	p@s$W0rd
Truncate @ N	'N	Truncate word at position N	'6	p@ssW0rd	p@ssW0
Replace	sXY	Replace all instances of X with Y	ss$	p@ssW0rd	p@$$W0rd
Purge	@X	Purge all instances of X	@s	p@ssW0rd	p@W0rd
Duplicate first N	zN	Duplicate first character N times	z2	p@ssW0rd	ppp@ssW0rd
Duplicate last N	ZN	Duplicate last character N times	Z2	p@ssW0rd	p@ssW0rddd
Duplicate all	q	Duplicate every character	q	p@ssW0rd	pp@@ssssWW00rrdd
Swap front	k	Swap first two characters	k	p@ssW0rd	@pssW0rd
Swap back	K	Swap last two characters	K	p@ssW0rd	p@ssW0dr
Swap @ N	*NM	Swap character at position N with character at position M	*34	p@ssW0rd	p@sWs0rd
Bitwise shift left	LN	Bitwise shift left character @ N	L2	p@ssW0rd	p@æsW0rd
Bitwise shift right	RN	Bitwise shift right character @ N	R2	p@ssW0rd	p@9sW0rd
ASCII increment	+N	Increment character @ N by 1 ascii value	+2	p@ssW0rd	p@tsW0rd
ASCII decrement	-N	Decrement character @ N by 1 ascii value	-1	p@ssW0rd	p?ssW0rd
Replace N + 1	.N	Replace character @ N with value at @ N plus 1	.1	p@ssW0rd	psssW0rd
Replace N - 1	,N	Replace character @ N with value at @ N minus 1	,1	p@ssW0rd	ppssW0rd
Duplicate block front	yN	Duplicate first N characters	y2	p@ssW0rd	p@p@ssW0rd
Duplicate block back	YN	Duplicate last N characters	Y2	p@ssW0rd	p@ssW0rdrd
Title	E	Lower case the whole line, then upper case the first letter and every letter after a space	E	p@ssW0rd	P@ssw0rd W0rld
Title w/separator	e	Lower case the whole line, then upper case the first letter and every letter after a custom separator character	e-	p@ssW0rd	P@ssw0rd-W0rld