When using the SWP checkout option using hashing, please use the standard hash for transaction signing:
http://www.paymentsgateway.com/developerDocumentation/Integration/securewebpay/checkout.aspx
Hashing Format for Transaction Signing
HMAC-MD5("pg_apilogin_id | pg_transaction_type | pg_version_number | pg_total_amount | pg_utc_time | pg_transaction_order_number", “Secure Transaction Key” )
The following example will demonstrate what is needed to perform the correct computation of the algorithm:
<FORMMETHOD="post" ACTION="https://sandbox.paymentsgateway.net/swp/co/default.aspx"> <input name="pg_billto_postal_name_first" type="text" value="Bob"/> <input name="pg_billto_postal_name_last" type="text" value="Smith"/> <input type="hidden" name="pg_api_login_id" value="APILOGINID"/> <input type="hidden" name="pg_transaction_type" value="10"/> <input type="hidden" name="pg_version_number" value="1.0"/> <input type="hidden" name="pg_total_amount" value="5.00"/> <input type="hidden" name="pg_utc_time" value="634094514514687490"/> <input type="hidden" name="pg_transaction_order_number" value="100055"/> <input type="hidden" name="pg_ts_hash" value="4bac0b9badbea7730cd41c334384bdfa"/> <input TYPE=SUBMIT> </FORM>
Note: 'pg_ts_hash' was computed like this:
pg_ts_hash=HMAC-MD5("APILOGINID|10|1.0|5.00|634094514514687490|100055", "SECURETRANSACTIONKEY")
Have you generated your API Login ID and Secure Transaction Key? If not, you’ll need to log into our gateway under “Gateway Settings”>Gateway Key and generate both items; https://sandbox.paymentsgateway.net/vt3/login.aspx.