我使用以下代码进行AES-128加密,对16字节的单个块进行编码,但编码值的长度为2个32字节的块 . 我错过了什么吗?
plainEnc = AES.encrypt("thisisapassword!");
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.*;
import sun.misc.*;
public class AES {
private static final String ALGO = "AES";
private static final byte[] keyValue =
new byte[] { 'T', 'h', 'e', 'B', 'e', 's', 't',
'S', 'e', 'c', 'r','e', 't', 'K', 'e', 'y' };
public static String encrypt(String Data) throws Exception {
System.out.println("string length: " + (Data.getBytes()).length); //length = 16
Key key = generateKey();
Cipher chiper = Cipher.getInstance(ALGO);
chiper.init(Cipher.ENCRYPT_MODE, key);
byte[] encVal = chiper.doFinal(Data.getBytes());
System.out.println("output length: " + encVal.length); //length = 32
String encryptedValue = new BASE64Encoder().encode(encVal);
return encryptedValue;
}
public static String decrypt(String encryptedData) throws Exception {
Key key = generateKey();
Cipher chiper = Cipher.getInstance(ALGO);
chiper.init(Cipher.DECRYPT_MODE, key);
byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedData);
byte[] decValue = chiper.doFinal(decordedValue);
String decryptedValue = new String(decValue);
return decryptedValue;
}
private static Key generateKey() throws Exception {
Key key = new SecretKeySpec(keyValue, ALGO);
return key;
}
}
1 回答
Cipher.getInstance("AES")
返回使用PKCS#5填充的密码 . 在所有情况下都会添加此填充 - 当明文已经是块大小的倍数时,会添加整个填充块 .在
Cipher.getInstance()
调用中明确指定您的意图,以避免依赖于默认值并可能导致混淆:您还将看到您正在使用ECB模式,这在几乎任何情况下都是一个糟糕的选择 .