SimpleLogin | Protect your online identity with email alias

1. Quick start

2. General Architecture

3. Self Hosting

4. Contributing Guide

5. API

6. OAuth2/OpenID Connect

Your email address is your online identity. When you use the same email address everywhere, you can be easily tracked and lose your privacy. In addition, you become an easy target for spammers and phishing attempts.

SimpleLogin allows you to create a different email address (alias) for each website.

At the heart of SimpleLogin is

email alias

All components in SimpleLogin, including the web app, Chrome/Firefox extension, Android/iOS app are open-source and available on https://github.com/simple-login

SimpleLogin server can be self-hosted. The self-hosting instructions are mostly based on Docker.

SimpleLogin roadmap is at https://trello.com/b/4d6A69I4/open-roadmap, feel free to submit new ideas or vote on features you want to happen :).

Quick start

If you have Docker installed, run the following command to start SimpleLogin local server:

docker run --name sl -it --rm \
    -e RESET_DB=true \
    -e CONFIG=/code/example.env \
    -p 7777:7777 \
    simplelogin/app:3.2.2 python server.py

Then open http://localhost:7777, you should be able to login with

[email protected]/password

To use SimpleLogin aliases, you need to deploy it on your server with some DNS setup though, the following section will show a step-by-step guide on how to get your own email forwarder service!

General Architecture

SimpleLogin backend consists of 2 main components:

• the

  webapp

  used by several clients: web UI (the dashboard), browser extension (Chrome & Firefox for now), OAuth clients (apps that integrate "Login with SimpleLogin" button) and mobile app (work in progress).

• the

  email handler

  : implements the email forwarding (i.e. alias receiving email) and email sending (i.e. alias sending email).

Self hosting

Prerequisites

• a Linux server (either a VM or dedicated server). This doc shows the setup for Ubuntu 18.04 LTS but the steps could be adapted for other popular Linux distributions. As most of components run as Docker container and Docker can be a bit heavy, having at least 2 GB of RAM is recommended. The server needs to have the port 25 (email), 80, 443 (for the webapp), 22 (so you can ssh into it) open.

• a domain that you can config the DNS. It could be a sub-domain. In the rest of the doc, let's say it's

  mydomain.com

  for the email and

  app.mydomain.com

  for SimpleLogin webapp. Please make sure to replace these values by your domain name whenever they appear in the doc. A trick we use is to download this README file on your computer and replace all

  mydomain.com

  occurrences by your domain.

Except for the DNS setup that is usually done on your domain registrar interface, all the below steps are to be done on your server. The commands are to run with

bash

zsh

fish

Some utility packages

These packages are used to verify the setup. Install them by:

sudo apt install -y dnsutils

Create a directory to store SimpleLogin data:

mkdir sl
mkdir sl/pgp # to store PGP key
mkdir sl/db # to store database
mkdir sl/upload # to store quarantine emails

DKIM

From Wikipedia https://en.wikipedia.org/wiki/DomainKeysIdentifiedMail

DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in emails (email spoofing), a technique often used in phishing and email spam.

Setting up DKIM is highly recommended to reduce the chance your emails ending up in the recipient's Spam folder.

First you need to generate a private and public key for DKIM:

openssl genrsa -out dkim.key 1024
openssl rsa -in dkim.key -pubout -out dkim.pub.key

You will need the files

dkim.key

dkim.pub.key

For email gurus, we have chosen 1024 key length instead of 2048 for DNS simplicity as some registrars don't play well with long TXT record.

DNS

Please note that DNS changes could take up to 24 hours to propagate. In practice, it's a lot faster though (~1 minute or so in our test). In DNS setup, we usually use domain with a trailing dot (

.

MX record

Create a MX record that points

mydomain.com.

app.mydomain.com.

To verify if the DNS works, the following command

dig @1.1.1.1 mydomain.com mx

should return:

mydomain.com.   3600    IN  MX  10 app.mydomain.com.

A record

An A record that points

app.mydomain.com.

dig @1.1.1.1 app.mydomain.com a

should return your server IP.

DKIM

Set up DKIM by adding a TXT record for

dkim._domainkey.mydomain.com.

v=DKIM1; k=rsa; p=PUBLIC_KEY

with

PUBLIC_KEY

dkim.pub.key

-----BEGIN PUBLIC KEY-----

-----END PUBLIC KEY-----

For example, if your

dkim.pub.key

-----BEGIN PUBLIC KEY-----
ab
cd
ef
gh
-----END PUBLIC KEY-----

then the

PUBLIC_KEY

abcdefgh

You can get the

PUBLIC_KEY

sed "s/-----BEGIN PUBLIC KEY-----/v=DKIM1; k=rsa; p=/g" dkim.pub.key | sed 's/-----END PUBLIC KEY-----//g' |tr -d '\n'

To verify, the following command

dig @1.1.1.1 dkim._domainkey.mydomain.com txt

should return the above value.

SPF

From Wikipedia https://en.wikipedia.org/wiki/SenderPolicyFramework

Sender Policy Framework (SPF) is an email authentication method designed to detect forging sender addresses during the delivery of the email

Similar to DKIM, setting up SPF is highly recommended. Add a TXT record for

mydomain.com.

v=spf1 mx -all

What it means is only your server can send email with

@mydomain.com

dig @1.1.1.1 mydomain.com txt

should return the above value.

DMARC

From Wikipedia https://en.wikipedia.org/wiki/DMARC

It (DMARC) is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing

Setting up DMARC is also recommended. Add a TXT record for

_dmarc.mydomain.com.

v=DMARC1; p=quarantine; adkim=r; aspf=r

This is a

relaxed

v=DMARC1; p=reject; adkim=s; aspf=s

To verify, the following command

dig @1.1.1.1 _dmarc.mydomain.com txt

should return the set value.

For more information on DMARC, please consult https://tools.ietf.org/html/rfc7489

Docker

Now the boring DNS stuffs are done, let's do something more fun!

If you don't already have Docker installed on your server, please follow the steps on Docker CE for Ubuntu to install Docker.

Tips: if you are not using

root

sudo

docker

sudo usermod -a -G docker $USER

Prepare the Docker network

This Docker network will be used by the other Docker containers run in the next steps. Later, we will setup Postfix to authorize this network.

sudo docker network create -d bridge \
    --subnet=240.0.0.0/24 \
    --gateway=240.0.0.1 \
    sl-network

Postgres

This section creates a Postgres database using Docker.

If you already have a Postgres database in use, you can skip this section and just copy the database configuration (i.e. host, port, username, password, database name) to use in the next sections.

Run a Postgres Docker container as your Postgres database server. Make sure to replace

myuser

mypassword

sudo docker run -d \
    --name sl-db \
    -e POSTGRES_PASSWORD=mypassword \
    -e POSTGRES_USER=myuser \
    -e POSTGRES_DB=simplelogin \
    -p 5432:5432 \
    -v $(pwd)/sl/db:/var/lib/postgresql/data \
    --restart always \
    --network="sl-network" \
    postgres:12.1

To test whether the database operates correctly or not, run the following command:

sudo docker exec -it sl-db psql -U myuser simplelogin

you should be logged in the postgres console. Type

exit

Postfix

Install

postfix

postfix-pgsql

sudo apt-get install -y postfix postfix-pgsql -y

Choose "Internet Site" in Postfix installation window then keep using the proposed value as System mail name in the next window.

Replace

/etc/postfix/main.cf

mydomain.com

# POSTFIX config file, adapted for SimpleLogin
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

appending .domain is the MUA's job.
append_dot_mydomain = no
Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
fresh installs.
compatibility_level = 2
TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtp_tls_security_level = may
smtpd_tls_security_level = may
See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
information on enabling SSL in the smtp client.
alias_maps = hash:/etc/aliases
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 240.0.0.0/24
Set your domain here
mydestination =
myhostname = app.mydomain.com
mydomain = mydomain.com
myorigin = mydomain.com
relay_domains = pgsql:/etc/postfix/pgsql-relay-domains.cf
transport_maps = pgsql:/etc/postfix/pgsql-transport-maps.cf
HELO restrictions
smtpd_delay_reject = yes
smtpd_helo_required = yes
smtpd_helo_restrictions =
    permit_mynetworks,
    reject_non_fqdn_helo_hostname,
    reject_invalid_helo_hostname,
    permit
Sender restrictions:
smtpd_sender_restrictions =
    permit_mynetworks,
    reject_non_fqdn_sender,
    reject_unknown_sender_domain,
    permit
Recipient restrictions:
smtpd_recipient_restrictions =
   reject_unauth_pipelining,
   reject_non_fqdn_recipient,
   reject_unknown_recipient_domain,
   permit_mynetworks,
   reject_unauth_destination,
   reject_rbl_client zen.spamhaus.org,
   reject_rbl_client bl.spamcop.net,
   permit

Create the

/etc/postfix/pgsql-relay-domains.cf

mydomain.com

# postgres config
hosts = localhost
user = myuser
password = mypassword
dbname = simplelogin

query = SELECT domain FROM custom_domain WHERE domain='%s' AND verified=true
    UNION SELECT '%s' WHERE '%s' = 'mydomain.com' LIMIT 1;

Create the

/etc/postfix/pgsql-transport-maps.cf

mydomain.com

# postgres config
hosts = localhost
user = myuser
password = mypassword
dbname = simplelogin

forward to smtp:127.0.0.1:20381 for custom domain AND email domain
query = SELECT 'smtp:127.0.0.1:20381' FROM custom_domain WHERE domain = '%s' AND verified=true
    UNION SELECT 'smtp:127.0.0.1:20381' WHERE '%s' = 'mydomain.com' LIMIT 1;

Finally, restart Postfix

sudo systemctl restart postfix

Run SimpleLogin Docker containers

To run the server, you need a config file. Please have a look at config example for an example to create one. Some parameters are optional and are commented out by default. Some have "dummy" values, fill them up if you want to enable these features (Paddle, AWS, etc).

Let's put your config file at

~/simplelogin.env

mydomain.com

FLASK_SECRET

Make sure to update the following variables and replace these values by yours.

# WebApp URL
URL=http://app.mydomain.com

domain used to create alias
EMAIL_DOMAIN=mydomain.com
transactional email is sent from this email address
[email protected]
custom domain needs to point to these MX servers
EMAIL_SERVERS_WITH_PRIORITY=[(10, "app.mydomain.com.")]
By default, new aliases must end with ".{random_word}". This is to avoid a person taking all "nice" aliases.
this option doesn't make sense in self-hosted. Set this variable to disable this option.
DISABLE_ALIAS_SUFFIX=1
If you want to use another MTA to send email, you could set the address of your MTA here
By default, emails are sent using the the same Postfix server that receives emails
POSTFIX_SERVER=my-postfix.com
the DKIM private key used to compute DKIM-Signature
DKIM_PRIVATE_KEY_PATH=/dkim.key
the DKIM public key used to setup custom domain DKIM
DKIM_PUBLIC_KEY_PATH=/dkim.pub.key
DB Connection
DB_URI=postgresql://myuser:[email protected]:5432/simplelogin
FLASK_SECRET=put_something_secret_here
GNUPGHOME=/sl/pgp
LOCAL_FILE_UPLOAD=1

Before running the webapp, you need to prepare the database by running the migration:

sudo docker run --rm \
    --name sl-migration \
    -v $(pwd)/sl:/sl \
    -v $(pwd)/sl/upload:/code/static/upload \
    -v $(pwd)/dkim.key:/dkim.key \
    -v $(pwd)/dkim.pub.key:/dkim.pub.key \
    -v $(pwd)/simplelogin.env:/code/.env \
    --network="sl-network" \
    simplelogin/app:3.2.2 flask db upgrade

This command could take a while to download the

simplelogin/app

Init data

sudo docker run --rm \
    --name sl-init \
    -v $(pwd)/sl:/sl \
    -v $(pwd)/simplelogin.env:/code/.env \
    -v $(pwd)/dkim.key:/dkim.key \
    -v $(pwd)/dkim.pub.key:/dkim.pub.key \
    --network="sl-network" \
    simplelogin/app:3.2.2 python init_app.py

Now, it's time to run the

webapp

sudo docker run -d \
    --name sl-app \
    -v $(pwd)/sl:/sl \
    -v $(pwd)/sl/upload:/code/static/upload \
    -v $(pwd)/simplelogin.env:/code/.env \
    -v $(pwd)/dkim.key:/dkim.key \
    -v $(pwd)/dkim.pub.key:/dkim.pub.key \
    -p 7777:7777 \
    --restart always \
    --network="sl-network" \
    simplelogin/app:3.2.2

Next run the

email handler

sudo docker run -d \
    --name sl-email \
    -v $(pwd)/sl:/sl \
    -v $(pwd)/sl/upload:/code/static/upload \
    -v $(pwd)/simplelogin.env:/code/.env \
    -v $(pwd)/dkim.key:/dkim.key \
    -v $(pwd)/dkim.pub.key:/dkim.pub.key \
    -p 20381:20381 \
    --restart always \
    --network="sl-network" \
    simplelogin/app:3.2.2 python email_handler.py

Nginx

Install Nginx and make sure to replace

mydomain.com

sudo apt-get install -y nginx

Then, create

/etc/nginx/sites-enabled/simplelogin

server {
    server_name  app.mydomain.com;

location / {
    proxy_pass http://localhost:7777;
}
}

Reload Nginx with the command below

sudo systemctl reload nginx

At this step, you should also setup the SSL for Nginx. Certbot can be a good option if you want a free SSL certificate.

Enjoy!

If all the above steps are successful, open http://app.mydomain.com/ and create your first account!

By default, new accounts are not premium so don't have unlimited alias. To make your account premium, please go to the database, table "users" and set "lifetime" column to "1" or "TRUE".

You don't have to pay anything to SimpleLogin to use all its features. You could make a donation to SimpleLogin on our Patreon page at https://www.patreon.com/simplelogin if you wish though.

Misc

The above self-hosting instructions correspond to a freshly Ubuntu server and doesn't cover all possible server configuration. Below are pointers to different topics:

• Enable SSL
• UFW - uncomplicated firewall
• SES - Amazon Simple Email Service
• Upgrade existing SimpleLogin installation
• Enforce SPF
• Postfix TLS

Contributing

All work on SimpleLogin happens directly on GitHub.

Run code locally

The project uses - Python 3.7+ and poetry to manage dependencies - Node v10 for front-end.

First, install all dependencies by running the following command. Feel free to use

virtualenv

poetry install

On Mac, sometimes you might need to install some other packages like

brew install pkg-config libffi openssl postgresql

You also need to install

gpg

brew install gnupg

Then make sure all tests pass

pytest

Install npm packages

cd static && npm install

To run the code locally, please create a local setting file based on

example.env

cp example.env .env

Make sure to uncomment the

RESET_DB=true

Feel free to custom your

.env

You don't need all the parameters, for example, if you don't update images to s3, then

BUCKET

AWS_ACCESS_KEY_ID

GITHUB_CLIENT_ID

example.env

python3 server.py

then open http://localhost:7777, you should be able to login with the following account

[email protected] / password

Database migration

The database migration is handled by

alembic

Whenever the model changes, a new migration has to be created.

If you have Docker installed, you can create the migration by the following script:

sh new_migration.sh

Make sure to review the migration script before committing it. Sometimes (very rarely though), the automatically generated script can be incorrect.

We cannot use the local database to generate migration script as the local database doesn't use migration. It is created via

db.create_all()

fake_data()

Code structure

The repo consists of the three following entry points:

• wsgi.py and server.py: the webapp.
• email_handler.py: the email handler.
• cron.py: the cronjob.

Here are the small sum-ups of the directory structures and their roles:

• app/: main Flask app. It is structured into different packages representing different features like oauth, api, dashboard, etc.
• local_data/: contains files to facilitate the local development. They are replaced during the deployment.
• migrations/: generated by flask-migrate. Edit these files will be only edited when you spot (very rare) errors on the database migration files.
• static/: files available at

  /static

  url.
• templates/: contains both html and email templates.
• tests/: tests. We don't really distinguish unit, functional or integration test. A test is simply here to make sure a feature works correctly.

The code is formatted using https://github.com/psf/black, to format the code, simply run

black .

Test sending email

swaks is used for sending test emails to the

email_handler

mailcatcher is used to receive forwarded emails.

There are several steps to set up the email handler

1) run mailcatcher

mailcatcher

2) Make sure to set the following variables in the

.env

NOT_SEND_EMAIL=true
POSTFIX_SERVER=localhost
POSTFIX_PORT=1025

3) Run email_handler

python email_handler.py

4) Send a test email

swaks --to [email protected] --from [email protected] --server 127.0.0.1:20381

Now open http://localhost:1080/, you should see the test email.

❤️ Contributors

Thanks go to these wonderful people:

Dung Nguyen Van

Giuseppe Federico

Ninh Dinh

Tung Nguyen V. N.

Son Nguyen Kim

Raymond Nook

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