Add an electronic signature to a PDF

[PrSunflower]

Hi, thank you very much to all devs, Sumatra is a great PDF reader and has replaced Adobe Acrobat for me... except for one feature! 😄

It would be great if it was possible to add an electronic signature (not a cryptographic digital signature) just like the "Fill & Sign" tool in Acrobat Reader.

Basically I want to add a PNG picture of my signature on top of an existing PDF document.

[GitHubRulesOK]

@kjk in some apps this is most easily done using the annotation features with a custom stamp. there is an open issue https://github.com/sumatrapdfreader/sumatrapdf/issues/1681 that when moving custom stamps they get destroyed, that would need to be fixed first.

[metya]

Are there any plans for that feature?)

[GitHubRulesOK]

@metya which feature ? Adding an image to a PDF is trivial for many powerful paid Editors, but is not a native feature in MuPDF-GL reader It will need someone to write an editor function just to stamp a static png of my signature.

For significantly complex secured electronic signatures as raised by OP it needs a team as big as the one amongst the tens of thousands employed by Adobe

[PrSunflower]

@GitHubRulesOK thanks for the precision 👌

For significantly complex secured electronic signatures as raised by OP it needs a team as big as the one amongst the tens of thousands employed by Adobe

Yeah that's why I asked for electronic signatures, not digital signatures. I cannot ask that to a team of voluntary developers.
Moreover implementing digital signatures would require validation from certificate authorities and I am not sure if that's compatible with the developers' vision for their free & open-source software.

Side note: What a coincidence it's been exactly 1 year since I've created this issue!

[GitHubRulesOK]

Personally I have a low regard of the value of any means of signing, unless there is a form of Escroue which is basically what is provided by Full Witnessed Certified Digital Signatures (and even then are open to abuse)

[fkrivsky]

This would be super useful feature. I've been signing a lot of documents lately (since Covid basically) using Foxit Reader and this feature missing in Sumatra is a deal breaker for me...

[GitHubRulesOK]

The common signature stamping of pages (just like running through a bulk rubber stamping machine) can be done at 1000's pages per minute by any command line tool (there is no need for a GUI, if the page position is the same.) Likewise it is a waste of time rubber stamping one or more pages to approve actions since an e-mail "my word is my bond" saying "sanctioned" (let it happen) should be good enough. the key is 3rd party holding the deed. 1590s, in law, "a writing fully executed by the parties, but put into the custody of a third person to hold until the fulfilment of some condition, Like death will and in pdf terms that requires an electronic locked (encrypted) witness service.

[fkrivsky]

The common signature stamping of pages (just like running through a bulk rubber stamping machine) can be done at 1000's pages per minute by any command line tool (there is no need for a GUI, if the page position is the same.) Likewise it is a waste of time rubber stamping one or more pages to approve actions since an e-mail "my word is my bond" saying "sanctioned" (let it happen) should be good enough. the key is 3rd party holding the deed. 1590s, in law, "a writing fully executed by the parties, but put into the custody of a third person to hold until the fulfilment of some condition, Like death will and in pdf terms that requires an electronic locked (encrypted) witness service.

In my country we don't use 1590s laws. Also I meant like 50 different documents in the last couple of years, not the best choice of words I see :) A "lot" comparatively to the past... I just need to review a document and place the signature stamp manually wherever needed, which is a common practice here.

[llewynS]

Personally I have a low regard of the value of any means of signing, unless there is a form of Escroue which is basically what is provided by Full Witnessed Certified Digital Signatures (and even then are open to abuse)

Your low regard is irrelevant to the request. A custom stamp that includes ones signature is a basic feature that is useful in most countries. Not having the feature would reduce the number of people that find this program useful, e.g I just downloaded it purely for this and have no use for it without this feature. Being able to place your signature on a pdf removes the need to print, sign, and rescan. A personal signature is not secure, so it doesn't reduce validity, it does reduce waste, and it is more convenient. Your country is extremely officious if they don't allow this.

[GitHubRulesOK]

@llewynS without laboring the point I got paid well for injecting my image and the image of checker and line manager and his boss on every document I produced, because i was paid less than them. the real method of verification was i sent documents through a chain that they should have actioned the bulk receipt of and not rejected.

[caramdache]

I am also in need of being able to insert an image into a PDF document. The document types vary, so it's not able to set programmatically (I wish it was).

Not having this feature is also holding me back from switching totally from Adobe Reader or Foxit to Sumatra PDF.

[GitHubRulesOK]

I use Tracker exchange as lighter than Foxit and it's easy to set both to jump from one to the other on same page without closing and opening either.

[caramdache]

I use Tracker exchange as lighter than Foxit and it's easy to set both to jump from one to the other on same page without closing and opening either.

Excellent indeed!

Here's how to do it, just in case anyone comes around here:

1. Install Tracker Exchange (now `PDF-XChange Editor').
2. Open a PDF document in SumaryPDF.
3. File/Open in PDF-XChange
4. Edit the document in PDF-XChange, then File/Save
5. SumatraPDF refreshes automatically and displays the update PDF.

[GitHubRulesOK]

@caramdache and others You can do the same with Edge inking or any free text overwrite, beware Edge uses an unconventional HTML/Word means to scale text which MuPDF/SumatraPDF will revert to conventional PDF spaced plainer text. The bonus is easier to add up to 256 chars in many languages, however avoid using more than 256 in any comments (SumatraPDF has had to apply a limitation).

There is an overarching limit that dual working is only possible in PDFs under 32 MB

The point about open one in the other is SumatraPDF can call MSEdge.exe with the active page to be inked and show on save, but not so easily the other way. But in exchange using a customised "launch" call SumatraPDF with filename and page ID and conversely in SumatraPDF an ExternalViewers command passing filename and page number to exchange.

[polar147]

The MuPDF disponibilize the mutool that can digital sign PDF files

https://www.mupdf.com/docs/manual-mutool-sign.html

[AlexErrant]

Firefox can do some basic edits to pdf https://www.mozilla.org/en-US/firefox/features/pdf-editor/ including

• Add text
• Add drawings (or your signature)
• Add image

[GitHubRulesOK]

There is nothing really special about signing. Just the ease with which it may be added (and removed, PDF is no more secure signed than unsigned) and thus signatures are simply added and removed just like text when coded/decoded.

Here a text file with a PDF extension and a signing box in SumatraPDF. Clicking the link can invoke Adobe signing and read the returned signed file. That Adobe Digital Signature is acceptable in Most Legal jurisdictions and delete able, detectable too, like in any PDF!

Here is that text file (to see how PDFs can be decoded simply read it with notepad) open in SumatraPDF and click on the link under the box, sign it and its a legal document. Abracadabra2 (1).pdf

and that signed lock copy with signature redacted (removed) is available to be signed again by anybody else