Java-String-Encryptor-Decryptor/index.html at master · Jumman04/Java-String-Encryptor-Decryptor · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Java Code Generator</title>

<link rel="stylesheet"
href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/default.min.css">

<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/languages/java.min.js"></script>

<style>
body{
    margin:0;
    padding:20px;
    font-family:Arial,sans-serif;
}
pre{
    white-space:pre-wrap;
    word-wrap:break-word;
}
</style>
</head>
<body>

<pre><code id="code" class="language-java"></code></pre>

<script>

function shiftChars(input, shift){
    let output = "";
    for(let i = 0; i < input.length; i++){
        output += String.fromCharCode(
            input.charCodeAt(i) + shift
        );
    }
    return output;
}

function randomBase64Key(){
    const bytes = new Uint8Array(16);
    crypto.getRandomValues(bytes);

    let binary = "";
    bytes.forEach(b => binary += String.fromCharCode(b));

    return btoa(binary).replace(/=/g,"");
}

function getParam(name){
    return new URLSearchParams(location.search).get(name);
}

const string = getParam("string");
const code = document.getElementById("code");

if(!string){

    const currentUrl =
        location.origin +
        location.pathname;

    code.textContent =
`Exception in thread "main" java.lang.IllegalStateException: string must not be null
    at com.jummania.link.Main.main(Main.java:10)

Usage: ${currentUrl}?string=your_encrypted_text_here`;

}else{

    const base64Key = randomBase64Key();
    const encKeyChars = shiftChars(base64Key, 1);

    const shiftedEnc =
        shiftChars(
            btoa(string).replace(/=/g,""),
            -1
        );

    const created =
        new Date().toLocaleDateString();

    code.textContent =
`public class Jummania {

    public String getString() throws Exception {
        return getString("${encKeyChars}", "${shiftedEnc}");
    }

    private String getString(
            String secretKey,
            String encryptedText
    ) throws Exception {

        String string =
                shiftChars(encryptedText, 1);

        byte[] encryptedTextByte =
                java.util.Base64
                        .getDecoder()
                        .decode(string);

        javax.crypto.Cipher cipher =
                javax.crypto.Cipher
                        .getInstance("AES");

        cipher.init(
                javax.crypto.Cipher.DECRYPT_MODE,
                getSecretKey(secretKey)
        );

        return new String(
                cipher.doFinal(encryptedTextByte)
        );
    }

    private javax.crypto.SecretKey
    getSecretKey(String key){

        String string =
                shiftChars(key, -1);

        byte[] decodedKey =
                java.util.Base64
                        .getDecoder()
                        .decode(string);

        return new javax.crypto.spec.SecretKeySpec(
                decodedKey,
                0,
                decodedKey.length,
                "AES"
        );
    }

    private String shiftChars(
            String input,
            int shift
    ){
        StringBuilder result =
                new StringBuilder();

        for(char c : input.toCharArray()){
            result.append(
                    (char)(c + shift)
            );
        }

        return result.toString();
    }
}`;
}

hljs.highlightAll();

</script>

</body>
</html>