dendrite/clientapi/auth/auth.go

72 lines
2.3 KiB
Go

// Copyright 2024 New Vector Ltd.
// Copyright 2017 Vector Creations Ltd
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
// Please see LICENSE files in the repository root for full details.
// Package auth implements authentication checks and storage.
package auth
import (
"context"
"crypto/rand"
"encoding/base64"
"fmt"
"net/http"
"strings"
"github.com/element-hq/dendrite/userapi/api"
)
// 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)
}
// 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")
}