Dot Net Code Snippets

How to Validate the CreditCard in asp.net ??

To validate the CreditCard first you have to check the Card Type then followed by
the no.of digits..etc.. on that Specific Card type. here i am using Luhn Algorithm to validate.

So you have place these algorithm on Separate Class file ie: Create

CardValidator.cs on the App_Code Folder and paste the below code.

using System;

public enum CardType
{
    MasterCard, BankCard, Visa, AmericanExpress, Discover, DinersClub, JCB
};

public sealed class CardValidator
{
    private CardValidator() { } // static only

    public static bool Validate(CardType cardType, string cardNumber)
   {
      byte[] number = new byte[16]; // number to validate

      // Remove non-digits
      int len = 0;
      for(int i = 0; i < cardNumber.Length; i++)
      {
         if(char.IsDigit(cardNumber, i))
         {
            if(len == 16) return false; // number has too many digits
            number[len++] = byte.Parse(cardNumber[i].ToString ());
         }
      }

      // Validate based on card type, first if tests length, second tests prefix
      switch(cardType)
      {
         case CardType.MasterCard:
            if(len != 16)
               return false;
            if(number[0] != 5 || number[1] == 0 || number[1] > 5)
               return false;
            break;

         case CardType.BankCard:
            if(len != 16)
               return false;
            if(number[0] != 5 || number[1] != 6 || number[2] > 1)
               return false;
            break;

         case CardType.Visa:
            if(len != 16 && len != 13)
               return false;
            if(number[0] != 4)
               return false;
            break;

         case CardType.AmericanExpress:
            if(len != 15)
               return false;
            if(number[0] != 3 || (number[1] != 4 && number[1] != 7))
               return false;
            break;

         case CardType.Discover:
            if(len != 16)
               return false;
            if(number[0] != 6 || number[1] != 0 || number[2] != 1 || number[3] != 

1)
               return false;
            break;

         case CardType.DinersClub:
            if(len != 14)
               return false;
            if(number[0] != 3 || (number[1] != 0 && number[1] != 6 && number[1] 

!= 8)
               || number[1] == 0 && number[2] > 5)
               return false;
            break;

         case CardType.JCB:
            if(len != 16 && len != 15)
               return false;
            if(number[0] != 3 || number[1] != 5)
               return false;
            break;
        
      }

      // Use Luhn Algorithm to validate
      int sum = 0;
      for(int i = len - 1; i >= 0; i--)
      {
         if(i % 2 == len % 2)
         {
            int n = number[i] * 2;
            sum += (n / 10) + (n % 10);
         }
         else
            sum += number[i];
      }
      return (sum % 10 == 0);
   }
}

I have the task of payment method through paypal pro using Credit Card.i was

googled a lot with paypal site , fourms and came with the sample code.

The PayPal Name-Value Pair API (NVP API) enables you to leverage thefunctionality of the PayPal API by simply sending an HTTP request to PayPal and specifying request parameters using name-value pairs. The NVP API is a lightweight alternative to the PayPal SOAP API and provides access to the same set of functionality as the SOAP API.

Ref: https://www.paypal.com/IntegrationCenter/ic_nvp.html

Here i am usin NVP API for payment through CreditCard using website Payment Pro

Method , we can also use SOAP API for this we need to do

1)setExpressionCheckout

2) DoExpressionCheckout

3) GetExpressionCheckout.

Either we can use API or through Code. I am Registering on Sandbox.paypal to check the code. we have to create the Buyer , seller Account to check the amount has been transferred or not , so it will automatically create the creditcard no, cardtype for the test account, we have to use this to check the Amount Transfer
or not. While testing , the amount was not deducted on the buyer account but it will credited on Seller account  as this is sanbox test, this is not an issue ,while you upload it on live , it will work smoothly.As i was tested with Sandbox - so you can check it on live.

One of the main advantage of this method is , it will not redirect the user to paypal site,instead the process has been doing on background from the same site after successfull transaction it will give the Transactionid ,
act etc.. so you can store this thing on DB.


While page Designing make sure you have these Fields

try
        {
              bool validateCard = false;
              if (ddlCCType.SelectedValue.ToString() == "Visa")
              {
                  validateCard = CardValidator.Validate( CardType.Visa , 

txtCCNumber.Text);
              }
              else if (ddlCCType.SelectedValue.ToString() == "MasterCard")
              {
                  validateCard = CardValidator.Validate(CardType.MasterCard , 

txtCCNumber.Text);
              }
              else if (ddlCCType.SelectedValue.ToString() == "AMEX")
              {
                  validateCard = CardValidator.Validate(CardType.AmericanExpress, 

txtCCNumber.Text);
              }

            if (validateCard != false)
            {
                  string ipaddress;

                ipaddress = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

                if (ipaddress == "" || ipaddress == null)
                {
                    ipaddress = Request.ServerVariables["REMOTE_ADDR"];

                }
        Session["ipAddress"] = ipaddress;

         //API Credentials (3-token)

            string strUsername = "troy2._1261822640_biz_api1.gmail.com";

            string strPassword = "1261822646";

            string strSignature = 

"An5ns1Kso7MWUdW4ErQKJJJ4qi4-A60C4mgCoX2-L9FhwhF2rfGtRPeI";

            string strCredentials = "USER=" + strUsername + "&PWD=" + strPassword 

+ "&SIGNATURE=" + strSignature;
        
            // For Sandbox testing use this API 
            string strNVPSandboxServer = "https://api-3t.sandbox.paypal.com/nvp";

            // Fpr Live Server use this API
            string strNVPLiveServer = "https://api-3t.paypal.com/nvp";

            string strAPIVersion = "2.3";

// here i am assigning the credit card type cardno,expiry date/month to
 //the session variable and pass it here 

                       string strNVP = strCredentials + 

"&METHOD=DoDirectPayment&CREDITCARDTYPE=" + Session["cardType"].ToString() + 

"&ACCT=" + Session["cardNo"].ToString() + "&EXPDATE=" + 

Session["expiryDate"].ToString() + "&CVV2=808&AMT=" + Amount_Label.Text + 

"&FIRSTNAME=" + FirstName_Label.Text + "&LASTNAME=" + LastName_Label.Text + 

"&IPADDRESS=" + Session["ipAddress"].ToString() + "&STREET=" + address1 + "+" + 

address2 + "&CITY=" + city + "&STATE=" + state + "&COUNTRY=" + country + "&ZIP=" 

+ zip + "&COUNTRYCODE=US&PAYMENTACTION=Sale&VERSION=" + strAPIVersion;

  //Create web request and web response objects, make sure you using the correct 

server (sandbox/live)

            HttpWebRequest wrWebRequest = 

(HttpWebRequest)WebRequest.Create(strNVPSandboxServer);

            ////Set WebRequest Properties
            wrWebRequest.Method = "POST";

            //// write the form values into the request message
            StreamWriter requestWriter = new 

StreamWriter(wrWebRequest.GetRequestStream());

            requestWriter.Write(strNVP);
            requestWriter.Close();

            //// Get the response.
            HttpWebResponse hwrWebResponse = 

(HttpWebResponse)wrWebRequest.GetResponse();

            StreamReader responseReader = new 

StreamReader(wrWebRequest.GetResponse().GetResponseStream());

            //// and read the response
            string responseData = responseReader.ReadToEnd();

            responseReader.Close();
            Response.Write(Server.UrlDecode(responseData));
               
            }
            else
            {
                validateCard_Label.Text = "Please check your card number...";
            }
            
            
          
        }
        catch (Exception ex)
        {
            throw ex;
        } 

Finally , once your Transaction is success you will get the output ie:TransactionID with ack

EX: Output