Digital signatures in pdf.js

[soa-x]

Hi! We are interested about when or if you´re going to implement the Signature Data View (Xades, Pades & Cades) in the PDF viewer (PDF.js)

Kind Regards

Alejandro Pinedo, SOA-X

[brendandahl]

There are currently no imminent plans to implement this feature. We haven't seen it come up much so it hasn't been a priority. We're always looking for more contributors though, so we'd welcome any patches to add this feature. If you're interested in adding it feel free to stop by our IRC channel(#pdfjs irc.mozilla.org) if you have questions.

Brendan

[fermo111]

Hi

what is the present state on the implementation of this feature?

Thanks

[yurydelendik]

@fermo111 Not implemented yet, but I will be glad to coach somebody who is willing to take this task.

[wolvz]

@yurydelendik I'm interested in implementing the feature of presenting digital signatures of PDF files in pdf.js. How can I contact you?

[yurydelendik]

@wolvz please find me at IRC irc.mozilla.org channel #pdfjs (that's simplest) or join any of our public meetings to coordinate stuff.

[wolvz]

I'm trying to implement SigWidgetAnnotation (like TextAnnotation, LinkAnnotation), in annotation.js, for supporting digital signatures in pdf.js. The signature is showing up in the pdf viewer, and I already can extract and verify the certificates embbeded in the DER-encoded PKCS7 object... Now I'm moving into the next step, which is to verify the message digest of the file. For that I need to have access to the file contents... I dont' know if it's possible or not to have access to that from annotation.js, but I can't figure it out. The best I could do was to get the contents in core.js using:

var contentStreamPromise = this.pdfManager.ensure(this, 'getContentStream',[]); var dataPromises = Promise.all([contentStreamPromise]); dataPromises.then(function(data) { var contentStream = data[0]; var contents = contentStream.str.bytes; return contents; });

Can someone please enlighten me on what is the best way to get file contents in annotation.js? Thanks in advance...

[yurydelendik]

https://forums.adobe.com/message/6660799

[ashrafulkarim]

wolvz, any progress in this regard?

[corynewey]

@yurydelendik @wolvz I am extremely interested in the digital signature display feature. I cloned wolvz's repository and built the code but when I try to use it, I'm getting a promise rejection with this error: "require is not defined". Could anyone explain what would cause that error and how I could fix it? Also, I am very willing to continue the work on this feature. I've worked with pdf's in Java via the iText library but working with them in javascript is something I've never tried before. Could someone direct me to some documentation/tutorial that could get me pointed in the right direction so that I can figure out where to start as I try to move this feature further down the field?

[mrpandya007]

I am confused. What i have to do in my pdf.js library to show digital signature pdf in pdfJS

[mrpandya007]

This signature and certificate both showing in pdf.. but when i open it in pdf.js it wont showing there.

[wolvz]

@mrpandya007, the digital signature doesn't show because the developers chose to hide it until they have signature verification feature working. If I recall, if you want them simply to show up you have to comment lines 389 to 392 here: https://github.com/mozilla/pdf.js/blob/master/src/core/annotation.js#L389 Not sure though, and I can't test it right now.

[mrpandya007]

@wolvz, Thanx for the response but its already commented. PLease look into this,, Crystal report's generated pdf signature is not showing but DevExpress generated pdf is showing it properly

[mrpandya007]

Please answer me .... what i have to do.. I can give you that pdf to test

[timvandermeij]

There is no good support for digital signatures yet, so this will have to be implemented.

[mrpandya007]

How many days it will take to fix this problem of digital signature because we are dependent on your lib.

[timvandermeij]

It might take a long time as this feature will have to be developed by someone and there are currently higher-priority issues.

[mrpandya007]

Why i am facing such issue of "=" sign in Headings, only in pdf.js, after downloading the file it gone. any solution please. It is happens only in telerik generated pdf.

[timvandermeij]

@mrpandya007 Please do not post unrelated issues inside other issues. Open a separate issue for that problem.

[ssindelar]

I also encountered the same problem. While I don't necessarily require the signature validation it would be in my case sufficient enough to just show the signature image. Maybe till signature validation is implemented instead of not showing the image it would be better to show the image and annotate it with a small text that says something like "Signature validation not implemented. Signature status unknown"? So at least visiually the pdf would show what you would expect.

[landyg]

Is there a timeline for when this issue will be addressed? Or should we consider another product?

[timvandermeij]

Nobody is working on this yet as far as I know, so if someone is willing to work on this, feel free to submit a PR.

[DORNINEM]

Hi, A PDF.JS version that is able to only displaydigital signature fields should be enough for many users... Is there any "fork" who is able to do this ? Regards

[wolvz]

@DORNINEM you just need to comment out the piece of code that hides the signature annotations. But anyway, here is the fork you asked for: https://github.com/wolvz/pdf.js

[DORNINEM]

@wolvz !! Thanks a lot. I'm wondering why this feature is not in the official version, as it wokrs very fine. I tested with some of my signed PDF files (from 1 to 6 different signature fields) and the result is perfec ! I'm really sure that the real need is to display these fields, not to validate the signature. Signature validation is best done on the server side as it require some times certificates not installed on a local certificate repository.

[maximlefebvre]

Hello,

Someone can explain which line we have to comment or uncomment to allow pdf.js to display the digital signature ?

Thanks for all information :)

[timvandermeij]

@maximlefebvre According to https://github.com/wolvz/pdf.js/commit/7df3f4fe6e21b888358fd7718cb15e3c266ba066, that should be enough to let PDF.js display the signature. Note however that this has not been verified by the PDF.js team as a stable solution (hence why it is not in the official codebase yet), but it might work as a temporary solution.

[viveksjain]

We are interested in implementing signature verification. It seems @wolvz started work on this but didn't complete it - do you have any partial code that we could work on top of?

[amolc]

@wolvz , can you please help us by making a small note to understand your repo. I am unable to understand how to start checking your code. We are trying to implement signature and we may be able to complete your project and help the community.

[rmhrisk]

We have implemented both signing and signature verification of PDFs in browser using https://pkijs, you can see an early signature verification demo here: https://pkijs.org/examples/PDFexample.html we have not yet integrated with PDFjs but will be doing that in the not so distant future. Our intention is to release most of this as OSS and give back any changes to PDFjs that are necessary to make integration smooth.

[viveksjain]

Awesome, thanks @rmhrisk! However, I am not sure how to create a CA bundle file. Do you have details on how to do so? I would imagine when this is integrated with pdf.js it would be more "plug and play" where it comes with Adobe Root CA by default and can verify the certificate chain, right? And do you have a expected timeline for pdf.js integration? Your work is greatly appreciated!

[rmhrisk]

There is one here: http://curl.haxx.se/ca/cacert.pem and one checked into the repository under samples.

There is a tool to create one here: https://github.com/PeculiarVentures/tl-create

[rmhrisk]

I can't share an ETA at this time, we are limited on resources and this is important to us but we need to finish some more complex parts first.

[viveksjain]

I tried the one you linked to, as well as some certificates I tried to extract from the PDF using Adobe Reader, but I always get the error "TypeError: Cannot read property 'signature_time_stamp' of undefined" (in Safari/Chrome stable/Chrome canary).

I happen to have some time this coming week, so let me know if I can help with the merging into pdf.js in any way.

[rmhrisk]

That sample only supports basic signatures, no timestamping or LTV at this time. Feel free to ping me at rmh at unmitigatedrisk dot com

[viveksjain]

Ah, I see. For reference, finally got it to work in Chrome/Firefox (but not Safari, which apparently only supports prefixed WebCrypto) using this CA bundle and this PDF file.

[rmhrisk]

Yes that too, its not only the prefixed issue but they also only support enough webcrypto to handle netflix drm cases. For example they dont let you export the public key for a keypair you generate!? This is a good resource for verifing browser support - https://diafygi.github.io/webcrypto-examples/

[mrpconnor]

@viveksjain Can you confirm how you got it working in Chrome/Firefox

I've tried using the development plugin in firefox however it still appears to fail to show signatures. http://mozilla.github.io/pdf.js/extensions/firefox/pdf.js.xpi

[rmhrisk]

@complience he got the sample code located at https://pkijs.org/examples/PDFexample.html working not PDFjs

[viveksjain]

Hi @complience, I have a proof-of-concept working at https://github.com/viveksjain/pdf.js/tree/sig-verify-support. You can try it by using git clone --recursive https://github.com/viveksjain/pdf.js.git. With a little bit more work it should be ready for a pull request into this repo, but I just haven't had the time yet.

[marklagendijk]

@viveksjain nice! What is still needed before it is ready for a pull request?

[robinblandford-d4h]

+1 Delighted to get this functionality.

[dgbeck]

Yes this will be a great value add to the community, opening the door for many use cases. Thank you!!

[xrkolovos]

+1 for this functionality

[tmetzke]

+1 for this functionality

[timvandermeij]

To all the people above, please make use of GitHub's new +1 reaction button instead of adding comments here.

[gimoteco]

+ 1 for this functionallity

[jimmy-collazos]

👍 + 1 for this functionallity

[timvandermeij]

Again, please use GitHub's reaction button on the top comment to upvote this functionality, which will help us prioritize the issue. Adding "+1" comments causes unnecessary notifications for the developers.

[linus-amg]

"TypeError: Cannot read property 'signature_time_stamp' of undefined" using the branch of @viveksjain