Text watermark to pdf using Itext

Need to add a text watermark to the edge of pdf's that I already have. The script will be used as CLI in a linux distribution, will have a configuration file where I can set default paths, usage should be like this: pdfscriptname -source path_of_source_pdf -text the_text_that_is_going_to_be_appended_to_the_pdf. as the return value should be the path for the watermarked pdf file. I also want to add to the CLI command a -password to secure the pdf to prevent edition of to export contents of the pdf file. please add "thunder" to your proposal subject. looking for an experienced person, don't have time for someone to try and see if he/she can do it.