Pdf signing with x509 or capicom

[adde]

HI Matteo,
I read your article at simple talk.com.You gave very good explanation
of x509 certificates.That example shows how to digitally sign the
data.I want to sign the pdf,is there any method available in that
DLL.I tried this:-
1.Convert pdf into byte array.
2.sign the byte array as told by you.
3.convert byte[] into pdf again

but it is not solving my purpose

[we-coffee staff]

Hi Ashish,

There are at least two different modes to sign a pdf document.

1. Use the PKCS#7 standard to obtain a signed data message. This
contains your pdf as bytes array, the certificate that signed the
message, and other useful attribute … you need to use it when you want
sign “externally” the pdf. The pdf remain unchanged, but you can
save, for example in a database, the pdf with it signature, the
signature date etc… This is the simple way. You can read more at
www.we-coffee.com/bonnie/bonnie-web.aspx

2. Use the Adobe SDK to perform an “internally” signature of the pdf.
After the signature, the same will appears inside the document when
you open it. To do so you need to use the Adobe SDK that you can
download from the adobe site. This because the signature is saved
inside the pdf document and must be encoded as the PDF standard
states. This solution is very complex to implement and it require the
knowledge of Adobe SDK, Adobe file format and maybe C++. If you need
this type of solution, the most cost-saving way is to search third
partly libraries (open source or commercial) available on internet.


I hope this will help you