Hagrid

Hagrid is a verifying OpenPGP key server. When a new key is uploaded a token is sent to each user ID via email. This token can be used to verify the user ID. Keys can be queried by their verified user IDs (exact match) and their primary keys fingerprint. Keys can be deleted by clicking a link send to all user IDs.

Quick Start

Building Hagrid required a working Rust nightly toolchain. The key server uses the filesystem to store keys, user IDs and tokens. To run it, supply the absolute path to where you want the database to live and the absolute path to the template directory.

cp Rocket.toml.dist Rocket.toml
cargo run --bin hagrid

This will spawn a web server listening on port 8080.

Hagrid uses sendmail for mailing, so you also need a working local mailer setup.

Usage

HKP

Hagrid implements a subset of the HKP protocol so that tools like GnuPG and OpenKeychain can use it without modification.

GET /pks/lookup?op=get&options=mr&search=<QUERY>

Returns an ASCII Armored key matching the query. Query may be:

• An exact email address query of the form localpart@example.org.
• A hexadecimal representation of a long KeyID of either a primary key, or a subkey (069C0C348DD82C19, optionally prefixed by 0x).
• A hexadecimal representation of a Fingerprint of either a primary key, or a subkey (8E8C33FA4626337976D97978069C0C348DD82C19, optionally prefixed by 0x).

Note that while the hexadecimal digits may use either case, using upper case letters is more efficient with Hagrid.

GET /pks/lookup?op=index&options=mr&search=<QUERY>

Returns a machine-readable list of keys matching the query. Query may have the forms detailed above. Hagrid always returns either one or no keys at all.

POST /pks/add

Keys may be submitted using a POST request to /pks/add, the body of the request being a application/x-www-form-urlencoded query. keytext must be the key to submit, either ASCII Armored or not.

Limitations

By design, Hagrid cannot (or intentionally chooses not to) implement the full HKP protocol. The main limitations are:

• No support for op=vindex,
• only exact matches for user IDs are returned (i.e. exact=on is always assumed),
• the fingerprint variable is ignored,
• the nm option is ignored,
• op=index returns either one or no keys,
• uploads are restricted to 1 MiB,
• all packets that aren't public keys, user IDs or signatures are filtered out.

VKS

Hagrid has its own URL scheme to fetch keys.

GET /vks/v1/by-fingerprint/<FINGERPRINT>

Retrieves the key with the given Fingerprint. Fingerprint may refer to the primary key, or any subkey. Hexadecimal digits MUST be uppercase, and MUST NOT be prefixed with 0x. The returned key is ASCII Armored.

GET /vks/v1/by-keyid/<KEY-ID>

Retrieves the key with the given long KeyID. KeyID may refer to the primary key, or any subkey. Hexadecimal digits MUST be uppercase, and MUST NOT be prefixed with 0x. The returned key is ASCII Armored.

GET /vks/v1/by-email/<URL-encoded user ID>

Retrieves the key with the given User ID. Only exact matches are accepted. Lookup by User ID requires opt-in by the key's owner. The returned key is ASCII Armored.

Building

Building Hagrid requires a working nightly Rust toolchain. The easiest way to get the toolchain is to download rustup. After rustup is installed, get the nightly compiler and tools:

cd hagrid
rustup override set nightly

The web server can now be built with the cargo command:

cargo build --release

After compilation a binary is placed in target/release/ called hagrid. The binary is linked statically and can be copied everywhere.

cp target/release/hagrid /usr/local/bin

To deploy the key server copy all directories under dist/ to a writable location, and create a suitable configuration file.

mkdir /var/lib/hagrid
cp -R dist/* /var/lib/hagrid
cp Rocket.toml.dist /var/lib/hagrid/Rocket.toml
$EDITOR /var/lib/hagrid/Rocket.toml
/usr/bin/env --chdir=/var/lib/hagrid ROCKET_ENV=production hagrid

This will spawn the server in foreground. The server will put all keys and runtime data under the base folder (/var/lib/hagrid in the above example).

Reverse Proxy

Hagrid is designed to defer lookups to reverse proxy server like Nginx and Apache. The key database is a set of 3 directories with static files in them. The directory structure reflects Hagrids URL scheme. This way, lookups via /vks/v1/by-finingerprint, /vks/v1/by-keyid, and /vks/v1/by-email can be handled by (multiple) simple HTTP server(s). A sample configuration for Nginx is part of the repository (nginx.conf).

Community

We're in ##hagrid on Freenode.