python-ewp

This module provides the functions necessary to add support for PayPal's Encrypted Website Payments to your shopping cart. The module is provided as an extension written in C to simplify the process of invoking the necessary OpenSSL functions for signing and encrypting data. Support is provided for both Python 2 and Python 3.

Requirements

In order to build the ewp module, you will need the following installed:

• a C compiler (such as GCC or Clang)
• Python development files (python-dev on Debian / Ubuntu)
• OpenSSL development files (libssl-dev on Debian / Ubuntu)

Installation

To build and install the module, use the following command:

pip install ewp

Usage

The module provides two functions:

signature = sign(key_fn, cert_fn, input)

• key_fn - filename of PEM-encoded private key
• cert_fn - filename of PEM-encoded X509 certificate
• input - data to sign

ciphertext = encrypt(cert_fn, input)

• cert_fn - filename of PEM-encoded X509 certificate
• input - data to sign

Example

The following example assumes you have a private key named "test.key", an X509 certificate named "test.crt", and a copy of the PayPal certificate named "paypal.crt" in the current directory:

import ewp

# String consisting of key=value lines separated by '\n'
data = "12345..."

signature = ewp.sign('test.key', 'test.crt', data)
ciphertext = ewp.encrypt('paypal.crt', signature)

ciphertext can then be used as the value for the <input name="encrypted"> field.