Android AES Encryption

Import Javax.crypto.Cipher;
Import Javax.crypto.KeyGenerator;
Import Javax.crypto.SecretKey;
Import Javax.crypto.spec.IvParameterSpec;
Import Javax.crypto.spec.SecretKeySpec;

/**
* @ Effect:
* Modify Person:
* @ Date:
*
*/
public class Aesutils {
public static final String key = "1123131313131313131313131313131313";
/**
* Encryption
*
* @param cleartext
* @return
*/
public static string Encrypt (string cleartext) {
byte[] result = NULL;
try {
byte[] Rawkey = Getrawkey (Key.getbytes ());
result = Encrypt (Rawkey, cleartext.getbytes ());
} catch (Exception e) {
E.printstacktrace ();
}
String content = Tohex (result);
return content;

}

/**
* Decryption
*
* @param encrypted
* @return
*/
public static string decrypt (string encrypted) {
Byte[] Rawkey;
try {
Rawkey = Getrawkey (Key.getbytes ());
byte[] enc = tobyte (encrypted);
Byte[] result = Decrypt (rawkey, ENC);
String coentn = new string (result);
return COENTN;
} catch (Exception e) {
E.printstacktrace ();
return null;
}
}

/**
* @param seed
* @return
* @throws Exception "rsa/none/pkcs1padding"
*/
private static byte[] Getrawkey (byte[] seed) throws Exception {
Keygenerator KGen = keygenerator.getinstance ("AES");
SecureRandom sr = null;
if (Build.VERSION.SDK_INT > 17) {
Cryptographic random number generator
sr = securerandom.getinstance ("Sha1prng", "Crypto");//android4.22 need this.
} else {
sr = securerandom.getinstance ("sha1prng"); Original
}
Kgen.init (+, SR);
Secretkey SKey = Kgen.generatekey ();
Byte[] raw = skey.getencoded ();
return raw;
}

private static byte[] Encrypt (byte[] raw, byte[] clear) throws Exception {
Secretkeyspec Skeyspec = new Secretkeyspec (Raw, "AES");
Cipher Cipher = cipher.getinstance ("AES");
Cipher Cipher = cipher.getinstance ("aes/cbc/pkcs5padding");
Cipher.init (Cipher.encrypt_mode, Skeyspec, New Ivparameterspec (
New Byte[cipher.getblocksize ()));
Byte[] Encrypted = cipher.dofinal (clear);
return encrypted;
}

private static byte[] Decrypt (byte[] raw, byte[] encrypted)
Throws Exception {
Secretkeyspec Skeyspec = new Secretkeyspec (Raw, "AES");
Cipher Cipher = cipher.getinstance ("AES");
Cipher Cipher = cipher.getinstance ("aes/cbc/pkcs5padding");
Cipher.init (Cipher.decrypt_mode, Skeyspec, New Ivparameterspec (
New Byte[cipher.getblocksize ()));
byte[] decrypted = cipher.dofinal (encrypted);
return decrypted;
}

public static string Tohex (String txt) {
Return Tohex (Txt.getbytes ());
}

public static string Fromhex (String hex) {
return new String (ToByte (hex));
}

public static byte[] ToByte (String hexstring) {
int len = Hexstring.length ()/2;
Byte[] result = new Byte[len];
for (int i = 0; i < len; i++)
Result[i] = integer.valueof (hexstring.substring (2 * I, 2 * i + 2),
). Bytevalue ();
return result;
}

public static String Tohex (byte[] buf) {
if (buf = = null)
Return "";
StringBuffer result = new StringBuffer (2 * buf.length);
for (int i = 0; i < buf.length; i++) {
Appendhex (result, buf[i]);
}
return result.tostring ();
}

private static void Appendhex (StringBuffer sb, byte b) {
Final String HEX = "0123456789ABCDEF";
Sb.append (Hex.charat ((b >> 4) & 0x0f)). Append (Hex.charat (b & 0x0f));
}
}

Android AES Encryption