Convert admin api docs to markdown (#10089)

So that they render nicely in mdbook (see #10086), and so that we no longer have a mix of structured text languages in our documentation (excluding files outside of `docs/`).

changelog.d/10089.doc

@@ -0,0 +1 @@
+Convert the remaining Admin API documentation files to markdown.

docs/admin_api/account_validity.md

@@ -0,0 +1,42 @@
+# Account validity API
+
+This API allows a server administrator to manage the validity of an account. To
+use it, you must enable the account validity feature (under
+`account_validity`) in Synapse's configuration.
+
+## Renew account
+
+This API extends the validity of an account by as much time as configured in the
+`period` parameter from the `account_validity` configuration.
+
+The API is:
+
+```
+POST /_synapse/admin/v1/account_validity/validity
+```
+
+with the following body:
+
+```json
+{
+    "user_id": "<user ID for the account to renew>",
+    "expiration_ts": 0,
+    "enable_renewal_emails": true
+}
+```
+
+
+`expiration_ts` is an optional parameter and overrides the expiration date,
+which otherwise defaults to now + validity period.
+
+`enable_renewal_emails` is also an optional parameter and enables/disables
+sending renewal emails to the user. Defaults to true.
+
+The API returns with the new expiration date for this account, as a timestamp in
+milliseconds since epoch:
+
+```json
+{
+    "expiration_ts": 0
+}
+```

docs/admin_api/purge_history_api.rst → docs/admin_api/purge_history_api.md

@@ -1,5 +1,4 @@
-Purge History API
-=================
+# Purge History API
 
 The purge history API allows server admins to purge historic events from their
 database, reclaiming disk space.
@@ -13,65 +12,67 @@ delete the last message in a room.
 
 The API is:
 
-``POST /_synapse/admin/v1/purge_history/<room_id>[/<event_id>]``
+```
+POST /_synapse/admin/v1/purge_history/<room_id>[/<event_id>]
+```
 
-To use it, you will need to authenticate by providing an ``access_token`` for a
-server admin: see `README.rst <README.rst>`_.
+To use it, you will need to authenticate by providing an `access_token` for a
+server admin: [Admin API](README.rst)
 
 By default, events sent by local users are not deleted, as they may represent
 the only copies of this content in existence. (Events sent by remote users are
 deleted.)
 
 Room state data (such as joins, leaves, topic) is always preserved.
 
-To delete local message events as well, set ``delete_local_events`` in the body:
+To delete local message events as well, set `delete_local_events` in the body:
 
-.. code:: json
-
-   {
-       "delete_local_events": true
-   }
+```
+{
+   "delete_local_events": true
+}
+```
 
 The caller must specify the point in the room to purge up to. This can be
 specified by including an event_id in the URI, or by setting a
-``purge_up_to_event_id`` or ``purge_up_to_ts`` in the request body. If an event
+`purge_up_to_event_id` or `purge_up_to_ts` in the request body. If an event
 id is given, that event (and others at the same graph depth) will be retained.
-If ``purge_up_to_ts`` is given, it should be a timestamp since the unix epoch,
+If `purge_up_to_ts` is given, it should be a timestamp since the unix epoch,
 in milliseconds.
 
 The API starts the purge running, and returns immediately with a JSON body with
 a purge id:
 
-.. code:: json
-
-    {
-        "purge_id": "<opaque id>"
-    }
+```json
+{
+    "purge_id": "<opaque id>"
+}
+```
 
-Purge status query
-------------------
+## Purge status query
 
 It is possible to poll for updates on recent purges with a second API;
 
-``GET /_synapse/admin/v1/purge_history_status/<purge_id>``
+```
+GET /_synapse/admin/v1/purge_history_status/<purge_id>
+```
 
-Again, you will need to authenticate by providing an ``access_token`` for a
+Again, you will need to authenticate by providing an `access_token` for a
 server admin.
 
 This API returns a JSON body like the following:
 
-.. code:: json
-
-    {
-        "status": "active"
-    }
+```json
+{
+    "status": "active"
+}
+```
 
-The status will be one of ``active``, ``complete``, or ``failed``.
+The status will be one of `active`, `complete`, or `failed`.
 
-Reclaim disk space (Postgres)
------------------------------
+## Reclaim disk space (Postgres)
 
 To reclaim the disk space and return it to the operating system, you need to run
 `VACUUM FULL;` on the database.
 
-https://www.postgresql.org/docs/current/sql-vacuum.html
+<https://www.postgresql.org/docs/current/sql-vacuum.html>

docs/admin_api/register_api.md

@@ -0,0 +1,73 @@
+# Shared-Secret Registration
+
+This API allows for the creation of users in an administrative and
+non-interactive way. This is generally used for bootstrapping a Synapse
+instance with administrator accounts.
+
+To authenticate yourself to the server, you will need both the shared secret
+(`registration_shared_secret` in the homeserver configuration), and a
+one-time nonce. If the registration shared secret is not configured, this API
+is not enabled.
+
+To fetch the nonce, you need to request one from the API:
+
+```
+> GET /_synapse/admin/v1/register
+
+< {"nonce": "thisisanonce"}
+```
+
+Once you have the nonce, you can make a `POST` to the same URL with a JSON
+body containing the nonce, username, password, whether they are an admin
+(optional, False by default), and a HMAC digest of the content. Also you can
+set the displayname (optional, `username` by default).
+
+As an example:
+
+```
+> POST /_synapse/admin/v1/register
+> {
+   "nonce": "thisisanonce",
+   "username": "pepper_roni",
+   "displayname": "Pepper Roni",
+   "password": "pizza",
+   "admin": true,
+   "mac": "mac_digest_here"
+  }
+
+< {
+   "access_token": "token_here",
+   "user_id": "@pepper_roni:localhost",
+   "home_server": "test",
+   "device_id": "device_id_here"
+  }
+```
+
+The MAC is the hex digest output of the HMAC-SHA1 algorithm, with the key being
+the shared secret and the content being the nonce, user, password, either the
+string "admin" or "notadmin", and optionally the user_type
+each separated by NULs. For an example of generation in Python:
+
+```python
+import hmac, hashlib
+
+def generate_mac(nonce, user, password, admin=False, user_type=None):
+
+    mac = hmac.new(
+      key=shared_secret,
+      digestmod=hashlib.sha1,
+    )
+
+    mac.update(nonce.encode('utf8'))
+    mac.update(b"\x00")
+    mac.update(user.encode('utf8'))
+    mac.update(b"\x00")
+    mac.update(password.encode('utf8'))
+    mac.update(b"\x00")
+    mac.update(b"admin" if admin else b"notadmin")
+    if user_type:
+        mac.update(b"\x00")
+        mac.update(user_type.encode('utf8'))
+
+    return mac.hexdigest()
+```