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/** |
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* Under Attack mode - Proof of Work challenge solver |
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* |
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* Reads challenge parameters from the form data attributes |
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* and solves the SHA-256 proof-of-work before auto-submitting. |
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* |
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* @package Vigilante |
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*/ |
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(function() { |
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'use strict'; |
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|
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var form = document.getElementById( 'ua-form' ); |
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if ( ! form ) { |
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return; |
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} |
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|
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var nonce = form.getAttribute( 'data-nonce' ); |
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var difficulty = parseInt( form.getAttribute( 'data-difficulty' ), 10 ); |
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|
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if ( ! nonce || ! difficulty ) { |
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return; |
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} |
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|
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var prefix = ''; |
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for ( var p = 0; p < difficulty; p++ ) { |
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prefix += '0'; |
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} |
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|
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/** |
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* Find a valid proof-of-work solution using SubtleCrypto SHA-256 |
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*/ |
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async function findSolution() { |
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var encoder = new TextEncoder(); |
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var c = 0; |
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|
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while ( true ) { |
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var attempt = c.toString( 36 ); |
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var data = encoder.encode( nonce + attempt ); |
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var hashBuffer = await crypto.subtle.digest( 'SHA-256', data ); |
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var hashArray = new Uint8Array( hashBuffer ); |
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var hex = ''; |
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|
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for ( var j = 0; j < hashArray.length; j++ ) { |
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hex += ( '0' + hashArray[j].toString( 16 ) ).slice( -2 ); |
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} |
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|
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if ( hex.substring( 0, difficulty ) === prefix ) { |
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document.getElementById( 'ua-response' ).value = attempt; |
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form.submit(); |
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return; |
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} |
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|
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c++; |
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|
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// Yield every 1000 iterations to keep UI responsive |
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if ( c % 1000 === 0 ) { |
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await new Promise( function( r ) { setTimeout( r, 0 ); } ); |
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} |
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} |
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} |
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|
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// Start after a small delay for visual feedback |
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setTimeout( findSolution, 500 ); |
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})(); |
