gecko-dev/services/common/tokenserverclient.js

259 lines
8.3 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const EXPORTED_SYMBOLS = [
"TokenServerClient",
"TokenServerClientError",
"TokenServerClientNetworkError",
"TokenServerClientServerError"
];
const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
Cu.import("resource://services-common/log4moz.js");
Cu.import("resource://services-common/preferences.js");
Cu.import("resource://services-common/rest.js");
Cu.import("resource://services-common/utils.js");
const Prefs = new Preferences("services.common.tokenserverclient.");
/**
* Represents a TokenServerClient error that occurred on the client.
*
* This is the base type for all errors raised by client operations.
*
* @param message
* (string) Error message.
*/
function TokenServerClientError(message) {
this.name = "TokenServerClientError";
this.message = message || "Client error.";
}
TokenServerClientError.prototype = new Error();
TokenServerClientError.prototype.constructor = TokenServerClientError;
/**
* Represents a TokenServerClient error that occurred in the network layer.
*
* @param error
* The underlying error thrown by the network layer.
*/
function TokenServerClientNetworkError(error) {
this.name = "TokenServerClientNetworkError";
this.error = error;
}
TokenServerClientNetworkError.prototype = new TokenServerClientError();
TokenServerClientNetworkError.prototype.constructor =
TokenServerClientNetworkError;
/**
* Represents a TokenServerClient error that occurred on the server.
*
* This type will be encountered for all non-200 response codes from the
* server.
*
* @param message
* (string) Error message.
*/
function TokenServerClientServerError(message) {
this.name = "TokenServerClientServerError";
this.message = message || "Server error.";
}
TokenServerClientServerError.prototype = new TokenServerClientError();
TokenServerClientServerError.prototype.constructor =
TokenServerClientServerError;
/**
* Represents a client to the Token Server.
*
* http://docs.services.mozilla.com/token/index.html
*
* The Token Server supports obtaining tokens for arbitrary apps by
* constructing URI paths of the form <app>/<app_version>. However, the service
* discovery mechanism emphasizes the use of full URIs and tries to not force
* the client to manipulate URIs. This client currently enforces this practice
* by not implementing an API which would perform URI manipulation.
*
* If you are tempted to implement this API in the future, consider this your
* warning that you may be doing it wrong and that you should store full URIs
* instead.
*
* Areas to Improve:
*
* - The server sends a JSON response on error. The client does not currently
* parse this. It might be convenient if it did.
* - Currently all non-200 status codes are rolled into one error type. It
* might be helpful if callers had a richer API that communicated who was
* at fault (e.g. differentiating a 503 from a 401).
*/
function TokenServerClient() {
this._log = Log4Moz.repository.getLogger("Common.TokenServerClient");
this._log.level = Log4Moz.Level[Prefs.get("logger.level")];
}
TokenServerClient.prototype = {
/**
* Logger instance.
*/
_log: null,
/**
* Obtain a token from a BrowserID assertion against a specific URL.
*
* This asynchronously obtains the token. The callback receives 2 arguments.
* The first signifies an error and is a TokenServerClientError (or derived)
* type when an error occurs. If an HTTP response was seen, a RESTResponse
* instance will be stored in the "response" property of this object.
*
* The second argument to the callback is a map containing the results from
* the server. This map has the following keys:
*
* id (string) HTTP MAC public key identifier.
* key (string) HTTP MAC shared symmetric key.
* endpoint (string) URL where service can be connected to.
* uid (string) user ID for requested service.
*
* e.g.
*
* let client = new TokenServerClient();
* let assertion = getBrowserIDAssertionFromSomewhere();
* let url = "https://token.services.mozilla.com/1.0/sync/2.0";
*
* client.getTokenFromBrowserIDAssertion(url, assertion,
* function(error, result) {
* if (error) {
* // Do error handling.
* return;
* }
*
* let {id: id, key: key, uid: uid, endpoint: endpoint} = result;
* // Do stuff with data and carry on.
* });
*
* @param url
* (string) URL to fetch token from.
* @param assertion
* (string) BrowserID assertion to exchange token for.
* @param cb
* (function) Callback to be invoked with result of operation.
*/
getTokenFromBrowserIDAssertion:
function getTokenFromBrowserIDAssertion(url, assertion, cb) {
if (!url) {
throw new TokenServerClientError("url argument is not valid.");
}
if (!assertion) {
throw new TokenServerClientError("assertion argument is not valid.");
}
if (!cb) {
throw new TokenServerClientError("cb argument is not valid.");
}
this._log.debug("Beginning BID assertion exchange: " + url);
let req = new RESTRequest(url);
req.setHeader("accept", "application/json");
req.setHeader("authorization", "Browser-ID " + assertion);
let client = this;
req.get(function onResponse(error) {
if (error) {
cb(new TokenServerClientNetworkError(error), null);
return;
}
let self = this;
function callCallback(error, result) {
if (!cb) {
self._log.warn("Callback already called! Did it throw?");
return;
}
try {
cb(error, result);
} catch (ex) {
self._log.warn("Exception when calling user-supplied callback: " +
CommonUtils.exceptionStr(ex));
}
cb = null;
}
try {
client._processTokenResponse(this.response, callCallback);
} catch (ex) {
this._log.warn("Error processing token server response: " +
CommonUtils.exceptionStr(ex));
let error = new TokenServerClientError(ex);
error.response = this.response;
callCallback(error, null);
}
});
},
/**
* Handler to process token request responses.
*
* @param response
* RESTResponse from token HTTP request.
* @param cb
* The original callback passed to the public API.
*/
_processTokenResponse: function processTokenResponse(response, cb) {
this._log.debug("Got token response.");
if (!response.success) {
this._log.info("Non-200 response code to token request: " +
response.status);
this._log.debug("Response body: " + response.body);
let error = new TokenServerClientServerError("Non 200 response code: " +
response.status);
error.response = response;
cb(error, null);
return;
}
let ct = response.headers["content-type"];
if (ct != "application/json" && ct.indexOf("application/json;") != 0) {
let error = new TokenServerClientError("Unsupported media type: " + ct);
error.response = response;
cb(error, null);
return;
}
let result;
try {
result = JSON.parse(response.body);
} catch (ex) {
let error = new TokenServerClientServerError("Invalid JSON returned " +
"from server.");
error.response = response;
cb(error, null);
return;
}
for each (let k in ["id", "key", "api_endpoint", "uid"]) {
if (!(k in result)) {
let error = new TokenServerClientServerError("Expected key not " +
" present in result: " +
k);
error.response = response;
cb(error, null);
return;
}
}
this._log.debug("Successful token response: " + result.id);
cb(null, {
id: result.id,
key: result.key,
endpoint: result.api_endpoint,
uid: result.uid,
});
}
};