https://community.adobe.com/t5/acrobat/flatten-pdf-after-signature/m-p/12032659#M312513
This seems to be what I wanted: All fields become readonly after at least one is signed. On 12.05.21 20:42, Tilman Hausherr wrote: > Am 12.05.2021 um 16:27 schrieb Ranjeet Kuruvilla: >> https://apache.googlesource.com/pdfbox/+/trunk/examples/src/main/java/org/apache/pdfbox/examples/signature/ShowSignature.java >> >> >> I am using 2.0.23 and Preflight 2.0.23. >> >> It is possible to sign a document and then change a field (check or >> uncheck a checkbox for example). >> >> I want to either >> >> a. make it impossible to change a value after even one signature has >> been given > > use certification signature ( SigUtils.setMDPPermission() ). While > saving incrementally will still be possible, Adobe will complain > (depending on the value used) > >> >> or >> >> b. find out which field was altered after signature > > If it is saved normally, then the signature verification will fail; if > you save incrementally, PDFBox can't tell, but Adobe will mention it. > > Tilman > > >> >> . How can I do that? >> >> I do not think ShowSignature can do that. >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
