Remove duplicated registration/login APIs

Currently the spec duplicates all of the account-management APIs. There's still
work to be done here, but the complete duplication is confusing.

api/client-server/v2_alpha/registration.yaml

@@ -89,6 +89,11 @@ paths:
             These errors may be returned at any stage of the registration process,
             including after authentication if the requested user ID was registered
             whilst the client was performing authentication.
+
+            Home Servers MUST perform the relevant checks and return these codes before
+            performing `User-Interactive Authentication`_, although they may also return
+            them after authentication is completed if, for example, the requested user ID
+            was registered whilst the client was performing authentication.
           examples:
             application/json: |-
               {

specification/client_server_api.rst

@@ -349,67 +349,21 @@ This MUST return an HTML page which can perform this authentication stage. This
 page must attempt to call the JavaScript function ``window.onAuthDone`` when
 the authentication has been completed.
 
-Registration
-~~~~~~~~~~~~
+API calls using the User-Interactive Authentication mechanism
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 This section refers to API Version 2. These API calls currently use the prefix
 ``/_matrix/client/v2_alpha``.
 
-Registering for a user account is done using the request::
-
-  POST $V2PREFIX/register
-
-This API endpoint uses the `User-Interactive Authentication API`_.
-This API endpoint does not require an access token.
-
-.. _User-Interactive Authentication API: `sect:auth-api`_
-
-The body of the POST request is a JSON object containing:
-
-username
-  Optional. This is the local part of the desired Matrix ID. If omitted, the
-  Home Server must generate a Matrix ID local part.
-password
-  Required. The desired password for the account.
-bind_email
-  Optional. If ``true``, the server binds the email used for authentication to
-  the Matrix ID with the ID Server.
-
-On success, this returns a JSON object with keys:
-
-user_id
-  The fully-qualified Matrix ID that has been registered.
-access_token
-  An access token for the new account.
-home_server
-  The hostname of the Home Server on which the account has been registered.
-refresh_token
-  A token that may be exchanged for a new ``access_token`` using the
-  ``/tokenrefresh`` API endpoint.
-
-This endpoint may also return the following error codes:
-
-M_USER_IN_USE
-  If the Matrix ID is already in use
-M_EXCLUSIVE
-  If the requested Matrix ID is in the exclusive namespace of an application
-  service.
-
-Home Servers MUST perform the relevant checks and return these codes before
-performing `User-Interactive Authentication`_, although they may also return
-them after authentication is completed if, for example, the requested user ID
-was registered whilst the client was performing authentication.
-
 .. _User-Interactive Authentication: `sect:auth-api`_
 
+{{v2_registration_http_api}}
+
 Old V1 API docs: |register|_
 
 {{login_http_api}}
 
 Changing Password
 +++++++++++++++++
-This section refers to API Version 2. These API calls currently use the prefix
-``/_matrix/client/v2_alpha``.
-
 Request::
 
   POST $V2PREFIX/account/password
@@ -432,9 +386,6 @@ database.
 
 Adding Account Administrative Contact Information
 +++++++++++++++++++++++++++++++++++++++++++++++++
-This section refers to API Version 2. These API calls currently use the prefix
-``/_matrix/client/v2_alpha``.
-
 Request::
 
   POST $V2PREFIX/account/3pid
@@ -470,9 +421,6 @@ M_THREEPID_AUTH_FAILED
 
 Fetching Currently Associated Contact Information
 +++++++++++++++++++++++++++++++++++++++++++++++++
-This section refers to API Version 2. These API calls currently use the prefix
-``/_matrix/client/v2_alpha``.
-
 Request::
 
   GET $V2PREFIX/account/3pid
@@ -982,107 +930,6 @@ member's state, by making a request to
     "membership": "ban"
   }
 
-Account operations
-------------------
-
-Registration
-~~~~~~~~~~~~
-This API endpoint uses the `User-Interactive Authentication API`_.
-
-{{v2_registration_http_api}}
-
-Login
-~~~~~
-
-{{login_http_api}}
-
-Changing Password
-~~~~~~~~~~~~~~~~~
-This section refers to API Version 2. These API calls currently use the prefix
-``/_matrix/client/v2_alpha``.
-
-Request::
-
-  POST $V2PREFIX/account/password
-
-This API endpoint uses the User-Interactive Authentication API. An access token
-should be submitted to this endpoint if the client has an active session. The
-Home Server may change the flows available depending on whether a valid access
-token is provided.
-
-The body of the POST request is a JSON object containing:
-
-new_password
-  The new password for the account.
-
-On success, an empty JSON object is returned.
-
-The error code M_NOT_FOUND is returned if the user authenticated with a third
-party identifier but the Home Server could not find a matching account in its
-database.
-
-Adding a Third Party Identifier
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-This section refers to API Version 2. These API calls currently use the prefix
-``/_matrix/client/v2_alpha``.
-
-Request::
-
-  POST $V2PREFIX/account/3pid
-
-Used to add a third party identifier to the user's account.
-
-The body of the POST request is a JSON object containing:
-
-threePidCreds
-  An object containing third party identifier credentials.
-bind
-  Optional. A boolean indicating whether the Home Server should also bind this
-  third party identifier to the account's matrix ID with the Identity Server. If
-  supplied and true, the Home Server must bind the 3pid accordingly.
-
-The third party identifier credentials object comprises:
-
-id_server
-  The colon-separated hostname and port of the Identity Server used to
-  authenticate the third party identifier. If the port is the default, it and the
-  colon should be omitted.
-sid
-  The session ID given by the Identity Server
-client_secret
-  The client secret used in the session with the Identity Server.
-
-On success, the empty JSON object is returned.
-
-May also return error codes:
-
-M_THREEPID_AUTH_FAILED
-  If the credentials provided could not be verified with the ID Server.
-
-Fetching Currently Associated Third Party Identifiers
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-This section refers to API Version 2. These API calls currently use the prefix
-``/_matrix/client/v2_alpha``.
-
-Request::
-
-  GET $V2PREFIX/account/3pid
-
-This returns a list of third party identifiers that the Home Server has
-associated with the user's account. This is *not* the same as the list of third
-party identifiers bound to the user's Matrix ID in Identity Servers. Identifiers
-in this list may be used by the Home Server as, for example, identifiers that it
-will accept to reset the user's account password.
-
-Returns a JSON object with the key ``threepids`` whose contents is an array of
-objects with the following keys:
-
-medium
-  The medium of the 3pid (eg, ``email``)
-address
-  The textual address of the 3pid, eg. the email address
-
-
 Profiles
 --------