greenlock-express.js/http-middleware.js

155 lines
5.8 KiB
JavaScript

"use strict";
var HttpMiddleware = module.exports;
var servernameRe = /^[a-z0-9\.\-]+$/i;
var challengePrefix = "/.well-known/acme-challenge/";
HttpMiddleware.create = function(gl, defaultApp) {
if (defaultApp && "function" !== typeof defaultApp) {
throw new Error("use greenlock.httpMiddleware() or greenlock.httpMiddleware(function (req, res) {})");
}
return function(req, res, next) {
var hostname = HttpMiddleware.sanitizeHostname(req);
req.on("error", function(err) {
explainError(gl, err, "http_01_middleware_socket", hostname);
});
// Skip unless the path begins with /.well-known/acme-challenge/
if (!hostname || 0 !== req.url.indexOf(challengePrefix)) {
skipChallenge(req, res, next, defaultApp);
return;
}
// HEADERS SENT DEBUG NOTE #2
// at this point, it's most likely Let's Encrypt server
// (or greenlock itself) performing the verification process
// Hmmm... perhaps we should change the greenlock prefix to test
// Anyway, we just got fast the first place where we could
// be sending headers.
var token = req.url.slice(challengePrefix.length);
var done = false;
var countA = 0;
var countB = 0;
gl.getAcmeHttp01ChallengeResponse({ type: "http-01", servername: hostname, token: token })
.catch(function(err) {
countA += 1;
// HEADERS SENT DEBUG NOTE #3
// This is the second possible time we could be sending headers
respondToError(gl, res, err, "http_01_middleware_challenge_response", hostname);
done = true;
return { __done: true };
})
.then(function(result) {
countB += 1;
if (result && result.__done) {
return;
}
if (done) {
console.error("Sanity check fail: `done` is in a quantum state of both true and false... huh?");
return;
}
// HEADERS SENT DEBUG NOTE #4b
// This is the third/fourth possible time send headers
return respondWithGrace(res, result, hostname, token);
})
.catch(function(err) {
// HEADERS SENT DEBUG NOTE #5
// I really don't see how this can be possible.
// Every case appears to be accounted for
console.error();
console.error("[warning] Developer Error:" + (err.code || err.context || ""), countA, countB);
console.error(err.stack);
console.error();
console.error(
"This is probably the error that happens routinely on http2 connections, but we're not sure why."
);
console.error("To track the status or help contribute,");
console.error("visit: https://git.rootprojects.org/root/greenlock-express.js/issues/9");
console.error();
try {
res.end("Internal Server Error [1003]: See logs for details.");
} catch (e) {
// ignore
}
});
};
};
function skipChallenge(req, res, next, defaultApp) {
if ("function" === typeof defaultApp) {
defaultApp(req, res, next);
} else if ("function" === typeof next) {
next();
} else {
res.statusCode = 500;
res.end("[500] Developer Error: app.use('/', greenlock.httpMiddleware()) or greenlock.httpMiddleware(app)");
}
}
function respondWithGrace(res, result, hostname, token) {
var keyAuth = result && result.keyAuthorization;
// HEADERS SENT DEBUG NOTE #4b
// This is (still) the third/fourth possible time we could be sending headers
if (keyAuth && "string" === typeof keyAuth) {
res.setHeader("Content-Type", "text/plain; charset=utf-8");
res.end(keyAuth);
return;
}
res.statusCode = 404;
res.setHeader("Content-Type", "application/json; charset=utf-8");
res.end(JSON.stringify({ error: { message: "domain '" + hostname + "' has no token '" + token + "'." } }));
}
function explainError(gl, err, ctx, hostname) {
if (!err.servername) {
err.servername = hostname;
}
if (!err.context) {
err.context = ctx;
}
// leaving this in the build for now because it will help with existing error reports
console.error("[warning] network connection error:", (err.context || "") + " " + err.message);
(gl.notify || gl._notify)("error", err);
return err;
}
function respondToError(gl, res, err, ctx, hostname) {
// HEADERS SENT DEBUG NOTE #3b
// This is (still) the second possible time we could be sending headers
err = explainError(gl, err, ctx, hostname);
res.statusCode = 500;
res.end("Internal Server Error [1004]: See logs for details.");
}
HttpMiddleware.getHostname = function(req) {
return req.hostname || req.headers["x-forwarded-host"] || (req.headers.host || "");
};
HttpMiddleware.sanitizeHostname = function(req) {
// we can trust XFH because spoofing causes no ham in this limited use-case scenario
// (and only telebit would be legitimately setting XFH)
var servername = HttpMiddleware.getHostname(req)
.toLowerCase()
.replace(/:.*/, "");
try {
req.hostname = servername;
} catch (e) {
// read-only express property
}
if (req.headers["x-forwarded-host"]) {
req.headers["x-forwarded-host"] = servername;
}
try {
req.headers.host = servername;
} catch (e) {
// TODO is this a possible error?
}
return (servernameRe.test(servername) && -1 === servername.indexOf("..") && servername) || "";
};