AES encryption using Java and decryption using Javascript

Question

I am making an application which needs Java based AES Encryption and JavaScript based decryption. I am using the following code for encryption as a basic form.

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Answer 1

1. Your Java code uses the 128-bit AES key while your JavaScript code uses the 256-bit AES key.

2. Your Java code uses the "Abcdefghijklmnop".getBytes() as the actual key value, while your JavaScript code uses the "Abcdefghijklmnop" as the passphrase from which the actual key is derived.

3. The default transformation for Java AES is AES/ECB/PKCS5Padding, while default transformation for CryptoJS is AES/CBC/PKCS7Padding.

One way to fix your example is to fix the JavaScript side:

// this is Base64 representation of the Java counterpart
// byte[] keyValue = new byte[] { 'A', 'b', 'c', 'd', 'e', 'f', 'g',
//                'h', 'i', 'j', 'k','l', 'm', 'n', 'o', 'p'};
// String keyForJS = new BASE64Encoder().encode(keyValue);
var base64Key = "QWJjZGVmZ2hpamtsbW5vcA==";
console.log( "base64Key = " + base64Key );

// this is the actual key as a sequence of bytes
var key = CryptoJS.enc.Base64.parse(base64Key);
console.log( "key = " + key );

// this is the plain text
var plaintText = "Hello, World!";
console.log( "plaintText = " + plaintText );

// this is Base64-encoded encrypted data
var encryptedData = CryptoJS.AES.encrypt(plaintText, key, {
    mode: CryptoJS.mode.ECB,
    padding: CryptoJS.pad.Pkcs7
});
console.log( "encryptedData = " + encryptedData );

// this is the decrypted data as a sequence of bytes
var decryptedData = CryptoJS.AES.decrypt( encryptedData, key, {
    mode: CryptoJS.mode.ECB,
    padding: CryptoJS.pad.Pkcs7
} );
console.log( "decryptedData = " + decryptedData );

// this is the decrypted data as a string
var decryptedText = decryptedData.toString( CryptoJS.enc.Utf8 );
console.log( "decryptedText = " + decryptedText );