Hi, Here's a brief summery on AS2. Files are encoded as attachments in a S/MIME message. This is what we call an AS2 message. Those messages are sent using the HTTP/HTTPS, usually POST The Messages can be signed, encrypted. This is optional according to the specs. Also, the Messages may request a MDN. (to provide non-repudiation) This is optional too. MDN is typically not encrypted. If there are problems receiving or interpreting the original AS2 message, a "failed" MDN may be sent back. Both "failed" MDN and not receiving MDN (when it is requested) are considered as failures according to specs.
I tried out Mendelson. They provide a AS2 server for testing [1] and a nice user interface. The endpoints are referred to as business partners in AS2 jargon. Mendelson allows to configure business partners. A business partner can be a local station or a remote station. In a local config, we need to specify private keys for encryption and signing. These are picked from a PKCS12 key-store file. The URL to receive MDN can be also configured. In a remote business partner, notable options are sending URL, encryption and signing algorithms (can choose not to sign/encrypt) and its public keys. I'm looking at its source to understand how they handle S/MIME messages. Will update the thread. On Fri, Mar 23, 2012 at 12:17 PM, Amila Manoj <[email protected]> wrote: > Hi all, > > As I previously mentioned in the JIRA [0], I'm interested in adding > $subject for Synapse as my GSoC 2012 project. > I went through some AS2 and EDIFACT resources, including [1] [2]. > > To add AS2 support to Synapse, I think the task is to write a new > transport (as described in Axis2 documentation). > Once the transport is complete, Synapse will be able to mediate AS2 based > messages across other transports that Synapse support. > > Like all other transport components of Synapse, AS2 transport should > include a receiver and a sender. > These will be configurable in the axis2.xml file of Synapse. > Configuring Synapse using axis2.xml for AS2 will look like: > <transportReceiver name="as2" > class="org.apache.synapse.transport.as2.AS2TransportListener"> > ...parameters... > </transportReceiver> > and similarly, > <transportSender name="as2" > class="org.apache.synapse.transport.as2.AS2TransportSender"> > ...parameters... > </transportSender> > > According to the specifications, AS2 can be used send appropriately > packaged EDI, XML, or other business data, using HTTP POST. > I think the focus should be to support EDIFACT based messages. > > Since Synapse uses SOAP as the common message representation, we should > convert incoming messages into a SOAP representation. > However, EDIFACT messages are non-XML. Therefore we'll have to convert > them into XML and wrap it within a SOAP envelope. > (Similar to what's done in FIX transport [3]). For this purpose, I think > XML/EDIFACT format can be used [4] > Found this [7] library to convert EDIFACT TO XML (GPLv3), which might be > useful. > > Usually AS2 clients are called "Trading partners". When sending a message, > they can request an acknowledgement message called MDN (Message Disposition > Notification). > There are several options to send MDN, Sync, ASync, NoMDN etc. I think > this is somewhat similar to axis2's MEP (message exchange patterns). (MDN > vs. NoMDN for in-out vs. in-only MEPs. Sync vs. ASying for Blocking vs. > Non-blocking MEPs) > > Found 2 open source implementations of AS2 for java: > OpenAS2 (BSD) [5] > Mendelson (GPL) [6] > These days I'm trying out those implementations to get a better > understanding of AS2. > > I Will read on how security requirements specified in AS2 can be handled > with Synapse. > Will also look into more details on how other transports in Synapse (like > FIX) are written. > > Any suggestions, pointers to the things I've missed are very much > appreciated. > > [0] - https://issues.apache.org/jira/browse/SYNAPSE-860 > [1] - http://www.ietf.org/rfc/rfc4130.txt > [2] - > http://www.unece.org/tradewelcome/areas-of-work/un-centre-for-trade-facilitation-and-e-business-uncefact/outputs/standards/unedifact/tradeedifactrules/part-4-edifact-rules-for-electronic-data-interchange-for-administration-commerce-and-transport/part-4-unedifact-rules-chapter-22-syntax-rules.html > [3] - > http://svn.apache.org/viewvc/synapse/trunk/java/modules/transports/optional/fix/src/main/java/org/apache/synapse/transport > /fix/FIXUtils.java?view=markup > [4] - http://en.wikipedia.org/wiki/XML/EDIFACT > [5] - http://sourceforge.net/projects/openas2/ > [6] - http://sourceforge.net/projects/mec-as2/ > [7] - https://github.com/metormote/edifact-xml > > > Thanks, > Amila > > -- > Amila Manoj Silva > Undergraduate > Department of Computer Science and Engineering > University of Moratuwa > http://amilamanoj.blogspot.com/ > [1]- http://as2.mendelson-e-c.com:8080/webas2/ -- Amila Manoj Silva Undergraduate Department of Computer Science and Engineering University of Moratuwa http://amilamanoj.blogspot.com/
