FUK #

No one gives a fuk… so you need to take it yourself.

Fetch User Keys - simple tool for fetching SSH keys from various sources.

Sources #

• Raw - no fetching, just raw key from the configuration
• Forges
  • GitHub
  • SourceHut
  • GitLab
  • Forgejo
  • Tangled (via ATProto)
• Host keys via ssh-keyscan
• well-known URI per https://c2sp.org/well-known-ssh-hosts

Reason #

In my case the reason was to be able to easily fetch set of SSH keys for use with agenix, tool for managing secrets while working with Nix deployments. However, usage can be extended to other situations as well:

• Managing allowed_signers to check SSH signatures under commits and stuff
• Fetching authorized_keys to allow users to upload their keys without admin manual intervention

Usage #

Define configuration file, for example keys.toml in form:

[[entry]]
name = "hauleth"
keys = [
    { sourcehut = "~hauleth" },
    { github = "hauleth" }
]

[[entry]]
name = "heimdall"
keys = [
    { host = [ "heimdall" ] }
]

Now you can run

fuk keys.toml > keys.json

And get JSON document containing all keys provided by these:

{
    "hauleth": [
        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIN7q0wm7C+EX0ORpRxeyhvWTT2BMPjSRQIZmbzPLIiHC"
    ],
    "heimdall": [
        "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC36MGQHLsmS1aUtRYyC40lguLR4/sRXDxwT8ieSkGgLFc95xQ/7m8tIYmtCTwIMvN9gzJkW6ufbWfuX1iBYoWVVO/QdJz/5/Nl4ZofyfdFSk4ZYaWSOnMlY7vV9K0L0WsEEf1R3Erf42Ek051PcO8IeTtYTxkaugrBOPSVmzBOZu9osnJbatCsODe7uIWRU8jd5gmL7a9pmk9Q8nWDDXzu4bWd9Dg1M1d+rIY368J4LNOzknPZUkOcK1TpLkutB6bozvaeKSBNaqihA0un1VETArhiUmUY6a0y5e34PNLQjbl5UqHS5tmU5jmolDIJV2hF78+XrgaZf+CNoQ1Ac3QJ",
        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIEZsoYDw74ez/2YLPZMDQgN/KxyGiXHZt+CowWMiyoyL"
    ]
}