QR Code format
- QR Codes contain an Uri with the
openpgp4fpr
scheme and the full OpenPGP v4 key fingerprint, such asOPENPGP4FPR:73EE2314F65FA92EC2390D3A718C070100012282
. - The Uri is fully uppercase to use the more efficient alphanumeric encoding that does not support lowercase letters.
- Only full fingerprints are supported, not key IDs. After scanning, OpenKeychain allows for certification of keys and this is only secure with full fingerprints.
- OpenKeychain also supports opening
openpgp4fpr
Uris with full fingerprints via Android'sandroid.intent.action.VIEW
Intent.
vCard support
OpenKeychain supports OpenPGP key fingerprints encoded in QR Code vCards. Key to be imported is retrieved from vCard's KEY
field.
The following example shows how to embed a public key fingerprint as an openpgp4fpr
scheme URI inside the vCard:
BEGIN:VCARD
FN:Linus Torvalds
EMAIL:torvalds.at.kernel.org
KEY:OPENPGP4FPR:ABAF11C65A2970B130ABE3C479BE3E4300411886
END:VCARD
After encoding this text as a QR Code and scanning it with OpenKeychain's built-in QR Code scanner the key with fingerprint ABAF11C65A2970B130ABE3C479BE3E4300411886
will be imported.
About openpgp4fpr
(copied from effigies/openpgp4info)
In 2010, the Monkeysphere project introduced the openpgp4fpr:<FINGERPRINT>
scheme for sharing OpenPGP version 4 key fingerprints, where <FINGERPRINT>
is the full 40 hex character fingerprint of a master key, and has since been adopted in vCards for sharing public keys.
Perhaps more significantly, several Android applications (APG/OpenKeychain, and the Guardian Project's GnuPG port) now accept this scheme as a means of quickly exchanging public keys via QR codes. The Android "intents" interface paves the way for openpgp4fpr
URIs to become increasingly common.
In early 2015, the WHATWG accepted openpgp4fpr:
as a whitelisted scheme.