Hosting a Web Key Directory (without dynamic service)

Ideally a Web Key Directory will be created and maintained through a web service, but organizations or individuals may want to just host a WKD without a service, instead relying on a flat file structure which must be recreated whenever a public key changes.

How-tos

Using GnuPG's included gpg-wks-server executable to provide a dynamic Web Key Service

• Hosting with website content management (Introduction by Phil Pennock, written 2020-01-12)
• GnuPG Web Key Directory Setup by Mike Kuketz (in German, written 2019-09-11)
• Hosting a Web Key Directory – for UberLab users (last updated 2021-08-03)
• GnuPG Micro Howto § Web Key Directory Setup by Florian Latzel (in German, last updated 2025-07-20)
• End-to-End Encryption: PGP keys via WKD by Giacomo Tesio (in Italian, written 2025-11-16)

Using other keyserver software

• Mailvelope Keyserver can act as a Web Key Directory host with a small patch and a reverse proxy, like Caddy.

Requirements

• A web server that provides https with a trusted certificate.

Test

After setting it up the following should work with your email address (on a GNU/Linux system with GnuPG installed ). It does not import your pubkey.

   gpg --homedir "$(mktemp -d)" --verbose --locate-keys your.email@example.org

An alternative test with extra output is:

gpg-wks-client --check -v --debug=ipc your.email@example.org

Using gpg-wks-client from GnuPG (since v2.2.12)

GnuPG 2.2.12 has an improved gpg-wks-client tool which can be used to create a local file under the subdir openpgpkey, which has to be created.

It takes the (public) keys from the GnuPG keyring, so the keys need to be known to GnuPG.

PATTERN="@example.org"
gpg --list-options show-only-fpr-mbox  -k $PATTERN | gpg-wks-client -v --install-key

(Note for windows 10 - PowerShell: You may require path names to the binary, e.g. 'C:\Program Files(x86)\GnuPG\bin\gpg-wks-client.exe')

Details:

• The gnupg keyring is searched for all public keys (-k) matching the defined pattern, the output is generated as fingerprint user_id values (show-only-fpr-mbox).
• WKD will be only useful for keys of the domain serving the directory. If you specify other patterns (e.g. "jane.Doe@example.org"), all keys matching that pattern will be considered for the update (which will be useless in the case of domains you do not serve, but useful if you only want to update a subset of keys).
• This listing will then be piped to gpg-wks-client, which will create the appropiate folder structure and entries for each result.
• the output will be written to the openpgpkey folder (or any folder you specify with the -C option). See publishing for the final placements and additional adaptions.

Method with older GnuPG version

Use the generate-openpgpkey-hu script in the wkd-tools Mercurial repository; this implementation uses Python 2 and either the python-gnupg or PyMe modules.

There is an alternative implementation using Python 3 and python-gnupg available on GitLab.

Usage

You can either export all the keys in your keyring which belong to a domain or provide an explicit keyring containing the keys you want to publish.

The call:

    ./generate-openpgpkey-hu example.com hu

Will create a directory called hu containing all the keys with @example.com mail addresses.

If there are multiple valid keys for a user in your keyring this command will error out. In that case you can prepare a keyring with only the keys you want to publish, e.g.:

    gpg --export 94A5C9A03C2FE5CA3B095D8E1FDF723CF462B6B1 | \
    gpg --no-default-keyring --keyring ./wkd-keyring.gpg --import

And then provide that keyring to generate-openpgpkey-hu:

    ./generate-openpgpkey-hu example.com hu wkd-keyring.gpg

Publishing

The hu directory has to be published on your server as https://openpgpkey.example.com/.well-known/openpgpkey/example.com/hu/ (or https://example.com/.well-known/openpgpkey/hu/ if openpgpkey.example.com is not resolvable via DNS).

On your server create the according directory and set the permissions according to your system. Make sure that there is no automatic directory listing for .well-known/openpgpkey/example.com/hu/ (or .well-known/openpgpkey/hu if using the fallback "direct" URL scheme).

Starting with draft 05 the OpenPGP Web Key Directory specification requires that a policy file https://openpgpkey.example.com/.well-known/openpgpkey/example.com/policy (or https://example.com/.well-known/openpgpkey/policy if using the "direct" URL scheme) is available. It can be an empty file, which fits well here, because it is only relevant for the update protocol anyway.

A free WKD Checker web service can verify the functionality of the WKD.

This example Makefile automates the hu directory generation and publishing (using the python script for the older gnupg version method as documented above). Edit the variables at the top of the makefile to your RSYNC_TARGET The KEYRING variable is optional and can be empty.