access: a token with a limit changes no credentials

A token's limit narrows every endpoint but those under /auth, which any
registered user may call. Among them, PUT and DELETE /auth/keys/{id}
change the keys the user logs in with, and POST /auth/logout ends every
token of the user. With the token a dashboard hands to another member's
(the member list, read, five minutes), its holder could add a key of its
own and log in by it as the user, with everything the user may do.

These now take a password or a token without a limit
(Need::Credentials, refused where Caps::limited). A narrowed token still
refreshes within its limit, says who it is, lists the user's keys and
ends its own session (DELETE /auth/session): a dashboard opened from
another member's logs out with it.

1 files changed, 23 insertions, 1 deletions

diff --git a/src/api/access.rs b/src/api/access.rs
index 6d26139..6977a0a 100644
--- a/src/api/access.rs
+++ b/src/api/access.rs
@@ -252,8 +252,13 @@ enum Need {
     Store,
     /// Looking at this node (its figures, peers, dashboard): any capability.
     Observe,
-    /// Logging in, refreshing, asking who one is: any registered user.
+    /// Logging in, refreshing, asking who one is, ending one's session: any registered
+    /// user.
     Auth,
+    /// Changing what one logs in with (one's keys), or ending every token one has: a
+    /// user not narrowed by a token's limit. A token handed over to read the member list
+    /// for five minutes adds no key that logs in as its user.
+    Credentials,
     /// A right on protocol data.
     Protocol(Right, Vec<String>),
 }
@@ -271,6 +276,8 @@ fn needed(method: &Method, path: &str, node: &str) -> Need {
     let local = |right, name: &str| protocol(right, &[meta::LOCAL, node, name]);
     if under("/store") || under("/stream") {
         Need::Store
+    } else if (under("/auth/keys") && !looking) || path == "/auth/logout" {
+        Need::Credentials
     } else if under("/auth") {
         Need::Auth
     } else if (path == "/peers" && looking) || path == "/admin/stats" || under("/admin/dashboard") {
@@ -307,6 +314,10 @@ fn needed(method: &Method, path: &str, node: &str) -> Need {
 fn allowed(need: Need, access: &Access) -> bool {
     match need {
         Need::Store | Need::Auth => true,
+        Need::Credentials => match access {
+            Access::Everything => true,
+            Access::Caps(caps) => !caps.limited(),
+        },
         Need::Observe => match access {
             Access::Everything => true,
             Access::Caps(caps) => !caps.is_empty(),
@@ -413,6 +424,17 @@ mod tests {
         assert!(allowed(need(&Method::GET, "/admin/stats"), &handed));
         assert!(allowed(need(&Method::GET, "/peers"), &handed));
         for (method, at) in [
+            (Method::POST, "/auth/refresh"),
+            (Method::DELETE, "/auth/session"),
+            (Method::GET, "/auth/whoami"),
+            (Method::GET, "/auth/keys"),
+        ] {
+            assert!(allowed(need(&method, at), &handed), "{method} {at}");
+        }
+        for (method, at) in [
+            (Method::PUT, "/auth/keys/laptop"),
+            (Method::DELETE, "/auth/keys/laptop"),
+            (Method::POST, "/auth/logout"),
             (Method::DELETE, "/peers/continuum:00"),
             (Method::POST, "/admin/remakes"),
             (Method::GET, "/admin/document"),