[英]javax.crypto.BadPaddingException as I try to convert hex string to byte array. Why do I get it?
當我嘗試將hex string
轉換為byte array
此異常:
Aug 15, 2013 10:17:32 PM Tester main
SEVERE: null
javax.crypto.BadPaddingException: Given final block not properly padded
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:811)
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:676)
at com.sun.crypto.provider.BlowfishCipher.engineDoFinal(BlowfishCipher.java:319)
at javax.crypto.Cipher.doFinal(Cipher.java:1978)
at Tester.main(Tester.java:21)
以下是嘗試這樣做的代碼:
try {
KeyGenerator keyGenerator = KeyGenerator.getInstance("Blowfish");
SecretKey secretKey = keyGenerator.generateKey();
Cipher cipher = Cipher.getInstance("Blowfish");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
String decryptSt = new String(cipher.doFinal(DatatypeConverter.parseHexBinary("f250d7a040859d66541e2ab4a83eb2225d4fff880f7d2506")));
System.out.println(decryptSt);
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(Tester.class.getName()).log(Level.SEVERE, null, ex);
} catch (NoSuchPaddingException ex) {
Logger.getLogger(Tester.class.getName()).log(Level.SEVERE, null, ex);
} catch (InvalidKeyException ex) {
Logger.getLogger(Tester.class.getName()).log(Level.SEVERE, null, ex);
} catch (IllegalBlockSizeException ex) {
Logger.getLogger(Tester.class.getName()).log(Level.SEVERE, null, ex);
} catch (BadPaddingException ex) {
Logger.getLogger(Tester.class.getName()).log(Level.SEVERE, null, ex);
}
問題是什么 ? 我為什么要例外?
您永遠無法使用隨機密鑰解密。 如果這樣做,您將獲得由隨機字節組成的純文本。 但是,該密碼嘗試解封郵件。 由於找不到有效的填充,您將收到此異常。 請注意-通過“運氣”,大約每256個一次-填充可能是正確的,在這種情況下,您只需將隨機字節檢索為純文本即可。
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