8VpTrWk2

1public static void main(String[] args) throws Exception {
2
3    String textA = "";
4    String textB="";
5
6    byte[] thisismykey = "Hello How manyBytes are in@hts A".getBytes();
7    SecretKey secKey = new SecretKeySpec(thisismykey, "AES");
8
9
10    Cipher aesCipher = Cipher.getInstance("AES");
11
12    //turn your original text to byte
13    byte[] myoriginaltexttobyte = "Your Plain Text Here".getBytes();
14    //activate the encrypt method
15    aesCipher.init(Cipher.ENCRYPT_MODE, secKey);
16    //encrypt the text and assign the encrypted text to a byte array
17    byte[] bytecipheredoforgtext = aesCipher.doFinal(myoriginaltexttobyte);
18    //change it to string with new string
19    textA = new String(bytecipheredoforgtext);
20    System.out.println(textA);
21
22    //get the bytes of encrypted text and assign it to a byte array
23    byte[] byteofencryptedtext = textA.getBytes();
24    //activate the decrypt mode of the cipher
25    aesCipher.init(Cipher.DECRYPT_MODE, secKey);
26    //decrypt the encrypted text and assign it to a byte array
27    byte[] byteofencryptedbacktonormaltext = aesCipher.doFinal(byteofencryptedtext);
28    //change it to string with new string
29    textB = new String(byteofencryptedbacktonormaltext);
30    System.out.println(textB);
31}
32	
33public class CipherFinalB {
34
35//from https://stackoverflow.com/questions/20796042/aes-encryption-and-decryption-with-java/20796446#20796446
36private final byte[] thisismykey;
37private final SecretKey secKey;
38private final Cipher aesCipher;
39public CipherFinalB() throws NoSuchPaddingException, NoSuchAlgorithmException {
40    thisismykey = "HellodHowfmanyBytesgarehin@htseA".getBytes();
41    secKey = new SecretKeySpec(thisismykey, "AES");
42
43    aesCipher = Cipher.getInstance("AES");
44
45}public String encrypt (String originaltext) throws InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
46    byte[] myoriginaltexttobyte =originaltext.getBytes();
47    aesCipher.init(Cipher.ENCRYPT_MODE, secKey);
48    byte[] bytecipheredoforgtext = aesCipher.doFinal(myoriginaltexttobyte);
49    String textA = new String(bytecipheredoforgtext);
50    System.out.println(textA);
51    return new String(bytecipheredoforgtext);
52}
53
54public String decrypt (String encryptedtext) throws InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
55    byte[] byteofencryptedtext = encryptedtext.getBytes();
56    aesCipher.init(Cipher.DECRYPT_MODE, secKey);
57    byte[] byteofencryptedbacktonormaltext = aesCipher.doFinal(byteofencryptedtext);
58    return new String(byteofencryptedbacktonormaltext);
59}
60
61}
62	
63Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
64at java.base/com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:936)
65    at java.base/com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:847)
66    at java.base/com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:446)
67    at java.base/javax.crypto.Cipher.doFinal(Cipher.java:2191)
68    at main.CipherFinalB.decrypt(CipherFinalB.java:66)
69    at main.CipherTest.main(CipherTest.java:16)