root/trunk/system/config/payment.php

<?php
/**
 * @package  Payment
 *
 * Settings related to the Payment library.
 * This file has settings for each driver.
 * You should copy the 'default' and the specific
 * driver you are working with to your application/config/payment.php file.
 *
 * Options:
 *  driver - default driver to use
 *  test_mode - Turn TEST MODE on or off
 *  curl_settings - Set any custom cURL settings here. These defaults usualy work well.
 *                  see http://us.php.net/manual/en/function.curl-setopt.php for details
 */
$config['default'] = array
(
    'driver'        => 'Authorize',
    'test_mode'     => TRUE,
    'curl_config'   => array(CURLOPT_HEADER         => FALSE,
                             CURLOPT_RETURNTRANSFER => TRUE,
                             CURLOPT_SSL_VERIFYPEER => FALSE)
);

/**
 * Authorize.net Options:
 *  auth_net_login_id - the transaction login ID; provided by gateway provider
 *  auth_net_tran_key - the transaction key; provided by gateway provider
 */
$config['Authorize'] = array
(
    'auth_net_login_id' => '',
    'auth_net_tran_key' => ''
);

/**
 * YourPay.net Options:
 *  merchant_id - the merchant ID number
 *  certificate - the location on your server of the certificate file.
 */
$config['Yourpay'] = array
(
    'merchant_id' => '',
    'certificate' => './path/to/certificate.pem'
);

/**
 * TrustCommerce Options:
 *  custid - the customer ID assigned to you by TrustCommerce
 *  password - the password assigned to you by TrustCommerce
 *  media - "cc" for credit card or "ach" for ACH.
 *  tclink_library - the location of the tclink library (relative to your index file) you need to compile to get this driver to work.
 */
$config['Trustcommerce'] = array
(
    'custid' => '',
    'password' => '',
    'media' => 'cc',
    'tclink_library' => './path/to/library.so'
);

/**
 * TridentGateway Options:
 *  profile_id - the profile ID assigned to you by Merchant e-Services
 *  profile_key - the profile password assigned to you by Merchant e-Services
 *  transaction_type - D=Sale, C=Credit, P=Pre-Auth, O=Offline, V-Void, S=Settle Pre-Auth, U=Refund, T= Store card data., X=Delete Card Store Data
 */
$config['Trident'] = array
(
    'profile_id' => '',
    'profile_key' => '',
    'transaction_type' => 'D'
);

/**
 * PayPal Options:
 *  API_UserName - the username to use
 *  API_Password - the password to use
 *  API_Signature - the api signature to use
 *  ReturnUrl - the URL to send the user to after they login with paypal
 *  CANCELURL - the URL to send the user to if they cancel the paypal transaction
 *  CURRENCYCODE - the Currency Code to to the transactions in (What do you want to get paid in?)
 */
$config['Paypal'] = array
(
    'USER'         => '-your-paypal-api-username',
    'PWD'          => '-your-paypal-api-password',
    'SIGNATURE'    => '-your-paypal-api-security-signiature',
    'ENDPOINT'     => 'https://api-3t.paypal.com/nvp',

    'RETURNURL'     => 'http://yoursite.com',
    'CANCELURL'     => 'http://yoursite.com/canceled',

    // -- sandbox authorization details are generic
    'SANDBOX_USER'      => 'sdk-three_api1.sdk.com',
    'SANDBOX_PWD'       => 'QFZCWN5HZM8VBG7Q',
    'SANDBOX_SIGNATURE' => 'A.d9eRKfd1yVkRrtmMfCFLTqa6M9AyodL0SJkhYztxUi8W9pCXF6.4NI',
    'SANDBOX_ENDPOINT'  => 'https://api-3t.sandbox.paypal.com/nvp',

    'VERSION'      => '3.2',
    'CURRENCYCODE' => 'USD',
);

/**
 * PayPalpro Options:
 *  USER      - API user name to use
 *  PWD       - API password to use
 *  SIGNATURE - API signature to use
 *
 *  ENDPOINT  - API url used by live transaction
 *
 *  SANDBOX_USER      - User name used in test mode
 *  SANDBOX_PWD       - Pass word used in test mode
 *  SANDBOX_SIGNATURE - Security signiature used in test mode
 *  SANDBOX_ENDPOINT  - API url used for test mode transaction
 *
 *  VERSION   - API version to use
 *  CURRENCYCODE - can only currently be USD
 *
 */
$config['Paypalpro'] = array
(

    'USER'         => '-your-paypal-api-username',
    'PWD'          => '-your-paypal-api-password',
    'SIGNATURE'    => '-your-paypal-api-security-signiature',
    'ENDPOINT'     => 'https://api-3t.paypal.com/nvp',

    // -- sandbox authorization details are generic
    'SANDBOX_USER'      => 'sdk-three_api1.sdk.com',
    'SANDBOX_PWD'       => 'QFZCWN5HZM8VBG7Q',
    'SANDBOX_SIGNATURE' => 'A.d9eRKfd1yVkRrtmMfCFLTqa6M9AyodL0SJkhYztxUi8W9pCXF6.4NI',
    'SANDBOX_ENDPOINT'  => 'https://api-3t.sandbox.paypal.com/nvp',

    'VERSION'      => '3.2',
    'CURRENCYCODE' => 'USD',

    'curl_config'  => array
    (
        CURLOPT_HEADER         => FALSE,
        CURLOPT_SSL_VERIFYPEER => FALSE,
        CURLOPT_SSL_VERIFYHOST => FALSE,
        CURLOPT_VERBOSE        => TRUE,
        CURLOPT_RETURNTRANSFER => TRUE,
        CURLOPT_POST           => TRUE
    )

);