San Song Daddy :): How to do AES encryption&decryption in java?

How to do AES encryption&decryption in java?

By Errong Leng – 27 Apr 2023 – View online →

Photo by Museum of New Zealand - Te Papa Tongarewa / Unsplash

show you the code:



	@Override
	public String aesEncrypt(String input) {
	try {
	Cipher cipher = Cipher.getInstance(aliasAlgorithm);
	cipher.init(Cipher.ENCRYPT_MODE,
	new SecretKeySpec(Base64.getDecoder().decode(aliasKey), "AES"),
	new IvParameterSpec(Base64.getDecoder().decode(aliasIv)));
	byte[] cipherText = cipher.doFinal(input.getBytes(StandardCharsets.UTF_8));
	return Base64.getUrlEncoder().encodeToString(cipherText);
	} catch (Exception e) {
	log.error("alias encrypt error", e);
	throw null;
	}
	}

	@Override
	public String aesDecrypt(String encryption) {
	try {
	Cipher cipher = Cipher.getInstance(aliasAlgorithm);
	cipher.init(Cipher.DECRYPT_MODE,
	new SecretKeySpec(Base64.getDecoder().decode(aliasKey), "AES"),
	new IvParameterSpec(Base64.getDecoder().decode(aliasIv)));
	byte[] plainText = cipher.doFinal(Base64.getUrlDecoder().decode(encryption));
	return new String(plainText);
	} catch (Exception e) {
	log.error("alias decrypt error", e);
	throw null;
	}
	}

view raw AESCipher.java hosted with ❤ by GitHub

Base64 UrlEncoder for query parameter

the key and iv are configured in properties in base64 format. So I use Base64 Decoder decode them before create SecretKeySpec and IvParameterSpec.

new SecretKeySpec(Base64.getDecoder().decode(aliasKey), "AES"),
	new IvParameterSpec(Base64.getDecoder().decode(aliasIv)));

Since I am using AES to encrypt query parameter which will be transport via internet. so I use Base64 UrlEncoder for encrption and UrlDecoder for decryption.

return Base64.getUrlEncoder().encodeToString(cipherText);

byte[] plainText = cipher.doFinal(Base64.getUrlDecoder().decode(encryption));

References:

https://social.msdn.microsoft.com/Forums/en-US/f62047bc-9027-48d5-b613-d417179be582/best-encryption-for-query-string?forum=aspmvc

https://en.wikipedia.org/wiki/Advanced_Encryption_Standard