CCAvenue payment integration php

• Integrating CCavenue payment gateway is simple
• We need a merchant id and working for implementing payment gateway
• These two details will be given by CCavenue
• They use a redirect model for payment
• ie the user will be rediected to there site for making the payment

• Before for sending the details to CCavenue we need to save the details so that we can verify the details after the payment

• we need to generate a signature(checksum) that is it contain some details like amount, orderid, working key, merchantid and rediecturl

• On the buy page on submitting we need a serverside validation of the details the user have entered and after that the user details need to be stored in our DB after the payment is successfully completed 

• After entering all the details we need to redirect to another page it contain a form and the CCavenue form variables which are in hidden and we need to auto submit after loading the page

----------------------Page content--------------------------------------

<?php

$Merchant_Id = "your_merchantid";//

$Amount = "amount";

$Order_Id ="orderid";//unique Id that should be passed to payment gateway

$WorkingKey = "working_key";//Given to merchant by ccavenue

$Redirect_Url ="sucessurl";

$Checksum = getCheckSum($Merchant_Id,$Amount,$Order_Id ,$Redirect_Url,$WorkingKey);                 // Validate All value

//creating a signature using the given details for security reasons

function getchecksum($MerchantId,$Amount,$OrderId ,$URL,$WorkingKey)

{

$str ="$MerchantId|$OrderId|$Amount|$URL|$WorkingKey";

$adler = 1;

$adler = adler32($adler,$str);

return $adler;

}

//functions

function adler32($adler , $str)

{

$BASE = 65521 ;

$s1 = $adler & 0xffff ;

$s2 = ($adler >> 16) & 0xffff;

for($i = 0 ; $i < strlen($str) ; $i++)

{

$s1 = ($s1 + Ord($str[$i])) % $BASE ;

$s2 = ($s2 + $s1) % $BASE ;

}

return leftshift($s2 , 16) + $s1;

}

//leftshift function

function leftshift($str , $num)

{

$str = DecBin($str);

for( $i = 0 ; $i < (64 - strlen($str)) ; $i++)

$str = "0".$str ;

for($i = 0 ; $i < $num ; $i++)

{

$str = $str."0";

$str = substr($str , 1 ) ;

}

return cdec($str) ;

}

//cdec function

function cdec($num)

{

for ($n = 0 ; $n < strlen($num) ; $n++)

{

$temp = $num[$n] ;

$dec = $dec + $temp*pow(2 , strlen($num) - $n - 1);

}

return $dec;

}

?>

<form id="ccavenue" method="post" action="https://www.ccavenue.com/shopzone/cc_details.jsp">

<input type=hidden name="Merchant_Id" value="Merchant_Id">

<input type="hidden" name="Amount" value="Amount">

<input type="hidden" name="Order_Id" value="Order_Id">

<input type="hidden" name="Redirect_Url" value="success url">

<input type="hidden" name="TxnType" value="A">

<input type="hidden" name="ActionID" value="TXN">

<input type="hidden" name="Checksum" value="<?php echo $Checksum; ?>">

<input type="hidden" name="billing_cust_name" value="name of user">

<input type="hidden" name="billing_cust_address" value="address of user">

<input type="hidden" name="billing_cust_country" value="user country">

<input type="hidden" name="billing_cust_state" value="state of user">

<input type="hidden" name="billing_cust_city" value="city">

<input type="hidden" name="billing_zip" value="zip/pin code">

<input type="hidden" name="billing_cust_tel" value="telphone no">

<input type="hidden" name="billing_cust_email" value="emailid">

<input type="hidden" name="delivery_cust_name" value="user name">

<input type="hidden" name="delivery_cust_address" value="delivering address">

<input type="hidden" name="delivery_cust_country" value="delivering country">

<input type="hidden" name="delivery_cust_state" value="delivering state">

<input type="hidden" name="delivery_cust_tel" value="telphone no">

<input type="hidden" name="delivery_cust_notes" value="this is a test">

<input type="hidden" name="Merchant_Param" value="">

<input type="hidden" name="billing_zip_code" value="zip/pin">

<input type="hidden" name="delivery_cust_city" value="city">

<input type="submit" value="Buy Now" />

</form>

------------------End of page content--------------------------------------

• After the successful payment,CCavenue will redirect to our successurl with the some details as post url/get url

• there are mainly 3 auth_status are there they are 
• Y successfully authorised by gateway
• N Unsuccessful transaction
• B not authenicated at this pont of time

• we need to verify the payment gateway details send by CCavenue is tampered or not for that we have to use the Verify checksum function

       --------------------------------------------------------------------------------------------

//Verify the the checksum

function verifychecksum($MerchantId,$OrderId,$Amount,$AuthDesc,$CheckSum,$WorkingKey)

{

$str = "$MerchantId|$OrderId|$Amount|$AuthDesc|$WorkingKey";

$adler = 1;

$adler = adler32($adler,$str);

if($adler == $CheckSum)

return "true" ;

else

return "false" ;

}

//functions

function adler32($adler , $str)

{

$BASE = 65521 ;

$s1 = $adler & 0xffff ;

$s2 = ($adler >> 16) & 0xffff;

for($i = 0 ; $i < strlen($str) ; $i++)

{

$s1 = ($s1 + Ord($str[$i])) % $BASE ;

$s2 = ($s2 + $s1) % $BASE ;

}

return leftshift($s2 , 16) + $s1;

}

//leftshift function

function leftshift($str , $num)

{

$str = DecBin($str);

for( $i = 0 ; $i < (64 - strlen($str)) ; $i++)

$str = "0".$str ;

for($i = 0 ; $i < $num ; $i++)

{

$str = $str."0";

$str = substr($str , 1 ) ;

}

return cdec($str) ;

}

//cdec function

function cdec($num)

{

for ($n = 0 ; $n < strlen($num) ; $n++)

{

$temp = $num[$n] ;

$dec = $dec + $temp*pow(2 , strlen($num) - $n - 1);

}

return $dec;

}

           ---------------------------------------------------------------------------------

• we need to pass the details into it, if it returns true than the details are ok and payment was successfull redirect to success page
• if it returns false then the details are tampered while sending to our application and something wrong has occured and redirect to failed /unsuccessful page