OTP dummy client (enc/dec)

wipedlifepotato · February 27, 2021, 7:27am

(encrypt decrypt by a key file[with offset]) client https://github.com/wipedlifepotato/OTPDUMMY

SkewedZeppelin · February 28, 2021, 8:44pm

wipedlifepotato/OTPDUMMY/blob/main/app/src/main/java/com/livingstonei2p/otpdummy/OTP/OTP.java#L37


    byte[] messageArray;
    if (isEncrypted) {
        messageArray = Base64.decode(message,Base64.DEFAULT);
    }else messageArray = (byte[])message.getBytes(Charset.defaultCharset() );
    byte[] cryptedMessage = new byte[messageArray.length+1];
    int x;
    for(x=0;x<messageArray.length;x++){
        byte tmp=i.readByte();
        cryptedMessage[x]= (byte)((messageArray[x])^(tmp))  ;//0x7f?
        assert (cryptedMessage[x]^(tmp) ) == messageArray[x];
    }
    i.close();
    this.offset = offset + x;
    if(isEncrypted) return new String(cryptedMessage, "UTF-8");
    return Base64.encodeToString(cryptedMessage, 0, cryptedMessage.length, Base64.DEFAULT);
}
public String doCryptDecrypt(String message) throws FileNotFoundException, IOException{
    return doCryptDecrypt(message, false);
}

Isn’t this just a XOR cipher, that has many weaknesses and can be trivially broken?

wipedlifepotato · February 28, 2021, 9:10pm

For some guys… https://ru.m.wikipedia.org/wiki/%D0%A8%D0%B8%D1%84%D1%80_%D0%92%D0%B5%D1%80%D0%BD%D0%B0%D0%BC%D0%B0

пн, 1 мар. 2021 г., 3:54 SkewedZeppelin via F-Droid Forum <forum@f-droid.org>:

Morgoth · February 28, 2021, 9:17pm

Fixed url: https://en.wikipedia.org/wiki/One-time_pad