Today an anonymous developer has left us a PC tool named SPKG Tool version 1.0 for both windows and linux. Check out the readme file and the download link below. PS: If you DO NOT know what this is then you should not download.
Requirements:
- fail0verflow key folder
- spkg (3.56+) and pkg (0.80-3.55) key/iv
- disabled ecdsa check in spu_pkg_rvk_verifier
Usage:
- spkg in.pkg out.spkg_hdr
or
- spkg in.spkg_hdr out.decrypted_spkg -d
Thanks to:
- Fail0verflow for their tools
- Anyone that thinks replacing a coldboot logo means creating his/her own cfw