Crypto JS decrypt in Java

 

To decrypt data that was encrypted using CryptoJS in JavaScript in Java, you can use the following steps:

1). Make sure you have the necessary dependencies installed. You will need to include the org.bouncycastle library in your project. You can do this by adding the following dependency to your build.gradle file:

dependencies {

  implementation 'org.bouncycastle:bcypt-jdk15on:1.64'

}

2). Use the CryptoJS.AES.decrypt function in JavaScript to decrypt the data. This function takes two arguments: the encrypted data and the encryption key.

var decrypted = CryptoJS.AES.decrypt(encryptedData, encryptionKey);

3). Convert the decrypted data from a CryptoJS.lib.WordArray object to a Java byte[] array. You can do this using the decrypted. words and decrypted.sigBytes properties of the WordArray object:

byte[] decryptedBytes = new byte[decrypted.sigBytes];

for (int i = 0; i < decrypted.sigBytes; i++) {

  decryptedBytes[i] = (byte) (decrypted.words[i >>> 2] >>> (24 - (i % 4) * 8));

}

4).Use the Java SecretKeySpec and Cipher classes to decrypt the byte[] array using the AES algorithm.

SecretKeySpec keySpec = new SecretKeySpec(key, "AES");

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

cipher.init(Cipher.DECRYPT_MODE, keySpec);

byte[] decryptedData = cipher.doFinal(decryptedBytes);

That's it! You should now have the decrypted data in the decryptedData byte[] array.

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