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java aes
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import javax.crypto.Cipher; | |
import javax.crypto.Mac; | |
import javax.crypto.spec.IvParameterSpec; | |
import javax.crypto.spec.SecretKeySpec; | |
import java.security.AlgorithmParameters; | |
import java.security.spec.KeySpec; | |
import javax.crypto.Cipher; | |
import javax.crypto.SecretKey; | |
import javax.crypto.SecretKeyFactory; | |
import javax.crypto.spec.IvParameterSpec; | |
import javax.crypto.spec.PBEKeySpec; | |
import javax.crypto.spec.SecretKeySpec; | |
class EncryptorDecryptor { | |
public static String bin2hex(byte[] data) | |
{ | |
if (data==null) | |
{ | |
return null; | |
} | |
int len = data.length; | |
String str = ""; | |
for (int i=0; i<len; i++) { | |
if ((data[i]&0xFF)<16) | |
str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF); | |
else | |
str = str + java.lang.Integer.toHexString(data[i]&0xFF); | |
} | |
return str; | |
} | |
public static byte[] hex2bin(String str) { | |
if (str==null) { | |
return null; | |
} else if (str.length() < 2) { | |
return null; | |
} else { | |
int len = str.length() / 2; | |
byte[] buffer = new byte[len]; | |
for (int i=0; i<len; i++) { | |
buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16); | |
} | |
return buffer; | |
} | |
} | |
public static String encrypt(String salt, String iv, String plaintext, String pwd) throws Exception { | |
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1"); | |
KeySpec spec = new PBEKeySpec(pwd.toCharArray(), hex2bin(salt), 1024, 256); | |
SecretKey tmp = factory.generateSecret(spec); | |
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES"); | |
byte[] iv_bytes = hex2bin(iv); | |
String value = new String(iv_bytes); | |
IvParameterSpec ivspec = new IvParameterSpec(iv_bytes); | |
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); | |
cipher.init(Cipher.ENCRYPT_MODE, secret, ivspec); | |
byte[] encrypted = cipher.doFinal(plaintext.getBytes()); | |
return new String(bin2hex(encrypted)); | |
} | |
public static String decrypt(String salt, String iv, String payload, String pwd) throws Exception { | |
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1"); | |
KeySpec spec = new PBEKeySpec(pwd.toCharArray(), hex2bin(salt), 1024, 256); | |
SecretKey tmp = factory.generateSecret(spec); | |
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES"); | |
byte[] iv_bytes = hex2bin(iv); | |
String value = new String(iv_bytes); | |
IvParameterSpec ivspec = new IvParameterSpec(iv_bytes); | |
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); | |
cipher.init(Cipher.DECRYPT_MODE, secret, ivspec); | |
byte[] payload_bytes = hex2bin(payload); | |
byte[] decrypted = cipher.doFinal(payload_bytes); | |
return new String(decrypted); | |
} | |
} | |
public class Aes { | |
public static void main(String []args) { | |
try { | |
// find maxiumum length allowed | |
//int maxKeyLen = Cipher.getMaxAllowedKeyLength("AES"); | |
String word; | |
word = EncryptorDecryptor.decrypt("DD", "0E4F0A415B4C186D8C057DBFE0FDF17B", "F220CD133E99E5128B73ED5D87D6380A", "key"); | |
System.out.println(word); | |
} | |
catch(Exception e) | |
{ | |
System.out.println(e); | |
} | |
} | |
} | |
if invalid key length is error thrown | |
http://stackoverflow.com/questions/19503926/java-security-aes-encryption-key-length |
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