Factor out collaboration code (#2313)

Co-authored-by: Lipis <lipiridis@gmail.com>
Co-authored-by: dwelle <luzar.david@gmail.com>
This commit is contained in:
Aakansha Doshi 2020-12-05 20:00:53 +05:30 committed by GitHub
parent d8a0dc3b4d
commit e617ccc252
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
41 changed files with 2250 additions and 2018 deletions

View file

@ -1,164 +0,0 @@
import { createIV, getImportedKey } from "./index";
import { ExcalidrawElement } from "../element/types";
import { getSceneVersion } from "../element";
import Portal from "../components/Portal";
import { restoreElements } from "./restore";
let firebasePromise: Promise<
typeof import("firebase/app").default
> | null = null;
const loadFirebase = async () => {
const firebase = (
await import(/* webpackChunkName: "firebase" */ "firebase/app")
).default;
await import(/* webpackChunkName: "firestore" */ "firebase/firestore");
const firebaseConfig = JSON.parse(process.env.REACT_APP_FIREBASE_CONFIG);
firebase.initializeApp(firebaseConfig);
return firebase;
};
const getFirebase = async (): Promise<
typeof import("firebase/app").default
> => {
if (!firebasePromise) {
firebasePromise = loadFirebase();
}
const firebase = await firebasePromise!;
return firebase;
};
interface FirebaseStoredScene {
sceneVersion: number;
iv: firebase.default.firestore.Blob;
ciphertext: firebase.default.firestore.Blob;
}
const encryptElements = async (
key: string,
elements: readonly ExcalidrawElement[],
): Promise<{ ciphertext: ArrayBuffer; iv: Uint8Array }> => {
const importedKey = await getImportedKey(key, "encrypt");
const iv = createIV();
const json = JSON.stringify(elements);
const encoded = new TextEncoder().encode(json);
const ciphertext = await window.crypto.subtle.encrypt(
{
name: "AES-GCM",
iv,
},
importedKey,
encoded,
);
return { ciphertext, iv };
};
const decryptElements = async (
key: string,
iv: Uint8Array,
ciphertext: ArrayBuffer,
): Promise<readonly ExcalidrawElement[]> => {
const importedKey = await getImportedKey(key, "decrypt");
const decrypted = await window.crypto.subtle.decrypt(
{
name: "AES-GCM",
iv,
},
importedKey,
ciphertext,
);
const decodedData = new TextDecoder("utf-8").decode(
new Uint8Array(decrypted) as any,
);
return JSON.parse(decodedData);
};
const firebaseSceneVersionCache = new WeakMap<SocketIOClient.Socket, number>();
export const isSavedToFirebase = (
portal: Portal,
elements: readonly ExcalidrawElement[],
): boolean => {
if (portal.socket && portal.roomId && portal.roomKey) {
const sceneVersion = getSceneVersion(elements);
return firebaseSceneVersionCache.get(portal.socket) === sceneVersion;
}
// if no room exists, consider the room saved so that we don't unnecessarily
// prevent unload (there's nothing we could do at that point anyway)
return true;
};
export const saveToFirebase = async (
portal: Portal,
elements: readonly ExcalidrawElement[],
) => {
const { roomId, roomKey, socket } = portal;
if (
// if no room exists, consider the room saved because there's nothing we can
// do at this point
!roomId ||
!roomKey ||
!socket ||
isSavedToFirebase(portal, elements)
) {
return true;
}
const firebase = await getFirebase();
const sceneVersion = getSceneVersion(elements);
const { ciphertext, iv } = await encryptElements(roomKey, elements);
const nextDocData = {
sceneVersion,
ciphertext: firebase.firestore.Blob.fromUint8Array(
new Uint8Array(ciphertext),
),
iv: firebase.firestore.Blob.fromUint8Array(iv),
} as FirebaseStoredScene;
const db = firebase.firestore();
const docRef = db.collection("scenes").doc(roomId);
const didUpdate = await db.runTransaction(async (transaction) => {
const doc = await transaction.get(docRef);
if (!doc.exists) {
transaction.set(docRef, nextDocData);
return true;
}
const prevDocData = doc.data() as FirebaseStoredScene;
if (prevDocData.sceneVersion >= nextDocData.sceneVersion) {
return false;
}
transaction.update(docRef, nextDocData);
return true;
});
if (didUpdate) {
firebaseSceneVersionCache.set(socket, sceneVersion);
}
return didUpdate;
};
export const loadFromFirebase = async (
roomId: string,
roomKey: string,
): Promise<readonly ExcalidrawElement[] | null> => {
const firebase = await getFirebase();
const db = firebase.firestore();
const docRef = db.collection("scenes").doc(roomId);
const doc = await docRef.get();
if (!doc.exists) {
return null;
}
const storedScene = doc.data() as FirebaseStoredScene;
const ciphertext = storedScene.ciphertext.toUint8Array();
const iv = storedScene.iv.toUint8Array();
return restoreElements(await decryptElements(roomKey, iv, ciphertext));
};

View file

@ -12,162 +12,14 @@ import {
import { t } from "../i18n";
import { exportToCanvas, exportToSvg } from "../scene/export";
import { ExportType } from "../scene/types";
import { AppState } from "../types";
import { canvasToBlob } from "./blob";
import { AppState } from "../types";
import { serializeAsJSON } from "./json";
import { restore } from "./restore";
import { ImportedDataState } from "./types";
export { loadFromBlob } from "./blob";
export { loadFromJSON, saveAsJSON } from "./json";
const BACKEND_GET = process.env.REACT_APP_BACKEND_V1_GET_URL;
const BACKEND_V2_POST = process.env.REACT_APP_BACKEND_V2_POST_URL;
const BACKEND_V2_GET = process.env.REACT_APP_BACKEND_V2_GET_URL;
export const SOCKET_SERVER = process.env.REACT_APP_SOCKET_SERVER_URL;
export type EncryptedData = {
data: ArrayBuffer;
iv: Uint8Array;
};
export type SocketUpdateDataSource = {
SCENE_INIT: {
type: "SCENE_INIT";
payload: {
elements: readonly ExcalidrawElement[];
};
};
SCENE_UPDATE: {
type: "SCENE_UPDATE";
payload: {
elements: readonly ExcalidrawElement[];
};
};
MOUSE_LOCATION: {
type: "MOUSE_LOCATION";
payload: {
socketId: string;
pointer: { x: number; y: number };
button: "down" | "up";
selectedElementIds: AppState["selectedElementIds"];
username: string;
};
};
};
export type SocketUpdateDataIncoming =
| SocketUpdateDataSource[keyof SocketUpdateDataSource]
| {
type: "INVALID_RESPONSE";
};
const byteToHex = (byte: number): string => `0${byte.toString(16)}`.slice(-2);
const generateRandomID = async () => {
const arr = new Uint8Array(10);
window.crypto.getRandomValues(arr);
return Array.from(arr, byteToHex).join("");
};
const generateEncryptionKey = async () => {
const key = await window.crypto.subtle.generateKey(
{
name: "AES-GCM",
length: 128,
},
true, // extractable
["encrypt", "decrypt"],
);
return (await window.crypto.subtle.exportKey("jwk", key)).k;
};
export const createIV = () => {
const arr = new Uint8Array(12);
return window.crypto.getRandomValues(arr);
};
export const getCollaborationLinkData = (link: string) => {
if (link.length === 0) {
return;
}
const hash = new URL(link).hash;
return hash.match(/^#room=([a-zA-Z0-9_-]+),([a-zA-Z0-9_-]+)$/);
};
export const generateCollaborationLink = async () => {
const id = await generateRandomID();
const key = await generateEncryptionKey();
return `${window.location.origin}${window.location.pathname}#room=${id},${key}`;
};
export const getImportedKey = (key: string, usage: KeyUsage) =>
window.crypto.subtle.importKey(
"jwk",
{
alg: "A128GCM",
ext: true,
k: key,
key_ops: ["encrypt", "decrypt"],
kty: "oct",
},
{
name: "AES-GCM",
length: 128,
},
false, // extractable
[usage],
);
export const encryptAESGEM = async (
data: Uint8Array,
key: string,
): Promise<EncryptedData> => {
const importedKey = await getImportedKey(key, "encrypt");
const iv = createIV();
return {
data: await window.crypto.subtle.encrypt(
{
name: "AES-GCM",
iv,
},
importedKey,
data,
),
iv,
};
};
export const decryptAESGEM = async (
data: ArrayBuffer,
key: string,
iv: Uint8Array,
): Promise<SocketUpdateDataIncoming> => {
try {
const importedKey = await getImportedKey(key, "decrypt");
const decrypted = await window.crypto.subtle.decrypt(
{
name: "AES-GCM",
iv,
},
importedKey,
data,
);
const decodedData = new TextDecoder("utf-8").decode(
new Uint8Array(decrypted) as any,
);
return JSON.parse(decodedData);
} catch (error) {
window.alert(t("alerts.decryptFailed"));
console.error(error);
}
return {
type: "INVALID_RESPONSE",
};
};
export const exportToBackend = async (
elements: readonly ExcalidrawElement[],
@ -226,53 +78,6 @@ export const exportToBackend = async (
}
};
const importFromBackend = async (
id: string | null,
privateKey?: string | null,
): Promise<ImportedDataState> => {
try {
const response = await fetch(
privateKey ? `${BACKEND_V2_GET}${id}` : `${BACKEND_GET}${id}.json`,
);
if (!response.ok) {
window.alert(t("alerts.importBackendFailed"));
return {};
}
let data: ImportedDataState;
if (privateKey) {
const buffer = await response.arrayBuffer();
const key = await getImportedKey(privateKey, "decrypt");
const iv = new Uint8Array(12);
const decrypted = await window.crypto.subtle.decrypt(
{
name: "AES-GCM",
iv,
},
key,
buffer,
);
// We need to convert the decrypted array buffer to a string
const string = new window.TextDecoder("utf-8").decode(
new Uint8Array(decrypted) as any,
);
data = JSON.parse(string);
} else {
// Legacy format
data = await response.json();
}
trackEvent(EVENT_IO, "import");
return {
elements: data.elements || null,
appState: data.appState || null,
};
} catch (error) {
window.alert(t("alerts.importBackendFailed"));
console.error(error);
return {};
}
};
export const exportCanvas = async (
type: ExportType,
elements: readonly NonDeletedExcalidrawElement[],
@ -378,30 +183,3 @@ export const exportCanvas = async (
tempCanvas.remove();
}
};
export const loadScene = async (
id: string | null,
privateKey: string | null,
// Supply initialData even if importing from backend to ensure we restore
// localStorage user settings which we do not persist on server.
// Non-optional so we don't forget to pass it even if `undefined`.
initialData: ImportedDataState | undefined | null,
) => {
let data;
if (id != null) {
// the private key is used to decrypt the content from the server, take
// extra care not to leak it
data = restore(
await importFromBackend(id, privateKey),
initialData?.appState,
);
} else {
data = restore(initialData || {}, null);
}
return {
elements: data.elements,
appState: data.appState,
commitToHistory: false,
};
};

View file

@ -1,103 +0,0 @@
import { ExcalidrawElement } from "../element/types";
import { AppState } from "../types";
import { clearAppStateForLocalStorage, getDefaultAppState } from "../appState";
import { STORAGE_KEYS } from "../constants";
import { clearElementsForLocalStorage } from "../element";
export const saveUsernameToLocalStorage = (username: string) => {
try {
localStorage.setItem(
STORAGE_KEYS.LOCAL_STORAGE_COLLAB,
JSON.stringify({ username }),
);
} catch (error) {
// Unable to access window.localStorage
console.error(error);
}
};
export const importUsernameFromLocalStorage = (): string | null => {
try {
const data = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_COLLAB);
if (data) {
return JSON.parse(data).username;
}
} catch (error) {
// Unable to access localStorage
console.error(error);
}
return null;
};
export const saveToLocalStorage = (
elements: readonly ExcalidrawElement[],
appState: AppState,
) => {
try {
localStorage.setItem(
STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS,
JSON.stringify(clearElementsForLocalStorage(elements)),
);
localStorage.setItem(
STORAGE_KEYS.LOCAL_STORAGE_APP_STATE,
JSON.stringify(clearAppStateForLocalStorage(appState)),
);
} catch (error) {
// Unable to access window.localStorage
console.error(error);
}
};
export const importFromLocalStorage = () => {
let savedElements = null;
let savedState = null;
try {
savedElements = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS);
savedState = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_APP_STATE);
} catch (error) {
// Unable to access localStorage
console.error(error);
}
let elements: ExcalidrawElement[] = [];
if (savedElements) {
try {
elements = clearElementsForLocalStorage(JSON.parse(savedElements));
} catch (error) {
console.error(error);
// Do nothing because elements array is already empty
}
}
let appState = null;
if (savedState) {
try {
appState = {
...getDefaultAppState(),
...clearAppStateForLocalStorage(
JSON.parse(savedState) as Partial<AppState>,
),
};
} catch (error) {
console.error(error);
// Do nothing because appState is already null
}
}
return { elements, appState };
};
export const getTotalStorageSize = () => {
const appState = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_APP_STATE);
const collab = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_COLLAB);
const elements = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS);
const library = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_LIBRARY);
const appStateSize = appState ? JSON.stringify(appState).length : 0;
const collabSize = collab ? JSON.stringify(collab).length : 0;
const elementsSize = elements ? JSON.stringify(elements).length : 0;
const librarySize = library ? JSON.stringify(library).length : 0;
return appStateSize + collabSize + elementsSize + librarySize;
};

View file

@ -173,7 +173,7 @@ const restoreAppState = (
};
export const restore = (
data: ImportedDataState,
data: ImportedDataState | null,
/**
* Local AppState (`this.state` or initial state from localStorage) so that we
* don't overwrite local state with default values (when values not
@ -183,7 +183,7 @@ export const restore = (
localAppState: Partial<AppState> | null | undefined,
): DataState => {
return {
elements: restoreElements(data.elements),
appState: restoreAppState(data.appState, localAppState || null),
elements: restoreElements(data?.elements),
appState: restoreAppState(data?.appState, localAppState || null),
};
};