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/* 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
import { AccountCreationUtils } from "resource:///modules/accountcreation/AccountCreationUtils.sys.mjs";
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
});
const {
Abortable,
ddump,
Exception,
PriorityOrderAbortable,
PromiseAbortable,
readURLasUTF8,
runAsync,
SuccessiveAbortable,
TimeoutAbortable,
} = AccountCreationUtils;
/**
* A callback that will be called when a configuration was retrieved and
* parsed successfully.
*
* @callback SuccessCallback
* @param {AccountConfig} config - The AccountConfig object.
*/
/**
* A callback that will be called when there was an error while retrieving
* or parsing the configuration.
*
* This is expected (e.g. when there's no config for a domain at the checked
* location). So do not unconditionally show this to the user.
*
* @callback ErrorCallback
* @param {Error|string} error - An Error instance or error string.
*/
/**
* Tries to find a configuration for this ISP on the local harddisk, in the
* application install directory's "isp" subdirectory.
* Params @see fetchConfigFromISP()
*/
function fetchConfigFromDisk(domain, successCallback, errorCallback) {
return new TimeoutAbortable(
runAsync(function () {
try {
// <TB installdir>/isp/example.com.xml
var configLocation = Services.dirsvc.get("CurProcD", Ci.nsIFile);
configLocation.append("isp");
configLocation.append(lazy.Sanitizer.hostname(domain) + ".xml");
if (!configLocation.exists() || !configLocation.isReadable()) {
errorCallback(new Exception("local file not found"));
return;
}
var contents = readURLasUTF8(Services.io.newFileURI(configLocation));
const domParser = new DOMParser();
const xml = JXON.build(domParser.parseFromString(contents, "text/xml"));
successCallback(lazy.readFromXML(xml, "disk"));
} catch (e) {
errorCallback(e);
}
})
);
}
/**
* Tries to get a configuration from the ISP / mail provider directly.
*
* Disclaimers:
* - To support domain hosters, we cannot use SSL. That means we
* rely on insecure DNS and http, which means the results may be
* forged when under attack. The same is true for guessConfig(), though.
*
* @param domain {String} - The domain part of the user's email address
* @param emailAddress {String} - The user's email address
* @param successCallback {Function(config {AccountConfig}})} A callback that
* will be called when we could retrieve a configuration.
* The AccountConfig object will be passed in as first parameter.
* @param errorCallback {Function(ex)} - A callback that
* will be called when we could not retrieve a configuration,
* for whatever reason. This is expected (e.g. when there's no config
* for this domain at this location),
* so do not unconditionally show this to the user.
* The first parameter will be an exception object or error string.
*/
function fetchConfigFromISP(
domain,
emailAddress,
successCallback,
errorCallback
) {
const httpsOnly = Services.prefs.getBoolPref(
"mailnews.auto_config.fetchFromISP.sslOnly"
);
return _fetchConfigFromIsp(
domain,
emailAddress,
httpsOnly,
true, // useOptionalUrl
successCallback,
errorCallback
);
}
/**
* Tries to get a configuration from the ISP / mail provider directly.
*
* @param {string} domain - The domain part of the user's email address.
* @param {string} emailAddress - The user's email address.
* @param {boolean} httpsOnly - If true, only uses https-variants of the
* autoconfig URLs.
* @param {boolean} useOptionalUrl - If false, the /.well-known URLs will be
* skipped when checking for a configuration.
* @param {SuccessCallback} successCallback - Will be called when a valid
* config was successfully retrieved.
* @param {ErrorCallback} errorCallback - Will be called when no valid config
* could be retrieved.
*
* @returns {Abortable} - A handle for this async operation which you can cancel.
*/
function _fetchConfigFromIsp(
domain,
emailAddress,
httpsOnly,
useOptionalUrl,
successCallback,
errorCallback
) {
if (
!Services.prefs.getBoolPref("mailnews.auto_config.fetchFromISP.enabled")
) {
errorCallback(new Exception("ISP fetch disabled per user preference"));
return new Abortable();
}
const sanitizedDomain = lazy.Sanitizer.hostname(domain);
const conf1 = `autoconfig.${sanitizedDomain}/mail/config-v1.1.xml`;
const conf2 = `${sanitizedDomain}/.well-known/autoconfig/mail/config-v1.1.xml`;
// This list is sorted by decreasing priority
var urls = ["https://" + conf1];
if (useOptionalUrl) {
urls.push("https://" + conf2);
}
if (!httpsOnly) {
urls.push("http://" + conf1);
if (useOptionalUrl) {
urls.push("http://" + conf2);
}
}
const callArgs = {
urlArgs: {
emailaddress: emailAddress,
},
};
if (
!Services.prefs.getBoolPref(
"mailnews.auto_config.fetchFromISP.sendEmailAddress"
)
) {
delete callArgs.urlArgs.emailaddress;
}
const priority = new PriorityOrderAbortable(
(xml, call) =>
successCallback(lazy.readFromXML(xml, `isp-${call.foundMsg}`)),
errorCallback
);
for (const url of urls) {
const call = priority.addCall();
call.foundMsg = url.startsWith("https") ? "https" : "http";
const fetchHttp = lazy.FetchHTTP.create(
url,
callArgs,
call.successCallback(),
call.errorCallback()
);
call.setAbortable(fetchHttp);
fetchHttp.start();
}
return priority;
}
/**
* Tries to get a configuration for this ISP from a central database at
* Mozilla servers.
* Params @see fetchConfigFromISP()
*/
function fetchConfigFromDB(domain, successCallback, errorCallback) {
let url = Services.prefs.getCharPref("mailnews.auto_config_url");
if (!url) {
errorCallback(new Exception("no URL for ISP DB configured"));
return new Abortable();
}
domain = lazy.Sanitizer.hostname(domain);
// If we don't specify a place to put the domain, put it at the end.
if (!url.includes("{{domain}}")) {
url = url + domain;
} else {
url = url.replace("{{domain}}", domain);
}
const fetchHttp = lazy.FetchHTTP.create(
url,
{ timeout: 10000 }, // 10 seconds
function (result) {
successCallback(lazy.readFromXML(result, "db"));
},
errorCallback
);
fetchHttp.start();
return fetchHttp;
}
/**
* Does a lookup of DNS MX, to get the server that is responsible for
* receiving mail for this domain. Then it takes the domain of that
* server, and does another lookup (in ISPDB and at ISP autoconfig
* server) and if such a config is found, returns that.
*
* Disclaimers:
* - DNS is unprotected, meaning the results could be forged.
* The same is true for fetchConfigFromISP() and guessConfig(), though.
* - DNS MX tells us the incoming server, not the mailbox (IMAP) server.
* They are different. This mechanism is only an approximation
* for hosted domains (yourname.com is served by mx.hoster.com and
* therefore imap.hoster.com - that "therefore" is exactly the
* conclusional jump we make here.) and alternative domains
* (e.g. yahoo.de -> yahoo.com).
* - We make a look up for the base domain. E.g. if MX is
* mx1.incoming.servers.hoster.com, we look up hoster.com.
* Thanks to Services.eTLD, we also get bbc.co.uk right.
*
* Params @see fetchConfigFromISP()
*/
function fetchConfigForMX(
domain,
emailAddress,
successCallback,
errorCallback
) {
function fetchConfig(runner, lookupDomain) {
const ispCall = runner.addCall();
const ispFetch = _fetchConfigFromIsp(
lookupDomain,
emailAddress,
true, // httpsOnly
false, // useOptionalUrl
ispCall.successCallback(),
ispCall.errorCallback()
);
ispCall.setAbortable(ispFetch);
const dbCall = runner.addCall();
const dbFetch = fetchConfigFromDB(
lookupDomain,
dbCall.successCallback(),
dbCall.errorCallback()
);
dbCall.setAbortable(dbFetch);
}
const sanitizedDomain = lazy.Sanitizer.hostname(domain);
const sucAbortable = new SuccessiveAbortable();
const time = Date.now();
sucAbortable.current = getMX(
sanitizedDomain,
function (mxHostname) {
// success
ddump("getmx took " + (Date.now() - time) + "ms");
const sld = Services.eTLD.getBaseDomainFromHost(mxHostname);
ddump("base domain " + sld + " for " + mxHostname);
if (sld == sanitizedDomain) {
errorCallback(
new Exception("MX lookup would be no different from domain")
);
return;
}
// In addition to just the base domain, also check the full domain of the MX server
// to differentiate between Outlook.com/Hotmail and Office365 business domains.
let mxDomain;
try {
mxDomain = Services.eTLD.getNextSubDomain(mxHostname);
} catch (ex) {
// e.g. hostname doesn't have enough components
console.error(ex); // not fatal
}
const priority = new PriorityOrderAbortable(
successCallback,
errorCallback
);
if (mxDomain && sld != mxDomain) {
fetchConfig(priority, mxDomain);
}
fetchConfig(priority, sld);
sucAbortable.current = priority;
},
errorCallback
);
return sucAbortable;
}
/**
* Queries the DNS MX records for a given domain. Calls `successCallback` with
* the hostname of the MX server. If there are several entries with different
* preference values, only the most preferred (i.e. has the lowest value)
* is used. If there are several most preferred servers (i.e. round robin),
* only one of them is used.
*
* @param {string} sanitizedDomain @see fetchConfigFromISP()
* @param {function(hostname {string})} - successCallback
* Called when we found an MX for the domain.
* For |hostname|, see description above.
* @param {function({Exception|string})} errorCallback @see fetchConfigFromISP()
*/
function getMX(sanitizedDomain, successCallback, errorCallback) {
return new PromiseAbortable(
DNS.mx(sanitizedDomain),
function (records) {
const filteredRecs = records.filter(record => record.host);
if (filteredRecs.length > 0) {
const sortedRecs = filteredRecs.sort((a, b) => a.prio > b.prio);
const firstHost = sortedRecs[0].host;
successCallback(firstHost);
} else {
errorCallback(
new Exception(
"No hostname found in MX records for sanitizedDomain=" +
sanitizedDomain
)
);
}
},
errorCallback
);
}
export const FetchConfig = {
forMX: fetchConfigForMX,
fromDB: fetchConfigFromDB,
fromISP: fetchConfigFromISP,
fromDisk: fetchConfigFromDisk,
};