我有以下方法:
public String decrypt(String strToBeDecrypted) {
try {
strToBeDecrypted = URLDecoder.decode(strToBeDecrypted, "UTF-8");
DESKeySpec desKeySpec = new DESKeySpec(key);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey skey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.DECRYPT_MODE, skey, ivSpec);
byte[] keyByteArray = new BASE64Decoder().decodeBuffer(strToBeDecrypted);
byte[] original = cipher.doFinal(keyByteArray);
return new String(original, "UTF-8");
} catch (Exception e) {
logger.error(ExceptionUtil.getDetailedMessage(e));
}
return "";
}
这是抛出
"name=javax.crypto.IllegalBlockSizeException;message=Input length must be multiple of 8 when decrypting with padded cipher;"
在下面一行:
byte[] original = cipher.doFinal(keyByteArray);
有人可以告诉我这里有什么问题吗?
它所指的输入长度是密文的长度(strToBeDecrypted),它期望是块大小的倍数。暗示默认情况下,库期望填充您的输入。
这意味着您要么需要在解密时将填充设置为'none'(因为这是加密时使用的'填充'),要么您已经以某种方式破坏了密文。
尝试将“ DES”更改为“ DES / ECB / NoPadding”。我不知道您的实现使用的默认密码模式是什么,但是通常是“ ECB”或“ CBC”。如果这两个都不起作用,则说明您的密文正在沿线的某个位置被破坏。
请使用此。它对我有用。
public String decrypt(String message) throws Exception {
final MessageDigest md = MessageDigest.getInstance("md5");
final byte[] digestOfPassword = md.digest("HG58YZ3CR9"
.getBytes("utf-8"));
final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
for (int j = 0, k = 16; j < 8;) {
keyBytes[k++] = keyBytes[j++];
}
final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
final Cipher decipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
decipher.init(Cipher.DECRYPT_MODE, key, iv);
final byte[] encData = new sun.misc.BASE64Decoder().decodeBuffer(message);
final byte[] plainText = decipher.doFinal(encData);
return new String(plainText, "UTF-8");
}