mendelson opensource AS2 1.1 b51 released

Profile picture for user service

Hi all,

a new version of the community version of the mendelson AS2 software has been released.

You could download your version at

*The key generator could generate EC keys now
*Support for RFC 5753 (Use of Elliptic Curve Cryptography (ECC) Algorithms in Cryptographic Message Syntax (CMS))
*Support for signature generation and validation using EC keys and certificates
*The certificate manager displays the trust chain of every certificate now
*The "Toggle refresh" button now disables the log output, too

*The Algorithm Protection Attribute of signatures could be disabled per partner as there are several older AS2 programs out that could not deal with it

*On receipt of multiple payloads there were generated n tabs in the client but the content was always the one of the first payload
*The manual send process of data did not transfer the right original filename
*EC keys were not displayed in a proper way in the certificate manager
*The original filename is kept now on (manual) transaction resend
*The JKS export of private keys failed
*The p7b import of certificates did not work with more than 2 certificates in the chain
*The p7b export of the certificate manager did not export the whole trust chain
*The passwords had not been set for JKS key import - this resulted in a "cannot recover key" message

Updates (3rd party libs):
*Update to BC 1.54 (crypto API, see
*Update to HSQLDB 2.3.4 (Database)
*Update to javamail 1.5.6
*Update to Apache MINA 2.0.16

The mendelson opensource AS2 will run fine with Java 64 bit VMs. If you have problems with the memory consumption please install a 64 bit java VM (not included), patch the VM with the "jurisdiction policy strength files" (Oracle download) and set the main memory of the JVM to 4 GB.

Please have a look at the included file "upgrade_howto.txt", it explains how to upgrade from an older version of mendelson opensource AS2.

Thank you all for your feedback and your help

Your mendelson dev team




Hello again
and thank you for your support. The workaround worked! But we found an other error, which is critical. Some(very few .. 1-2 per day) messages have an error but won't be shown in the error notification or log! They have the following error:
SendOrderSender.send [java.lang.NullPointerException]: null
Processing error on the file "***" for the relation "***": "null".

The main problem is, that those error can run unnoticed, since we don't get any notification.

I hope you can help me again.

Profile picture for user service


these NullPointers could happen if you modify the interal keystores with external programs - did you do this? We added a new config check to the commercial version some days ago that checks periodically the configuration regarding this issue because we found it at a customers systems?



Hi All, I can't seem to find the disable feature of Algorithm Protection Attribute in the current version we are using. We are using mendelson opensource as2 1.1 build 51. How do we disable this feature, do we need to update the source code?


Hi Support,
I have this monitoring system and I am displaying the server state page using http://yourserver:yourport/as2/ServerState. It was working when I was using the build 49 but after I upgraded to build 51, it is showing "Error connecting to AS2 processing unit: null". Do I need to reconfigure something to make this work again or am I missing something?