We are using Aspose.Words to digitally sign our generated pdfs, this works great but when viewed within Adobe pdf reader we are seeing “This signers identity is invalid” highlighted by the signature having one or more problems.
Digging in deeper it seems this is due to our certificates CA not being in the list of trusted providers managed by Adobes AATL list (https://helpx.adobe.com/in/acrobat/kb/approved-trust-list1.html). We can get around this by trusting it explicitly however this is not an option for our customers.
Going through the certificate list of trusted certificate providers by Adobe it seems all of these require a usb device to manually sign a document, not sure Microsoft will be keen on letting us plug that into their cloud. Also I have yet to see any with access to a pfx file.
Do you have any knowledge of any certificate authorities we can use that provide a pfx? The main impact for us is that customers may be concerned about the authenticity of the document if the signature is treated as suspicious?