Is there any sample Java code that does AES encryption exactly like this website?

Question

http://www.hanewin.net/encrypt/aes/aes-test.htm

If you go to this website and enter the following:

"Key In Hex":        00000000000000000000000000123456

"Plain Text in Hex": 00000000000000000000000000000000

And click on "Encrypt" button you will see the ciphertext in hex is:

3fa9f2a6e4c2b440fb6f676076a8ba04

Is there a Java program out there that I can do this (I.e. Is there an AES library that will input the "Key In Hex" above with the "Plain Text In Hex" above and generate the Ciphertext in Hex above? )?

I would appreciate any advice or links to Java sample code that does this.

http://stackoverflow.com/questions/992019/java-256-bit-aes-password-based-encryption see if this helps — Ashwin, Oct 27 '12 at 18:16
http://docs.oracle.com/javase/6/docs/technotes/guides/security/crypto/CryptoSpec.html#BlowKeyEx Although this example uses Blowfish. — ignis, Oct 27 '12 at 18:17
Thanks for the input guys, but I"m still not clear how the code would look like. — user1068636, Oct 27 '12 at 18:29
It's important to note that this mode should not be used in practice since it has weak security properties. — CodesInChaos, Oct 27 '12 at 21:03

score 12 · Accepted Answer · answered Oct 27 '12 at 20:06

See the code below for the standard way to do this with JCE classes.

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;

public class EncryptionExample {

  public static void main(String[] args) throws Exception {
    final String keyHex = "00000000000000000000000000123456";
    final String plaintextHex = "00000000000000000000000000000000";

    SecretKey key = new SecretKeySpec(DatatypeConverter
        .parseHexBinary(keyHex), "AES");

    Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding");
    cipher.init(Cipher.ENCRYPT_MODE, key);

    byte[] result = cipher.doFinal(DatatypeConverter
        .parseHexBinary(plaintextHex));

    System.out.println(DatatypeConverter.printHexBinary(result));
  }
}

Prints:

3FA9F2A6E4C2B440FB6F676076A8BA04

ECB (Electronic Codebook) block mode should not be used unless you only encrypt data smaller than 128 bit See https://proandroiddev.com/security-best-practices-symmetric-encryption-with-aes-in-java-7616beaaade9 for a nice example CBC or CTR is better option — long, Sep 01 '20 at 12:06

score 0 · Answer 2 · answered Mar 17 '14 at 02:20

instead of converting bytes to HEX, you may convert to Base64 as well. I like using Apache Commons for this. Here is an example.

To compile you need additional Apache Commons Codec jar, which is available here:

http://commons.apache.org/proper/commons-codec/download_codec.cgi

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

public class Encryptor {
    public static String encrypt(String key1, String key2, String value) {
        try {
            IvParameterSpec iv = new IvParameterSpec(key2.getBytes("UTF-8"));

            SecretKeySpec skeySpec = new SecretKeySpec(key1.getBytes("UTF-8"),
                    "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
            byte[] encrypted = cipher.doFinal(value.getBytes());
            System.out.println("encrypted string:"
                    + Base64.encodeBase64String(encrypted));
            return Base64.encodeBase64String(encrypted);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    public static String decrypt(String key1, String key2, String encrypted) {
        try {
            IvParameterSpec iv = new IvParameterSpec(key2.getBytes("UTF-8"));

            SecretKeySpec skeySpec = new SecretKeySpec(key1.getBytes("UTF-8"),
                    "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
            byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));

            return new String(original);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    public static void main(String[] args) {

        String key1 = "Bar12345Bar12345"; // 128 bit key
        String key2 = "ThisIsASecretKet";
        System.out.println(decrypt(key1, key2,
                encrypt(key1, key2, "Hello World")));
    }
}

Is there any sample Java code that does AES encryption exactly like this website?

2 Answers2

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