caccl-authorizer
Version:
Acquires Canvas tokens through via OAuth, stores refresh tokens, and refreshes access tokens when they expire.
417 lines • 25.1 kB
JavaScript
"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g = Object.create((typeof Iterator === "function" ? Iterator : Object).prototype);
return g.next = verb(0), g["throw"] = verb(1), g["return"] = verb(2), typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
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op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.getAccessToken = void 0;
// Import CACCL modules
var caccl_error_1 = __importDefault(require("caccl-error"));
var caccl_send_request_1 = __importDefault(require("caccl-send-request"));
var caccl_lti_1 = require("caccl-lti");
var caccl_memory_store_1 = __importDefault(require("caccl-memory-store"));
// Import shared types
var ErrorCode_js_1 = __importDefault(require("./shared/types/ErrorCode.js"));
// Import shared constants
var CACCL_PATHS_1 = __importDefault(require("./shared/constants/CACCL_PATHS"));
var TOKEN_LIFESPAN_SEC_js_1 = __importDefault(require("./shared/constants/TOKEN_LIFESPAN_SEC.js"));
// Constants
var FIVE_MINS_MS = 300000;
// Store a copy of the token store
var tokenStore;
// Store a copy of the developer credentials
var developerCredentials;
// Check if this is a dev environment
var thisIsDevEnvironment = (process.env.NODE_ENV === 'development');
/*------------------------------------------------------------------------*/
/* Helpers */
/*------------------------------------------------------------------------*/
/**
* Refresh the user's authorization
* @author Gabe Abrams
* @param req - express request object
* @returns the new token pack
*/
var refreshAuth = function (req) { return __awaiter(void 0, void 0, void 0, function () {
var _a, launched, launchInfo, tokenPack, specificCanvasCreds, body, expiresIn, newTokenPack, err_1;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
// Make sure caccl has been initialized
if (!tokenStore || !developerCredentials) {
throw new caccl_error_1.default({
message: 'We could not extend your Canvas authorization because CACCL Authorizer has not been initialized yet.',
code: ErrorCode_js_1.default.NotInitialized,
});
}
_a = (0, caccl_lti_1.getLaunchInfo)(req), launched = _a.launched, launchInfo = _a.launchInfo;
if (!launched) {
throw new caccl_error_1.default({
message: 'We could not extend your Canvas authorization because your session has expired.',
code: ErrorCode_js_1.default.RefreshFailedDueToSessionExpiry,
});
}
return [4 /*yield*/, tokenStore.get("".concat(launchInfo.canvasHost, "/").concat(launchInfo.userId))];
case 1:
tokenPack = _b.sent();
if (!tokenPack) {
throw new caccl_error_1.default({
message: 'We could not extend your Canvas authorization because your refresh credentials could not be found.',
code: ErrorCode_js_1.default.RefreshFailedDueToTokenMissing,
});
}
specificCanvasCreds = developerCredentials[launchInfo.canvasHost];
if (!specificCanvasCreds) {
// No credentials for this Canvas host
throw new caccl_error_1.default({
message: 'Your Canvas session could not be extended. Please contact support.',
code: ErrorCode_js_1.default.NoCreds,
});
}
_b.label = 2;
case 2:
_b.trys.push([2, 5, , 6]);
return [4 /*yield*/, (0, caccl_send_request_1.default)({
host: launchInfo.canvasHost,
path: '/login/oauth2/token',
method: 'POST',
params: {
grant_type: 'refresh_token',
refresh_token: tokenPack.refreshToken,
client_id: specificCanvasCreds.clientId,
client_secret: specificCanvasCreds.clientSecret,
},
})];
case 3:
body = (_b.sent()).body;
expiresIn = (body.expires_in * 0.99 * 1000);
newTokenPack = {
accessToken: body.access_token,
refreshToken: (body.refresh_token || tokenPack.refreshToken),
accessTokenExpiry: (Date.now() + expiresIn),
canvasHost: launchInfo.canvasHost,
};
// Save in the store
return [4 /*yield*/, tokenStore.set("".concat(launchInfo.canvasHost, "/").concat(launchInfo.userId), newTokenPack)];
case 4:
// Save in the store
_b.sent();
// Return new token pack
return [2 /*return*/, newTokenPack];
case 5:
err_1 = _b.sent();
throw new caccl_error_1.default({
message: 'Your Canvas session could not be extended. Please contact support.',
code: ErrorCode_js_1.default.RefreshFailed,
});
case 6: return [2 /*return*/];
}
});
}); };
/*------------------------------------------------------------------------*/
/* Main Functionality */
/*------------------------------------------------------------------------*/
/**
* Initializes the token manager on the given express app
* @author Gabriel Abrams
* @param {object} opts object containing all arguments
* @param {object} opts.app - express app
* @param {DeveloperCredentials} opts.developerCredentials canvas app developer
* credentials map
* @param {InitCACCLStore} [opts.initTokenStore=memory store factory] a function
* that creates a store for keeping track of user's API tokens and auth status
* @param {string[]} [opts.scopes] list of scope strings
* (e.g. url:GET|/api/v1/courses). These scopes will be included
* in all authorization requests
*/
var initAuth = function (opts) { return __awaiter(void 0, void 0, void 0, function () {
var scopesQueryAddon;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
// Check if required opts are included
if (!opts
|| !opts.app
|| !opts.developerCredentials) {
throw new caccl_error_1.default({
message: 'Token manager initialized improperly: at least one required option was not included. We require app, developerCredentials',
code: ErrorCode_js_1.default.RequiredOptionExcluded,
});
}
// Make sure init isn't called more than once
if (tokenStore || developerCredentials) {
throw new caccl_error_1.default({
message: 'CACCL Authorizer cannot be initialized more than one.',
code: ErrorCode_js_1.default.InitializedMoreThanOnce,
});
}
scopesQueryAddon = (opts.scopes
? "&scope=".concat(encodeURIComponent(opts.scopes.join(' ')))
: '');
return [4 /*yield*/, (opts.initTokenStore
? opts.initTokenStore(TOKEN_LIFESPAN_SEC_js_1.default)
: (0, caccl_memory_store_1.default)(TOKEN_LIFESPAN_SEC_js_1.default))];
case 1:
// Initialize token store
tokenStore = _a.sent();
// Save copy of credentials
developerCredentials = opts.developerCredentials;
/*------------------------------------------------------------------------*/
/* Authorization Process */
/*------------------------------------------------------------------------*/
// Step 0: Intercept errors
opts.app.get(CACCL_PATHS_1.default.AUTHORIZE, function (req, res, next) { return __awaiter(void 0, void 0, void 0, function () {
var error, description;
return __generator(this, function (_a) {
if (req.query.error || req.query.error_description) {
error = (String(req.query.error || 'unknown_error')
.split('_')
.map(function (word) {
if (word.length <= 1) {
return word.toUpperCase();
}
// Capitalize the word
return "".concat(word.substring(0, 1).toUpperCase()).concat(word.substring(1));
})
.join(' '));
description = decodeURIComponent(String(req.query.error_description
|| 'No+further+description+could+be+found.')).replace(/\+/g, ' ');
return [2 /*return*/, res.status(403).send("A launch error occurred: ".concat(error, ". ").concat(description))];
}
// No error occurred. Continue
return [2 /*return*/, next()];
});
}); });
// Step 1: Try to refresh, if not possible, redirect to authorization screen
opts.app.get(CACCL_PATHS_1.default.AUTHORIZE, function (req, res, next) { return __awaiter(void 0, void 0, void 0, function () {
var _a, launched, launchInfo, tokenPack, err_2, devCreds, appHost, authURL;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
_a = (0, caccl_lti_1.getLaunchInfo)(req), launched = _a.launched, launchInfo = _a.launchInfo;
if (!launched) {
// No session! Cannot authorize without session
return [2 /*return*/, res.status(403).send('We could not authorize you with Canvas because your session has expired.')];
}
// Skip if not step 1
if (req.query.code && req.query.state) {
return [2 /*return*/, next()];
}
// Only allow auth if LTI launch occurred
if (!launched) {
// Cannot authorize
return [2 /*return*/, res.status(403).send('Your session has expired. Please launch this app again via Canvas.')];
}
return [4 /*yield*/, tokenStore.get("".concat(launchInfo.canvasHost, "/").concat(launchInfo.userId))];
case 1:
tokenPack = _b.sent();
if (!tokenPack) return [3 /*break*/, 5];
_b.label = 2;
case 2:
_b.trys.push([2, 4, , 5]);
return [4 /*yield*/, refreshAuth(req)];
case 3:
_b.sent();
// Refresh successful!
// We're done authorizing. Redirect to homepage
return [2 /*return*/, res.redirect(CACCL_PATHS_1.default.HOME)];
case 4:
err_2 = _b.sent();
// Refresh failed. Show error to user
return [2 /*return*/, res.status(403).send('Your Canvas authorization has expired and we could not refresh your credentials.')];
case 5:
devCreds = opts.developerCredentials[launchInfo.canvasHost];
if (!devCreds) {
return [2 /*return*/, res.status(404).send('We could not authorize you with Canvas because this app is not prepared for use with this Canvas instance.')];
}
appHost = (thisIsDevEnvironment
? 'localhost:8080'
: req.hostname);
authURL = "https://".concat(launchInfo.canvasHost, "/login/oauth2/auth?client_id=").concat(devCreds.clientId, "&response_type=code&redirect_uri=https://").concat(appHost).concat(CACCL_PATHS_1.default.AUTHORIZE, "&state=caccl").concat(scopesQueryAddon);
return [2 /*return*/, res.redirect(authURL)];
}
});
}); });
// Step 2: Receive code or denial
opts.app.get(CACCL_PATHS_1.default.AUTHORIZE, function (req, res, next) { return __awaiter(void 0, void 0, void 0, function () {
var _a, code, error, _b, launched, launchInfo, specificCanvasCreds, response, err_3, body, expiresIn, newTokenPack, err_4;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
// Skip unless we have a code OR error and state indicates this is CACCL
if (!req.query
|| !req.query.state
|| req.query.state !== 'caccl'
|| (!req.query.code && !req.query.error)) {
return [2 /*return*/, next()];
}
_a = req.query, code = _a.code, error = _a.error;
// Check for invalid Canvas response
if (!code && !error) {
// Canvas responded weirdly
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because Canvas responded in an unexpected way.')];
}
_b = (0, caccl_lti_1.getLaunchInfo)(req), launched = _b.launched, launchInfo = _b.launchInfo;
if (!launched) {
// No session
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because your session has expired.')];
}
// Check if we encountered an internal error
if (!code
&& error
&& error === 'unsupported_response_type') {
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because Canvas would not start the authorization process.')];
}
// Check if access was denied
if (!code) {
// Access was denied
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because your access was denied. Please contact your Canvas support team.')];
}
specificCanvasCreds = developerCredentials[launchInfo.canvasHost];
if (!specificCanvasCreds) {
// No credentials for this Canvas host
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because this app is not ready to integrate with your instance of Canvas.')];
}
_c.label = 1;
case 1:
_c.trys.push([1, 3, , 4]);
return [4 /*yield*/, (0, caccl_send_request_1.default)({
host: launchInfo.canvasHost,
path: '/login/oauth2/token',
method: 'POST',
params: {
code: code,
grant_type: 'authorization_code',
client_id: specificCanvasCreds.clientId,
client_secret: specificCanvasCreds.clientSecret,
redirect_uri: "https://".concat(req.hostname).concat(CACCL_PATHS_1.default.AUTHORIZE),
},
})];
case 2:
response = _c.sent();
return [3 /*break*/, 4];
case 3:
err_3 = _c.sent();
// Could not trade auth code for tokens
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because Canvas did not respond to our request for tokens.')];
case 4:
body = response.body;
// Detect invalid client_secret error
if (body.error && body.error === 'invalid_client') {
// Save status
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because Canvas would not recognize this app.')];
}
expiresIn = (body.expires_in * 0.99 * 1000);
newTokenPack = {
accessToken: body.access_token,
refreshToken: body.refresh_token,
accessTokenExpiry: (Date.now() + expiresIn),
canvasHost: launchInfo.canvasHost,
};
_c.label = 5;
case 5:
_c.trys.push([5, 7, , 8]);
return [4 /*yield*/, tokenStore.set("".concat(launchInfo.canvasHost, "/").concat(launchInfo.userId), newTokenPack)];
case 6:
_c.sent();
return [3 /*break*/, 8];
case 7:
err_4 = _c.sent();
return [2 /*return*/, res.status(403).send('We could not get your authorization with Canvas because your credentials could not be stored.')];
case 8:
// We're done authorizing. Redirect to homepage
return [2 /*return*/, res.redirect(CACCL_PATHS_1.default.HOME)];
}
});
}); });
return [2 /*return*/];
}
});
}); };
/*------------------------------------------------------------------------*/
/* Get Access Token */
/*------------------------------------------------------------------------*/
/**
* Get the user's current access token
* @author Gabe Abrams
* @async
* @param {express.Request} req express request instance
* @returns {Promise<string>} user's current access token
*/
var getAccessToken = function (req) { return __awaiter(void 0, void 0, void 0, function () {
var _a, launched, launchInfo, tokenPack;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
_a = (0, caccl_lti_1.getLaunchInfo)(req), launched = _a.launched, launchInfo = _a.launchInfo;
// Show an error if user has not launched
if (!launched) {
throw new caccl_error_1.default({
message: 'We could not find the current user\'s access token because the current user has no session.',
code: ErrorCode_js_1.default.GetFailedNoSession,
});
}
return [4 /*yield*/, tokenStore.get("".concat(launchInfo.canvasHost, "/").concat(launchInfo.userId))];
case 1:
tokenPack = _b.sent();
if (!tokenPack) {
// User is not authorized
throw new caccl_error_1.default({
message: 'We could not find the current user\'s access token because the current user is not authorized.',
code: ErrorCode_js_1.default.GetFailedNoAuthorization,
});
}
if (!(Date.now() >= tokenPack.accessTokenExpiry - FIVE_MINS_MS)) return [3 /*break*/, 3];
return [4 /*yield*/, refreshAuth(req)];
case 2:
// Need to refresh!
tokenPack = _b.sent();
_b.label = 3;
case 3:
// Return the access token
return [2 /*return*/, tokenPack.accessToken];
}
});
}); };
exports.getAccessToken = getAccessToken;
/*------------------------------------------------------------------------*/
/* Exports */
/*------------------------------------------------------------------------*/
// Export initAuth
exports.default = initAuth;
//# sourceMappingURL=index.js.map