2. Not write anything that isn't allowed
>
>
> Leonard
>
> From: Pablo Ariel Schulklapper
> Date: Thu, 29 Sep 2011 17:22:02 -0700
> To: "podofo-users@lists.sourceforge.net" <
> podofo-users@lists.sourceforge.net>
> Subject: Re: [Podofo-users] UR3
Yes, append == incremental update.
Incremental update doesn't break a signature - since it doesn't change the
byte range that was signed. HOWEVER, depending on what you change with
that update you MAY cause it to become invalid.
How? Because if the certification bits (Perms) say not to allow fo
2011/10/2 Leonard Rosenthol :
> The ONLY POSSIBLE way to write data to a "Reader Enabled" file w/o breaking
> the signature is:
>
> Write in Append mode
> Not write anything that isn't allowed
By Append you mean write an incremental update?
How can I do that without breaking the signature? :-)
Be
00
To:
"podofo-users@lists.sourceforge.net<mailto:podofo-users@lists.sourceforge.net>"
mailto:podofo-users@lists.sourceforge.net>>
Subject: Re: [Podofo-users] UR3
Hi Martin,
Thanks for your reply, I am not sure why but I didn't receive it in my email...
I plan to keep th
Hi Martin,
Thanks for your reply, I am not sure why but I didn't receive it in my
email...
I plan to keep the signature unmodified, but I want to modify the writing
algorithm to use same object order, so byte ranges would not get modified so
frequently and the original signature would be still val
Hi,
I have a PDF that has extended rights for Adobe Reader, so it can be saved
in Adobe Reader with values in its textfields. When I modify it with PoDoFo,
the digital signature in UR3 becomes invalid and Adobe Reader no longer
recognizes the extended rights as valid.
If I wanted to modify PoDoFo'
2011/9/29 Pablo Ariel Schulklapper :
> If I wanted to modify PoDoFo's writing algorithm to solve this problem, do
> you think that is doable?
No. You would have to break the signature, which is unlikely if not impossible.
Best
Martin
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