Grease data included in file header

[olastor]

Environment

• OS: Linux
• rage version: 0.9.2

What were you trying to do

Creating a plugin

What happened

After successfull test encryption via the plugin, the file header (in the encrypted file) not only included the keys wrapped with my plugin, but also some random grease data. I am not sure if I understand the spec here correctly. Is this intended to happen? I don't see why adding that to the header would bring any benefit. It seems to increase the file size unnecessarily.

-> my-plugin [...]
[...]
-> my-plugin [...]
[...]
-> @r9C{x-grease k#qL>i 2bU A;2E1 c~K8{S
2xeT0hKe3O8p8r+KvoMTHGxtT/TU6rYiJf6zaAdeLworBC/H7GYVWgwKjGBGKWSx
1DNhTkIih+iQQ3uctoAmIVqPBSQFEo8crEtJeiC9pOEE6G05x6vyYXW0CBqBetw4

--- [...]

[...]

[str4d]

Yes this is intentional. rage adds it randomly with low probability, with the intention of ensuring that age's one joint remains functional (that is, ensuring that age file parsers always handle stanza parsing correctly, instead of taking shortcuts based on the "expected" stanzas). See also my comments in #365 (comment).

The spec you referenced is the age-plugin protocol, which is separately greased. It shares the stanza format, but is otherwise independent (grease in that protocol doesn't become part of a file, and vice versa).

[nnathan]

Necroing this thread.

@str4d is there a way to stop greasing the encryption; I want to be able to calculate deterministic sized ciphertext sizes, and I cannot do this when there's an RNG in the mix.