Lock accounts: keep receiving mail, no sign-in, hand to delegates

A locked account can't sign in (it fails as a wrong password does), its
sessions end on every node, refresh tokens stop working, and its Sieve
scripts forward and reply to nothing. Mail keeps arriving.

Delegates get real ACL grants on the account's mailboxes, calendars,
address books and files at read, organize or full, with the rights they
replaced restored on unlock. Folders made later are granted after the
create and in a daily sweep. Organize delegates can't destroy; send-as
needs organize or full. The JMAP session marks delegated accounts in
urn:inbuxa:jmap.

New inbuxa:AccountLock object with get/set, permissions 665-668, and a
Compliance > Locked Accounts entry in the schema. Lock, unlock and
delegate changes need a reason and are audited; delegate access and
writes are audited too (audit-hold-lock spec AL-1 to AL-12).

crates/common/src/audit.rs

@@ -35,6 +35,7 @@ const KIND_ACCOUNT_ACCESS: u8 = 0;
 const KIND_BLOB_ACCESS: u8 = 1;
 const KIND_SIGN_IN: u8 = 2;
 const KIND_SIGN_IN_FAILED: u8 = 3;
+const KIND_DELEGATE_ACCESS: u8 = 4;
 
 /// The permissions that make an account an administrator for AU-1.4: every
 /// `sys*` permission a plain user doesn't get by default, and impersonation.
@@ -369,6 +370,80 @@ impl Server {
         }));
     }
 
+    /// AL-9: a delegate reaching a locked account: its access once an hour,
+    /// and every change it makes there, one record per method call.
+    pub async fn audit_delegate(
+        &self,
+        token: &AccessToken,
+        locked_id: u32,
+        access: &str,
+        write: Option<&str>,
+        error: Option<&trc::Error>,
+    ) {
+        let first = self.audit().first_access_this_hour(
+            token.account_id(),
+            locked_id,
+            KIND_DELEGATE_ACCESS,
+            now(),
+        );
+        if !first && write.is_none() {
+            return;
+        }
+        let actor = self.audit_actor(token).await;
+        let target = Target {
+            kind: "account".into(),
+            id: Some(Id::from(locked_id).to_string()),
+            name: Some(self.audit_account_name(locked_id).await),
+            account_id: Some(locked_id),
+            tenant_id: self
+                .account(locked_id)
+                .await
+                .ok()
+                .and_then(|account| account.id_tenant),
+        };
+        let mut records = Vec::new();
+        if first {
+            records.push(Record {
+                at: ms(),
+                actor: actor.clone(),
+                via: token.origin().cloned(),
+                remote_ip: None,
+                action: Action::AccountAccess,
+                target: target.clone(),
+                changes: vec![],
+                details: Some(format!("As a delegate ({access})")),
+                reason: None,
+                outcome: Outcome::success(),
+            });
+        }
+        if let Some(method) = write {
+            records.push(Record {
+                at: ms(),
+                actor,
+                via: token.origin().cloned(),
+                remote_ip: None,
+                action: Action::Update,
+                target,
+                changes: vec![],
+                details: Some(format!("{method} as a delegate ({access})")),
+                reason: None,
+                outcome: match error {
+                    None => Outcome::success(),
+                    Some(err) => Outcome::refused(
+                        "error",
+                        err.value_as_str(trc::Key::Details).map(str::to_string),
+                    ),
+                },
+            });
+        }
+        for record in records {
+            if !self.audit_note(record).await && first {
+                self.audit()
+                    .forget_access(token.account_id(), locked_id, KIND_DELEGATE_ACCESS);
+            }
+        }
+    }
+
     /// AU-7: removes entries past the retention period.
     pub async fn audit_purge(&self) -> trc::Result<usize> {
         let settings = log::settings(self.store()).await?;