A format validator checks the structure of a keyset without exposing its values. It is the right first step whenever a tool rejects a file, because it separates “this file is malformed” from “this file is fine but does not match what the operation expects”.
What a validator checks
- Parsing. That the file can be read as a keyset at all, which catches encoding and line-ending problems.
- Naming. That entry names follow the expected form and case.
- Consistency. That whitespace, separators and blank lines are within what a parser tolerates.
- Coverage. That the categories the keyset ought to carry are present — reported as a list of names, never as values.
- Revision tags. That the revision context the file indicates is internally consistent.
What a validator cannot do
It cannot tell you whether a keyset is “genuine”, whether it will work with a particular piece of content, or whether a value is correct. Structure and cryptographic correctness are different properties, and only the first is checkable locally in a meaningful way.
Run it locally
Structural validation should happen on your own machine. Uploading a keyset to an online checker hands the material to a third party and creates exactly the disclosure problem the handling guide warns about.
Common errors a validator surfaces
- A file that does not parse — see file-format problems.
- One entry rejected while others load — see invalid key.
- A structurally valid file that a tool still ignores — see tool cannot recognise keyset.