Support for m.login.token (#2014)

* Add GOPATH to PATH in find-lint.sh.

The user doesn't necessarily have it in PATH.

* Refactor LoginTypePassword and Type to support m.login.token and m.login.sso.

For login token:

* m.login.token will require deleting the token after completeAuth has
  generated an access token, so a cleanup function is returned by
  Type.Login.
* Allowing different login types will require parsing the /login body
  twice: first to extract the "type" and then the type-specific parsing.
  Thus, we will have to buffer the request JSON in /login, like
  UserInteractive already does.

For SSO:

* NewUserInteractive will have to also use GetAccountByLocalpart. It
  makes more sense to just pass a (narrowed-down) accountDB interface
  to it than adding more function pointers.

Code quality:

* Passing around (and down-casting) interface{} for login request types
  has drawbacks in terms of type-safety, and no inherent benefits. We
  always decode JSON anyway. Hence renaming to Type.LoginFromJSON. Code
  that directly uses LoginTypePassword with parsed data can still use
  Login.
* Removed a TODO for SSO. This is already tracked in #1297.
* httputil.UnmarshalJSON is useful because it returns a JSONResponse.

This change is intended to have no functional changes.

* Support login tokens in User API.

This adds full lifecycle functions for login tokens: create, query, delete.

* Support m.login.token in /login.

* Fixes for PR review.

* Set @matrix-org/dendrite-core as repository code owner

* Return event NID from `StoreEvent`, match PSQL vs SQLite behaviour, tweak backfill persistence (#2071)

Co-authored-by: kegsay <kegan@matrix.org>
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

clientapi/auth/login_token.go

@@ -0,0 +1,83 @@
+// Copyright 2021 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
+	"github.com/matrix-org/dendrite/clientapi/httputil"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/setup/config"
+	uapi "github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/util"
+)
+
+// LoginTypeToken describes how to authenticate with a login token.
+type LoginTypeToken struct {
+	UserAPI uapi.LoginTokenInternalAPI
+	Config  *config.ClientAPI
+}
+
+// Name implements Type.
+func (t *LoginTypeToken) Name() string {
+	return authtypes.LoginTypeToken
+}
+
+// LoginFromJSON implements Type. The cleanup function deletes the token from
+// the database on success.
+func (t *LoginTypeToken) LoginFromJSON(ctx context.Context, reqBytes []byte) (*Login, LoginCleanupFunc, *util.JSONResponse) {
+	var r loginTokenRequest
+	if err := httputil.UnmarshalJSON(reqBytes, &r); err != nil {
+		return nil, nil, err
+	}
+
+	var res uapi.QueryLoginTokenResponse
+	if err := t.UserAPI.QueryLoginToken(ctx, &uapi.QueryLoginTokenRequest{Token: r.Token}, &res); err != nil {
+		util.GetLogger(ctx).WithError(err).Error("UserAPI.QueryLoginToken failed")
+		jsonErr := jsonerror.InternalServerError()
+		return nil, nil, &jsonErr
+	}
+	if res.Data == nil {
+		return nil, nil, &util.JSONResponse{
+			Code: http.StatusForbidden,
+			JSON: jsonerror.Forbidden("invalid login token"),
+		}
+	}
+
+	r.Login.Identifier.Type = "m.id.user"
+	r.Login.Identifier.User = res.Data.UserID
+
+	cleanup := func(ctx context.Context, authRes *util.JSONResponse) {
+		if authRes == nil {
+			util.GetLogger(ctx).Error("No JSONResponse provided to LoginTokenType cleanup function")
+			return
+		}
+		if authRes.Code == http.StatusOK {
+			var res uapi.PerformLoginTokenDeletionResponse
+			if err := t.UserAPI.PerformLoginTokenDeletion(ctx, &uapi.PerformLoginTokenDeletionRequest{Token: r.Token}, &res); err != nil {
+				util.GetLogger(ctx).WithError(err).Error("UserAPI.PerformLoginTokenDeletion failed")
+			}
+		}
+	}
+	return &r.Login, cleanup, nil
+}
+
+// loginTokenRequest struct to hold the possible parameters from an HTTP request.
+type loginTokenRequest struct {
+	Login
+	Token string `json:"token"`
+}