xorDecrypt.js

xorDecrypt.js

function xorDecrypt(cipherText, hexKey) {
    // Convert the hexadecimal key to a byte array
    let key = hexKey.match(/.{1,2}/g).map(byte => parseInt(byte, 16));
    
    // Decode the base64 encoded cipher text to a byte array
    let cipherBytes = atob(cipherText).split('').map(char => char.charCodeAt(0));
    
    // XOR decryption
    let plainBytes = cipherBytes.map((byte, index) => byte ^ key[index % key.length]);
    
    // Convert the byte array to a string
    let plainText = String.fromCharCode.apply(null, plainBytes);
    
    return plainText;
}

// Example usage
let cipherText = 'U29tZUVuY3J5cHRlZERhdGE='; // base64 encoded XOR encrypted text
let hexKey = '1a2b3c4d'; // hexadecimal key
let decryptedText = xorDecrypt(cipherText, hexKey);
console.log(decryptedText);