<?php
/*
 * Autor Mihkel-Mikelis Putrinsh <mihkel@ww.ee>,
 * Wõrgu Wõlurid OÜ http://ww.ee
 * 
 * See koodijupp on loodud ja avalikuks tehtud 2006. aasta teisel augustil.
 * Kommentaarid on teretulnud.
 * */

Class BankLink
{
   /* kataloog, kus hoitakse avalikke võtmeid
    * kujul
    * /webroot/osslkeys/HP/pubkey.pem
    * /webroot/osslkeys/EYP/pubkey.pem
    * /webroot/osslkeys/...
    * */
   var $keyDir = "/webroot/osslkeys";
   

   function BankLink()
   {
   }

   /* avalik funktsioon allkirjastamiseks
    * */
   function createSignature( &$VK_a )
   {
      $data = $this->_composeData( &$VK_a );
      
      $pkeyid = openssl_get_privatekey( $this->_privKey() );

      openssl_sign( $data, $signature, $pkeyid );
      $VK_MAC = base64_encode( $signature );

      openssl_free_key( $pkeyid );

      return $VK_MAC;
   }

   /* avalik funktsioon allkirja kontrollimiseks
    * */
   function verifySignature( $VK_a )
   {
      $VK_MAC = $VK_a['VK_MAC'];
      $signature = base64_decode( $VK_MAC );

      switch( $VK_a['VK_SERVICE'] )
      {
         case '1101':
            $data =
               $this->_padIt( $VK_a['VK_SERVICE'] ) .
               $this->_padIt( $VK_a['VK_VERSION'] ) .
               $this->_padIt( $VK_a['VK_SND_ID'] ) .
               $this->_padIt( $VK_a['VK_REC_ID'] ) .
               $this->_padIt( $VK_a['VK_STAMP'] ) .
               $this->_padIt( $VK_a['VK_T_NO'] ) .
               $this->_padIt( $VK_a['VK_AMOUNT'] ) .
               $this->_padIt( $VK_a['VK_CURR'] ) .
               $this->_padIt( $VK_a['VK_REC_ACC'] ) .
               $this->_padIt( $VK_a['VK_REC_NAME'] ) .
               $this->_padIt( $VK_a['VK_SND_ACC'] ) .
               $this->_padIt( $VK_a['VK_SND_NAME'] ) .
               $this->_padIt( $VK_a['VK_REF'] ) .
               $this->_padIt( $VK_a['VK_MSG'] ) .
               $this->_padIt( $VK_a['VK_T_DATE'] );
            break;
         case '1901':
            $data =
               $this->_padIt( $VK_a['VK_SERVICE'] ) .
               $this->_padIt( $VK_a['VK_VERSION'] ) .
               $this->_padIt( $VK_a['VK_SND_ID'] ) .
               $this->_padIt( $VK_a['VK_REC_ID'] ) .
               $this->_padIt( $VK_a['VK_STAMP'] ) .
               $this->_padIt( $VK_a['VK_REF'] ) .
               $this->_padIt( $VK_a['VK_MSG'] );
            break;
      }

      $cert = $this->_readPubKey( $VK_a['VK_SND_ID'] );
      $pubkey = openssl_get_publickey( $cert );

      $out = openssl_verify( $data, $signature, $pubkey );

      openssl_free_key( $pubkeyid );
      return $out;
   }

   /*
    * sisesed abifunktsioonid
    * */
   
   function _readPubKey( $VK_SND_ID = '' )
   {
      $key_file = $this->keyDir . "/$VK_SND_ID/pubkey.pem";
      $fp = fopen( $key_file, "r" );
      $cert = fread( $fp, 8192 );
      fclose( $fp );

      return $cert;
   }
   
   function _composeData( &$VK_a )
   {
      foreach( $VK_a as $data_bit )
      {
         $data .= $this->_padIt( $data_bit );
      }
      return $data;
   }

   function _padIt( $str = "" )
   {
      return str_pad( strlen( $str ), 3, "0", STR_PAD_LEFT ) . $str;
   }

   /* Siia pange kaupnehe privaatvõti. eraldi failis hoida ei soovita
    * */
   function _privKey()
   {
      return "-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----";
   }
}

?>