AS2Sender Class

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The AS2Sender class implements an AS2 / EDI-INT client.

Syntax

class ipworksedi.AS2Sender

Remarks

The AS2Sender component may be used to send EDI or other messages over HTTP/S, using the AS2 protocol. It may also be used to verify synchronous or asynchronous server responses.

A typical AS2 transaction is as follows:

(1) The sender sends an EDI document to the receiver using HTTP or HTTPS. Typically the document will be signed and encrypted (particularly if SSL is not used). A signed receipt will also be requested.

(2) The receiver decrypts the message and verifies the signature.

(3) The receiver sends a signed receipt back to the client. The signature is over the hash of an MDN, which contains a hash of the received message.

When sending an EDI message, the client should specify, at a minimum, as2_from and as2_to, url, and edi_data. The post method should then be invoked.

To secure the EDI transmission, the message may be signed and/or encrypted by setting the appropriate certificates. By default, the class will apply message security if the appropriate certificates are specified. To sign the data, set signing_cert. To encrypt, set recipient_certs. If the recipient uses different certificates for signing and encryption it will also be necessary to set receipt_signer_cert.

SSL will also be used if the scheme in url is "https". If your trading partner is using a self-signed certificate, it will be necessary to set ssl_accept_server_cert or trap the on_ssl_server_authentication event to accept the certificate.

The message may also be compressed by setting compression_format.

To request a receipt, or Message Disposition Notification (MDN), simply set the mdn_to property. The mdn_options property may be used to customize the request. By default, the class will request a signed MDN over an SHA1 hash.

The class supports both synchronous and asynchronous MDN receipt delivery. By default, the class requests synchronous MDN receipt delivery, and the MDN will be returned in the HTTP reply. To request asynchronous MDN delivery, set the mdn_delivery_option to the URL where MDN's are to be delivered.

The HTTP reply will automatically be processed by the class. If an MDN was requested, post will validate the MDN and (if signed) establish non-repudiation of receipt. Any errors or warnings will cause the class to throw an exception.

In either case, after the EDI transaction is processed successfully, the mdn_receipt will be populated with the appropriate values.

Validating Asynchronous MDNs

The class may also be used to process and verify asynchronous MDNs. To do this, you should invoke read_async_receipt. This will read the receipt from the current HTTP context (or from mdn_receipt, if set manually), and allow you to determine your trading partner's identity and the message ID. You should then set receipt_signer_cert and original_content_mic, and finally invoke verify_receipt.