我正在开发一个Android应用程序，想在将字符串发送到数据库之前对其进行加密，目前加密已经成功。但是当我尝试解密字符串时，出现了"BadPaddingException"异常，我不知道问题出在哪里。以下是代码：
public final static String HEX = "36A52C8FB7DF9A3F";
public static String encrypt(String seed, String cleartext) throws Exception
{
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception
{
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
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), 16).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 byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
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.init(Cipher.ENCRYPT_MODE, skeySpec);
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.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
我使用以下代码进行加密和解密：
String encrypted = encrypt(HEX, "some text");
String decrypted = decrypt(HEX, encrypted);
请问有人可以帮我吗？
非常感谢！！
编辑：问题还没有解决，但是我有更多的信息。首先，我在一个Java项目中进行加密，然后在一个Android项目中进行解密。我尝试在同一个Java项目中进行解密，没有任何问题，但是如果我在Android中尝试解密，它就不起作用。问题出现在“getRawKey”方法中（请查看kgen.generateKey（）注释）：
JAVA：
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed); //Seed: [51, 54, 65, 53, 50, 67, 56, 70, 66, 55, 68, 70, 57, 65, 51, 70]
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey(); //skey.key = [-97, -52, 45, -95, -64, -58, 16, -20, 124, -50, -104, 58, 23, -75, 88, 94]
byte[] raw = skey.getEncoded();
return raw;
}
安卓系统：
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed); //Seed: [51, 54, 65, 53, 50, 67, 56, 70, 66, 55, 68, 70, 57, 65, 51, 70]
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey(); //skey.key = [-114, 32, 16, -52, -81, 125, -88, 88, -76, 20, -117, -11, 33, -61, 32, -91]
byte[] raw = skey.getEncoded();
return raw;
}
我不是密码学专家，但是如果使用相同的种子，如何可能得到不同的密钥呢？