fluxer/packages/media_proxy_utils/src/MediaProxySigner.tsx
2026-02-17 12:22:36 +00:00

62 lines
2.0 KiB
TypeScript

/*
* Copyright (C) 2026 Fluxer Contributors
*
* This file is part of Fluxer.
*
* Fluxer is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Fluxer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
*/
import crypto from 'node:crypto';
const BASE64_URL_PADDING_REGEX = /=*$/;
export interface MediaProxySignerOptions {
mediaProxySecretKey: string;
}
export interface IMediaProxySigner {
createSignature(proxyUrlPath: string): string;
verifySignature(proxyUrlPath: string, providedSignature: string): boolean;
}
class MediaProxySigner implements IMediaProxySigner {
private readonly mediaProxySecretKey: string;
constructor(options: MediaProxySignerOptions) {
this.mediaProxySecretKey = options.mediaProxySecretKey;
}
createSignature(proxyUrlPath: string): string {
const hmac = crypto.createHmac('sha256', this.mediaProxySecretKey);
hmac.update(proxyUrlPath);
return hmac.digest('base64url').replace(BASE64_URL_PADDING_REGEX, '');
}
verifySignature(proxyUrlPath: string, providedSignature: string): boolean {
const expectedSignature = this.createSignature(proxyUrlPath);
const expectedBuffer = Buffer.from(expectedSignature, 'utf8');
const providedBuffer = Buffer.from(providedSignature, 'utf8');
if (expectedBuffer.length !== providedBuffer.length) {
return false;
}
return crypto.timingSafeEqual(expectedBuffer, providedBuffer);
}
}
export function createMediaProxySigner(options: MediaProxySignerOptions): IMediaProxySigner {
return new MediaProxySigner(options);
}