dendrite/clientapi/auth/auth.go
2023-05-17 00:33:27 +00:00

128 lines
4.1 KiB
Go

// Copyright 2017 Vector Creations Ltd
//
// 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 implements authentication checks and storage.
package auth
import (
"context"
"crypto/rand"
"encoding/base64"
"fmt"
"net/http"
"strings"
"github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib/spec"
"github.com/matrix-org/util"
)
// OWASP recommends at least 128 bits of entropy for tokens: https://www.owasp.org/index.php/Insufficient_Session-ID_Length
// 32 bytes => 256 bits
var tokenByteLength = 32
// DeviceDatabase represents a device database.
type DeviceDatabase interface {
// Look up the device matching the given access token.
GetDeviceByAccessToken(ctx context.Context, token string) (*api.Device, error)
}
// AccountDatabase represents an account database.
type AccountDatabase interface {
// Look up the account matching the given localpart.
GetAccountByLocalpart(ctx context.Context, localpart string) (*api.Account, error)
GetAccountByPassword(ctx context.Context, localpart, password string) (*api.Account, error)
}
// VerifyUserFromRequest authenticates the HTTP request,
// on success returns Device of the requester.
// Finds local user or an application service user.
// Note: For an AS user, AS dummy device is returned.
// On failure returns an JSON error response which can be sent to the client.
func VerifyUserFromRequest(
req *http.Request, userAPI api.QueryAcccessTokenAPI,
) (*api.Device, *util.JSONResponse) {
// Try to find the Application Service user
token, err := ExtractAccessToken(req)
if err != nil {
return nil, &util.JSONResponse{
Code: http.StatusUnauthorized,
JSON: spec.MissingToken(err.Error()),
}
}
var res api.QueryAccessTokenResponse
err = userAPI.QueryAccessToken(req.Context(), &api.QueryAccessTokenRequest{
AccessToken: token,
AppServiceUserID: req.URL.Query().Get("user_id"),
}, &res)
if err != nil {
util.GetLogger(req.Context()).WithError(err).Error("userAPI.QueryAccessToken failed")
return nil, &util.JSONResponse{
Code: http.StatusInternalServerError,
JSON: spec.InternalServerError{},
}
}
if res.Err != "" {
if strings.HasPrefix(strings.ToLower(res.Err), "forbidden:") { // TODO: use actual error and no string comparison
return nil, &util.JSONResponse{
Code: http.StatusForbidden,
JSON: spec.Forbidden(res.Err),
}
}
}
if res.Device == nil {
return nil, &util.JSONResponse{
Code: http.StatusUnauthorized,
JSON: spec.UnknownToken("Unknown token"),
}
}
return res.Device, nil
}
// GenerateAccessToken creates a new access token. Returns an error if failed to generate
// random bytes.
func GenerateAccessToken() (string, error) {
b := make([]byte, tokenByteLength)
if _, err := rand.Read(b); err != nil {
return "", err
}
// url-safe no padding
return base64.RawURLEncoding.EncodeToString(b), nil
}
// 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) {
// cf https://github.com/matrix-org/synapse/blob/v0.19.2/synapse/api/auth.py#L631
authBearer := req.Header.Get("Authorization")
queryToken := req.URL.Query().Get("access_token")
if authBearer != "" && queryToken != "" {
return "", fmt.Errorf("mixing Authorization headers and access_token query parameters")
}
if queryToken != "" {
return queryToken, nil
}
if authBearer != "" {
parts := strings.SplitN(authBearer, " ", 2)
if len(parts) != 2 || parts[0] != "Bearer" {
return "", fmt.Errorf("invalid Authorization header")
}
return parts[1], nil
}
return "", fmt.Errorf("missing access token")
}