diff --git a/index.js b/index.js
index 5c708fe..5fb9339 100644
--- a/index.js
+++ b/index.js
@@ -1,4 +1,6 @@
-'use strict';
+"use strict";
+/*global Promise*/
+require("./lib/compat.js");
 
 // I hate this code so much.
 // Soooo many shims for backwards compatibility (some stuff dating back to v1)
@@ -6,43 +8,44 @@
 
 var DAY = 24 * 60 * 60 * 1000;
 //var MIN = 60 * 1000;
-var ACME = require('acme-v2/compat').ACME;
-var pkg = require('./package.json');
-var PromiseA;
-try {
-  PromiseA = require('bluebird');
-} catch(e) {
-  PromiseA = global.Promise;
-}
-if (!PromiseA.promisify) {
-  PromiseA.promisify = require('util').promisify;
-}
+var ACME = require("acme-v2/compat").ACME;
+var pkg = require("./package.json");
+var util = require("util");
+
 function promisifyAllSelf(obj) {
-  if (obj.__promisified) { return obj; }
-  Object.keys(obj).forEach(function (key) {
-    if ('function' === typeof obj[key] && !/Async$/.test(key)) {
-      obj[key + 'Async'] = PromiseA.promisify(obj[key]);
-    }
-  });
-  obj.__promisified = true;
-  return obj;
+	if (obj.__promisified) {
+		return obj;
+	}
+	Object.keys(obj).forEach(function(key) {
+		if ("function" === typeof obj[key] && !/Async$/.test(key)) {
+			obj[key + "Async"] = util.promisify(obj[key]);
+		}
+	});
+	obj.__promisified = true;
+	return obj;
 }
 function promisifyAllStore(obj) {
-  Object.keys(obj).forEach(function (key) {
-    if ('function' !== typeof obj[key] || /Async$/.test(key)) { return; }
+	Object.keys(obj).forEach(function(key) {
+		if ("function" !== typeof obj[key] || /Async$/.test(key)) {
+			return;
+		}
 
-    var p;
-    if (0 === obj[key].length || 1 === obj[key].length) {
-      // wrap just in case it's synchronous (or improperly throws)
-      p = function (opts) { return PromiseA.resolve().then(function () { return obj[key](opts); }); };
-    } else {
-      p = PromiseA.promisify(obj[key]);
-    }
-    // internal backwards compat
-    obj[key + 'Async'] = p;
-  });
-  obj.__promisified = true;
-  return obj;
+		var p;
+		if (0 === obj[key].length || 1 === obj[key].length) {
+			// wrap just in case it's synchronous (or improperly throws)
+			p = function(opts) {
+				return Promise.resolve().then(function() {
+					return obj[key](opts);
+				});
+			};
+		} else {
+			p = util.promisify(obj[key]);
+		}
+		// internal backwards compat
+		obj[key + "Async"] = p;
+	});
+	obj.__promisified = true;
+	return obj;
 }
 
 var Greenlock = module.exports;
@@ -52,311 +55,373 @@ Greenlock.LE = Greenlock;
 var ipc = {};
 
 function _log(debug) {
-  if (debug) {
-    var args = Array.prototype.slice.call(arguments);
-    args.shift();
-    args.unshift("[gl/index.js]");
-    console.log.apply(console, args);
-  }
+	if (debug) {
+		var args = Array.prototype.slice.call(arguments);
+		args.shift();
+		args.unshift("[gl/index.js]");
+		console.log.apply(console, args);
+	}
 }
 
 Greenlock.defaults = {
-  productionServerUrl: 'https://acme-v01.api.letsencrypt.org/directory'
-, stagingServerUrl: 'https://acme-staging.api.letsencrypt.org/directory'
+	productionServerUrl: "https://acme-v01.api.letsencrypt.org/directory",
+	stagingServerUrl: "https://acme-staging.api.letsencrypt.org/directory",
 
-, rsaKeySize: ACME.rsaKeySize || 2048
-, challengeType: ACME.challengeType || 'http-01'
-, challengeTypes: ACME.challengeTypes || [ 'http-01', 'dns-01' ]
+	rsaKeySize: ACME.rsaKeySize || 2048,
+	challengeType: ACME.challengeType || "http-01",
+	challengeTypes: ACME.challengeTypes || ["http-01", "dns-01"],
 
-, acmeChallengePrefix: ACME.acmeChallengePrefix
+	acmeChallengePrefix: ACME.acmeChallengePrefix
 };
 
 // backwards compat
-Object.keys(Greenlock.defaults).forEach(function (key) {
-  Greenlock[key] = Greenlock.defaults[key];
+Object.keys(Greenlock.defaults).forEach(function(key) {
+	Greenlock[key] = Greenlock.defaults[key];
 });
 
 // show all possible options
 var u; // undefined
 Greenlock._undefined = {
-  acme: u
-, store: u
-//, challenge: u
-, challenges: u
-, sni: u
-, tlsOptions: u
+	acme: u,
+	store: u,
+	//, challenge: u
+	challenges: u,
+	sni: u,
+	tlsOptions: u,
 
-, register: u
-, check: u
+	register: u,
+	check: u,
 
-, renewWithin: u // le-auto-sni and core
-//, renewBy: u // le-auto-sni
-, acmeChallengePrefix: u
-, rsaKeySize: u
-, challengeType: u
-, server: u
-, version: u
-, agreeToTerms: u
-, _ipc: u
-, duplicate: u
-, _acmeUrls: u
+	renewWithin: u, // le-auto-sni and core
+	//, renewBy: u // le-auto-sni
+	acmeChallengePrefix: u,
+	rsaKeySize: u,
+	challengeType: u,
+	server: u,
+	version: u,
+	agreeToTerms: u,
+	_ipc: u,
+	duplicate: u,
+	_acmeUrls: u
 };
-Greenlock._undefine = function (gl) {
-  Object.keys(Greenlock._undefined).forEach(function (key) {
-    if (!(key in gl)) {
-      gl[key] = u;
-    }
-  });
+Greenlock._undefine = function(gl) {
+	Object.keys(Greenlock._undefined).forEach(function(key) {
+		if (!(key in gl)) {
+			gl[key] = u;
+		}
+	});
 
-  return gl;
+	return gl;
 };
-Greenlock.create = function (gl) {
-  if (!gl.store) {
-    console.warn("Deprecation Notice: You're haven't chosen a storage strategy."
-      + " The old default is 'le-store-certbot', but the new default will be 'greenlock-store-fs'."
-      + " Please `npm install greenlock-store-fs@3` and explicitly set `{ store: require('greenlock-store-fs') }`.");
-    gl.store = require('le-store-certbot').create({
-      debug: gl.debug
-    , configDir: gl.configDir
-    , logsDir: gl.logsDir
-    , webrootPath: gl.webrootPath
-    });
-  }
-  gl.core = require('./lib/core');
-  var log = gl.log || _log;
+Greenlock.create = function(gl) {
+	if (!gl.store) {
+		console.warn(
+			"Deprecation Notice: You're haven't chosen a storage strategy." +
+				" The old default is 'le-store-certbot', but the new default will be 'greenlock-store-fs'." +
+				" Please `npm install greenlock-store-fs@3` and explicitly set `{ store: require('greenlock-store-fs') }`."
+		);
+		gl.store = require("le-store-certbot").create({
+			debug: gl.debug,
+			configDir: gl.configDir,
+			logsDir: gl.logsDir,
+			webrootPath: gl.webrootPath
+		});
+	}
+	gl.core = require("./lib/core");
+	var log = gl.log || _log;
 
-  if (!gl.challenges) {
-    gl.challenges = {};
-  }
-  if (!gl.challenges['http-01']) {
-    gl.challenges['http-01'] = require('le-challenge-fs').create({
-      debug: gl.debug
-    , webrootPath: gl.webrootPath
-    });
-  }
-  if (!gl.challenges['dns-01']) {
-    try {
-      gl.challenges['dns-01'] = require('le-challenge-ddns').create({ debug: gl.debug });
-    } catch(e) {
-      try {
-        gl.challenges['dns-01'] = require('le-challenge-dns').create({ debug: gl.debug });
-      } catch(e) {
-        // not yet implemented
-      }
-    }
-  }
+	if (!gl.challenges) {
+		gl.challenges = {};
+	}
+	if (!gl.challenges["http-01"]) {
+		gl.challenges["http-01"] = require("le-challenge-fs").create({
+			debug: gl.debug,
+			webrootPath: gl.webrootPath
+		});
+	}
+	if (!gl.challenges["dns-01"]) {
+		try {
+			gl.challenges["dns-01"] = require("le-challenge-ddns").create({
+				debug: gl.debug
+			});
+		} catch (e) {
+			try {
+				gl.challenges["dns-01"] = require("le-challenge-dns").create({
+					debug: gl.debug
+				});
+			} catch (e) {
+				// not yet implemented
+			}
+		}
+	}
 
-  gl = Greenlock._undefine(gl);
-  gl.acmeChallengePrefix = Greenlock.acmeChallengePrefix;
-  gl.rsaKeySize = gl.rsaKeySize || Greenlock.rsaKeySize;
-  gl.challengeType = gl.challengeType || Greenlock.challengeType;
-  gl._ipc = ipc;
-  gl._communityPackage = gl._communityPackage || 'greenlock.js';
-  if ('greenlock.js' === gl._communityPackage) {
-    gl._communityPackageVersion = pkg.version;
-  } else {
-    gl._communityPackageVersion = gl._communityPackageVersion || ('greenlock.js-' + pkg.version);
-  }
-  gl.agreeToTerms = gl.agreeToTerms || function (args, agreeCb) {
-    agreeCb(new Error("'agreeToTerms' was not supplied to Greenlock and 'agreeTos' was not supplied to Greenlock.register"));
-  };
+	gl = Greenlock._undefine(gl);
+	gl.acmeChallengePrefix = Greenlock.acmeChallengePrefix;
+	gl.rsaKeySize = gl.rsaKeySize || Greenlock.rsaKeySize;
+	gl.challengeType = gl.challengeType || Greenlock.challengeType;
+	gl._ipc = ipc;
+	gl._communityPackage = gl._communityPackage || "greenlock.js";
+	if ("greenlock.js" === gl._communityPackage) {
+		gl._communityPackageVersion = pkg.version;
+	} else {
+		gl._communityPackageVersion =
+			gl._communityPackageVersion || "greenlock.js-" + pkg.version;
+	}
+	gl.agreeToTerms =
+		gl.agreeToTerms ||
+		function(args, agreeCb) {
+			agreeCb(
+				new Error(
+					"'agreeToTerms' was not supplied to Greenlock and 'agreeTos' was not supplied to Greenlock.register"
+				)
+			);
+		};
 
-  if (!gl.renewWithin) { gl.renewWithin = 14 * DAY; }
-  // renewBy has a default in le-sni-auto
+	if (!gl.renewWithin) {
+		gl.renewWithin = 14 * DAY;
+	}
+	// renewBy has a default in le-sni-auto
 
+	///////////////////////////
+	// BEGIN VERSION MADNESS //
+	///////////////////////////
 
+	gl.version = gl.version || "draft-11";
+	gl.server = gl.server || "https://acme-v02.api.letsencrypt.org/directory";
+	if (!gl.version) {
+		//console.warn("Please specify version: 'v01' (Let's Encrypt v1) or 'draft-12' (Let's Encrypt v2 / ACME draft 12)");
+		console.warn("");
+		console.warn("");
+		console.warn("");
+		console.warn("==========================================================");
+		console.warn("==                greenlock.js (v2.2.0+)                ==");
+		console.warn("==========================================================");
+		console.warn("");
+		console.warn("Please specify 'version' option:");
+		console.warn("");
+		console.warn("        'draft-12' for Let's Encrypt v2 and ACME draft 12");
+		console.warn("        ('v02' is an alias of 'draft-12'");
+		console.warn("");
+		console.warn("or");
+		console.warn("");
+		console.warn("        'v01' for Let's Encrypt v1 (deprecated)");
+		console.warn(
+			"         (also 'npm install --save le-acme-core' as this legacy dependency will soon be removed)"
+		);
+		console.warn("");
+		console.warn("This will be required in versions v2.3+");
+		console.warn("");
+		console.warn("");
+	} else if ("v02" === gl.version) {
+		gl.version = "draft-11";
+	} else if ("draft-12" === gl.version) {
+		gl.version = "draft-11";
+	} else if ("draft-11" === gl.version) {
+		// no-op
+	} else if ("v01" !== gl.version) {
+		throw new Error("Unrecognized version '" + gl.version + "'");
+	}
 
-  ///////////////////////////
-  // BEGIN VERSION MADNESS //
-  ///////////////////////////
+	if (!gl.server) {
+		throw new Error(
+			"opts.server must specify an ACME directory URL, such as 'https://acme-staging-v02.api.letsencrypt.org/directory'"
+		);
+	}
+	if ("staging" === gl.server || "production" === gl.server) {
+		if ("staging" === gl.server) {
+			gl.server = "https://acme-staging.api.letsencrypt.org/directory";
+			gl.version = "v01";
+			gl._deprecatedServerName = "staging";
+		} else if ("production" === gl.server) {
+			gl.server = "https://acme-v01.api.letsencrypt.org/directory";
+			gl.version = "v01";
+			gl._deprecatedServerName = "production";
+		}
+		console.warn("");
+		console.warn("");
+		console.warn("=== WARNING ===");
+		console.warn("");
+		console.warn(
+			"Due to versioning issues the '" +
+				gl._deprecatedServerName +
+				"' option is deprecated."
+		);
+		console.warn("Please specify the full url and version.");
+		console.warn("");
+		console.warn("For APIs add:");
+		console.warn('\t, "version": "' + gl.version + '"');
+		console.warn('\t, "server": "' + gl.server + '"');
+		console.warn("");
+		console.warn("For the CLI add:");
+		console.warn("\t--acme-url '" + gl.server + "' \\");
+		console.warn("\t--acme-version '" + gl.version + "' \\");
+		console.warn("");
+		console.warn("");
+	}
 
-  gl.version = gl.version || 'draft-11';
-  gl.server = gl.server || 'https://acme-v02.api.letsencrypt.org/directory';
-  if (!gl.version) {
-    //console.warn("Please specify version: 'v01' (Let's Encrypt v1) or 'draft-12' (Let's Encrypt v2 / ACME draft 12)");
-    console.warn("");
-    console.warn("");
-    console.warn("");
-    console.warn("==========================================================");
-    console.warn("==                greenlock.js (v2.2.0+)                ==");
-    console.warn("==========================================================");
-    console.warn("");
-    console.warn("Please specify 'version' option:");
-    console.warn("");
-    console.warn("        'draft-12' for Let's Encrypt v2 and ACME draft 12");
-    console.warn("        ('v02' is an alias of 'draft-12'");
-    console.warn("");
-    console.warn("or");
-    console.warn("");
-    console.warn("        'v01' for Let's Encrypt v1 (deprecated)");
-    console.warn("         (also 'npm install --save le-acme-core' as this legacy dependency will soon be removed)");
-    console.warn("");
-    console.warn("This will be required in versions v2.3+");
-    console.warn("");
-    console.warn("");
-  } else if ('v02' === gl.version) {
-    gl.version = 'draft-11';
-  } else if ('draft-12' === gl.version) {
-    gl.version = 'draft-11';
-  } else if ('draft-11' === gl.version) {
-    // no-op
-  } else if ('v01' !== gl.version) {
-    throw new Error("Unrecognized version '" + gl.version + "'");
-  }
+	function loadLeV01() {
+		console.warn("");
+		console.warn("=== WARNING ===");
+		console.warn("");
+		console.warn("Let's Encrypt v1 is deprecated.");
+		console.warn("Please update to Let's Encrypt v2 (ACME draft 12)");
+		console.warn("");
+		try {
+			return require("le-acme-core").ACME;
+		} catch (e) {
+			console.error("");
+			console.error("=== Error (easy-to-fix) ===");
+			console.error("");
+			console.error(
+				"Hey, this isn't a big deal, but you need to manually add v1 support:"
+			);
+			console.error("");
+			console.error("        npm install --save le-acme-core");
+			console.error("");
+			console.error(
+				"Just run that real quick, restart, and everything will work great."
+			);
+			console.error("");
+			console.error("");
+			process.exit(e.code || 13);
+		}
+	}
 
-  if (!gl.server) {
-    throw new Error("opts.server must specify an ACME directory URL, such as 'https://acme-staging-v02.api.letsencrypt.org/directory'");
-  }
-  if ('staging' === gl.server || 'production' === gl.server) {
-    if ('staging' === gl.server) {
-      gl.server = 'https://acme-staging.api.letsencrypt.org/directory';
-      gl.version = 'v01';
-      gl._deprecatedServerName = 'staging';
-    }
-    else if ('production' === gl.server) {
-      gl.server = 'https://acme-v01.api.letsencrypt.org/directory';
-      gl.version = 'v01';
-      gl._deprecatedServerName = 'production';
-    }
-    console.warn("");
-    console.warn("");
-    console.warn("=== WARNING ===");
-    console.warn("");
-    console.warn("Due to versioning issues the '" + gl._deprecatedServerName + "' option is deprecated.");
-    console.warn("Please specify the full url and version.");
-    console.warn("");
-    console.warn("For APIs add:");
-    console.warn("\t, \"version\": \"" + gl.version + "\"");
-    console.warn("\t, \"server\": \"" + gl.server + "\"");
-    console.warn("");
-    console.warn("For the CLI add:");
-    console.warn("\t--acme-url '" + gl.server + "' \\");
-    console.warn("\t--acme-version '" + gl.version + "' \\");
-    console.warn("");
-    console.warn("");
-  }
+	if (
+		-1 !==
+		[
+			"https://acme-v02.api.letsencrypt.org/directory",
+			"https://acme-staging-v02.api.letsencrypt.org/directory"
+		].indexOf(gl.server)
+	) {
+		if ("draft-11" !== gl.version) {
+			console.warn(
+				"Detected Let's Encrypt v02 URL. Changing version to draft-12."
+			);
+			gl.version = "draft-11";
+		}
+	} else if (
+		-1 !==
+			[
+				"https://acme-v01.api.letsencrypt.org/directory",
+				"https://acme-staging.api.letsencrypt.org/directory"
+			].indexOf(gl.server) ||
+		"v01" === gl.version
+	) {
+		if ("v01" !== gl.version) {
+			console.warn(
+				"Detected Let's Encrypt v01 URL (deprecated). Changing version to v01."
+			);
+			gl.version = "v01";
+		}
+	}
+	if ("v01" === gl.version) {
+		ACME = loadLeV01();
+	}
+	/////////////////////////
+	// END VERSION MADNESS //
+	/////////////////////////
 
-  function loadLeV01() {
-    console.warn("");
-    console.warn("=== WARNING ===");
-    console.warn("");
-    console.warn("Let's Encrypt v1 is deprecated.");
-    console.warn("Please update to Let's Encrypt v2 (ACME draft 12)");
-    console.warn("");
-    try {
-      return require('le-acme-core').ACME;
-    } catch(e) {
-      console.error("");
-      console.error("=== Error (easy-to-fix) ===");
-      console.error("");
-      console.error("Hey, this isn't a big deal, but you need to manually add v1 support:");
-      console.error("");
-      console.error("        npm install --save le-acme-core");
-      console.error("");
-      console.error("Just run that real quick, restart, and everything will work great.");
-      console.error("");
-      console.error("");
-      process.exit(e.code || 13);
-    }
-  }
+	gl.acme =
+		gl.acme ||
+		ACME.create({
+			debug: gl.debug,
+			skipChallengeTest: gl.skipChallengeTest,
+			skipDryRun: gl.skipDryRun
+		});
+	if (gl.acme.create) {
+		gl.acme = gl.acme.create(gl);
+	}
+	gl.acme = promisifyAllSelf(gl.acme);
+	gl._acmeOpts =
+		(gl.acme.getOptions && gl.acme.getOptions()) || gl.acme.options || {};
+	Object.keys(gl._acmeOpts).forEach(function(key) {
+		if (!(key in gl)) {
+			gl[key] = gl._acmeOpts[key];
+		}
+	});
 
-  if (-1 !== [
-      'https://acme-v02.api.letsencrypt.org/directory'
-    , 'https://acme-staging-v02.api.letsencrypt.org/directory' ].indexOf(gl.server)
-  ) {
-    if ('draft-11' !== gl.version) {
-      console.warn("Detected Let's Encrypt v02 URL. Changing version to draft-12.");
-      gl.version = 'draft-11';
-    }
-  } else if (-1 !== [
-      'https://acme-v01.api.letsencrypt.org/directory'
-    , 'https://acme-staging.api.letsencrypt.org/directory' ].indexOf(gl.server)
-    || 'v01' === gl.version
-  ) {
-    if ('v01' !== gl.version) {
-      console.warn("Detected Let's Encrypt v01 URL (deprecated). Changing version to v01.");
-      gl.version = 'v01';
-    }
-  }
-  if ('v01' === gl.version) {
-    ACME = loadLeV01();
-  }
-  /////////////////////////
-  // END VERSION MADNESS //
-  /////////////////////////
+	try {
+		if (gl.store.create) {
+			gl.store = gl.store.create(gl);
+		}
+		gl.store = promisifyAllSelf(gl.store);
+		gl.store.accounts = promisifyAllStore(gl.store.accounts);
+		gl.store.certificates = promisifyAllStore(gl.store.certificates);
+		gl._storeOpts =
+			(gl.store.getOptions && gl.store.getOptions()) || gl.store.options || {};
+	} catch (e) {
+		console.error(e);
+		console.error(
+			"\nPROBABLE CAUSE:\n" +
+				"\tYour greenlock-store module should have a create function and return { options, accounts, certificates }\n"
+		);
+		process.exit(18);
+		return;
+	}
+	Object.keys(gl._storeOpts).forEach(function(key) {
+		if (!(key in gl)) {
+			gl[key] = gl._storeOpts[key];
+		}
+	});
 
+	//
+	// Backwards compat for <= v2.1.7
+	//
+	if (gl.challenge) {
+		console.warn(
+			"Deprecated use of gl.challenge. Use gl.challenges['" +
+				Greenlock.challengeType +
+				"'] instead."
+		);
+		gl.challenges[gl.challengeType] = gl.challenge;
+		gl.challenge = undefined;
+	}
 
+	Object.keys(gl.challenges || {}).forEach(function(challengeType) {
+		var challenger = gl.challenges[challengeType];
 
-  gl.acme = gl.acme || ACME.create({ debug: gl.debug });
-  if (gl.acme.create) {
-    gl.acme = gl.acme.create(gl);
-  }
-  gl.acme = promisifyAllSelf(gl.acme);
-  gl._acmeOpts = gl.acme.getOptions && gl.acme.getOptions() || gl.acme.options || {};
-  Object.keys(gl._acmeOpts).forEach(function (key) {
-    if (!(key in gl)) {
-      gl[key] = gl._acmeOpts[key];
-    }
-  });
+		if (challenger.create) {
+			challenger = gl.challenges[challengeType] = challenger.create(gl);
+		}
+		challenger = gl.challenges[challengeType] = promisifyAllSelf(challenger);
+		gl["_challengeOpts_" + challengeType] =
+			(challenger.getOptions && challenger.getOptions()) ||
+			challenger.options ||
+			{};
+		Object.keys(gl["_challengeOpts_" + challengeType]).forEach(function(key) {
+			if (!(key in gl)) {
+				gl[key] = gl["_challengeOpts_" + challengeType][key];
+			}
+		});
 
-  try {
-    if (gl.store.create) { gl.store = gl.store.create(gl); }
-    gl.store = promisifyAllSelf(gl.store);
-    gl.store.accounts = promisifyAllStore(gl.store.accounts);
-    gl.store.certificates = promisifyAllStore(gl.store.certificates);
-    gl._storeOpts = gl.store.getOptions && gl.store.getOptions() || gl.store.options || {};
-  } catch(e) {
-    console.error(e);
-    console.error("\nPROBABLE CAUSE:\n"
-      + "\tYour greenlock-store module should have a create function and return { options, accounts, certificates }\n");
-    process.exit(18);
-    return;
-  }
-  Object.keys(gl._storeOpts).forEach(function (key) {
-    if (!(key in gl)) {
-      gl[key] = gl._storeOpts[key];
-    }
-  });
+		// TODO wrap these here and now with tplCopy?
+		if (!challenger.set || ![5, 2, 1].includes(challenger.set.length)) {
+			throw new Error(
+				"gl.challenges[" +
+					challengeType +
+					"].set receives the wrong number of arguments." +
+					" You must define setChallenge as function (opts) { return Promise.resolve(); }"
+			);
+		}
+		if (challenger.get && ![4, 2, 1].includes(challenger.get.length)) {
+			throw new Error(
+				"gl.challenges[" +
+					challengeType +
+					"].get receives the wrong number of arguments." +
+					" You must define getChallenge as function (opts) { return Promise.resolve(); }"
+			);
+		}
+		if (!challenger.remove || ![4, 2, 1].includes(challenger.remove.length)) {
+			throw new Error(
+				"gl.challenges[" +
+					challengeType +
+					"].remove receives the wrong number of arguments." +
+					" You must define removeChallenge as function (opts) { return Promise.resolve(); }"
+			);
+		}
 
-
-  //
-  // Backwards compat for <= v2.1.7
-  //
-  if (gl.challenge) {
-    console.warn("Deprecated use of gl.challenge. Use gl.challenges['" + Greenlock.challengeType + "'] instead.");
-    gl.challenges[gl.challengeType] = gl.challenge;
-    gl.challenge = undefined;
-  }
-
-  Object.keys(gl.challenges||{}).forEach(function (challengeType) {
-    var challenger = gl.challenges[challengeType];
-
-    if (challenger.create) {
-      challenger = gl.challenges[challengeType] = challenger.create(gl);
-    }
-    challenger = gl.challenges[challengeType] = promisifyAllSelf(challenger);
-    gl['_challengeOpts_' + challengeType] = challenger.getOptions && challenger.getOptions() || challenger.options || {};
-    Object.keys(gl['_challengeOpts_' + challengeType]).forEach(function (key) {
-      if (!(key in gl)) {
-        gl[key] = gl['_challengeOpts_' + challengeType][key];
-      }
-    });
-
-    // TODO wrap these here and now with tplCopy?
-    if (!challenger.set || ![5,2,1].includes(challenger.set.length)) {
-      throw new Error("gl.challenges[" + challengeType + "].set receives the wrong number of arguments."
-        + " You must define setChallenge as function (opts) { return Promise.resolve(); }");
-    }
-    if (challenger.get && ![4,2,1].includes(challenger.get.length)) {
-      throw new Error("gl.challenges[" + challengeType + "].get receives the wrong number of arguments."
-        + " You must define getChallenge as function (opts) { return Promise.resolve(); }");
-    }
-    if (!challenger.remove || ![4,2,1].includes(challenger.remove.length)) {
-      throw new Error("gl.challenges[" + challengeType + "].remove receives the wrong number of arguments."
-        + " You must define removeChallenge as function (opts) { return Promise.resolve(); }");
-    }
-
-/*
+		/*
     if (!gl._challengeWarn && (!challenger.loopback || 4 !== challenger.loopback.length)) {
       gl._challengeWarn = true;
       console.warn("gl.challenges[" + challengeType + "].loopback should be defined as function (opts, domain, token, cb) { ... } and should prove (by external means) that the ACME server challenge '" + challengeType + "' will succeed");
@@ -366,309 +431,386 @@ Greenlock.create = function (gl) {
       console.warn("gl.challenges[" + challengeType + "].test should be defined as function (opts, domain, token, keyAuthorization, cb) { ... } and should prove (by external means) that the ACME server challenge '" + challengeType + "' will succeed");
     }
 */
-  });
+	});
 
-  gl.sni = gl.sni || null;
-  gl.tlsOptions = gl.tlsOptions || gl.httpsOptions || {};
+	gl.sni = gl.sni || null;
+	gl.tlsOptions = gl.tlsOptions || gl.httpsOptions || {};
 
-  // Workaround for https://github.com/nodejs/node/issues/22389
-  gl._updateServernames = function (cert) {
-    if (!gl._certnames) { gl._certnames = {}; }
+	// Workaround for https://github.com/nodejs/node/issues/22389
+	gl._updateServernames = function(cert) {
+		if (!gl._certnames) {
+			gl._certnames = {};
+		}
 
-    // Note: Any given domain could exist on multiple certs
-    // (especially during renewal where some may be added)
-    // hence we use a separate object for each domain and list each domain on it
-    // to get the minimal full set associated with each cert and domain
-    var allDomains = [cert.subject].concat(cert.altnames.slice(0));
-    allDomains.forEach(function (name) {
-      name = name.toLowerCase();
-      if (!gl._certnames[name]) {
-        gl._certnames[name] = {};
-      }
-      allDomains.forEach(function (name2) {
-        name2 = name2.toLowerCase();
-        gl._certnames[name][name2] = true;
-      });
-    });
-  };
-  gl._checkServername = function (safeHost, servername) {
-    // odd, but acceptable
-    if (!safeHost || !servername) { return true; }
-    if (safeHost === servername) { return true; }
-    // connection established with servername and session is re-used for allowed name
-    if (gl._certnames[servername] && gl._certnames[servername][safeHost]) {
-      return true;
-    }
-    return false;
-  };
+		// Note: Any given domain could exist on multiple certs
+		// (especially during renewal where some may be added)
+		// hence we use a separate object for each domain and list each domain on it
+		// to get the minimal full set associated with each cert and domain
+		var allDomains = [cert.subject].concat(cert.altnames.slice(0));
+		allDomains.forEach(function(name) {
+			name = name.toLowerCase();
+			if (!gl._certnames[name]) {
+				gl._certnames[name] = {};
+			}
+			allDomains.forEach(function(name2) {
+				name2 = name2.toLowerCase();
+				gl._certnames[name][name2] = true;
+			});
+		});
+	};
+	gl._checkServername = function(safeHost, servername) {
+		// odd, but acceptable
+		if (!safeHost || !servername) {
+			return true;
+		}
+		if (safeHost === servername) {
+			return true;
+		}
+		// connection established with servername and session is re-used for allowed name
+		if (gl._certnames[servername] && gl._certnames[servername][safeHost]) {
+			return true;
+		}
+		return false;
+	};
 
-  if (!gl.tlsOptions.SNICallback) {
-    if (!gl.getCertificatesAsync && !gl.getCertificates) {
-      if (Array.isArray(gl.approveDomains)) {
-        gl.approvedDomains = gl.approveDomains;
-        gl.approveDomains = null;
-      }
-      if (!gl.approveDomains) {
-        gl.approveDomains = function (lexOpts, cb) {
-          var err;
-          var emsg;
+	if (!gl.tlsOptions.SNICallback) {
+		if (!gl.getCertificatesAsync && !gl.getCertificates) {
+			if (Array.isArray(gl.approveDomains)) {
+				gl.approvedDomains = gl.approveDomains;
+				gl.approveDomains = null;
+			}
+			if (!gl.approveDomains) {
+				gl.approveDomains = function(lexOpts, cb) {
+					var err;
+					var emsg;
 
-          if (!gl.email) {
-            throw new Error("le-sni-auto is not properly configured. Missing email");
-          }
-          if (!gl.agreeTos) {
-            throw new Error("le-sni-auto is not properly configured. Missing agreeTos");
-          }
-          if (!/[a-z]/i.test(lexOpts.domain)) {
-            cb(new Error("le-sni-auto does not allow IP addresses in SNI"));
-            return;
-          }
+					if (!gl.email) {
+						throw new Error(
+							"le-sni-auto is not properly configured. Missing email"
+						);
+					}
+					if (!gl.agreeTos) {
+						throw new Error(
+							"le-sni-auto is not properly configured. Missing agreeTos"
+						);
+					}
+					if (!/[a-z]/i.test(lexOpts.domain)) {
+						cb(new Error("le-sni-auto does not allow IP addresses in SNI"));
+						return;
+					}
 
-          if (!Array.isArray(gl.approvedDomains)) {
-            // The acme-v2 package uses pre-flight test challenges to
-            // verify that each requested domain is hosted by the server
-            // these checks are sufficient for most use cases
-            return cb(null, lexOpts);
-          }
+					if (!Array.isArray(gl.approvedDomains)) {
+						// The acme-v2 package uses pre-flight test challenges to
+						// verify that each requested domain is hosted by the server
+						// these checks are sufficient for most use cases
+						return cb(null, lexOpts);
+					}
 
-          if (lexOpts.domains.every(function (domain) {
-            return -1 !== gl.approvedDomains.indexOf(domain);
-          })) {
-            // commented this out because people expect to be able to edit the list of domains
-            // lexOpts.domains = gl.approvedDomains.slice(0);
-            lexOpts.email = gl.email;
-            lexOpts.agreeTos = gl.agreeTos;
-            lexOpts.communityMember = gl.communityMember;
-            lexOpts.telemetry = gl.telemetry;
-            return cb(null, lexOpts);
-          }
+					if (
+						lexOpts.domains.every(function(domain) {
+							return -1 !== gl.approvedDomains.indexOf(domain);
+						})
+					) {
+						// commented this out because people expect to be able to edit the list of domains
+						// lexOpts.domains = gl.approvedDomains.slice(0);
+						lexOpts.email = gl.email;
+						lexOpts.agreeTos = gl.agreeTos;
+						lexOpts.communityMember = gl.communityMember;
+						lexOpts.telemetry = gl.telemetry;
+						return cb(null, lexOpts);
+					}
 
-          emsg = "tls SNI for '" + lexOpts.domains.join(',') + "' rejected: not in list '" + gl.approvedDomains + "'";
-          log(gl.debug, emsg, lexOpts.domains, gl.approvedDomains);
-          err = new Error(emsg);
-          err.code = 'E_REJECT_SNI';
-          cb(err);
-        };
-      }
+					emsg =
+						"tls SNI for '" +
+						lexOpts.domains.join(",") +
+						"' rejected: not in list '" +
+						gl.approvedDomains +
+						"'";
+					log(gl.debug, emsg, lexOpts.domains, gl.approvedDomains);
+					err = new Error(emsg);
+					err.code = "E_REJECT_SNI";
+					cb(err);
+				};
+			}
 
-      gl.getCertificates = function (domain, certs, cb) {
-        // certs come from current in-memory cache, not lookup
-        log(gl.debug, 'gl.getCertificates called for', domain, 'with certs for', certs && certs.altnames || 'NONE');
-        var opts = {
-          domain: domain, domains: certs && certs.altnames || [ domain ]
-        , certs: certs, certificate: {}, account: {}
-        };
-        opts.wildname = '*.' + (domain||'').split('.').slice(1).join('.');
+			gl.getCertificates = function(domain, certs, cb) {
+				// certs come from current in-memory cache, not lookup
+				log(
+					gl.debug,
+					"gl.getCertificates called for",
+					domain,
+					"with certs for",
+					(certs && certs.altnames) || "NONE"
+				);
+				var opts = {
+					domain: domain,
+					domains: (certs && certs.altnames) || [domain],
+					certs: certs,
+					certificate: {},
+					account: {}
+				};
+				opts.wildname =
+					"*." +
+					(domain || "")
+						.split(".")
+						.slice(1)
+						.join(".");
 
-        function cb2(results) {
-          log(gl.debug, 'gl.approveDomains called with certs for', results.certs && results.certs.altnames || 'NONE', 'and options:');
-          log(gl.debug, results.options);
-          var err;
-          if (!results) {
-            err = new Error('E_REJECT_SNI');
-            err.code = 'E_REJECT_SNI';
-            eb2(err);
-            return;
-          }
+				function cb2(results) {
+					log(
+						gl.debug,
+						"gl.approveDomains called with certs for",
+						(results.certs && results.certs.altnames) || "NONE",
+						"and options:"
+					);
+					log(gl.debug, results.options || results);
+					var err;
+					if (!results) {
+						err = new Error("E_REJECT_SNI");
+						err.code = "E_REJECT_SNI";
+						eb2(err);
+						return;
+					}
 
-          var options = results.options || results;
-          if (opts !== options) {
-            Object.keys(options).forEach(function (key) {
-              if ('undefined' !== typeof options[key] && 'domain' !== key) {
-                opts[key] = options[key];
-              }
-            });
-            options = opts;
-          }
-          if (Array.isArray(options.altnames) && options.altnames.length) {
-            options.domains = options.altnames;
-          }
-          options.altnames = options.domains;
-          // just in case we get a completely different object from the one we originally created
-          if (!options.account) { options.account = {}; }
-          if (!options.certificate) { options.certificate = {}; }
-          if (results.certs) {
-            log(gl.debug, 'gl renewing');
-            return gl.core.certificates.renewAsync(options, results.certs).then(
-              function (certs) {
-                // Workaround for https://github.com/nodejs/node/issues/22389
-                gl._updateServernames(certs);
-                cb(null, certs);
-              }
-            , function (e) {
-                console.debug("Error renewing certificate for '" + domain + "':");
-                console.debug(e);
-                console.error("");
-                cb(e);
-              }
-            );
-          } else {
-            log(gl.debug, 'gl getting from disk or registering new');
-            return gl.core.certificates.getAsync(options).then(
-              function (certs) {
-                // Workaround for https://github.com/nodejs/node/issues/22389
-                gl._updateServernames(certs);
-                cb(null, certs);
-              }
-            , function (e) {
-                console.debug("Error loading/registering certificate for '" + domain + "':");
-                console.debug(e);
-                console.error("");
-                cb(e);
-              }
-            );
-          }
-        }
-        function eb2(_err) {
-          if (false !== gl.logRejectedDomains) {
-            console.error("[Error] approveDomains rejected tls sni '" + domain + "'");
-            console.error("[Error] (see https://git.coolaj86.com/coolaj86/greenlock.js/issues/11)");
-            if ('E_REJECT_SNI' !== _err.code) {
-              console.error("[Error] This is the rejection message:");
-              console.error(_err.message);
-            }
-            console.error("");
-          }
-          cb(_err);
-          return;
-        }
-        function mb2(_err, results) {
-          if (_err) { eb2(_err); return; }
-          cb2(results);
-        }
+					var options = results.options || results;
+					if (opts !== options) {
+						Object.keys(options).forEach(function(key) {
+							if ("undefined" !== typeof options[key] && "domain" !== key) {
+								opts[key] = options[key];
+							}
+						});
+						options = opts;
+					}
+					if (Array.isArray(options.altnames) && options.altnames.length) {
+						options.domains = options.altnames;
+					}
+					options.altnames = options.domains;
+					// just in case we get a completely different object from the one we originally created
+					if (!options.account) {
+						options.account = {};
+					}
+					if (!options.certificate) {
+						options.certificate = {};
+					}
+					if (results.certs) {
+						log(gl.debug, "gl renewing");
+						return gl.core.certificates.renewAsync(options, results.certs).then(
+							function(certs) {
+								// Workaround for https://github.com/nodejs/node/issues/22389
+								gl._updateServernames(certs);
+								cb(null, certs);
+							},
+							function(e) {
+								console.debug(
+									"Error renewing certificate for '" + domain + "':"
+								);
+								console.debug(e);
+								console.error("");
+								cb(e);
+							}
+						);
+					} else {
+						log(gl.debug, "gl getting from disk or registering new");
+						return gl.core.certificates.getAsync(options).then(
+							function(certs) {
+								// Workaround for https://github.com/nodejs/node/issues/22389
+								gl._updateServernames(certs);
+								cb(null, certs);
+							},
+							function(e) {
+								console.debug(
+									"Error loading/registering certificate for '" + domain + "':"
+								);
+								console.debug(e);
+								console.error("");
+								cb(e);
+							}
+						);
+					}
+				}
+				function eb2(_err) {
+					if (false !== gl.logRejectedDomains) {
+						console.error(
+							"[Error] approveDomains rejected tls sni '" + domain + "'"
+						);
+						console.error(
+							"[Error] (see https://git.coolaj86.com/coolaj86/greenlock.js/issues/11)"
+						);
+						if ("E_REJECT_SNI" !== _err.code) {
+							console.error("[Error] This is the rejection message:");
+							console.error(_err.message);
+						}
+						console.error("");
+					}
+					cb(_err);
+					return;
+				}
+				function mb2(_err, results) {
+					if (_err) {
+						eb2(_err);
+						return;
+					}
+					cb2(results);
+				}
 
-        try {
-          if (1 === gl.approveDomains.length) {
-            PromiseA.resolve(gl.approveDomains(opts)).then(cb2).catch(eb2);
-          } else if (2 === gl.approveDomains.length) {
-            gl.approveDomains(opts, mb2);
-          } else {
-            gl.approveDomains(opts, certs, mb2);
-          }
-        } catch(e) {
-          console.error("[ERROR] Something went wrong in approveDomains:");
-          console.error(e);
-          console.error("BUT WAIT! Good news: It's probably your fault, so you can probably fix it.");
-        }
-      };
-    }
-    gl.sni = gl.sni || require('le-sni-auto');
-    if (gl.sni.create) {
-      gl.sni = gl.sni.create(gl);
-    }
-    gl.tlsOptions.SNICallback = function (_domain, cb) {
-      // format and (lightly) sanitize sni so that users can be naive
-      // and not have to worry about SQL injection or fs discovery
-      var domain = (_domain||'').toLowerCase();
-      // hostname labels allow a-z, 0-9, -, and are separated by dots
-      // _ is sometimes allowed
-      // REGEX // https://www.codeproject.com/Questions/1063023/alphanumeric-validation-javascript-without-regex
-      if (!gl.__sni_allow_dangerous_names && (!/^[a-z0-9_\.\-]+$/i.test(domain) || -1 !== domain.indexOf('..'))) {
-        log(gl.debug, "invalid sni '" + domain + "'");
-        cb(new Error("invalid SNI"));
-        return;
-      }
+				try {
+					if (1 === gl.approveDomains.length) {
+						Promise.resolve(gl.approveDomains(opts))
+							.then(cb2)
+							.catch(eb2);
+					} else if (2 === gl.approveDomains.length) {
+						gl.approveDomains(opts, mb2);
+					} else {
+						gl.approveDomains(opts, certs, mb2);
+					}
+				} catch (e) {
+					console.error("[ERROR] Something went wrong in approveDomains:");
+					console.error(e);
+					console.error(
+						"BUT WAIT! Good news: It's probably your fault, so you can probably fix it."
+					);
+				}
+			};
+		}
+		gl.sni = gl.sni || require("le-sni-auto");
+		if (gl.sni.create) {
+			gl.sni = gl.sni.create(gl);
+		}
+		gl.tlsOptions.SNICallback = function(_domain, cb) {
+			// format and (lightly) sanitize sni so that users can be naive
+			// and not have to worry about SQL injection or fs discovery
+			var domain = (_domain || "").toLowerCase();
+			// hostname labels allow a-z, 0-9, -, and are separated by dots
+			// _ is sometimes allowed
+			// REGEX // https://www.codeproject.com/Questions/1063023/alphanumeric-validation-javascript-without-regex
+			if (
+				!gl.__sni_allow_dangerous_names &&
+				(!/^[a-z0-9_\.\-]+$/i.test(domain) || -1 !== domain.indexOf(".."))
+			) {
+				log(gl.debug, "invalid sni '" + domain + "'");
+				cb(new Error("invalid SNI"));
+				return;
+			}
 
-      try {
-        gl.sni.sniCallback(gl.__sni_preserve_case && _domain || domain, cb);
-      } catch(e) {
-        console.error("[ERROR] Something went wrong in the SNICallback:");
-        console.error(e);
-        cb(e);
-      }
-    };
-  }
+			try {
+				gl.sni.sniCallback((gl.__sni_preserve_case && _domain) || domain, cb);
+			} catch (e) {
+				console.error("[ERROR] Something went wrong in the SNICallback:");
+				console.error(e);
+				cb(e);
+			}
+		};
+	}
 
-  // We want to move to using tlsOptions instead of httpsOptions, but we also need to make
-  // sure anything that uses this object will still work if looking for httpsOptions.
-  gl.httpsOptions = gl.tlsOptions;
+	// We want to move to using tlsOptions instead of httpsOptions, but we also need to make
+	// sure anything that uses this object will still work if looking for httpsOptions.
+	gl.httpsOptions = gl.tlsOptions;
 
-  if (gl.core.create) {
-    gl.core = gl.core.create(gl);
-  }
+	if (gl.core.create) {
+		gl.core = gl.core.create(gl);
+	}
 
-  gl.renew = function (args, certs) {
-    return gl.core.certificates.renewAsync(args, certs);
-  };
+	gl.renew = function(args, certs) {
+		return gl.core.certificates.renewAsync(args, certs);
+	};
 
-  gl.register = function (args) {
-    return gl.core.certificates.getAsync(args);
-  };
+	gl.register = function(args) {
+		return gl.core.certificates.getAsync(args);
+	};
 
-  gl.check = function (args) {
-    // TODO must return email, domains, tos, pems
-    return gl.core.certificates.checkAsync(args);
-  };
+	gl.check = function(args) {
+		// TODO must return email, domains, tos, pems
+		return gl.core.certificates.checkAsync(args);
+	};
 
-  gl.middleware = gl.middleware || require('./lib/middleware');
-  if (gl.middleware.create) {
-    gl.middleware = gl.middleware.create(gl);
-  }
+	gl.middleware = gl.middleware || require("./lib/middleware");
+	if (gl.middleware.create) {
+		gl.middleware = gl.middleware.create(gl);
+	}
 
-  //var SERVERNAME_RE = /^[a-z0-9\.\-_]+$/;
-  var SERVERNAME_G = /[^a-z0-9\.\-_]/;
-  gl.middleware.sanitizeHost = function (app) {
-    return function (req, res, next) {
-      function realNext() {
-        if ('function' === typeof app) {
-          app(req, res);
-        } else if ('function' === typeof next) {
-          next();
-        } else {
-          res.statusCode = 500;
-          res.end("Error: no middleware assigned");
-        }
-      }
-      // Get the host:port combo, if it exists
-      var host = (req.headers.host||'').split(':');
+	//var SERVERNAME_RE = /^[a-z0-9\.\-_]+$/;
+	var SERVERNAME_G = /[^a-z0-9\.\-_]/;
+	gl.middleware.sanitizeHost = function(app) {
+		return function(req, res, next) {
+			function realNext() {
+				if ("function" === typeof app) {
+					app(req, res);
+				} else if ("function" === typeof next) {
+					next();
+				} else {
+					res.statusCode = 500;
+					res.end("Error: no middleware assigned");
+				}
+			}
+			// Get the host:port combo, if it exists
+			var host = (req.headers.host || "").split(":");
 
-      // if not, move along
-      if (!host[0]) { realNext(); return; }
+			// if not, move along
+			if (!host[0]) {
+				realNext();
+				return;
+			}
 
-      // if so, remove non-allowed characters
-      var safehost = host[0].toLowerCase().replace(SERVERNAME_G, '');
+			// if so, remove non-allowed characters
+			var safehost = host[0].toLowerCase().replace(SERVERNAME_G, "");
 
-      // if there were unallowed characters, complain
-      if (!gl.__sni_allow_dangerous_names && safehost.length !== host[0].length) {
-        res.statusCode = 400;
-        res.end("Malformed HTTP Header: 'Host: " + host[0] + "'");
-        return;
-      }
+			// if there were unallowed characters, complain
+			if (
+				!gl.__sni_allow_dangerous_names &&
+				safehost.length !== host[0].length
+			) {
+				res.statusCode = 400;
+				res.end("Malformed HTTP Header: 'Host: " + host[0] + "'");
+				return;
+			}
 
-      // make lowercase
-      if (!gl.__sni_preserve_case) {
-        host[0] = safehost;
-        req.headers.host = host.join(':');
-      }
+			// make lowercase
+			if (!gl.__sni_preserve_case) {
+				host[0] = safehost;
+				req.headers.host = host.join(":");
+			}
 
-      // Note: This sanitize function is also called on plain sockets, which don't need Domain Fronting checks
-      if (req.socket.encrypted && !gl.__sni_allow_domain_fronting) {
-        if (req.socket && 'string' === typeof req.socket.servername) {
-          // Workaround for https://github.com/nodejs/node/issues/22389
-          if (!gl._checkServername(safehost, req.socket.servername.toLowerCase())) {
-            res.statusCode = 400;
-            res.setHeader('Content-Type', 'text/html; charset=utf-8');
-            res.end(
-                "<h1>Domain Fronting Error</h1>"
-              + "<p>This connection was secured using TLS/SSL for '" + req.socket.servername.toLowerCase() + "'</p>"
-              + "<p>The HTTP request specified 'Host: " + safehost + "', which is (obviously) different.</p>"
-              + "<p>Because this looks like a domain fronting attack, the connection has been terminated.</p>"
-            );
-            return;
-          }
-        } else if (safehost && !gl.middleware.sanitizeHost._skip_fronting_check) {
-          // TODO how to handle wrapped sockets, as with telebit?
-          console.warn("\n\n\n[greenlock] WARN: no string for req.socket.servername,"
-            + " skipping fronting check for '" + safehost + "'\n\n\n");
-          gl.middleware.sanitizeHost._skip_fronting_check = true;
-        }
-      }
+			// Note: This sanitize function is also called on plain sockets, which don't need Domain Fronting checks
+			if (req.socket.encrypted && !gl.__sni_allow_domain_fronting) {
+				if (req.socket && "string" === typeof req.socket.servername) {
+					// Workaround for https://github.com/nodejs/node/issues/22389
+					if (
+						!gl._checkServername(safehost, req.socket.servername.toLowerCase())
+					) {
+						res.statusCode = 400;
+						res.setHeader("Content-Type", "text/html; charset=utf-8");
+						res.end(
+							"<h1>Domain Fronting Error</h1>" +
+								"<p>This connection was secured using TLS/SSL for '" +
+								req.socket.servername.toLowerCase() +
+								"'</p>" +
+								"<p>The HTTP request specified 'Host: " +
+								safehost +
+								"', which is (obviously) different.</p>" +
+								"<p>Because this looks like a domain fronting attack, the connection has been terminated.</p>"
+						);
+						return;
+					}
+				} else if (
+					safehost &&
+					!gl.middleware.sanitizeHost._skip_fronting_check
+				) {
+					// TODO how to handle wrapped sockets, as with telebit?
+					console.warn(
+						"\n\n\n[greenlock] WARN: no string for req.socket.servername," +
+							" skipping fronting check for '" +
+							safehost +
+							"'\n\n\n"
+					);
+					gl.middleware.sanitizeHost._skip_fronting_check = true;
+				}
+			}
 
-      // carry on
-      realNext();
-    };
-  };
-  gl.middleware.sanitizeHost._skip_fronting_check = false;
+			// carry on
+			realNext();
+		};
+	};
+	gl.middleware.sanitizeHost._skip_fronting_check = false;
 
-  return gl;
+	return gl;
 };
diff --git a/lib/compat.js b/lib/compat.js
new file mode 100644
index 0000000..0f46780
--- /dev/null
+++ b/lib/compat.js
@@ -0,0 +1,21 @@
+'use strict';
+
+function requireBluebird() {
+  try {
+    return require('bluebird');
+  } catch(e) {
+    console.error("");
+    console.error("DON'T PANIC. You're running an old version of node with incomplete Promise support.");
+    console.error("EASY FIX: `npm install --save bluebird`");
+    console.error("");
+    throw e;
+  }
+}
+
+if ('undefined' === typeof Promise) {
+  global.Promise = requireBluebird();
+}
+
+if ('function' !== typeof require('util').promisify) {
+  require('util').promisify = requireBluebird().promisify;
+}
diff --git a/lib/core.js b/lib/core.js
index c938e4e..f1d4956 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -1,11 +1,7 @@
 'use strict';
+/*global Promise*/
+require('./compat.js');
 
-var PromiseA;
-try {
-  PromiseA = require('bluebird');
-} catch(e) {
-  PromiseA = global.Promise;
-}
 var util = require('util');
 function promisifyAll(obj) {
   var aobj = {};
@@ -42,7 +38,7 @@ module.exports.create = function (gl) {
 
       // TODO check response header on request for cache time
       if ((now - gl._ipc.acmeUrlsUpdatedAt) < 10 * 60 * 1000) {
-        return PromiseA.resolve(gl._ipc.acmeUrls);
+        return Promise.resolve(gl._ipc.acmeUrls);
       }
 
       // TODO acme-v2/nocompat
@@ -79,7 +75,7 @@ module.exports.create = function (gl) {
               + " and 'rsaKeySize' must be 2048 or greater."
           );
           err.code = 'E_ARGS';
-          return PromiseA.reject(err);
+          return Promise.reject(err);
         }
 
         return utils.testEmail(args.email).then(function () {
@@ -156,9 +152,9 @@ module.exports.create = function (gl) {
                 if (newAccountKeypair) {
                   accountKeypairPromise = gl.store.accounts.setKeypairAsync(args, keypair);
                 }
-                return PromiseA.resolve(accountKeypairPromise).then(function () {
+                return Promise.resolve(accountKeypairPromise).then(function () {
                 // TODO move templating of arguments to right here?
-                if (!gl.store.accounts.setAsync) { return PromiseA.resolve({ keypair: keypair }); }
+                if (!gl.store.accounts.setAsync) { return Promise.resolve({ keypair: keypair }); }
                   return gl.store.accounts.setAsync(args, reg).then(function (account) {
                    if (account && 'object' !== typeof account) {
                       throw new Error("store.accounts.setAsync should either return 'null' or an object with at least a string 'id'");
@@ -181,7 +177,7 @@ module.exports.create = function (gl) {
         if (gl.store.accounts.checkAsync) {
           accountPromise = core.accounts.checkAsync(args);
         }
-        return PromiseA.resolve(accountPromise).then(function (account) {
+        return Promise.resolve(accountPromise).then(function (account) {
           if (!account) { return core.accounts.registerAsync(args); }
           if (account.keypair) { return account; }
 
@@ -201,7 +197,7 @@ module.exports.create = function (gl) {
         var requiredArgs = ['accountId', 'email', 'domains', 'domain'];
         if (!(args.account && (args.account.id || args.account.kid))
           && !requiredArgs.some(function (key) { return -1 !== Object.keys(args).indexOf(key); })) {
-          return PromiseA.reject(new Error(
+          return Promise.reject(new Error(
             "In order to register or retrieve an account one of '" + requiredArgs.join("', '") + "' must be present"
           ));
         }
@@ -213,7 +209,7 @@ module.exports.create = function (gl) {
 
         // we can re-register the same account until we're blue in the face and it's all the same
         // of course, we can also skip the lookup if we do store the account, but whatever
-        if (!gl.store.accounts.checkAsync) { return PromiseA.resolve(null); }
+        if (!gl.store.accounts.checkAsync) { return Promise.resolve(null); }
         return gl.store.accounts.checkAsync(args).then(function (account) {
 
           if (!account) {
@@ -240,7 +236,7 @@ module.exports.create = function (gl) {
         args = utils.tplCopy(copy);
 
         if (!Array.isArray(args.domains)) {
-          return PromiseA.reject(new Error('args.domains should be an array of domains'));
+          return Promise.reject(new Error('args.domains should be an array of domains'));
         }
         //if (-1 === args.domains.indexOf(args.subject)) // TODO relax the constraint once acme-v2 handles subject?
         if (args.subject !== args.domains[0]) {
@@ -250,7 +246,7 @@ module.exports.create = function (gl) {
           console.warn('\topts.domains: (set by you in approveDomains()) ' + args.domains.join(','));
           console.warn("Updating your code will prevent weird, random, hard-to-repro bugs during renewals");
           console.warn("(also this will be required in the next major version of greenlock)");
-          //return PromiseA.reject(new Error('certificate subject (primary domain) must be the first in opts.domains'));
+          //return Promise.reject(new Error('certificate subject (primary domain) must be the first in opts.domains'));
         }
         if (!(args.domains.length && args.domains.every(utils.isValidDomain))) {
           // NOTE: this library can't assume to handle the http loopback
@@ -258,7 +254,7 @@ module.exports.create = function (gl) {
           // so we do not check dns records or attempt a loopback here
           err = new Error("invalid domain name(s): '(" + args.subject + ') ' + args.domains.join(',') + "'");
           err.code = "INVALID_DOMAIN";
-          return PromiseA.reject(err);
+          return Promise.reject(err);
         }
 
         // If a previous request to (re)register a certificate is already underway we need
@@ -384,6 +380,9 @@ module.exports.create = function (gl) {
                   Object.keys(challenge).forEach(function (key) {
                     done[key] = challenge[key];
                   });
+                  // regression bugfix for le-challenge-cloudflare
+                  // (_acme-challege => _greenlock-dryrun-XXXX)
+                  copy.acmePrefix = (challenge.dnsHost||'').replace(/\.*/, '') || copy.acmePrefix;
                   gl.challenges[challenge.type].set(copy, challenge.altname, challenge.token, challenge.keyAuthorization, done);
                 }
               };
@@ -429,7 +428,7 @@ module.exports.create = function (gl) {
               args.keypair = domainKeypair;
               promise = gl.store.certificates.setKeypairAsync(args, domainKeypair);
             }
-            return PromiseA.resolve(promise).then(function () {
+            return Promise.resolve(promise).then(function () {
               return gl.store.certificates.setAsync(args).then(function () {
                 return results;
               });
@@ -455,7 +454,7 @@ module.exports.create = function (gl) {
             + new Date(renewableAt).toISOString() + "'. Set { duplicate: true } to force."
           );
           err.code = 'E_NOT_RENEWABLE';
-          return PromiseA.reject(err);
+          return Promise.reject(err);
         }
 
         // Either the cert has entered its renewal period
diff --git a/lib/utils.js b/lib/utils.js
index 36acb02..caa3fb1 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -1,12 +1,12 @@
 'use strict';
+require('./compat.js');
 
 var path = require('path');
 var homeRe = new RegExp("^~(\\/|\\\\|\\" + path.sep + ")");
 // very basic check. Allows *.example.com.
 var re = /^(\*\.)?[a-zA-Z0-9\.\-]+$/;
 var punycode = require('punycode');
-var promisify = (require('util').promisify || require('bluebird').promisify);
-var dnsResolveMxAsync = promisify(require('dns').resolveMx);
+var dnsResolveMxAsync = require('util').promisify(require('dns').resolveMx);
 
 module.exports.attachCertInfo = function (results) {
   var certInfo = require('cert-info').info(results.cert);
@@ -54,12 +54,24 @@ module.exports.merge = function (/*defaults, args*/) {
 
   allDefaults.forEach(function (defaults) {
     Object.keys(defaults).forEach(function (key) {
-      copy[key] = defaults[key];
+      if ('challenges' === key && copy[key] && defaults[key]) {
+        Object.keys(defaults[key]).forEach(function (k) {
+          copy[key][k] = defaults[key][k];
+        });
+      } else {
+        copy[key] = defaults[key];
+      }
     });
   });
 
   Object.keys(args).forEach(function (key) {
-    copy[key] = args[key];
+    if ('challenges' === key && copy[key] && args[key]) {
+        Object.keys(args[key]).forEach(function (k) {
+          copy[key][k] = args[key][k];
+        });
+    } else {
+      copy[key] = args[key];
+    }
   });
 
   return copy;
diff --git a/package.json b/package.json
index 5966c84..2f96add 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "greenlock",
-  "version": "2.7.22",
+  "version": "2.7.23",
   "description": "Greenlock is Let's Encrypt (ACME) client for node.js",
   "homepage": "https://greenlock.domains/",
   "main": "index.js",
diff --git a/tests/challenge-middleware.js b/tests/challenge-middleware.js
deleted file mode 100644
index f97d3ee..0000000
--- a/tests/challenge-middleware.js
+++ /dev/null
@@ -1,106 +0,0 @@
-'use strict';
-
-var PromiseA = require('bluebird');
-var path = require('path');
-var requestAsync = PromiseA.promisify(require('@coolaj86/request'));
-var LE = require('../').LE;
-var le = LE.create({
-  server: 'staging'
-, acme: require('le-acme-core').ACME.create()
-, store: require('le-store-certbot').create({
-    configDir: '~/letsencrypt.test/etc'.split('/').join(path.sep)
-  , webrootPath: '~/letsencrypt.test/var/:hostname'.split('/').join(path.sep)
-  })
-, challenge: require('le-challenge-fs').create({
-    webrootPath: '~/letsencrypt.test/var/:hostname'.split('/').join(path.sep)
-  })
-, debug: true
-});
-var utils = require('../lib/utils');
-
-if ('/.well-known/acme-challenge/' !== LE.acmeChallengePrefix) {
-  throw new Error("Bad constant 'acmeChallengePrefix'");
-}
-
-var baseUrl;
-// could use localhost as well, but for the sake of an FQDN for testing, we use this
-// also, example.com is just a junk domain to make sure that it is ignored
-// (even though it should always be an array of only one element in lib/core.js)
-var domains = [ 'localhost.daplie.com', 'example.com' ]; // or just localhost
-var token = 'token-id';
-var secret = 'key-secret';
-
-var tests = [
-  function () {
-    console.log('Test Url:', baseUrl + token);
-    return requestAsync({ url: baseUrl + token }).then(function (req) {
-      if (404 !== req.statusCode) {
-        console.log(req.statusCode);
-        throw new Error("Should be status 404");
-      }
-    });
-  }
-
-, function () {
-    var copy = utils.merge({ domains: domains }, le);
-    copy = utils.tplCopy(copy);
-    return PromiseA.promisify(le.challenge.set)(copy, domains[0], token, secret);
-  }
-
-, function () {
-    return requestAsync(baseUrl + token).then(function (req) {
-      if (200 !== req.statusCode) {
-        console.log(req.statusCode, req.body);
-        throw new Error("Should be status 200");
-      }
-
-      if (req.body !== secret) {
-        console.error(token, secret, req.body);
-        throw new Error("req.body should be secret");
-      }
-    });
-  }
-
-, function () {
-    var copy = utils.merge({ domains: domains }, le);
-    copy = utils.tplCopy(copy);
-    return PromiseA.promisify(le.challenge.remove)(copy, domains[0], token);
-  }
-
-, function () {
-    return requestAsync(baseUrl + token).then(function (req) {
-      if (404 !== req.statusCode) {
-        console.log(req.statusCode);
-        throw new Error("Should be status 404");
-      }
-    });
-  }
-];
-
-function run() {
-  //var express = require(express);
-  var server = require('http').createServer(le.middleware());
-  server.listen(0, function () {
-    console.log('Server running, proceeding to test.');
-    baseUrl = 'http://' + domains[0] + ':' + server.address().port + LE.acmeChallengePrefix;
-
-    function next() {
-      var test = tests.shift();
-      if (!test) {
-        console.info('All tests passed');
-        server.close();
-        return;
-      }
-
-      test().then(next, function (err) {
-        console.error('ERROR');
-        console.error(err.stack);
-        server.close();
-      });
-    }
-
-    next();
-  });
-}
-
-run();