这是我第一次在这里寻求帮助，我的部门（政府）已经在市场上发布了一些应用程序（Google Play），并且加密和描述工作非常好，直到昨天我在我的电脑上安装了 Jelly Bean 4.2关系。加密工作正常，它实际上是加密要存储的信息。虽然解密时，我得到了一个完全一样的异常：pad block损坏. 我检查了字符串，它在其他设备上与它一致（使用相同的密钥进行测试），这意味着它完全相同。问题是我们需要保持与以前版本的向后兼容性，这意味着如果我更改代码中的某些内容，它应该能够读取旧的加密信息。它存储在 SQLite 上的加密信息，因为我需要将其编码为 Base64。异常发生在这一行byte[] decrypted = cipher.doFinal(encrypted);
这是我的课：
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;
public class EncodeDecodeAES {
private final static String HEX = "0123456789ABCDEF";
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
String fromHex = toHex(result);
String base64 = new String(Base64.encodeToString(fromHex.getBytes(), 0));
return base64;
}
public static String decrypt(String seed, String encrypted) throws Exception {
String base64 = new String(Base64.decode(encrypted, 0));
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(base64);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
public static byte[] encryptBytes(String seed, byte[] cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext);
return result;
}
public static byte[] decryptBytes(String seed, byte[] encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = decrypt(rawKey, encrypted);
return result;
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
try {
kgen.init(256, sr);
} catch (Exception e) {
// Log.w(LOG, "This device doesn't suppor 256bits, trying 192bits.");
try {
kgen.init(192, sr);
} catch (Exception e1) {
// Log.w(LOG, "This device doesn't suppor 192bits, trying 128bits.");
kgen.init(128, 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.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;
}
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 void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
}
}
我想知道（如果有人帮助我），我对这段代码做错了什么，或者它是否是 Android 4.2 的问题，如果它是 4.2 的问题，是否有任何解决方法？
谢谢