Comment décoder le texte chiffrement Blowfish CFB en Java?

Question

Je ne peux pas décoder correctement le texte. Voici le code:

public void decode() { 
    byte[] KeyData = {0x2f, 0x18, (byte) 0xf5, (byte) 0x96, (byte) 0xa2, 0x17, 0x18, 0x29}; 
    byte[] IV = {0x01, 0x3d, (byte) 0xcf, (byte) 0xe2, (byte) 0xe3, (byte) 0xf9, (byte) 0xdd, (byte) 0x81}; 
    SecretKeySpec KS = new SecretKeySpec(KeyData, "Blowfish"); 
    Cipher cipher = null; 
    try { 
     cipher = Cipher.getInstance("Blowfish/CFB/NoPadding"); 
    } catch (NoSuchAlgorithmException e) { 
     e.printStackTrace(); 
    } catch (NoSuchPaddingException e) { 
     e.printStackTrace(); 
    } 

    byte[] ciphertext = hexToBytes("424749c1d3b497"); 

    // Decrypt 
    try { 
     cipher.init(Cipher.DECRYPT_MODE, KS, new javax.crypto.spec.IvParameterSpec(IV)); 
    } catch (InvalidKeyException e) { 
     e.printStackTrace(); 
    } catch (InvalidAlgorithmParameterException e) { 
     e.printStackTrace(); 
    } 
    byte[] message = new byte[0]; 
    try { 
     message = cipher.doFinal(ciphertext); 
    } catch (IllegalBlockSizeException e) { 
     e.printStackTrace(); 
    } catch (BadPaddingException e) { 
     e.printStackTrace(); 
    } 

    System.out.println("-- Decrypted -----------"); 
    System.out.println("HEX:\t " + bytesToHex(message)); 
    System.out.println("PLAIN:\t " + new String(message)); 

} 

public byte[] hexToBytes(String str) { 
    if (str == null) { 
     return null; 
    } else if (str.length() < 2) { 
     return null; 
    } else { 
     int len = str.length()/2; 
     byte[] buffer = new byte[len]; 
     for (int i = 0; i < len; i++) { 
      buffer[i] = (byte) Integer.parseInt(str.substring(i * 2, i * 2 + 2), 16); 
     } 
     return buffer; 
    } 

} 

public String bytesToHex(byte[] bytes) { 

    char[] hexChars = new char[bytes.length * 2]; 
    for (int j = 0; j < bytes.length; j++) { 
     int v = bytes[j] & 0xFF; 
     hexChars[j * 2] = hexArray[v >>> 4]; 
     hexChars[j * 2 + 1] = hexArray[v & 0x0F]; 
    } 
    return new String(hexChars); 
} 

Mon résultat: HEX: 37F8D5CEE036CD; PLAIN: 7����6�

résultat correct: HEX: 37363035353633; PLAIN: 7605563

Vérifiez le bon résultat ici:

http://blowfish.online-domain-tools.com/run/?inputType=frm-text&text=424749c1d3b497&text_type=hex&function=blowfish&mode=cfb&key=2F%2018%20F5%2096%20A2%2017%2018%2029&key_type=hex&iv=01%203D%20CF%20E2%20E3%20F9%20DD%2081&do=form-submit&decrypt=do

Answer 1

I a changé l'algorithme Nom et Modes

cipher = Cipher.getInstance("Blowfish/CFB8/NOPADDING"); 

et il m'a aidé