Hi,
has PDFTron for iOS something like preparing the document before signing? Something like the method document.preClose()?
I will explain. I have a pdf document that has filled the form data. Just before signing, I want to calculate the hash pdf document, prepare the signature ("Contents" in the signature field in "V" - dictionary parameter).
My questions:
1. How to prepare a document for signing, that means it will no longer change, and the hash must always be the same?
2. How to save the document as a byte array?
3. How to calculate a document hash (SHA256) using PDFTron?
Thanks,
LP
Something like the method document.preClose()?
Can you please elaborate on where you see this method?
1. How to prepare a document for signing, that means it will no longer change, and the hash must always be the same?
You will need to add or create a digital signature.
This sample shows you how to generate hash for the document. You don’t have to calculate it yourself, the PDFTron SDK does it for you.
DigitalSignatures: https://www.pdftron.com/documentation/samples#digitalsignatures
Please also look at the following samples:
For adding (InteractiveForms): https://www.pdftron.com/documentation/samples#interactiveforms
2. How to save the document as a byte array?
Please check Save and SaveToBuf method descriptions from the link below:
https://www.pdftron.com/api/ios/pdftron/Classes/PTPDFDoc.html#/c:objc(cs)PTPDFDoc(im)Save:flags:
https://www.pdftron.com/api/ios/pdftron/Classes/PTPDFDoc.html#/c:objc(cs)PTPDFDoc(im)SaveToBuf:
Read & Write a PDF File From/To Memory Buffer:
https://www.pdftron.com/documentation/samples#pdfdocmemory
3. How to calculate a document hash (SHA256) using PDFTron?
Please see the following forum post: https://groups.google.com/forum/#!searchin/pdfnet-sdk/hash|sort:date/pdfnet-sdk/H9tGP4Z9TW4/rNdk3SjABwAJ
Also, DigitalSignature sample https://www.pdftron.com/documentation/samples#digitalsignatures
-Yasser