index.ts•3.18 kB
/**
* Copyright 2021 Google LLC
*
* 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.
*/
import Base64 from "crypto-js/enc-base64";
import HmacSHA1 from "crypto-js/hmac-sha1";
import CryptoJS from "crypto-js";
/**
* Create a signature for a path and query string using HmacSHA1.
*
* ```ts
* const signature = createSignatureForPathAndQuery("/some-path?foo=bar", "secret");
* ```
* @param unsignedUrl The URL to sign.
* @param secret The secret to use for signing.
* @returns The signature of the signed url.
*/
export function createSignatureForPathAndQuery(
pathAndQuery: string,
secret: string
): string {
const decodedSecret = decodeSecret(secret);
// Sign the url with the decoded secret
const unsafeSignature = HmacSHA1(pathAndQuery, decodedSecret).toString(
Base64
);
// Convert from true base64 to 'web safe' base64
return unsafeSignature.replace(/\+/g, "-").replace(/\//g, "_");
}
/**
* Create a signature for a Google Maps request [URL](https://developer.mozilla.org/en-US/docs/Web/API/URL) or url string.
*
* ```ts
* const signature = createSignature("https://example.com/some-path?foo=bar", "secret");
* ```
*
* @param unsignedUrl The URL to sign.
* @param secret The secret to use for signing.
* @returns The signature of the signed url.
*/
export function createSignature(
unsignedUrl: URL | string,
secret: string
): string {
if (typeof unsignedUrl === "string") {
unsignedUrl = new URL(unsignedUrl);
}
// Strip off the protocol, scheme, and host portions of the URL, leaving only the path and the query
const pathAndQuery = `${unsignedUrl.pathname}${unsignedUrl.search}`;
return createSignatureForPathAndQuery(pathAndQuery, secret);
}
/**
* Returns a new [URL](https://developer.mozilla.org/en-US/docs/Web/API/URL) having a signature parameter.
*
* ```ts
* const signedUrl = signUrl("https://example.com/some-path?foo=bar", "secret");
* signedUrl.href; // "https://example.com/some-path?foo=bar&signature=..."
* ```
*
* @param unsignedUrl The URL to sign.
* @param secret The secret to use for signing.
* @returns The signature of the signed url.
*/
export function signUrl(unsignedUrl: URL | string, secret: string): URL {
if (typeof unsignedUrl === "string") {
unsignedUrl = new URL(unsignedUrl);
}
return new URL(
unsignedUrl.toString() +
"&signature=" +
createSignature(unsignedUrl, secret)
);
}
function decodeSecret(secret: string): CryptoJS.lib.WordArray {
// Convert from 'web safe' base64 to true base64
const unsafeSecret = secret.replace(/-/g, "+").replace(/_/g, "/");
// Base64 decode the secret
return Base64.parse(unsafeSecret);
}