Daniel Passos Without the trailing '=' the decoded file is identical but the last byte (the decoded file is 1 byte shorter). The library we currently use to parse the PKCS7 (node-forge) doesn't detect any error and correctly parses the PKCS7 even without that byte. I tried to update node-forge to the latest release but that didn't help.

I believe the best solution here would be to change the text field to a file upload field, so that the file gets BAS64 Encoded by the app, thus avoiding copy&paste mistakes.

In the meantime I'm looking to see if we can use some other library and/or provide a patch to node-forge.