As a newbie, I am going to ask a stupid question again. In my current project, I have to make website mixed with google docs, dropbox and mediafire. In addition, when a user will submit a file, that file will be checked whatever the file is digitally signed or not (http://en.wikipedia.org/wiki/Digital_signature).
Now, I need to show that, one file format (either doc or pdf) will be examined to determine that, is it digitally signed or not ? I read the doc file but there is no difference between a signed file and a unsigned file in reading. I thought I would try it in OPENSSL(php), but I did not find any document which indicates doc file can be read for digital signature.
Now, my alternative is java, C#, asp.net. But, I do not know whatever it is possible in any of this one?
In a word, my question is, How to get information of digital signature from a doc/pdf file and how can i verify its signed or not?
ANY OPINION will be a plus point for me (as a newbie, i am in big trouble).
THANK YOU VERY MUCH FOR READING THIS and sorry for my bad English.
Hm, that’s tough. .doc is largely a proprietary format with little to no open specifications (most informations covering that format are reverse-engineered). Regarding PDF: There are a lot of commercial solutions available to process PDFs. Including the parsing of signature informations. You could also try to set your own parser in place for that, since PDF is really an open format. But beware: It gets quite messy
THANKS A LOT Da:Sourcerer. Can you give me some link on getting digital certificate information from pdf. I wanted to do it in doc, but if i can do it in pdf, i will get some idea. Thanks a lot again, i am completely new and hopless