sbtools: factor key code, introduce crypto layer, move from open/read/... to fopen/fread/..., add support for encryption/decryption using a device when the key is not known, move sbtoelf to use getopt for command line

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30849 a1c6a512-1295-4272-9138-f99709370657
7 files changed