Begin fleshing out how CS API endpoints do auth properly

Without it being a GIGANTIC PITA

src/github.com/matrix-org/dendrite/clientapi/auth/auth.go

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package auth implements authentication checks and storage.
 package auth
 
 import (
@@ -19,31 +20,48 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/matrix-org/dendrite/clientapi/auth/storage/devices"
+	"github.com/matrix-org/dendrite/clientapi/auth/types"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/util"
 )
 
-// VerifyAccessToken verifies that an access token was supplied in the given HTTP request
-// and returns the user ID it corresponds to. Returns resErr (an error response which can be
-// sent to the client) if the token is invalid or there was a problem querying the database.
+// VerifyAccessToken TODO: Remove me.
 func VerifyAccessToken(req *http.Request) (userID string, resErr *util.JSONResponse) {
-	token, tokenErr := extractAccessToken(req)
-	if tokenErr != nil {
+	token, err := extractAccessToken(req)
+	if err != nil {
 		resErr = &util.JSONResponse{
 			Code: 401,
-			JSON: jsonerror.MissingToken(tokenErr.Error()),
+			JSON: jsonerror.MissingToken(err.Error()),
 		}
 		return
 	}
-	if token == "fail" {
-		res := util.ErrorResponse(fmt.Errorf("Fatal error"))
-		resErr = &res
-	}
-	// TODO: Check the token against the database
 	userID = token
 	return
 }
 
+// VerifyAccessTokenNew verifies that an access token was supplied in the given HTTP request
+// and returns the device it corresponds to. Returns resErr (an error response which can be
+// sent to the client) if the token is invalid or there was a problem querying the database.
+func VerifyAccessTokenNew(req *http.Request, deviceDB *devices.Database) (device *types.Device, resErr *util.JSONResponse) {
+	token, err := extractAccessToken(req)
+	if err != nil {
+		resErr = &util.JSONResponse{
+			Code: 401,
+			JSON: jsonerror.MissingToken(err.Error()),
+		}
+		return
+	}
+	device, err = deviceDB.GetDeviceByAccessToken(token)
+	if err != nil {
+		resErr = &util.JSONResponse{
+			Code: 500,
+			JSON: jsonerror.Unknown("Failed to check access token"),
+		}
+	}
+	return
+}
+
 // extractAccessToken from a request, or return an error detailing what went wrong. The
 // error message MUST be human-readable and comprehensible to the client.
 func extractAccessToken(req *http.Request) (string, error) {

src/github.com/matrix-org/dendrite/clientapi/auth/storage/devices/storage.go

@@ -14,6 +14,10 @@
 
 package devices
 
+import (
+	"github.com/matrix-org/dendrite/clientapi/auth/types"
+)
+
 // Database represents a device database.
 type Database struct {
 	// TODO
@@ -23,3 +27,11 @@ type Database struct {
 func NewDatabase() *Database {
 	return &Database{}
 }
+
+// GetDeviceByAccessToken returns the device matching the given access token.
+func (d *Database) GetDeviceByAccessToken(token string) (*types.Device, error) {
+	// TODO: Actual implementation
+	return &types.Device{
+		UserID: token,
+	}, nil
+}

src/github.com/matrix-org/dendrite/clientapi/routing/routing.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/matrix-org/dendrite/clientapi/auth/storage"
+	"github.com/matrix-org/dendrite/clientapi/auth/types"
 	"github.com/matrix-org/dendrite/clientapi/config"
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/dendrite/clientapi/readers"
@@ -151,6 +152,18 @@ func Setup(servMux *http.ServeMux, httpClient *http.Client, cfg config.ClientAPI
 	servMux.Handle("/api/", http.StripPrefix("/api", apiMux))
 }
 
+// make a util.JSONRequestHandler function into an http.Handler which checks the access token in the request.
+func makeAuthAPI(metricsName string, deviceDB *devices.Database, f func(*http.Request, types.Device) util.JSONResponse) http.Handler {
+	h := util.NewJSONRequestHandler(func(req *http.Request) util.JSONResponse {
+		device, resErr := auth.VerifyAccessToken(req, deviceDB)
+		if resErr != nil {
+			return resErr
+		}
+		return f(req, device)
+	})
+	return prometheus.InstrumentHandler(metricsName, util.MakeJSONAPI(h))
+}
+
 // make a util.JSONRequestHandler function into an http.Handler.
 func makeAPI(metricsName string, f func(*http.Request) util.JSONResponse) http.Handler {
 	h := util.NewJSONRequestHandler(f)