aka "mirage" aka "eyre oauth"
With Eyre now supporting both local identity authentication, and fake
guest identities, the logical next step is to support authentication
with real non-local identities. Here, we implement that, building on top
of the groundwork laid by #6561.
The primary change is adding a %real case to Eyre's $identity type, and
implementing an http<->ames<->ames handshaking protocol into Eyre for
negotiating approval of login attempts made by unauthenticated HTTP
clients.
The authentication flow, where a "visitor" logs into a "~host" as their
own "~client" identity can be described in brief as follows:
1) Visitor makes an HTTP request saying they are ~client.
2) ~host tells ~client, over Ames, about its own public-facing hostname.
3) ~client responds with its own public-facing hostname.
4) ~host forwards the visitor to ~client's eauth page.
5) Visitor, there already logged in as ~client, approves the login
attempt.
6) ~client shares a secret with ~host over Ames, and forwards the
visitor to ~host's eauth page, including the secret in the request.
7) ~host sees that the secrets received over Ames and HTTP match, and
gives the visitor a new session token, identifying them as ~client.
The negotiating of hostnames/URLs via Ames is crucial to keeping this
handshake sequence secure.
Discovering a ship's public-facing hostname happens when successful
local logins are made by reading out the Host header from the request.
Users may hard-code a value to override this.
Each eauth login attempt comes with a unique nonce. Both the host and
client track the lifetime of these. The corresponding Ames flow (which
goes from ~host -> ~client) is corked when the login attempt gets
aborted, or its associated session expires.
The logout functionality has been updated to let clients ask to be
logged out of sessions on other ships.
Concatenating before we truncate, instead of truncating the entropy by
itself, is slightly simpler.
Because this slightly changes the naming algorithm, we must update the
eyre tests to match.
This condition got incorrectly inverted during 0fee4ce. Of course, the
logic here is still subtly incorrect: if a session gets deleted before
the timer fires, then we set a second one. Unfortunately, we are now
here to fix the bug right now.
%name now returns the identity of the session associated with the
request. %host will always return the @p of the ship *handling* the
request.
The latter becomes especially important for guest sessions, who can only
interact with agents on the local ship, but will still need to specify
who that ship is.
Now that sessions with non-local identities can exist, the host/local
identity should be empowered to forcefully log off any session it hosts.
Additionally, we augment the logout logic with redirect functionality:
it now respects the "redirect" query parameter in the same way the login
page does. Still defaults to redirecting to the login page.
We previously had no mechanism for giving error responses, if a client
submitted an invalid request into a channel. Guest access makes this
important, because guests cannot interact with remote ships. Attempting
to do so will cause a gall crash.
Here, we add error handling logic to channel request processing. We
catch the invalid cases described above and invalidate the entire batch
of channel requests if they occur. We make sure to drop the moves and
revert the state we changed, and give a 400 to the client that
informally describes the problem(s).
aka "the open eyre" aka "universal basic identity"
Urbit already supports presence on the clearnet, but fails to expose any
of its interactive affordances to unauthenticated users. Here, we
improve this situation by granting "guest identity" @ps to every
unauthenticated HTTP request, and extending the channels functionality
to them.
Sessions no longer represent only the local identity. Instead, each
session has either the local identity, or a fake guest identity
associated with it.
Every request that does not provide a session key/cookie gets assigned
a fresh one with a guest identity on the spot. As a result, every
single request has an identity associated with it.
The identity of a request gets propagated into userspace, if the request
ends up there.
For normal HTTP requests, this means the src.bowl gets set to that
identity for both the watch and poke of the request. For backwards
compatibility, the authenticated flag on the request noun gets set at
normal: only true if the request came from the local identity.
For channel requests, this means the src.bowl gets set to that identity
for any pokes and watches it sends, and it can only send those to agents
running on the local ship.
The scry endpoint remains unchanged in its behavior: only available to
the local identity.
Notable implementation detail changes in this diff include:
- Factored all gall interactions out into +deal-as.
- Sessions no longer represent exclusively the local identity. This
matters a lot to +give-session-tokens, %code-changed, and logout
handling.
- Session management got factored out into explicit +start-session and
+close-session arms.
=case was added as an argument to read-s to support %cs subs
it was accidentally removed as an argument during a merge,
breaking %cs subs by causing it to always crash in a
comparison between case and [%da now], because case resolved
to the mold rather than a value. this commit restores
intended functionality.
The refactor from aeon to tako is from May 2022, but unmerged until
March 2023. In the meantime, I added another usage of aeon-flow in July
2022, which was converted to aeon-flow in March 2023, but the argument
itself was unchanged. This meant we didn't save the cache after +goad.
the issue with compiling not working is with doccords on the deferred
expression, not everything that follows (which would turn off doccords
for anything past =*)
see #6307
this turns doccord parsing off for =* and +*, which was not intended to
be allowed for the first release, but it ended up not compiling if
postfix doccords were put on either of these.
the right way to fix this is to actually implement doccord parsing for
=* and +*, but at least turning them off seems to fix the compile error here.
