v0.51 (November 14, 2020)

Software updates: * Upgraded Nextcloud from 17.0.6 to 20.0.1 (with Contacts from 3.3.0 to 3.4.1 and Calendar from 2.0.3 to 2.1.2) * Upgraded Roundcube to version 1.4.9. Mail: * The MTA-STA max_age value was increased to the normal one week. Control Panel: * Two-factor authentication can now be enabled for logins to the control panel. However, keep in mind that many online services (including domain name registrars, cloud server providers, and TLS certificate providers) may allow an attacker to take over your account or issue a fraudulent TLS certificate with only access to your email address, and this new two-factor authentication does not protect access to your inbox. It therefore remains very important that user accounts with administrative email addresses have strong passwords. * TLS certificate expiry dates are now shown in ISO8601 format for clarity. -----BEGIN PGP SIGNATURE----- iQFDBAABCgAtFiEEX0wOcxPM10RpOyrquSBB9MEL3YEFAl+v8k4PHGp0QG9jY2Ft cy5pbmZvAAoJELkgQfTBC92BMYUIAJTD1iKzY1SoDNSp8JMPn2sWusOnJNrnvYEV vsrBM4AzwJv3DIZKSkYCitbTQW2FsTcjF6Jl5PCavEmAGe55AIKAPM/52Uq6jqDE aR8EZvI9ca1i7yR7DOHEI043QSPmp/iCFD48vvmKgN/LZy67TaHaOlGJbc3nfpk0 y7ejMpF/6RP6ik4snnRQoWTFShaOpB9WcEVnUO7CHZdWcpSCZ55c9yi6A6ExGk7e 97R5+JN1MgOdZ6rzWZuMWiz7EZ/Ew4jYLZpOwg8qJm0HNbYJ6+/xxsQBwaQzyBw3 TsTl4GmunNPfoNrmKdJeLy0sBwiVBv/rysjWjim5v8jAYBoKoUQ= =2oRU -----END PGP SIGNATURE----- Merge tag 'v0.51' of https://github.com/mail-in-a-box/mailinabox v0.51 (November 14, 2020) Software updates: * Upgraded Nextcloud from 17.0.6 to 20.0.1 (with Contacts from 3.3.0 to 3.4.1 and Calendar from 2.0.3 to 2.1.2) * Upgraded Roundcube to version 1.4.9. Mail: * The MTA-STA max_age value was increased to the normal one week. Control Panel: * Two-factor authentication can now be enabled for logins to the control panel. However, keep in mind that many online services (including domain name registrars, cloud server providers, and TLS certificate providers) may allow an attacker to take over your account or issue a fraudulent TLS certificate with only access to your email address, and this new two-factor authentication does not protect access to your inbox. It therefore remains very important that user accounts with administrative email addresses have strong passwords. * TLS certificate expiry dates are now shown in ISO8601 format for clarity. # gpg verification failed. # Conflicts: # management/daemon.py # setup/bootstrap.sh # setup/mail-users.sh # tools/mail.py
2020-12-03 23:21:37 +02:00 · 2020-12-03 23:21:37 +02:00 · 19e2066969
commit 19e2066969
parent 38ac127344 92221f9efb
24 changed files with 1018 additions and 260 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -1,6 +1,23 @@
 CHANGELOG
 =========

+v0.51 (November 14, 2020)
+-------------------------
+
+Software updates:
+
+* Upgraded Nextcloud from 17.0.6 to 20.0.1 (with Contacts from 3.3.0 to 3.4.1 and Calendar from 2.0.3 to 2.1.2)
+* Upgraded Roundcube to version 1.4.9.
+
+Mail:
+
+* The MTA-STA max_age value was increased to the normal one week.
+
+Control Panel:
+
+* Two-factor authentication can now be enabled for logins to the control panel. However, keep in mind that many online services (including domain name registrars, cloud server providers, and TLS certificate providers) may allow an attacker to take over your account or issue a fraudulent TLS certificate with only access to your email address, and this new two-factor authentication does not protect access to your inbox. It therefore remains very important that user accounts with administrative email addresses have strong passwords.
+* TLS certificate expiry dates are now shown in ISO8601 format for clarity.
+
 v0.50 (September 25, 2020)
 --------------------------

--- a/README.md
+++ b/README.md
@ -249,7 +249,7 @@ by him:
 	$ curl -s https://keybase.io/joshdata/key.asc | gpg --import
 	gpg: key C10BDD81: public key "Joshua Tauberer <jt@occams.info>" imported

-	$ git verify-tag v0.50
+	$ git verify-tag v0.51
 	gpg: Signature made ..... using RSA key ID C10BDD81
 	gpg: Good signature from "Joshua Tauberer <jt@occams.info>"
 	gpg: WARNING: This key is not certified with a trusted signature!
@ -262,7 +262,7 @@ and on his [personal homepage](https://razor.occams.info/). (Of course, if this

 Checkout the tag corresponding to the most recent release:

-	$ git checkout v0.50
+	$ git checkout v0.51

 Begin the installation.

--- a/api/mailinabox.yml
+++ b/api/mailinabox.yml
@ -8,7 +8,7 @@ info:
    This API is documented in [**OpenAPI format**](http://spec.openapis.org/oas/v3.0.3).
    ([View the full HTTP specification](https://raw.githubusercontent.com/mail-in-a-box/mailinabox/api-spec/api/mailinabox.yml).)

-    All endpoints are relative to `https://{host}/admin` and are secured with [`Basic Access` authentication](https://en.wikipedia.org/wiki/Basic_access_authentication).
+    All endpoints are relative to `https://{host}/admin` and are secured with [`Basic Access` authentication](https://en.wikipedia.org/wiki/Basic_access_authentication). If you have multi-factor authentication enabled, authentication with a `user:password` combination will fail unless a valid OTP is supplied via the `x-auth-token` header. Authentication via a `user:user_key` pair is possible without the header being present.
  contact:
    name: Mail-in-a-Box support
    url: https://mailinabox.email/
@ -46,6 +46,9 @@ tags:
  - name: Web
    description: |
      Static web hosting operations, which include getting domain information and updating domain root directories.
+  - name: MFA
+    description: |
+      Manage multi-factor authentication schemes. Currently, only TOTP is supported.
  - name: System
    description: |
      System operations, which include system status checks, new version checks
@ -1662,6 +1665,101 @@ paths:
            text/html:
              schema:
                type: string
+  /mfa/status:
+    post:
+      tags:
+        - MFA
+      summary: Retrieve MFA status for you or another user
+      description: Retrieves which type of MFA is used and configuration
+      operationId: mfaStatus
+      x-codeSamples:
+        - lang: curl
+          source: |
+            curl -X POST "https://{host}/admin/mfa/status" \
+              -u "<email>:<password>"
+      responses:
+        200:
+          description: Successful operation
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/MfaStatusResponse'
+        403:
+          description: Forbidden
+          content:
+            text/html:
+              schema:
+                type: string
+  /mfa/totp/enable:
+    post:
+      tags:
+        - MFA
+      summary: Enable TOTP authentication
+      description: Enables TOTP authentication for the currently logged-in admin user
+      operationId: mfaTotpEnable
+      x-codeSamples:
+        - lang: curl
+          source: |
+            curl -X POST "https://{host}/admin/mfa/totp/enable" \
+              -d "code=123456" \
+              -d "secret=<string>" \
+              -u "<email>:<password>"
+      requestBody:
+        required: true
+        content:
+          application/x-www-form-urlencoded:
+            schema:
+              $ref: '#/components/schemas/MfaEnableRequest'
+      responses:
+        200:
+          description: Successful operation
+          content:
+            text/html:
+              schema:
+                $ref: '#/components/schemas/MfaEnableSuccessResponse'
+        400:
+          description: Bad request
+          content:
+            text/html:
+              schema:
+                type: string
+        403:
+          description: Forbidden
+          content:
+            text/html:
+              schema:
+                type: string
+  /mfa/disable:
+    post:
+      tags:
+        - MFA
+      summary: Disable multi-factor authentication for you or another user
+      description: Disables multi-factor authentication for the currently logged-in admin user or another user if a 'user' parameter is submitted. Either disables all multi-factor authentication methods or the method corresponding to the optional property `mfa_id`.
+      operationId: mfaTotpDisable
+      requestBody:
+        required: false
+        content:
+          application/x-www-form-urlencoded:
+            schema:
+              $ref: '#/components/schemas/MfaDisableRequest'
+      x-codeSamples:
+        - lang: curl
+          source: |
+            curl -X POST "https://{host}/admin/mfa/totp/disable" \
+              -u "<email>:<user_key>"
+      responses:
+        200:
+          description: Successful operation
+          content:
+            text/html:
+              schema:
+                $ref: '#/components/schemas/MfaDisableSuccessResponse'
+        403:
+          description: Forbidden
+          content:
+            text/html:
+              schema:
+                type: string
 components:
  securitySchemes:
    basicAuth:
@ -2529,3 +2627,54 @@ components:
      type: string
      example: web updated
      description: Web update response.
+    MfaStatusResponse:
+      type: object
+      properties:
+        enabled_mfa:
+          type: object
+          properties:
+            id:
+              type: string
+            type:
+              type: string
+            label:
+              type: string
+          nullable: true
+        new_mfa:
+          type: object
+          properties:
+            type:
+              type: string
+            secret:
+              type: string
+            qr_code_base64:
+              type: string
+    MfaEnableRequest:
+      type: object
+      required:
+        - secret
+        - code
+      properties:
+        secret:
+          type: string
+        code:
+          type: string
+        label:
+          type: string
+    MfaEnableSuccessResponse:
+      type: string
+    MfaEnableBadRequestResponse:
+      type: object
+      required:
+        - error
+      properties:
+        error:
+          type: string
+    MfaDisableRequest:
+      type: object
+      properties:
+        mfa_id:
+          type: string
+          nullable: true
+    MfaDisableSuccessResponse:
+      type: string
--- a/conf/mta-sts.txt
+++ b/conf/mta-sts.txt
@ -1,4 +1,4 @@
 version: STSv1
 mode: MODE
 mx: PRIMARY_HOSTNAME
-max_age: 86400
+max_age: 604800
--- a/management/auth.py
+++ b/management/auth.py
@ -1,9 +1,10 @@
-import base64, os, os.path, hmac
+import base64, os, os.path, hmac, json

 from flask import make_response

 import utils
 from mailconfig import get_mail_password, get_mail_user_privileges
+from mfa import get_hash_mfa_state, validate_auth_mfa

 DEFAULT_KEY_PATH   = '/var/lib/mailinabox/api.key'
 DEFAULT_AUTH_REALM = 'Mail-in-a-Box Management Server'
@ -72,17 +73,19 @@ class KeyAuthService:
 		if username in (None, ""):
 			raise ValueError("Authorization header invalid.")
 		elif username == self.key:
-			# The user passed the API key which grants administrative privs.
+			# The user passed the master API key which grants administrative privs.
 			return (None, ["admin"])
 		else:
-			# The user is trying to log in with a username and user-specific
-			# API key or password. Raises or returns privs.
-			return (username, self.get_user_credentials(username, password, env))
+			# The user is trying to log in with a username and either a password
+			# (and possibly a MFA token) or a user-specific API key.
+			return (username, self.check_user_auth(username, password, request, env))

-	def get_user_credentials(self, email, pw, env):
-		# Validate a user's credentials. On success returns a list of
-		# privileges (e.g. [] or ['admin']). On failure raises a ValueError
-		# with a login error message. 
+	def check_user_auth(self, email, pw, request, env):
+		# Validate a user's login email address and password. If MFA is enabled,
+		# check the MFA token in the X-Auth-Token header.
+		#
+		# On success returns a list of privileges (e.g. [] or ['admin']). On login
+		# failure, raises a ValueError with a login error message.

 		# Sanity check.
 		if email == "" or pw == "":
@ -112,6 +115,12 @@ class KeyAuthService:
 				# Login failed.
 				raise ValueError("Invalid password.")

+			# If MFA is enabled, check that MFA passes.
+			status, hints = validate_auth_mfa(email, request, env)
+			if not status:
+				# Login valid. Hints may have more info.
+				raise ValueError(",".join(hints))
+
 		# Get privileges for authorization. This call should never fail because by this
 		# point we know the email address is a valid user. But on error the call will
 		# return a tuple of an error message and an HTTP status code.
@ -122,16 +131,27 @@ class KeyAuthService:
 		return privs

 	def create_user_key(self, email, env):
-		# Store an HMAC with the client. The hashed message of the HMAC will be the user's
-		# email address & hashed password and the key will be the master API key. The user of
-		# course has their own email address and password. We assume they do not have the master
-		# API key (unless they are trusted anyway). The HMAC proves that they authenticated
-		# with us in some other way to get the HMAC. Including the password means that when
-		# a user's password is reset, the HMAC changes and they will correctly need to log
-		# in to the control panel again. This method raises a ValueError if the user does
-		# not exist, due to get_mail_password.
+		# Create a user API key, which is a shared secret that we can re-generate from
+		# static information in our database. The shared secret contains the user's
+		# email address, current hashed password, and current MFA state, so that the
+		# key becomes invalid if any of that information changes.
+		#
+		# Use an HMAC to generate the API key using our master API key as a key,
+		# which also means that the API key becomes invalid when our master API key
+		# changes --- i.e. when this process is restarted.
+		#
+		# Raises ValueError via get_mail_password if the user doesn't exist.
+
+		# Construct the HMAC message from the user's email address and current password.
 		msg = b"AUTH:" + email.encode("utf8") + b" " + get_mail_password(email, env).encode("utf8")
-		return hmac.new(self.key.encode('ascii'), msg, digestmod="sha256").hexdigest()
+
+		# Add to the message the current MFA state, which is a list of MFA information.
+		# Turn it into a string stably.
+		msg += b" " + json.dumps(get_hash_mfa_state(email, env), sort_keys=True).encode("utf8")
+
+		# Make the HMAC.
+		hash_key = self.key.encode('ascii')
+		return hmac.new(hash_key, msg, digestmod="sha256").hexdigest()

 	def _generate_key(self):
 		raw_key = os.urandom(32)
--- a/management/cli.py
+++ b/management/cli.py
@ -0,0 +1,170 @@
+#!/usr/bin/python3
+#
+# This is a command-line script for calling management APIs
+# on the Mail-in-a-Box control panel backend. The script
+# reads /var/lib/mailinabox/api.key for the backend's
+# root API key. This file is readable only by root, so this
+# tool can only be used as root.
+
+import sys, getpass, urllib.request, urllib.error, json, re, csv
+
+def mgmt(cmd, data=None, is_json=False):
+	# The base URL for the management daemon. (Listens on IPv4 only.)
+	mgmt_uri = 'http://127.0.0.1:10222'
+
+	setup_key_auth(mgmt_uri)
+
+	req = urllib.request.Request(mgmt_uri + cmd, urllib.parse.urlencode(data).encode("utf8") if data else None)
+	try:
+		response = urllib.request.urlopen(req)
+	except urllib.error.HTTPError as e:
+		if e.code == 401:
+			try:
+				print(e.read().decode("utf8"))
+			except:
+				pass
+			print("The management daemon refused access. The API key file may be out of sync. Try 'service mailinabox restart'.", file=sys.stderr)
+		elif hasattr(e, 'read'):
+			print(e.read().decode('utf8'), file=sys.stderr)
+		else:
+			print(e, file=sys.stderr)
+		sys.exit(1)
+	resp = response.read().decode('utf8')
+	if is_json: resp = json.loads(resp)
+	return resp
+
+def read_password():
+    while True:
+        first = getpass.getpass('password: ')
+        if len(first) < 8:
+            print("Passwords must be at least eight characters.")
+            continue
+        second = getpass.getpass(' (again): ')
+        if first != second:
+            print("Passwords not the same. Try again.")
+            continue
+        break
+    return first
+
+def setup_key_auth(mgmt_uri):
+	key = open('/var/lib/mailinabox/api.key').read().strip()
+
+	auth_handler = urllib.request.HTTPBasicAuthHandler()
+	auth_handler.add_password(
+		realm='Mail-in-a-Box Management Server',
+		uri=mgmt_uri,
+		user=key,
+		passwd='')
+	opener = urllib.request.build_opener(auth_handler)
+	urllib.request.install_opener(opener)
+
+if len(sys.argv) < 2:
+	print("""Usage:
+  {cli} system default-quota [new default]       (set default quota for system)
+  {cli} user                                     (lists users)
+  {cli} user add user@domain.com [password]
+  {cli} user password user@domain.com [password]
+  {cli} user remove user@domain.com
+  {cli} user make-admin user@domain.com
+  {cli} user quota user@domain [new-quota]
+  {cli} user remove-admin user@domain.com
+  {cli} user admins                              (lists admins)
+  {cli} user mfa show user@domain.com            (shows MFA devices for user, if any)
+  {cli} user mfa disable user@domain.com [id]    (disables MFA for user)
+  {cli} alias                                    (lists aliases)
+  {cli} alias add incoming.name@domain.com sent.to@other.domain.com
+  {cli} alias add incoming.name@domain.com 'sent.to@other.domain.com, multiple.people@other.domain.com'
+  {cli} alias remove incoming.name@domain.com
+
+Removing a mail user does not delete their mail folders on disk. It only prevents IMAP/SMTP login.
+""".format(
+	cli="management/cli.py"
+		))
+
+elif sys.argv[1] == "user" and len(sys.argv) == 2:
+	# Dump a list of users, one per line. Mark admins with an asterisk.
+	users = mgmt("/mail/users?format=json", is_json=True)
+	for domain in users:
+		for user in domain["users"]:
+			if user['status'] == 'inactive': continue
+			print(user['email'], end='')
+			if "admin" in user['privileges']:
+				print("*", end='')
+			if user['quota'] == '0':
+				print(" unlimited", end='')
+			else:
+				print(" " + user['quota'], end='')
+			print()
+
+elif sys.argv[1] == "user" and sys.argv[2] in ("add", "password"):
+	if len(sys.argv) < 5:
+		if len(sys.argv) < 4:
+			email = input("email: ")
+		else:
+			email = sys.argv[3]
+		pw = read_password()
+	else:
+		email, pw = sys.argv[3:5]
+
+	if sys.argv[2] == "add":
+		print(mgmt("/mail/users/add", { "email": email, "password": pw }))
+	elif sys.argv[2] == "password":
+		print(mgmt("/mail/users/password", { "email": email, "password": pw }))
+
+elif sys.argv[1] == "user" and sys.argv[2] == "remove" and len(sys.argv) == 4:
+	print(mgmt("/mail/users/remove", { "email": sys.argv[3] }))
+
+elif sys.argv[1] == "user" and sys.argv[2] in ("make-admin", "remove-admin") and len(sys.argv) == 4:
+	if sys.argv[2] == "make-admin":
+		action = "add"
+	else:
+		action = "remove"
+	print(mgmt("/mail/users/privileges/" + action, { "email": sys.argv[3], "privilege": "admin" }))
+
+elif sys.argv[1] == "user" and sys.argv[2] == "admins":
+	# Dump a list of admin users.
+	users = mgmt("/mail/users?format=json", is_json=True)
+	for domain in users:
+		for user in domain["users"]:
+			if "admin" in user['privileges']:
+				print(user['email'])
+
+elif sys.argv[1] == "user" and sys.argv[2] == "quota" and len(sys.argv) == 4:
+	# Set a user's quota
+	print(mgmt("/mail/users/quota?text=1&email=%s" % sys.argv[3]))
+
+elif sys.argv[1] == "user" and sys.argv[2] == "quota" and len(sys.argv) == 5:
+	# Set a user's quota
+	users = mgmt("/mail/users/quota", { "email": sys.argv[3], "quota": sys.argv[4] })
+
+elif sys.argv[1] == "user" and len(sys.argv) == 5 and sys.argv[2:4] == ["mfa", "show"]:
+	# Show MFA status for a user.
+	status = mgmt("/mfa/status", { "user": sys.argv[4] }, is_json=True)
+	W = csv.writer(sys.stdout)
+	W.writerow(["id", "type", "label"])
+	for mfa in status["enabled_mfa"]:
+		W.writerow([mfa["id"], mfa["type"], mfa["label"]])
+
+elif sys.argv[1] == "user" and len(sys.argv) in (5, 6) and sys.argv[2:4] == ["mfa", "disable"]:
+	# Disable MFA (all or a particular device) for a user.
+	print(mgmt("/mfa/disable", { "user": sys.argv[4], "mfa-id": sys.argv[5] if len(sys.argv) == 6 else None }))
+
+elif sys.argv[1] == "alias" and len(sys.argv) == 2:
+	print(mgmt("/mail/aliases"))
+
+elif sys.argv[1] == "alias" and sys.argv[2] == "add" and len(sys.argv) == 5:
+	print(mgmt("/mail/aliases/add", { "address": sys.argv[3], "forwards_to": sys.argv[4] }))
+
+elif sys.argv[1] == "alias" and sys.argv[2] == "remove" and len(sys.argv) == 4:
+	print(mgmt("/mail/aliases/remove", { "address": sys.argv[3] }))
+
+elif sys.argv[1] == "system" and sys.argv[2] == "default-quota" and len(sys.argv) == 3:
+	print(mgmt("/system/default-quota?text=1"))
+
+elif sys.argv[1] == "system" and sys.argv[2] == "default-quota" and len(sys.argv) == 4:
+	print(mgmt("/system/default-quota", { "default_quota": sys.argv[3]}))
+
+else:
+	print("Invalid command-line arguments.")
+	sys.exit(1)
+
--- a/management/daemon.py
+++ b/management/daemon.py
@ -1,15 +1,17 @@
 import os, os.path, re, json, time
-import subprocess
+import multiprocessing.pool, subprocess

 from functools import wraps

 from flask import Flask, request, render_template, abort, Response, send_from_directory, make_response

-import auth, utils, multiprocessing.pool
+import auth, utils
 from mailconfig import get_mail_users, get_mail_users_ex, get_admins, add_mail_user, set_mail_password, remove_mail_user
 from mailconfig import get_mail_user_privileges, add_remove_mail_user_privilege
 from mailconfig import get_mail_aliases, get_mail_aliases_ex, get_mail_domains, add_mail_alias, remove_mail_alias
 from mailconfig import get_mail_quota, set_mail_quota, get_default_quota, validate_quota
+from mfa import get_public_mfa_state, provision_totp, validate_totp_secret, enable_mfa, disable_mfa
+
 env = utils.load_environment()

 auth_service = auth.KeyAuthService()
@ -35,23 +37,31 @@ app = Flask(__name__, template_folder=os.path.abspath(os.path.join(os.path.dirna
 def authorized_personnel_only(viewfunc):
 	@wraps(viewfunc)
 	def newview(*args, **kwargs):
-		# Authenticate the passed credentials, which is either the API key or a username:password pair.
+		# Authenticate the passed credentials, which is either the API key or a username:password pair
+		# and an optional X-Auth-Token token.
 		error = None
+		privs = []
+
 		try:
 			email, privs = auth_service.authenticate(request, env)
 		except ValueError as e:
-			# Authentication failed.
-			privs = []
-			error = "Incorrect username or password"
-
 			# Write a line in the log recording the failed login
 			log_failed_login(request)

+			# Authentication failed.
+			error = str(e)
+
 		# Authorized to access an API view?
 		if "admin" in privs:
+			# Store the email address of the logged in user so it can be accessed
+			# from the API methods that affect the calling user.
+			request.user_email = email
+			request.user_privs = privs
+
 			# Call view func.
 			return viewfunc(*args, **kwargs)
-		elif not error:
+
+		if not error:
 			error = "You are not an administrator."

 		# Not authorized. Return a 401 (send auth) and a prompt to authorize by default.
@ -83,8 +93,8 @@ def authorized_personnel_only(viewfunc):
 def unauthorized(error):
 	return auth_service.make_unauthorized_response()

-def json_response(data):
-	return Response(json.dumps(data, indent=2, sort_keys=True)+'\n', status=200, mimetype='application/json')
+def json_response(data, status=200):
+	return Response(json.dumps(data, indent=2, sort_keys=True)+'\n', status=status, mimetype='application/json')

 ###################################

@ -119,12 +129,17 @@ def me():
 	try:
 		email, privs = auth_service.authenticate(request, env)
 	except ValueError as e:
+		if "missing-totp-token" in str(e):
+			return json_response({
+				"status": "missing-totp-token",
+				"reason": str(e),
+			})
+		else:
 			# Log the failed login
 			log_failed_login(request)
-
 			return json_response({
 				"status": "invalid",
-			"reason": "Incorrect username or password",
+				"reason": str(e),
 			})

 	resp = {
@ -406,6 +421,60 @@ def ssl_provision_certs():
 	requests = provision_certificates(env, limit_domains=None)
 	return json_response({ "requests": requests })

+# multi-factor auth
+
+@app.route('/mfa/status', methods=['POST'])
+@authorized_personnel_only
+def mfa_get_status():
+	# Anyone accessing this route is an admin, and we permit them to
+	# see the MFA status for any user if they submit a 'user' form
+	# field. But we don't include provisioning info since a user can
+	# only provision for themselves.
+	email = request.form.get('user', request.user_email) # user field if given, otherwise the user making the request
+	try:
+		resp = {
+			"enabled_mfa": get_public_mfa_state(email, env)
+		}
+		if email == request.user_email:
+			resp.update({
+				"new_mfa": {
+					"totp": provision_totp(email, env)
+				}
+			})
+	except ValueError as e:
+		return (str(e), 400)
+	return json_response(resp)
+
+@app.route('/mfa/totp/enable', methods=['POST'])
+@authorized_personnel_only
+def totp_post_enable():
+	secret = request.form.get('secret')
+	token = request.form.get('token')
+	label = request.form.get('label')
+	if type(token) != str:
+		return ("Bad Input", 400)
+	try:
+		validate_totp_secret(secret)
+		enable_mfa(request.user_email, "totp", secret, token, label, env)
+	except ValueError as e:
+		return (str(e), 400)
+	return "OK"
+
+@app.route('/mfa/disable', methods=['POST'])
+@authorized_personnel_only
+def totp_post_disable():
+	# Anyone accessing this route is an admin, and we permit them to
+	# disable the MFA status for any user if they submit a 'user' form
+	# field.
+	email = request.form.get('user', request.user_email) # user field if given, otherwise the user making the request
+	try:
+		result = disable_mfa(email, request.form.get('mfa-id') or None, env) # convert empty string to None
+	except ValueError as e:
+		return (str(e), 400)
+	if result: # success
+		return "OK"
+	else: # error
+		return ("Invalid user or MFA id.", 400)

 # WEB

--- a/management/mailconfig.py
+++ b/management/mailconfig.py
@ -720,7 +720,6 @@ def validate_password(pw):
 	if len(pw) < 8:
 		raise ValueError("Passwords must be at least eight characters.")

-
 if __name__ == "__main__":
 	import sys
 	if len(sys.argv) > 2 and sys.argv[1] == "validate-email":
--- a/management/mfa.py
+++ b/management/mfa.py
@ -0,0 +1,141 @@
+import base64
+import hmac
+import io
+import os
+import pyotp
+import qrcode
+
+from mailconfig import open_database
+
+def get_user_id(email, c):
+	c.execute('SELECT id FROM users WHERE email=?', (email,))
+	r = c.fetchone()
+	if not r: raise ValueError("User does not exist.")
+	return r[0]
+
+def get_mfa_state(email, env):
+	c = open_database(env)
+	c.execute('SELECT id, type, secret, mru_token, label FROM mfa WHERE user_id=?', (get_user_id(email, c),))
+	return [
+		{ "id": r[0], "type": r[1], "secret": r[2], "mru_token": r[3], "label": r[4] }
+		for r in c.fetchall()
+	]
+
+def get_public_mfa_state(email, env):
+	mfa_state = get_mfa_state(email, env)
+	return [
+		{ "id": s["id"], "type": s["type"], "label": s["label"] }
+		for s in mfa_state
+	]
+
+def get_hash_mfa_state(email, env):
+	mfa_state = get_mfa_state(email, env)
+	return [
+		{ "id": s["id"], "type": s["type"], "secret": s["secret"] }
+		for s in mfa_state
+	]
+
+def enable_mfa(email, type, secret, token, label, env):
+	if type == "totp":
+		validate_totp_secret(secret)
+		# Sanity check with the provide current token.
+		totp = pyotp.TOTP(secret)
+		if not totp.verify(token, valid_window=1):
+			raise ValueError("Invalid token.")
+	else:
+		raise ValueError("Invalid MFA type.")
+
+	conn, c = open_database(env, with_connection=True)
+	c.execute('INSERT INTO mfa (user_id, type, secret, label) VALUES (?, ?, ?, ?)', (get_user_id(email, c), type, secret, label))
+	conn.commit()
+
+def set_mru_token(email, mfa_id, token, env):
+	conn, c = open_database(env, with_connection=True)
+	c.execute('UPDATE mfa SET mru_token=? WHERE user_id=? AND id=?', (token, get_user_id(email, c), mfa_id))
+	conn.commit()
+
+def disable_mfa(email, mfa_id, env):
+	conn, c = open_database(env, with_connection=True)
+	if mfa_id is None:
+		# Disable all MFA for a user.
+		c.execute('DELETE FROM mfa WHERE user_id=?', (get_user_id(email, c),))
+	else:
+		# Disable a particular MFA mode for a user.
+		c.execute('DELETE FROM mfa WHERE user_id=? AND id=?', (get_user_id(email, c), mfa_id))
+	conn.commit()
+	return c.rowcount > 0
+
+def validate_totp_secret(secret):
+	if type(secret) != str or secret.strip() == "":
+		raise ValueError("No secret provided.")
+	if len(secret) != 32:
+		raise ValueError("Secret should be a 32 characters base32 string")
+
+def provision_totp(email, env):
+	# Make a new secret.
+	secret = base64.b32encode(os.urandom(20)).decode('utf-8')
+	validate_totp_secret(secret) # sanity check
+
+	# Make a URI that we encode within a QR code.
+	uri = pyotp.TOTP(secret).provisioning_uri(
+		name=email,
+		issuer_name=env["PRIMARY_HOSTNAME"] + " Mail-in-a-Box Control Panel"
+	)
+
+	# Generate a QR code as a base64-encode PNG image.
+	qr = qrcode.make(uri)
+	byte_arr = io.BytesIO()
+	qr.save(byte_arr, format='PNG')
+	png_b64 = base64.b64encode(byte_arr.getvalue()).decode('utf-8')
+
+	return {
+		"type": "totp",
+		"secret": secret,
+		"qr_code_base64": png_b64
+	}
+
+def validate_auth_mfa(email, request, env):
+	# Validates that a login request satisfies any MFA modes
+	# that have been enabled for the user's account. Returns
+	# a tuple (status, [hints]). status is True for a successful
+	# MFA login, False for a missing token. If status is False,
+	# hints is an array of codes that indicate what the user
+	# can try. Possible codes are:
+	# "missing-totp-token"
+	# "invalid-totp-token"
+
+	mfa_state = get_mfa_state(email, env)
+
+	# If no MFA modes are added, return True.
+	if len(mfa_state) == 0:
+		return (True, [])
+
+	# Try the enabled MFA modes.
+	hints = set()
+	for mfa_mode in mfa_state:
+		if mfa_mode["type"] == "totp":
+			# Check that a token is present in the X-Auth-Token header.
+			# If not, give a hint that one can be supplied.
+			token = request.headers.get('x-auth-token')
+			if not token:
+				hints.add("missing-totp-token")
+				continue
+
+			# Check for a replay attack.
+			if hmac.compare_digest(token, mfa_mode['mru_token'] or ""):
+				# If the token fails, skip this MFA mode.
+				hints.add("invalid-totp-token")
+				continue
+
+			# Check the token.
+			totp = pyotp.TOTP(mfa_mode["secret"])
+			if not totp.verify(token, valid_window=1):
+				hints.add("invalid-totp-token")
+				continue
+
+			# On success, record the token to prevent a replay attack.
+			set_mru_token(email, mfa_mode['id'], token, env)
+			return (True, [])
+
+	# On a failed login, indicate failure and any hints for what the user can do instead.
+	return (False, list(hints))
--- a/management/ssl_certificates.py
+++ b/management/ssl_certificates.py
@ -606,10 +606,10 @@ def check_certificate(domain, ssl_certificate, ssl_private_key, warn_if_expiring
 		ndays = (cert_expiration_date-now).days
 		if not rounded_time or ndays <= 10:
 			# Yikes better renew soon!
-			expiry_info = "The certificate expires in %d days on %s." % (ndays, cert_expiration_date.strftime("%x"))
+			expiry_info = "The certificate expires in %d days on %s." % (ndays, cert_expiration_date.date().isoformat())
 		else:
 			# We'll renew it with Lets Encrypt.
-			expiry_info = "The certificate expires on %s." % cert_expiration_date.strftime("%x")
+			expiry_info = "The certificate expires on %s." % cert_expiration_date.date().isoformat()

 		if warn_if_expiring_soon and ndays <= warn_if_expiring_soon:
 			# Warn on day 10 to give 4 days for us to automatically renew the
--- a/management/templates/index.html
+++ b/management/templates/index.html
@ -97,11 +97,14 @@
              </ul>
            </li>
            <li class="dropdown">
-              <a href="#" class="dropdown-toggle" data-toggle="dropdown">Mail <b class="caret"></b></a>
+              <a href="#" class="dropdown-toggle" data-toggle="dropdown">Mail &amp; Users <b class="caret"></b></a>
              <ul class="dropdown-menu">
                <li><a href="#mail-guide" onclick="return show_panel(this);">Instructions</a></li>
                <li><a href="#users" onclick="return show_panel(this);">Users</a></li>
                <li><a href="#aliases" onclick="return show_panel(this);">Aliases</a></li>
+                <li class="divider"></li>
+                <li class="dropdown-header">Your Account</li>
+                <li><a href="#mfa" onclick="return show_panel(this);">Two-Factor Authentication</a></li>
              </ul>
            </li>
            <li><a href="#sync_guide" onclick="return show_panel(this);">Contacts/Calendar</a></li>
@ -131,6 +134,10 @@
      {% include "custom-dns.html" %}
      </div>

+      <div id="panel_mfa" class="admin_panel">
+      {% include "mfa.html" %}
+      </div>
+
      <div id="panel_login" class="admin_panel">
      {% include "login.html" %}
      </div>
@ -292,7 +299,7 @@ function ajax_with_indicator(options) {
 }

 var api_credentials = ["", ""];
-function api(url, method, data, callback, callback_error) {
+function api(url, method, data, callback, callback_error, headers) {
  // from http://www.webtoolkit.info/javascript-base64.html
  function base64encode(input) {
    _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
@ -330,7 +337,7 @@ function api(url, method, data, callback, callback_error) {
    method: method,
    cache: false,
    data: data,
-
+    headers: headers,
    // the custom DNS api sends raw POST/PUT bodies --- prevent URL-encoding
    processData: typeof data != "string",
    mimeType: typeof data == "string" ? "text/plain; charset=ascii" : null,
@ -358,6 +365,16 @@ function api(url, method, data, callback, callback_error) {

 var current_panel = null;
 var switch_back_to_panel = null;
+
+function do_logout() {
+  api_credentials = ["", ""];
+  if (typeof localStorage != 'undefined')
+    localStorage.removeItem("miab-cp-credentials");
+  if (typeof sessionStorage != 'undefined')
+    sessionStorage.removeItem("miab-cp-credentials");
+  show_panel('login');
+}
+
 function show_panel(panelid) {
  if (panelid.getAttribute)
    // we might be passed an HTMLElement <a>.
--- a/management/templates/login.html
+++ b/management/templates/login.html
@ -1,4 +1,29 @@
-<h1 style="margin: 1em; text-align: center">{{hostname}}</h1>
+<style>
+  .title {
+    margin: 1em;
+    text-align: center;
+  }
+
+  .subtitle {
+    margin: 2em;
+    text-align: center;
+  }
+
+  .login {
+    margin: 0 auto;
+    max-width: 32em;
+  }
+
+  .login #loginOtp {
+    display: none;
+  }
+
+  #loginForm.is-twofactor #loginOtp {
+    display: block
+  }
+</style>
+
+<h1 class="title">{{hostname}}</h1>

 {% if no_users_exist or no_admins_exist %}
 <div class="row">
@ -7,23 +32,23 @@
  <p class="text-danger">There are no users on this system! To make an administrative user,
  log into this machine using SSH (like when you first set it up) and run:</p>
  <pre>cd mailinabox
-sudo tools/mail.py user add me@{{hostname}}
-sudo tools/mail.py user make-admin me@{{hostname}}</pre>
+sudo management/cli.py user add me@{{hostname}}
+sudo management/cli.py user make-admin me@{{hostname}}</pre>
  {% else %}
  <p class="text-danger">There are no administrative users on this system! To make an administrative user,
  log into this machine using SSH (like when you first set it up) and run:</p>
  <pre>cd mailinabox
-sudo tools/mail.py user make-admin me@{{hostname}}</pre>
+sudo management/cli.py user make-admin me@{{hostname}}</pre>
  {% endif %}
  <hr>
 </div>
 </div>
 {% endif %}

-<p style="margin: 2em; text-align: center;">Log in here for your Mail-in-a-Box control panel.</p>
+<p class="subtitle">Log in here for your Mail-in-a-Box control panel.</p>

-<div style="margin: 0 auto; max-width: 32em;">
-  <form class="form-horizontal" role="form" onsubmit="do_login(); return false;" method="get">
+<div class="login">
+  <form id="loginForm" class="form-horizontal" role="form" onsubmit="do_login(); return false;" method="get">
    <div class="form-group">
      <label for="inputEmail3" class="col-sm-3 control-label">Email</label>
      <div class="col-sm-9">
@ -36,6 +61,13 @@ sudo tools/mail.py user make-admin me@{{hostname}}</pre>
        <input name="password" type="password" class="form-control" id="loginPassword" placeholder="Password">
      </div>
    </div>
+    <div class="form-group" id="loginOtp">
+      <label for="loginOtpInput" class="col-sm-3 control-label">Code</label>
+      <div class="col-sm-9">
+          <input type="text" class="form-control" id="loginOtpInput" placeholder="6-digit code">
+          <div class="help-block" style="margin-top: 5px; font-size: 90%">Enter the six-digit code generated by your two factor authentication app.</div>
+      </div>
+    </div>
    <div class="form-group">
      <div class="col-sm-offset-3 col-sm-9">
        <div class="checkbox">
@ -53,7 +85,6 @@ sudo tools/mail.py user make-admin me@{{hostname}}</pre>
  </form>
 </div>

-
 <script>
 function do_login() {
  if ($('#loginEmail').val() == "") {
@ -62,6 +93,7 @@ function do_login() {
    });
    return false;
  }
+
  if ($('#loginPassword').val() == "") {
    show_modal_error("Login Failed", "Enter your email password.", function() {
        $('#loginPassword').focus();
@ -79,13 +111,25 @@ function do_login() {
  function(response) {
    // This API call always succeeds. It returns a JSON object indicating
    // whether the request was authenticated or not.
-    if (response.status != "ok") {
+    if (response.status != 'ok') {
+      if (response.status === 'missing-totp-token' || (response.status === 'invalid' && response.reason == 'invalid-totp-token')) {
+        $('#loginForm').addClass('is-twofactor');
+        if (response.reason === "invalid-totp-token") {
+          show_modal_error("Login Failed", "Incorrect two factor authentication token.");
+        } else {
+          setTimeout(() => {
+              $('#loginOtpInput').focus();
+          });
+        }
+      } else {
+        $('#loginForm').removeClass('is-twofactor');
+
        // Show why the login failed.
        show_modal_error("Login Failed", response.reason)

        // Reset any saved credentials.
        do_logout();
-
+      }
    } else if (!("api_key" in response)) {
      // Login succeeded but user might not be authorized!
      show_modal_error("Login Failed", "You are not an administrator on this system.")
@ -102,6 +146,8 @@ function do_login() {
      // Try to wipe the username/password information.
      $('#loginEmail').val('');
      $('#loginPassword').val('');
+      $('#loginOtpInput').val('');
+      $('#loginForm').removeClass('is-twofactor');

      // Remember the credentials.
      if (typeof localStorage != 'undefined' && typeof sessionStorage != 'undefined') {
@ -119,19 +165,16 @@ function do_login() {
      // which confuses the loading indicator.
      setTimeout(function() { show_panel(!switch_back_to_panel || switch_back_to_panel == "login" ? 'system_status' : switch_back_to_panel) }, 300);
    }
-  })
-}
-
-function do_logout() {
-  api_credentials = ["", ""];
-  if (typeof localStorage != 'undefined')
-    localStorage.removeItem("miab-cp-credentials");
-  if (typeof sessionStorage != 'undefined')
-    sessionStorage.removeItem("miab-cp-credentials");
-  show_panel('login');
+  },
+  undefined,
+  {
+    'x-auth-token': $('#loginOtpInput').val()
+  });
 }

 function show_login() {
+  $('#loginForm').removeClass('is-twofactor');
+  $('#loginOtpInput').val('');
  $('#loginEmail,#loginPassword').each(function() {
    var input = $(this);
    if (!$.trim(input.val())) {
--- a/management/templates/mfa.html
+++ b/management/templates/mfa.html
@ -0,0 +1,242 @@
+<style>
+    .twofactor #totp-setup,
+    .twofactor #disable-2fa,
+    .twofactor #output-2fa {
+        display: none;
+    }
+
+    .twofactor.loaded .loading-indicator {
+        display: none;
+    }
+
+    .twofactor.disabled #disable-2fa,
+    .twofactor.enabled #totp-setup {
+        display: none;
+    }
+
+    .twofactor.disabled #totp-setup,
+    .twofactor.enabled #disable-2fa {
+        display: block;
+    }
+
+    .twofactor #totp-setup-qr img {
+        display: block;
+        width: 256px;
+        max-width: 100%;
+        height: auto;
+    }
+
+    .twofactor #output-2fa.visible {
+        display: block;
+    }
+</style>
+
+<h2>Two-Factor Authentication</h2>
+
+<p>When two-factor authentication is enabled, you will be prompted to enter a six digit code from an
+authenticator app (usually on your phone) when you log into this control panel.</p>
+
+<div class="panel panel-danger">
+<div class="panel-heading">
+Enabling two-factor authentication does not protect access to your email
+</div>
+<div class="panel-body">
+Enabling two-factor authentication on this page only limits access to this control panel. Remember that most websites allow you to
+reset your password by checking your email, so anyone with access to your email can typically take over
+your other accounts. Additionally, if your email address or any alias that forwards to your email
+address is a typical domain control validation address (e.g admin@, administrator@, postmaster@, hostmaster@,
+webmaster@, abuse@), extra care should be taken to protect the account. <strong>Always use a strong password,
+and ensure every administrator account for this control panel does the same.</strong>
+</div>
+</div>
+
+<div class="twofactor">
+    <div class="loading-indicator">Loading...</div>
+
+    <form id="totp-setup">
+        <h3>Setup Instructions</h3>
+
+        <div class="form-group">
+            <p>1. Install <a href="https://freeotp.github.io/">FreeOTP</a> or <a href="https://www.pcworld.com/article/3225913/what-is-two-factor-authentication-and-which-2fa-apps-are-best.html">any
+            other two-factor authentication app</a> that supports TOTP.</p>
+        </div>
+
+        <div class="form-group">
+            <p style="margin-bottom: 0">2. Scan the QR code in the app or directly enter the secret into the app:</p>
+            <div id="totp-setup-qr"></div>
+        </div>
+
+        <div class="form-group">
+            <label for="otp-label" style="font-weight: normal">3. Optionally, give your device a label so that you can remember what device you set it up on:</label>
+            <input type="text" id="totp-setup-label" class="form-control" placeholder="my phone" />
+        </div>
+
+        <div class="form-group">
+            <label for="otp" style="font-weight: normal">4. Use the app to generate your first six-digit code and enter it here:</label>
+            <input type="text" id="totp-setup-token" class="form-control" placeholder="6-digit code" />
+        </div>
+
+        <input type="hidden" id="totp-setup-secret" />
+
+        <div class="form-group">
+            <p>When you click Enable Two-Factor Authentication, you will be logged out of the control panel and will have to log in
+            again, now using your two-factor authentication app.</p>
+            <button id="totp-setup-submit" disabled type="submit" class="btn">Enable Two-Factor Authentication</button>
+        </div>
+    </form>
+
+    <form id="disable-2fa">
+        <div class="form-group">
+            <p>Two-factor authentication is active for your account<span id="mfa-device-label"></span>.</p>
+            <p>You will have to log into the admin panel again after disabling two-factor authentication.</p>
+        </div>
+        <div class="form-group">
+            <button type="submit" class="btn btn-danger">Disable Two-Factor Authentication</button>
+        </div>
+    </form>
+
+    <div id="output-2fa" class="panel panel-danger">
+        <div class="panel-body"></div>
+    </div>
+</div>
+
+<script>
+    var el = {
+        disableForm: document.getElementById('disable-2fa'),
+        output: document.getElementById('output-2fa'),
+        totpSetupForm: document.getElementById('totp-setup'),
+        totpSetupToken: document.getElementById('totp-setup-token'),
+        totpSetupSecret: document.getElementById('totp-setup-secret'),
+        totpSetupLabel: document.getElementById('totp-setup-label'),
+        totpQr: document.getElementById('totp-setup-qr'),
+        totpSetupSubmit: document.querySelector('#totp-setup-submit'),
+        wrapper: document.querySelector('.twofactor')
+    }
+
+    function update_setup_disabled(evt) {
+        var val = evt.target.value.trim();
+
+        if (
+            typeof val !== 'string' ||
+            typeof el.totpSetupSecret.value !== 'string' ||
+            val.length !== 6 ||
+            el.totpSetupSecret.value.length !== 32 ||
+            !(/^\+?\d+$/.test(val))
+        ) {
+            el.totpSetupSubmit.setAttribute('disabled', '');
+        } else {
+            el.totpSetupSubmit.removeAttribute('disabled');
+        }
+    }
+
+    function render_totp_setup(provisioned_totp) {
+        var img = document.createElement('img');
+        img.src = "data:image/png;base64," + provisioned_totp.qr_code_base64;
+
+        var code = document.createElement('div');
+        code.innerHTML = `Secret: ${provisioned_totp.secret}`;
+
+        el.totpQr.appendChild(img);
+        el.totpQr.appendChild(code);
+
+        el.totpSetupToken.addEventListener('input', update_setup_disabled);
+        el.totpSetupForm.addEventListener('submit', do_enable_totp);
+
+        el.totpSetupSecret.setAttribute('value', provisioned_totp.secret);
+
+        el.wrapper.classList.add('disabled');
+    }
+
+    function render_disable(mfa) {
+        el.disableForm.addEventListener('submit', do_disable);
+        el.wrapper.classList.add('enabled');
+        if (mfa.label)
+          $("#mfa-device-label").text(" on device '" + mfa.label + "'");
+    }
+
+    function hide_error() {
+        el.output.querySelector('.panel-body').innerHTML = '';
+        el.output.classList.remove('visible');
+    }
+
+    function render_error(msg) {
+        el.output.querySelector('.panel-body').innerHTML = msg;
+        el.output.classList.add('visible');
+    }
+
+    function reset_view() {
+        el.wrapper.classList.remove('loaded', 'disabled', 'enabled');
+
+        el.disableForm.removeEventListener('submit', do_disable);
+
+        hide_error();
+
+        el.totpSetupForm.reset();
+        el.totpSetupForm.removeEventListener('submit', do_enable_totp);
+
+        el.totpSetupSecret.setAttribute('value', '');
+        el.totpSetupToken.removeEventListener('input', update_setup_disabled);
+
+        el.totpSetupSubmit.setAttribute('disabled', '');
+        el.totpQr.innerHTML = '';
+    }
+
+    function show_mfa() {
+        reset_view();
+
+        api(
+            '/mfa/status',
+            'POST',
+            {},
+            function(res) {
+                el.wrapper.classList.add('loaded');
+
+                var has_mfa = false;
+                res.enabled_mfa.forEach(function(mfa) {
+                    if (mfa.type == "totp") {
+                        render_disable(mfa);
+                        has_mfa = true;
+                    }
+                });
+
+                if (!has_mfa)
+                  render_totp_setup(res.new_mfa.totp);
+            }
+        );
+    }
+
+    function do_disable(evt) {
+        evt.preventDefault();
+        hide_error();
+
+        api(
+            '/mfa/disable',
+            'POST',
+            { type: 'totp' },
+            function() {
+                do_logout();
+            }
+        );
+
+        return false;
+    }
+
+    function do_enable_totp(evt) {
+        evt.preventDefault();
+        hide_error();
+
+        api(
+            '/mfa/totp/enable',
+            'POST',
+            {
+                token: $(el.totpSetupToken).val(),
+                secret: $(el.totpSetupSecret).val(),
+                label: $(el.totpSetupLabel).val()
+            },
+            function(res) { do_logout(); },
+            function(res) { render_error(res); }
+        );
+
+        return false;
+    }
+</script>
--- a/management/templates/system-backup.html
+++ b/management/templates/system-backup.html
@ -113,10 +113,10 @@
  </div>
  <!-- Common -->
  <div class="form-group backup-target-local backup-target-rsync backup-target-s3">
-    <label for="min-age" class="col-sm-2 control-label">Days:</label>
+    <label for="min-age" class="col-sm-2 control-label">Retention Days:</label>
    <div class="col-sm-8">
      <input type="number" class="form-control" rows="1" id="min-age">
-      <div class="small" style="margin-top: 2px">This is the <i>minimum</i> number of days backup data is kept for. The box makes an incremental backup, so backup data is often kept much longer. An incremental backup file that is less than this number of days old requires that all previous increments back to the most recent full backup, plus that full backup, remain available.</div>
+      <div class="small" style="margin-top: 2px">This is the minimum time backup data is kept for. The box makes an incremental backup most nights, which requires that previous backups back to the most recent full backup be preserved, so backup data is often kept much longer than this setting. Full backups are made periodically when the incremental backup data size exceeds a limit.</div>
    </div>
  </div>
  <div class="form-group">
--- a/management/web_update.py
+++ b/management/web_update.py
@ -146,7 +146,7 @@ def make_domain_config(domain, templates, ssl_certificates, env):
 		finally:
 			f.close()
 		return sha1.hexdigest()
-	nginx_conf_extra += "# ssl files sha1: %s / %s\n" % (hashfile(tls_cert["private-key"]), hashfile(tls_cert["certificate"]))
+	nginx_conf_extra += "\t# ssl files sha1: %s / %s\n" % (hashfile(tls_cert["private-key"]), hashfile(tls_cert["certificate"]))

 	# Add in any user customizations in YAML format.
 	hsts = "yes"
@ -188,9 +188,9 @@ def make_domain_config(domain, templates, ssl_certificates, env):

 	# Add the HSTS header.
 	if hsts == "yes":
-		nginx_conf_extra += "add_header Strict-Transport-Security \"max-age=15768000\" always;\n"
+		nginx_conf_extra += "\tadd_header Strict-Transport-Security \"max-age=15768000\" always;\n"
 	elif hsts == "preload":
-		nginx_conf_extra += "add_header Strict-Transport-Security \"max-age=15768000; includeSubDomains; preload\" always;\n"
+		nginx_conf_extra += "\tadd_header Strict-Transport-Security \"max-age=15768000; includeSubDomains; preload\" always;\n"

 	# Add in any user customizations in the includes/ folder.
 	nginx_conf_custom_include = os.path.join(env["STORAGE_ROOT"], "www", safe_domain_name(domain) + ".conf")
--- a/setup/bootstrap.sh
+++ b/setup/bootstrap.sh
@ -20,7 +20,7 @@ if [ -z "$TAG" ]; then
 	# want to display in status checks.
 	if [ "`lsb_release -d | sed 's/.*:\s*//' | sed 's/18\.04\.[0-9]/18.04/' `" == "Ubuntu 18.04 LTS" ]; then
 		# This machine is running Ubuntu 18.04.
-		TAG=v0.50-quota-0.22-beta
+		TAG=v0.51-quota-0.22-beta

 	elif [ "`lsb_release -d | sed 's/.*:\s*//' | sed 's/14\.04\.[0-9]/14.04/' `" == "Ubuntu 14.04 LTS" ]; then
 		# This machine is running Ubuntu 14.04.
--- a/setup/firstuser.sh
+++ b/setup/firstuser.sh
@ -1,6 +1,6 @@
 # If there aren't any mail users yet, create one.
-if [ -z "`tools/mail.py user`" ]; then
-	# The outut of "tools/mail.py user" is a list of mail users. If there
+if [ -z "`management/cli.py user`" ]; then
+	# The outut of "management/cli.py user" is a list of mail users. If there
 	# aren't any yet, it'll be empty.

 	# If we didn't ask for an email address at the start, do so now.
@ -47,11 +47,11 @@ if [ -z "`tools/mail.py user`" ]; then
 	fi

 	# Create the user's mail account. This will ask for a password if none was given above.
-	tools/mail.py user add $EMAIL_ADDR ${EMAIL_PW:-}
+	management/cli.py user add $EMAIL_ADDR ${EMAIL_PW:-}

 	# Make it an admin.
-	hide_output tools/mail.py user make-admin $EMAIL_ADDR
+	hide_output management/cli.py user make-admin $EMAIL_ADDR

 	# Create an alias to which we'll direct all automatically-created administrative aliases.
-	tools/mail.py alias add administrator@$PRIMARY_HOSTNAME $EMAIL_ADDR > /dev/null
+	management/cli.py alias add administrator@$PRIMARY_HOSTNAME $EMAIL_ADDR > /dev/null
 fi
--- a/setup/mail-users.sh
+++ b/setup/mail-users.sh
@ -22,6 +22,7 @@ if [ ! -f $db_path ]; then
 	echo Creating new user database: $db_path;
 	echo "CREATE TABLE users (id INTEGER PRIMARY KEY AUTOINCREMENT, email TEXT NOT NULL UNIQUE, password TEXT NOT NULL, extra, privileges TEXT NOT NULL DEFAULT '', quota TEXT NOT NULL DEFAULT '0');" | sqlite3 $db_path;
 	echo "CREATE TABLE aliases (id INTEGER PRIMARY KEY AUTOINCREMENT, source TEXT NOT NULL UNIQUE, destination TEXT NOT NULL, permitted_senders TEXT);" | sqlite3 $db_path;
+	echo "CREATE TABLE mfa (id INTEGER PRIMARY KEY AUTOINCREMENT, user_id INTEGER NOT NULL, type TEXT NOT NULL, secret TEXT NOT NULL, mru_token TEXT, label TEXT, FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE);" | sqlite3 $db_path;
 elif sqlite3 $db_path ".schema users" | grep --invert-match quota; then
    echo "ALTER TABLE users ADD COLUMN quota TEXT NOT NULL DEFAULT '0';" | sqlite3 $db_path;
 fi
--- a/setup/management.sh
+++ b/setup/management.sh
@ -50,6 +50,7 @@ hide_output $venv/bin/pip install --upgrade pip
 hide_output $venv/bin/pip install --upgrade \
 	rtyaml "email_validator>=1.0.0" "exclusiveprocess" \
 	flask dnspython python-dateutil \
+    qrcode[pil] pyotp \
 	"idna>=2.0.0" "cryptography==2.2.2" boto psutil postfix-mta-sts-resolver

 # CONFIGURATION
--- a/setup/migrate.py
+++ b/setup/migrate.py
@ -181,6 +181,12 @@ def migration_12(env):
            conn.commit()
            conn.close()

+def migration_13(env):
+	# Add the "mfa" table for configuring MFA for login to the control panel.
+	db = os.path.join(env["STORAGE_ROOT"], 'mail/users.sqlite')
+	shell("check_call", ["sqlite3", db, "CREATE TABLE mfa (id INTEGER PRIMARY KEY AUTOINCREMENT, user_id INTEGER NOT NULL, type TEXT NOT NULL, secret TEXT NOT NULL, mru_token TEXT, label TEXT, FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE);"])
+
+###########################################################

 def get_current_migration():
 	ver = 0
--- a/setup/nextcloud.sh
+++ b/setup/nextcloud.sh
@ -14,12 +14,18 @@ apt-get purge -qq -y owncloud* # we used to use the package manager
 apt_install php php-fpm \
 	php-cli php-sqlite3 php-gd php-imap php-curl php-pear curl \
 	php-dev php-gd php-xml php-mbstring php-zip php-apcu php-json \
-	php-intl php-imagick
+	php-intl php-imagick php-gmp php-bcmath

 InstallNextcloud() {

 	version=$1
 	hash=$2
+	version_contacts=$3
+	hash_contacts=$4
+	version_calendar=$5
+	hash_calendar=$6
+	version_user_external=$7
+	hash_user_external=$8

 	echo
 	echo "Upgrading to Nextcloud version $version"
@ -40,18 +46,18 @@ InstallNextcloud() {
 	# their github repositories.
 	mkdir -p /usr/local/lib/owncloud/apps

-	wget_verify https://github.com/nextcloud/contacts/releases/download/v3.3.0/contacts.tar.gz e55d0357c6785d3b1f3b5f21780cb6d41d32443a /tmp/contacts.tgz
+	wget_verify https://github.com/nextcloud/contacts/releases/download/v$version_contacts/contacts.tar.gz $hash_contacts /tmp/contacts.tgz
 	tar xf /tmp/contacts.tgz -C /usr/local/lib/owncloud/apps/
 	rm /tmp/contacts.tgz

-	wget_verify https://github.com/nextcloud/calendar/releases/download/v2.0.3/calendar.tar.gz 9d9717b29337613b72c74e9914c69b74b346c466 /tmp/calendar.tgz
+	wget_verify https://github.com/nextcloud/calendar/releases/download/v$version_calendar/calendar.tar.gz $hash_calendar /tmp/calendar.tgz
 	tar xf /tmp/calendar.tgz -C /usr/local/lib/owncloud/apps/
 	rm /tmp/calendar.tgz

 	# Starting with Nextcloud 15, the app user_external is no longer included in Nextcloud core,
 	# we will install from their github repository.
-	if [[ $version =~ ^1[567] ]]; then
-		wget_verify https://github.com/nextcloud/user_external/releases/download/v0.7.0/user_external-0.7.0.tar.gz 555a94811daaf5bdd336c5e48a78aa8567b86437 /tmp/user_external.tgz
+	if [ -n "$version_user_external" ]; then
+		wget_verify https://github.com/nextcloud/user_external/releases/download/v$version_user_external/user_external-$version_user_external.tar.gz $hash_user_external /tmp/user_external.tgz
 		tar -xf /tmp/user_external.tgz -C /usr/local/lib/owncloud/apps/
 		rm /tmp/user_external.tgz
 	fi
@ -91,8 +97,14 @@ InstallNextcloud() {
 }

 # Nextcloud Version to install. Checks are done down below to step through intermediate versions.
-nextcloud_ver=17.0.6
-nextcloud_hash=50b98d2c2f18510b9530e558ced9ab51eb4f11b0
+nextcloud_ver=20.0.1
+nextcloud_hash=f2b3faa570c541df73f209e873a1c2852e79eab8
+contacts_ver=3.4.1
+contacts_hash=aee680a75e95f26d9285efd3c1e25cf7f3bfd27e
+calendar_ver=2.1.2
+calendar_hash=930c07863bb7a65652dec34793802c8d80502336
+user_external_ver=1.0.0
+user_external_hash=3bf2609061d7214e7f0f69dd8883e55c4ec8f50a

 # Current Nextcloud Version, #1623
 # Checking /usr/local/lib/owncloud/version.php shows version of the Nextcloud application, not the DB
@ -141,23 +153,39 @@ if [ ! -d /usr/local/lib/owncloud/ ] || [[ ! ${CURRENT_NEXTCLOUD_VER} =~ ^$nextc
 			return 0
 		elif [[ ${CURRENT_NEXTCLOUD_VER} =~ ^13 ]]; then
 			# If we are running Nextcloud 13, upgrade to Nextcloud 14
-			InstallNextcloud 14.0.6 4e43a57340f04c2da306c8eea98e30040399ae5a
+			InstallNextcloud 14.0.6 4e43a57340f04c2da306c8eea98e30040399ae5a 3.3.0 e55d0357c6785d3b1f3b5f21780cb6d41d32443a 2.0.3 9d9717b29337613b72c74e9914c69b74b346c466
 			CURRENT_NEXTCLOUD_VER="14.0.6"
 		fi
 		if [[ ${CURRENT_NEXTCLOUD_VER} =~ ^14 ]]; then
 			# During the upgrade from Nextcloud 14 to 15, user_external may cause the upgrade to fail.
 			# We will disable it here before the upgrade and install it again after the upgrade.
 			hide_output sudo -u www-data php /usr/local/lib/owncloud/console.php app:disable user_external
-			InstallNextcloud 15.0.8 4129d8d4021c435f2e86876225fb7f15adf764a3
+			InstallNextcloud 15.0.8 4129d8d4021c435f2e86876225fb7f15adf764a3 3.3.0 e55d0357c6785d3b1f3b5f21780cb6d41d32443a 2.0.3 9d9717b29337613b72c74e9914c69b74b346c466 0.7.0 555a94811daaf5bdd336c5e48a78aa8567b86437
 			CURRENT_NEXTCLOUD_VER="15.0.8"
 		fi
 		if [[ ${CURRENT_NEXTCLOUD_VER} =~ ^15 ]]; then
-                        InstallNextcloud 16.0.6 0bb3098455ec89f5af77a652aad553ad40a88819
+                        InstallNextcloud 16.0.6 0bb3098455ec89f5af77a652aad553ad40a88819 3.3.0 e55d0357c6785d3b1f3b5f21780cb6d41d32443a 2.0.3 9d9717b29337613b72c74e9914c69b74b346c466 0.7.0 555a94811daaf5bdd336c5e48a78aa8567b86437
                        CURRENT_NEXTCLOUD_VER="16.0.6"
        	fi
+	        if [[ ${CURRENT_NEXTCLOUD_VER} =~ ^16 ]]; then
+                        InstallNextcloud 17.0.6 50b98d2c2f18510b9530e558ced9ab51eb4f11b0 3.3.0 e55d0357c6785d3b1f3b5f21780cb6d41d32443a 2.0.3 9d9717b29337613b72c74e9914c69b74b346c466 0.7.0 555a94811daaf5bdd336c5e48a78aa8567b86437
+                        CURRENT_NEXTCLOUD_VER="17.0.6"
+	        fi
+	        if [[ ${CURRENT_NEXTCLOUD_VER} =~ ^17 ]]; then
+			echo "ALTER TABLE oc_flow_operations ADD COLUMN entity VARCHAR;" | sqlite3 $STORAGE_ROOT/owncloud/owncloud.db
+                        InstallNextcloud 18.0.10 39c0021a8b8477c3f1733fddefacfa5ebf921c68 3.4.1 aee680a75e95f26d9285efd3c1e25cf7f3bfd27e 2.0.3 9d9717b29337613b72c74e9914c69b74b346c466 1.0.0 3bf2609061d7214e7f0f69dd8883e55c4ec8f50a
+                        CURRENT_NEXTCLOUD_VER="18.0.10"
+	        fi
+	        if [[ ${CURRENT_NEXTCLOUD_VER} =~ ^18 ]]; then
+                        InstallNextcloud 19.0.4 01e98791ba12f4860d3d4047b9803f97a1b55c60 3.4.1 aee680a75e95f26d9285efd3c1e25cf7f3bfd27e 2.0.3 9d9717b29337613b72c74e9914c69b74b346c466 1.0.0 3bf2609061d7214e7f0f69dd8883e55c4ec8f50a
+                        CURRENT_NEXTCLOUD_VER="19.0.4"
+	        fi
 	fi

-	InstallNextcloud $nextcloud_ver $nextcloud_hash
+	InstallNextcloud $nextcloud_ver $nextcloud_hash $contacts_ver $contacts_hash $calendar_ver $calendar_hash $user_external_ver $user_external_hash
+
+	# Nextcloud 20 needs to have some optional columns added
+	sudo -u www-data php /usr/local/lib/owncloud/occ db:add-missing-columns
 fi

 # ### Configuring Nextcloud
@ -324,7 +352,7 @@ rm -f /etc/cron.hourly/mailinabox-owncloud
 # and there's a lot they could mess up, so we don't make any users admins of Nextcloud.
 # But if we wanted to, we would do this:
 # ```
-# for user in $(tools/mail.py user admins); do
+# for user in $(management/cli.py user admins); do
 #	 sqlite3 $STORAGE_ROOT/owncloud/owncloud.db "INSERT OR IGNORE INTO oc_group_user VALUES ('admin', '$user')"
 # done
 # ```
--- a/setup/webmail.sh
+++ b/setup/webmail.sh
@ -28,8 +28,8 @@ apt_install \
 # Install Roundcube from source if it is not already present or if it is out of date.
 # Combine the Roundcube version number with the commit hash of plugins to track
 # whether we have the latest version of everything.
-VERSION=1.4.8
-HASH=3a6824fd68fef2e0d24f186cfbee5c6f9d6edbe9
+VERSION=1.4.9
+HASH=df650f4d3eae9eaae2d5a5f06d68665691daf57d
 PERSISTENT_LOGIN_VERSION=6b3fc450cae23ccb2f393d0ef67aa319e877e435
 HTML5_NOTIFIER_VERSION=4b370e3cd60dabd2f428a26f45b677ad1b7118d5
 CARDDAV_VERSION=3.0.3
--- a/tools/mail.py
+++ b/tools/mail.py
@ -1,148 +1,3 @@
-#!/usr/bin/python3
-
-import sys, getpass, urllib.request, urllib.error, json, re
-
-def mgmt(cmd, data=None, is_json=False):
-	# The base URL for the management daemon. (Listens on IPv4 only.)
-	mgmt_uri = 'http://127.0.0.1:10222'
-
-	setup_key_auth(mgmt_uri)
-
-	req = urllib.request.Request(mgmt_uri + cmd, urllib.parse.urlencode(data).encode("utf8") if data else None)
-	try:
-		response = urllib.request.urlopen(req)
-	except urllib.error.HTTPError as e:
-		if e.code == 401:
-			try:
-				print(e.read().decode("utf8"))
-			except:
-				pass
-			print("The management daemon refused access. The API key file may be out of sync. Try 'service mailinabox restart'.", file=sys.stderr)
-		elif hasattr(e, 'read'):
-			print(e.read().decode('utf8'), file=sys.stderr)
-		else:
-			print(e, file=sys.stderr)
-		sys.exit(1)
-	resp = response.read().decode('utf8')
-	if is_json: resp = json.loads(resp)
-	return resp
-
-def read_password():
-    while True:
-        first = getpass.getpass('password: ')
-        if len(first) < 8:
-            print("Passwords must be at least eight characters.")
-            continue
-        second = getpass.getpass(' (again): ')
-        if first != second:
-            print("Passwords not the same. Try again.")
-            continue
-        break
-    return first
-
-def setup_key_auth(mgmt_uri):
-	key = open('/var/lib/mailinabox/api.key').read().strip()
-
-	auth_handler = urllib.request.HTTPBasicAuthHandler()
-	auth_handler.add_password(
-		realm='Mail-in-a-Box Management Server',
-		uri=mgmt_uri,
-		user=key,
-		passwd='')
-	opener = urllib.request.build_opener(auth_handler)
-	urllib.request.install_opener(opener)
-
-if len(sys.argv) < 2:
-	print("Usage: ")
-	print("  tools/mail.py system default-quota [new default]")
-	print("  tools/mail.py user  (lists users with quotas)")
-	print("  tools/mail.py user add user@domain.com [password]")
-	print("  tools/mail.py user password user@domain.com [password]")
-	print("  tools/mail.py user quota user@domain [new-quota]")
-	print("  tools/mail.py user remove user@domain.com")
-	print("  tools/mail.py user make-admin user@domain.com")
-	print("  tools/mail.py user remove-admin user@domain.com")
-	print("  tools/mail.py user admins (lists admins)")
-	print("  tools/mail.py alias  (lists aliases)")
-	print("  tools/mail.py alias add incoming.name@domain.com sent.to@other.domain.com")
-	print("  tools/mail.py alias add incoming.name@domain.com 'sent.to@other.domain.com, multiple.people@other.domain.com'")
-	print("  tools/mail.py alias remove incoming.name@domain.com")
-	print()
-	print("Removing a mail user does not delete their mail folders on disk. It only prevents IMAP/SMTP login.")
-	print()
-
-elif sys.argv[1] == "user" and len(sys.argv) == 2:
-	# Dump a list of users, one per line. Mark admins with an asterisk.
-	users = mgmt("/mail/users?format=json", is_json=True)
-	for domain in users:
-		for user in domain["users"]:
-			if user['status'] == 'inactive': continue
-			print(user['email'], end='')
-			if "admin" in user['privileges']:
-				print("*", end='')
-			if user['quota'] == '0':
-				print(" unlimited", end='')
-			else:
-				print(" " + user['quota'], end='')
-			print()
-
-elif sys.argv[1] == "user" and sys.argv[2] in ("add", "password"):
-	if len(sys.argv) < 5:
-		if len(sys.argv) < 4:
-			email = input("email: ")
-		else:
-			email = sys.argv[3]
-		pw = read_password()
-	else:
-		email, pw = sys.argv[3:5]
-
-	if sys.argv[2] == "add":
-		print(mgmt("/mail/users/add", { "email": email, "password": pw }))
-	elif sys.argv[2] == "password":
-		print(mgmt("/mail/users/password", { "email": email, "password": pw }))
-
-elif sys.argv[1] == "user" and sys.argv[2] == "remove" and len(sys.argv) == 4:
-	print(mgmt("/mail/users/remove", { "email": sys.argv[3] }))
-
-elif sys.argv[1] == "user" and sys.argv[2] in ("make-admin", "remove-admin") and len(sys.argv) == 4:
-	if sys.argv[2] == "make-admin":
-		action = "add"
-	else:
-		action = "remove"
-	print(mgmt("/mail/users/privileges/" + action, { "email": sys.argv[3], "privilege": "admin" }))
-
-elif sys.argv[1] == "user" and sys.argv[2] == "admins":
-	# Dump a list of admin users.
-	users = mgmt("/mail/users?format=json", is_json=True)
-	for domain in users:
-		for user in domain["users"]:
-			if "admin" in user['privileges']:
-				print(user['email'])
-
-elif sys.argv[1] == "user" and sys.argv[2] == "quota" and len(sys.argv) == 4:
-	# Set a user's quota
-	print(mgmt("/mail/users/quota?text=1&email=%s" % sys.argv[3]))
-
-elif sys.argv[1] == "user" and sys.argv[2] == "quota" and len(sys.argv) == 5:
-	# Set a user's quota
-	users = mgmt("/mail/users/quota", { "email": sys.argv[3], "quota": sys.argv[4] })
-
-elif sys.argv[1] == "alias" and len(sys.argv) == 2:
-	print(mgmt("/mail/aliases"))
-
-elif sys.argv[1] == "alias" and sys.argv[2] == "add" and len(sys.argv) == 5:
-	print(mgmt("/mail/aliases/add", { "address": sys.argv[3], "forwards_to": sys.argv[4] }))
-
-elif sys.argv[1] == "alias" and sys.argv[2] == "remove" and len(sys.argv) == 4:
-	print(mgmt("/mail/aliases/remove", { "address": sys.argv[3] }))
-
-elif sys.argv[1] == "system" and sys.argv[2] == "default-quota" and len(sys.argv) == 3:
-	print(mgmt("/system/default-quota?text=1"))
-
-elif sys.argv[1] == "system" and sys.argv[2] == "default-quota" and len(sys.argv) == 4:
-	print(mgmt("/system/default-quota", { "default_quota": sys.argv[3]}))
-
-else:
-	print("Invalid command-line arguments.")
-	sys.exit(1)
-
+#!/bin/bash
+# This script has moved.
+management/cli.py "$@"