How can I remove a signature from a signed jar file / How can I unsign a jar?

Q: How can I unsign an existing jar file?

A: Follow the steps below to remove a signature from a jar file

    • Open the jar using WinRar or Winzip (jars are actually zip files)
    • Go into the META-INF directory
    • Delete all files (*.SF, *.RSA) but keep MANIFEST-MF.
winrar_manifest
Inside the MANIFEST-INF folder, remove all files except for MANIFEST.MF, ie files with extension .SF, .RSA. etc…
    • Open the MANIFEST.MF and Remove all entries below the line that reads “Codebase: *” (they are the entries that are signature related, see screenshot.
Inside MANIFEST.MF files, delete all entries related to class signatures (highlighted in blue)
Inside MANIFEST.MF files, delete all entries related to class signatures (highlighted in blue)
  • Save and close the MANIFEST.MF file (you will be prompted to update it in the bundle and should respond yes.)