Hi,
Thank you for relaying the message.
This new message provides much more relevant information even though that's still not precise enough.
Unfortunately, they didn't update yet the integration guides regarding SIM and AIM.
This thread from their community forum is quite better:
community.developer.authorize.net/t5/Int...not-match/td-p/65807
As you will read there, it seems that they are not organised well enough and rushed the change without updating the old documentations that are still used by a lot of people.
Of course, we didn't heard from the developers of Authorize.net that were supposed to contact us back. I suppose they must be overwhelmed with all the developers trying to reach them to get more information.
I went ahead and modified the authorize.net plugin based on the information I got from the message link and the community forum.
You can download the new version there:
You'll have to generate a signature key on your merchant account and paste it in the new "AUTHORIZE_SIGNATURE_KEY" field of the payment method. It should then hopefully still work like before.
Please first test with the sandbox/test accounts you have and let us know how it goes.
If it goes well, we'll be able to push these changes on our end.
I would recommend to not yet try on a live server as it seems others had a hard time generating the correct signature key based on the examples given by Authorize.net
Note that the plugin still has the MD5 hash field and if you fill it and don't fill the signature field, it should still work with the MD5 hash like before.
Let us know how your tests go.
Finally, our partner Obsidev has developed an Authorize.net plugin which uses the latest API of Authorize.net and will work right off the bat. It integrates in the checkout in a new way allowing for a credit card form built-in your checkout while still allowing for the credit card information to not go through your server for PCI-DSS compliance. We were waiting for HikaShop 4.0.2 to be released to be able to push it out. It should be available on our marketplace in a few days and it will be a good alternative to the plugin we have in HikaShop which uses old APIs of Authorize.net.