<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><span style="font-family:Arial,Helvetica,sans-serif">On Tue, Dec 13, 2022 at 1:59 PM Simon Josefsson via Gnupg-devel <<a href="mailto:gnupg-devel@gnupg.org">gnupg-devel@gnupg.org</a>> wrote:</span><br></div></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
  1) Use WDK to map ONE email address to ONE public key to use for<br>
  email.<br>
<br>
  2) Use WDK to find ALL public keys for an email address.<br></blockquote><div><br></div><div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">The second case, as you describe it, seems to be orthogonal to the first one, in the sense that they are independent of each-other. So, it can be implemented as a separate protocol. But probably it makes more sense to implement it as an extension of the current WKD protocol.</div></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
specifying that a plural-version of the URL returns all keys?  So let's<br>
assume we have this URL to return one public key only:<br>
<br>
 <a href="https://intevation.de/.well-known/openpgpkey/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4" rel="noreferrer" target="_blank">https://intevation.de/.well-known/openpgpkey/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4</a><br>
<br>
Then we could standardize the following (note plural 's') to return ALL<br>
keys for the given email address:<br>
<br>
 <a href="https://intevation.de/.well-known/openpgpkeys/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4" rel="noreferrer" target="_blank">https://intevation.de/.well-known/openpgpkeys/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4</a><br>
<br>
Alternatively, we could use URL parameters on the first URL like this:<br>
<br>
 <a href="https://intevation.de/.well-known/openpgpkey/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4?allkeys" rel="noreferrer" target="_blank">https://intevation.de/.well-known/openpgpkey/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4?allkeys</a><br>
<br>
Or perhaps a compromise -- based on the observation that registering<br>
multiple 'well-known' protocols has a cost, and that URL parameters like<br>
'?allkeys' works badly with HTTPS servers serving static content, how<br>
about a URL like this:<br>
<br>
 <a href="https://intevation.de/.well-known/openpgpkey/allkeys/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4" rel="noreferrer" target="_blank">https://intevation.de/.well-known/openpgpkey/allkeys/hu/it5sewh54rxz33fwmr8u6dy4bbz8itz4</a></blockquote><div><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">Does it make sense to look for a public key by its id? I mean something like this:</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><a href="https://intevation.de/.well-known/openpgpkey/id/847FC5C4337D9CDBD473B7A60967FD258D6414F9">https://intevation.de/.well-known/openpgpkey/id/847FC5C4337D9CDBD473B7A60967FD258D6414F9</a></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">There are two differences with the current well-known url:</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">1. Instead of "/hu/" (which means hashed-userid), there is "/id/" (which means the key id).</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">2. Instead of "it5sewh54rxz33fwmr8u6dy4bbz8itz4" which is the hash of "alice" (in case that the userid is "<a href="mailto:alice@intevation.de">alice@intevation.de</a>"), there is "847FC5C4337D9CDBD473B7A60967FD258D6414F9" which is the id of the key.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">In this case a client can easily ask for the public key that is needed to verify a certain signature.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">However I am not sure, can we find out the userids of the key that is used to sign? If not, then we cannot infer the domain of the well-known url.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">In this case we might need a directory service to lookup the userid(s) that are associated with a certain key id (think of it like a phone book -- you know the phone number and you can find the name of its owner). This directory service might be based on blockchains, or it might be a modified (simplified?) version of the current keyservers.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">However, if we have such a directory service, then we can just list the url where the public key is located, so maybe we don't need a "well-known url" format.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">Dashamir</div></div></div>