AES Encryption in Golang and Decryption in Java

Decrypting AES Encrypted Text in Java

To decrypt the AES encrypted text generated by the Golang function, a Java implementation is required. The Java code below demonstrates the decryption process:

public class AESDecryption {

    public static String decode(String base64Text, byte[] key) throws Exception {
        byte[] inputArr = Base64.getUrlDecoder().decode(base64Text);
        SecretKeySpec skSpec = new SecretKeySpec(key, "AES");
        Cipher cipher = Cipher.getInstance("AES/CFB/NoPadding");
        int blockSize = cipher.getBlockSize();
        IvParameterSpec iv = new IvParameterSpec(Arrays.copyOf(inputArr, blockSize));
        byte[] dataToDecrypt = Arrays.copyOfRange(inputArr, blockSize, inputArr.length);
        cipher.init(Cipher.DECRYPT_MODE, skSpec, iv);
        byte[] result = cipher.doFinal(dataToDecrypt);
        return new String(result, StandardCharsets.UTF_8);
    }

    public static void main(String[] args) {
        try {
            String encryptedText = "c1bpFhxn74yzHQs-vgLcW6E5yL8zJfgceEQgYl0=";
            byte[] key = "0123456789abcdef".getBytes();
            String decryptedText = decode(encryptedText, key);
            System.out.println("Decrypted text: "   decryptedText);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

This Java code should successfully decrypt the encrypted text generated by the Golang function and return the original plaintext.

Scala Version

The Scala version of the decryption code is as follows:

object AESDecryption {

    def decode(input: String, key: String): String = {
        val cipher = Cipher.getInstance("AES/CFB/NoPadding")
        val blockSize = cipher.getBlockSize()
        val keyBytes = key.getBytes()
        val inputArr = Base64.getUrlDecoder().decode(input)
        val skSpec = new SecretKeySpec(keyBytes, "AES")
        val iv = new IvParameterSpec(inputArr.slice(0, blockSize).toArray)
        val dataToDecrypt = inputArr.slice(blockSize, inputArr.size)
        cipher.init(Cipher.DECRYPT_MODE, skSpec, iv)
        new String(cipher.doFinal(dataToDecrypt.toArray))
    }

    def main(args: Array[String]): Unit = {
        val encryptedText = "c1bpFhxn74yzHQs-vgLcW6E5yL8zJfgceEQgYl0="
        val key = "0123456789abcdef"
        val decryptedText = decode(encryptedText, key)
        println("Decrypted text: "   decryptedText)
    }
}

This Scala code will also decrypt the AES encrypted text and print the plaintext.