AS2Secure is a PHP library that allows you to send and receive AS2 (Applicability Statement 2) messages from partners. The project is split into two parts: a client to send one or more documents to a partner and a server to receive one or more documents from a partner. Its main features are asyncronous and syncronous MDN, partner setup, digital signatures, message encryption, secure transport (using OpenSSL), support for SSL client authentication, and multiple attachments (AS2 1.2).
