>>>Hi all,
>>>
>>>I've got a requirement that for an existing PDF I need to protect it with a password.
>>>Can anyone recommend an API, usable from VFP (and possible .NET) to do this ?
>>>
>>>Thanks in advance,
>>>
>>>Walter
>>
>>Walter, you can use the PdfTK for that. They have a server operable from the command line that that we integrated easily into our applications where PDF manipulation functionalities were required.
>>
>>To get your password protected PDFs (variable arguments in bold):
>
>
>>pdftk.exe source.pdf output protected.pdf user_pw password
>>
>>PdfTk website and server's page: https://www.pdflabs.com/tools/pdftk-server/
>
>
>
>Thanks antonio, This seems to fit to what we need. One question left: Can you distribute it to clients ? Any specific install needed or can you just execute it as a exe file ?

Walter, to distribute the server to clients you need to purchase a Server license, unless your application is GPLicensed. Your clients may eventually purchase their own copies of the Toolkit Pro which includes a server, but you're not allowed to distribute it without a license.

An installer is normally required, but I don't know if it can be replaced by a simpler deployment of the exe + dll.