Unable to retrieve public key and signature.

Question

Hi,
I'am trying to send public key and signature from one client to another via server.
Both pub_key and signature are encrypted into base64. But i cant retrieve them correctly in server side.
I'am using ECDSA to sign message key_length 224bit. Sending and retrieving data via sockets.
SEND DATA FUNCTION Client.java
private static PrintWriter      output_stream = null;
private static Scanner      input_stream           = null;
private static void send_message(String message)
     if(user_name != null
          && message_text_area.getText().equals(SERVER_CLOSED) == false
          && message_text_area.getText().equals(SERVER_CONNECTED) == false
          && message_text_area.getText().equals(MAX_USERS_ONLINE) == false
          && message_text_area.getText().equals(CONNECTION_CLOSED) == false
          && message_text_area.getText().equals(GET_USER) == false
          && message_text_area.getText().equals(REMOVE_USER) == false
          && message_text_area.getText().equals(USER_EXISTS) == false
          && message_text_area.getText().equals(USER_NICK) == false){   
         String signature = new BASE64Encoder().encode(ecdsa_parameters.sign_message(SESSION_KEY_PAIR.getPrivate(), message_text_area.getText().trim()));
         String public_key = new BASE64Encoder().encode(SESSION_KEY_PAIR.getPublic().getEncoded());
         if (signature != null && SESSION_KEY_PAIR != null){
          synchronized(output_stream)
              output_stream.println(USER_NICK);
              output_stream.println(user_name);
              output_stream.println(user_nick);
              output_stream.println(message_text_area.getText().trim());
                    //PUblic key and signature in base64
                    output_stream.println(public_key);     
              output_stream.println(signature);
                //length and data of them
          System.out.println(public_key.length());
          System.out.println(signature.length());          
          System.out.println(public_key);
          System.out.println(signature);
          append_message(user_nick+": "+message_text_area.getText().trim());
          message_text_area.setText(null);
         }else{
          append_message("E_C_002: Unable to generate keys or signature.");
     }else{
         append_message("User is not selected or incorrect message");
    }HANDLER.JAVA (SERVER SIDE RETRIEVE)
private Scanner           input_data           = null;
private PrintStream      output_data           = null;
if(recieved_data.equals(USER_NICK)){
               String user_name = input_data.nextLine();
               String user_nick = input_data.nextLine();
               String message = input_data.nextLine();
               String public_key = "";
               for (int i=0; i<5; i++){
                   if(i == 0){
                    public_key = public_key+""+input_data.next();
                   }else{
                    public_key = public_key+"\n"+input_data.next();
               String signature = "";
               for (int i=0; i<2; i++){
                   if(i == 0){
                    signature = signature+""+input_data.next();
                   }else{
                    signature = signature+"\n"+input_data.next();
                        //output length and data of key and signature
               System.out.println(public_key.length());
               System.out.println(signature.length());
               System.out.println(public_key);
               System.out.println(signature);
               Server.users_messages.addElement(user_name+""+SEPARATOR+""+user_nick+""+SEPARATOR+""+message+""+SEPARATOR+""+public_key+""+SEPARATOR+""+signature);               
          }It seems that length of key and signature in server side are different form client.
Maybe I'am missing something that correspond sending data in base64????
All project is here http://fmf.vtu.lt/~knugmanov/Elliptic%20curve%20cryptography%20instant%20messenger.rar
(import into eclypse).
For ECC I use iaik classes.
Thanks in adv.
Kiril

Answer 1

here is a code from
http://www.exampledepot.com/egs/java.security/GetKeyFromKs.html
This example retrieves from a keystore, the private and public key associated with an alias.
private and public key are having the same alias ?
i know a alias for my key but i believe thats for private key not for public key ......is it true that both private and public key have the same alias ?
and KeyPair is an interface and so its difficult to get a key out of it
public KeyPair getPrivateKey(KeyStore keystore, String alias, char[] password) {
        try {
            // Get private key
            Key key = keystore.getKey(alias, password);
            if (key instanceof PrivateKey) {
                // Get certificate of public key
                java.security.cert.Certificate cert = keystore.getCertificate(alias);
                // Get public key
                PublicKey publicKey = cert.getPublicKey();
                // Return a key pair
                return new KeyPair(publicKey, (PrivateKey)key);
        } catch (UnrecoverableKeyException e) {
        } catch (NoSuchAlgorithmException e) {
        } catch (KeyStoreException e) {
        return null;
    }Message was edited by:
Unknown_Citizen
Message was edited by:
Unknown_Citizen
Message was edited by:
Unknown_Citizen