Appending remote PADES signatures

[arvinjarvin]

Hi

Hope you're well

Wondering how I can append a remote PADES signature with your library, which is a base64 returned by an external signing service.

[vbuch]

Hi,
You would need to implement a Signer. The package only has one such implementation currently - https://github.com/vbuch/node-signpdf/blob/develop/packages/signer-p12/src/P12Signer.js but as you can see the abstract is quite simple https://github.com/vbuch/node-signpdf/blob/develop/packages/utils/src/Signer.js#L4

[vbuch]

It's the signature only. It will be used here: https://github.com/vbuch/node-signpdf/blob/develop/packages/signpdf/src/signpdf.js#L79
The idea is that @signpdf/signpdf will deal with the PDF part. The Signer should only care of crypto.

[vbuch]

You should probably have a look at #230
You didn't say what the external signing service would be...

[masterviana]

It's the signature only. It will be used here: https://github.com/vbuch/node-signpdf/blob/develop/packages/signpdf/src/signpdf.js#L79 The idea is that @signpdf/signpdf will deal with the PDF part. The Signer should only care of crypto.

Just to clarify, the PDFBuffer we receive in our custom signer is the complete PDF buffer without the signature itself. It's ready to be hashed and signed, like creating SignedAttr and CMS. Then, @signpdf/signpdf handles adding the signature to the correct location in /Contents and padding it if necessary.