I use HTML2PDF tool to export my HTMLs to PDFs. It's a great tool !
However, I am having difficulties implementing Digital Signature Form Field for PDFs !
Basically, what I want, is to add the posibility for digital signing with one click by the client !
(I don't want to digitally sign the PDF with the server's key ! This PDF is downloaded by my clients and each of them must sign with its own digital signature).
Other PDF documents (probably created with other software) have the possibility of inserting a form field for signatures (like textbox, checkbox, radio button, etc.), that when the user clicks it, it automatically asks for the client's Digital Client Certificate (and the user Inserts its Cryptographic Token into the computer and can digitally sign the respective PDF).
How can I generate (I don't know, on the HTML side or on the PHP or PDF side) the necessary form field that when I export my PDF and download it, after opening it with Adobe Reader, for example, clicking on the respective field, the system having to ask me about my digital signature ?
I can always download the PDF manually and use Adobe Reader to Sign the PDF, but I saw other PDFs with forms built-in to digitally sign a document...
Or any other solution would be great...
Thank you !
Trying to digitally sign a PDF document locally by using a form field which I click and it directly asks me for to sign the document.
I cannot generate this kind of a PDF on the server side using PHP and HTML2PDF.
I might be able to do this from Adobe Acrobat Pro, for example, but the PDF is generated automatically on the Web Server.
Related
The below is the line of code I'm using it currently which converts ppt to pdf, however I want to protect pdf , Is there any possibility
PowerPointapp.ActivePresentation.SaveAs path & pdffileNm & ".pdf", 32
This is not possible with the default vba functions available!
See this, not tested by me, example of using an external library to save pdf with password in the past.
Protecting a PDF is not permanent, once the file is opened (using the users decryption key provided by handing over the password), the contents are available to the new owner to add comment or fill forms or otherwise modify by print or text edit or remove watermarks.
Adobe reader will use different parts of those keys to reduce user writes, but no other editor has to.
Browsers need to edit PDF in exactly the same way so my Firefox pdf reader allows me to correct / change web page content or the embedded pdf contents, exactly the same as any other browser or pdf viewer or editor can. The only protected PDF is an unpublished one.
I have a pdf document with multiple signature fields. The first field is signed with a certification signature. Whenever an approval signature is added to my document, a new revision is created and it is possible to view this specific revision in acrobat.
Is it also possible to view the original/initial version of the document? I cannot find this option in acrobat reader.
Edit: #mkl showed me the solution. I didn't find this option before, because I always used a rather old sample pdf from adobe (see screenshot).
For some reason the 'View signed version' option is not available there
[For] an approval signature [...] it is possible to view this specific revision in acrobat.
Is it also possible to view the original/initial version of the document? I cannot find this option in acrobat reader.
In your screen shot you show that the option to view the signed revision is immediately accessible from the signature panel for approval signatures but not for certification signatures.
If you right-click a signature there, though, to get its context menu, you'll find that option there for certification signatures, too:
PS: In English speaking forums it may be better to switch the language of a program to English before making a screen shot.
In a comment you say about that option that
for the sample doc I always used for evaluating, it is not available (see my edit). Do you have any idea what's different?
Your example file is not a "normal" PDF, it merely serves as a container for transporting a XFA form definition. (These piggyback XFA definitions have been deprecated in ISO 32000-2.)
When Adobe Reader (or an other XFA aware PDF viewer; there are not many) displays such a PDF, it ignores regular PDF contents completely and instead draws a form based on the attached XFA XML file.
Apparently Adobe's signature panel does not support the same features for such XFA PDFs as it does for "normal" PDFs.
I would like a PDF for some support workers, which should be easily editable.
I need it to ask on first open for a kind of Customer ID. This should be inserted into the document. Is this possible?
Thanks for help!
This requires either a smart PDF viewer (such as Adobe Acrobat (Reader) on computers, PDFExpert on iDevices, qPDF on Android) OR serverside support.
In the first case, you would use the app.response() method to let the user enter that identifier and then set the result to the according field's value. That could be placed in the PageOpen event of the page the document opens.
Also doing its purpose would be setting the focus to that field when the page opens.
With server support, you could set up a HTML page where the user enters the identifier, submit that to the server, and have the server prefilling the form, using either a ready application like FDFMerge by Appligent, or using one of the PDF creating libraries floating around (such as iText, pdflib, etc.).
I was wondering if it is possible to open a pdf file (located on a web server) in a web browser, edit it and then save it with the changes. Basically what I need is to open, edit and save a certificate protected pdf file in my web browser, without ever having to download a copy to my desktop. The pdf file contains textfields that needs to be filled out with text before saving the changes.
I know that it is possible to view pdf files in a browser, but im unsure if it is possible to edit it when it is protected by a certificate.
What you are asking can be performed in the following methods: First which is the simplest way is to use Adobe Forms server. If you would like to use your own PDF, you will need to extend reader extensions display the form in a frame and perform cross scripting to tell the form to post itself to the server. Note: read Adobe Reader Extension licensing extending reader extension has restriction on usage.
Obviously you can enable reader extension allow user to download edit and upload the file to your server.
Certified forms means you cannot change the form structure but you can fill the form and save it (if it is reader extension enabled)
Using Acrobat 9, if I sign a PDF using a self-signed certificate and then edit the PDF after I sign it, Acrobat will inform me that there is a valid signature on the document but that the document also has unsigned changes. If I then sign the PDF again and look in the signature panel, it will show the first signed revision with a valid signature, notate that changes were made after the first revision was signed and then show a second signed revision with a valid signature.
I am trying to duplicate that behavior using iTextSharp. In code, I create a PDF and sign it. Then, I edit the PDF and sign it again. When I open the document in Acrobat, it shows both revisions but marks the first revision as an invalid signature because the document was altered. From what I can gather, I think iTextSharp is signing the entire document rather than just the first revision inside that document. I have set the Append parameter to true in both the PdfStamper and PdfSignatureAppearance constructors, but it does not seem to have any effect.
Since I can get the desired result using Acrobat, I am assuming I am just not using iTextSharp correctly. Can anyone shed some light on this?
You have to update the existing PDF instead of rewriting it entirely. Set the following attributes to true to enable updating.
PdfReader reader;
...
reader.Appendable = true;
Adobe does this with layers I suppose. Each revision of the PDF is probably placed in a different layer and then signed. If iText supports layers, you may be able to do it in a similar way.