.github/workflows | ||
app | ||
docs | ||
local_data | ||
migrations | ||
static | ||
templates | ||
tests | ||
.dockerignore | ||
.env.example | ||
.gitignore | ||
CHANGELOG | ||
cron.py | ||
crontab.yml | ||
Dockerfile | ||
email_handler.py | ||
LICENSE | ||
pyproject.toml | ||
README.md | ||
requirements.in | ||
requirements.txt | ||
server.py | ||
shell.py | ||
wsgi.py |
SimpleLogin | Privacy-First Email Forwarding and Identity Provider Service
Yet another email forwarding service?
In some way yes... However, SimpleLogin is a bit different because:
-
Fully open source: both the server and client code (browser extension, JS library) are open source so anyone can freely inspect and (hopefully) improve the code.
-
Not just email alias: SimpleLogin is a privacy-first and developer-friendly identity provider that:
- offers privacy for users
- is simple to use for developers. SimpleLogin is a privacy-focused alternative to the "Login with Facebook/Google/Twitter" buttons.
-
The only email forwarding solution that is self-hostable: with our detailed self-hosting instructions and most of components running as Docker container, anyone who knows
ssh
is able to deploy SimpleLogin on their server. -
Plenty of features: browser extension, custom domain, catch-all alias, OAuth libraries, etc.
-
Open roadmap at https://trello.com/b/4d6A69I4/open-roadmap: you know the exciting features we are working on.
At the heart of SimpleLogin is email alias
: an alias is a normal email address but all emails sent to an alias are forwarded to your email inbox. SimpleLogin alias can also send emails: for your contact, the alias is therefore your email address. Use alias whenever you need to give out your email address to protect your online identity. More info on our website at https://simplelogin.io
Quick start
If you have Docker installed, run the following command to start SimpleLogin local server:
docker run -it --rm \
-e RESET_DB=true \
-e CONFIG=/code/.env.example \
-p 7777:7777 \
simplelogin/app:1.0.0 python server.py
Then open http://localhost:7777, you should be able to login with john@wick.com/password
account!
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!
Table of Contents
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 andapp.mydomain.com
for SimpleLogin webapp. Please make sure to replace these values by your domain name whenever they appear in the doc. -
[Optional] AWS S3, Sentry, Google/Facebook/Github developer accounts. These are necessary only if you want to activate these options.
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
(or any bash-compatible shell like zsh
) being the shell. If you use other shells like fish
, please make sure to adapt the commands.
DKIM
From Wikipedia https://en.wikipedia.org/wiki/DomainKeys_Identified_Mail
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
and dkim.pub.key
for the next steps.
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).
MX record
Create a MX record that points mydomain.com
to app.mydomain.com
with priority 10.
To verify if the DNS works, dig mydomain.com mx
should contain the following in the result.
mydomain.com. 3600 IN MX 10 app.mydomain.com.
A record
An A record that points app.mydomain.com
to your server IP. To verify, dig app.mydomain.com a
should return your server IP.
DKIM
Set up DKIM by adding a TXT record for dkim._domainkey.mydomain.com
with the following value:
v=DKIM1; k=rsa; p=PUBLIC_KEY
with PUBLIC_KEY
being your dkim.pub.key
but
- remove the
-----BEGIN PUBLIC KEY-----
and-----END PUBLIC KEY-----
- join all the lines on a single line.
For example, if your dkim.pub.key
is
-----BEGIN PUBLIC KEY-----
ab
cd
ef
gh
-----END PUBLIC KEY-----
then the PUBLIC_KEY
would be abcdefgh
.
To verify, dig dkim._domainkey.mydomain.com txt
should return the above value.
SPF
From Wikipedia https://en.wikipedia.org/wiki/Sender_Policy_Framework
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
with the value v=spf1 mx -all
. What it means is only your server can send email with @mydomain.com
domain. To verify, you can use dig mydomain.com txt
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 want to run Docker without the sudo
prefix, add your account to docker
group:
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.
docker network create -d bridge \
--subnet=240.0.0.0/24 \
--gateway=240.0.0.1 \
sl-network
Postgres
This section shows how to run a Postgres database using Docker. At the end of this section, you will have a database username and password which will be used in the next steps.
If you have already had a Postgres database in use, you can skip this section and just copy the database configuration (i.e. host, port, username, password, database name).
Run a Postgres Docker container as your Postgres database server. Make sure to replace myuser
and mypassword
with something more secret 😎.
docker run -d \
--name sl-db \
-e POSTGRES_PASSWORD=mypassword \
-e POSTGRES_USER=myuser \
-e POSTGRES_DB=simplelogin \
--network="sl-network" \
postgres
To test whether the database operates correctly or not, run the following command:
docker exec -it sl-db psql -U myuser simplelogin
you should be logged in the postgres console.
Postfix
Install postfix
and postfix-pgsql
. The latter is used to connect Postfix and the Postgres database in the next steps.
sudo apt-get install -y postfix postfix-pgsql
Choose "Internet Site" in Postfix installation window then keep using the proposed value as System mail name in the next window.
Run the following commands to setup Postfix. Make sure to replace mydomain.com
with the appropriate value of your domain.
sudo postconf -e 'myhostname = app.mydomain.com'
sudo postconf -e 'mydomain = mydomain.com'
sudo postconf -e 'myorigin = mydomain.com'
sudo postconf -e 'mydestination = localhost'
sudo postconf -e 'mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 240.0.0.0/24'
sudo postconf -e 'relay_domains = pgsql:/etc/postfix/pgsql-relay-domains.cf'
sudo postconf -e 'transport_maps = pgsql:/etc/postfix/pgsql-transport-maps.cf'
# HELO restrictions
sudo postconf -e 'smtpd_delay_reject = yes'
sudo postconf -e 'smtpd_helo_required = yes'
sudo postconf -e 'smtpd_helo_restrictions = permit_mynetworks, reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname, permit'
# Sender restriction
sudo postconf -e 'smtpd_sender_restrictions = permit_mynetworks, reject_non_fqdn_sender, reject_unknown_sender_domain, permit'
# Recipient restrictions
sudo postconf -e '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 relay-domains
file at /etc/postfix/pgsql-relay-domains.cf
and put the following content. Make sure that the database config is correctly set and replace mydomain.com
with your domain.
# 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 transport-maps
file at /etc/postfix/pgsql-transport-maps.cf
and put the following lines. Make sure that the database config is correctly set and replace mydomain.com
with your domain.
# 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
.
Make sure to update the following variables and replace these values by yours.
# Server url
URL=http://app.mydomain.com
EMAIL_DOMAIN=mydomain.com
SUPPORT_EMAIL=support@mydomain.com
EMAIL_SERVERS_WITH_PRIORITY=[(10, "app.mydomain.com.")]
DKIM_PRIVATE_KEY_PATH=/dkim.key
DKIM_PUBLIC_KEY_PATH=/dkim.pub.key
DB_URI=postgresql://myuser:mypassword@sl-db:5432/simplelogin
DISABLE_ALIAS_SUFFIX=1
Before running the webapp, you need to prepare the database by running the migration
docker run --rm \
--name sl-migration \
-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:1.0.0 flask db upgrade
This command could take a while to download the simplelogin/app
docker image.
Now, it's time to run the webapp
container!
docker run -d \
--name sl-app \
-v $(pwd)/simplelogin.env:/code/.env \
-v $(pwd)/dkim.key:/dkim.key \
-v $(pwd)/dkim.pub.key:/dkim.pub.key \
-p 7777:7777 \
--network="sl-network" \
simplelogin/app:1.0.0
Next run the email handler
docker run -d \
--name sl-email \
-v $(pwd)/simplelogin.env:/code/.env \
-v $(pwd)/dkim.key:/dkim.key \
-v $(pwd)/dkim.pub.key:/dkim.pub.key \
-p 20381:20381 \
--network="sl-network" \
simplelogin/app:1.0.0 python email_handler.py
[Optional] If you want to run the cronjob:
docker run -d \
--name sl-cron \
-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:1.0.0 yacron -c /code/crontab.yml
Nginx
Install Nginx
sudo apt-get install -y nginx
Then, create /etc/nginx/sites-enabled/simplelogin
with the following lines:
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 of 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".
Contributing
All work on SimpleLogin happens directly on GitHub.
Run code locally
The project uses Python 3.7+. First, install all dependencies by running the following command. Feel free to use virtualenv
or similar tools to isolate development environment.
pip3 install -r requirements.txt
Then make sure all tests pass
pytest
To run the code locally, please create a local setting file based on .env.example
:
cp .env.example .env
Make sure to uncomment the RESET_DB=true
to create the database locally.
Feel free to custom your .env
file, it would be your default setting when developing locally. This file is ignored by git.
You don't need all the parameters, for example, if you don't update images to s3, then
BUCKET
, AWS_ACCESS_KEY_ID
can be empty or if you don't use login with Github locally, GITHUB_CLIENT_ID
doesn't have to be filled. The .env.example
file contains minimal requirement so that if you run:
python3 server.py
then open http://localhost:7777, you should be able to login with the following account
john@wick.com / password
API
SimpleLogin current API clients are Chrome/Firefox/Safari extension and mobile (iOS/Android) app.
These clients rely on API Code
for authentication.
Once the Api Code
is obtained, either via user entering it (in Browser extension case) or by logging in (in Mobile case),
the client includes the api code
in Authentication
header in almost all requests.
For some endpoints, the hostname
should be passed in query string. hostname
is the the URL hostname (cf https://en.wikipedia.org/wiki/URL), for ex if URL is http://www.example.com/index.html then the hostname is www.example.com
. This information is important to know where an alias is used in order to suggest user the same alias if they want to create on alias on the same website in the future.
If error, the API returns 4** with body containing the error message, for example:
{
"error": "request body cannot be empty"
}
The error message could be displayed to user as-is, for example for when user exceeds their alias quota.
Some errors should be fixed during development however: for example error like request body cannot be empty
is there to catch development error and should never be shown to user.
All following endpoint return 401
status code if the API Key is incorrect.
GET /api/user_info
Given the API Key, return user name and whether user is premium. This endpoint could be used to validate the api key.
Input:
Authentication
header that contains the api key
Output: if api key is correct, return a json with user name and whether user is premium, for example:
{
"name": "John Wick",
"is_premium": false
}
If api key is incorrect, return 401.
GET /api/v2/alias/options
User alias info and suggestion. Used by the first extension screen when user opens the extension.
Input:
Authentication
header that contains the api key- (Optional but recommended)
hostname
passed in query string.
Output: a json with the following field:
- can_create: boolean. Whether user can create new alias
- suffixes: list of string. List of alias
suffix
that user can use. If user doesn't have custom domain, this list has a single element which is the alias default domain (simplelogin.co). - prefix_suggestion: string. Suggestion for the
alias prefix
. Usually this is the website name extracted fromhostname
. If nohostname
, then theprefix_suggestion
is empty. - existing: list of string. List of existing alias.
- recommendation: optional field, dictionary. If an alias is already used for this website, the recommendation will be returned. There are 2 subfields in
recommendation
:alias
which is the recommended alias andhostname
is the website on which this alias is used before.
For ex:
{
"can_create": true,
"existing": [
"my-first-alias.meo@sl.local",
"e1.cat@sl.local",
"e2.chat@sl.local",
"e3.cat@sl.local"
],
"prefix_suggestion": "test",
"recommendation": {
"alias": "e1.cat@sl.local",
"hostname": "www.test.com"
},
"suffixes": [
"@very-long-domain.com.net.org",
"@ab.cd",
".cat@sl.local"
]
}
POST /api/alias/custom/new
Create a new custom alias.
Input:
Authentication
header that contains the api key- (Optional but recommended)
hostname
passed in query string - Request Message Body in json (
Content-Type
isapplication/json
)- alias_prefix: string. The first part of the alias that user can choose.
- alias_suffix: should be one of the suffixes returned in the
GET /api/v2/alias/options
endpoint.
Output: If success, 201 with the new alias, for example
{
"alias": "www_groupon_com@my_domain.com"
}
POST /api/alias/random/new
Create a new random alias.
Input:
Authentication
header that contains the api key- (Optional but recommended)
hostname
passed in query string
Output: If success, 201 with the new alias, for example
{
"alias": "www_groupon_com@my_domain.com"
}
POST /api/auth/login
Input:
- password
- device: device name. Used to create the API Key. Should be humanly readable so user can manage later on the "API Key" page.
Output:
- name: user name, could be an empty string
- mfa_enabled: boolean
- mfa_key: only useful when user enables MFA. In this case, user needs to enter their OTP token in order to login.
- api_key: if MFA is not enabled, the
api key
is returned right away.
The api_key
is used in all subsequent requests. It's empty if MFA is enabled.
If user hasn't enabled MFA, mfa_key
is empty.
POST /api/auth/mfa
Input:
- mfa_token: OTP token that user enters
- mfa_key: MFA key obtained in previous auth request, e.g. /api/auth/login
- device: the device name, used to create an ApiKey associated with this device
Output:
- name: user name, could be an empty string
- api_key: if MFA is not enabled, the
api key
is returned right away.
The api_key
is used in all subsequent requests. It's empty if MFA is enabled.
If user hasn't enabled MFA, mfa_key
is empty.
Database migration
The database migration is handled by alembic
Whenever the model changes, a new migration has to be created
Set the database connection to use a current database (i.e. the one without the model changes you just made), for example, if you have a staging config at ~/config/simplelogin/staging.env
, you can do:
ln -sf ~/config/simplelogin/staging.env .env
Generate the migration script and make sure to review it before committing it. Sometimes (very rarely though), the migration generation can go wrong.
flask db migrate
In local the database creation in Sqlite doesn't use migration and uses directly db.create_all()
(cf fake_data()
method). This is because Sqlite doesn't handle well the migration. As sqlite is only used during development, the database is deleted and re-populated at each run.
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
OAuth flow
SL currently supports code and implicit flow.
Code flow
To trigger the code flow locally, you can go to the following url after running python server.py
:
http://localhost:7777/oauth/authorize?client_id=client-id&state=123456&response_type=code&redirect_uri=http%3A%2F%2Flocalhost%3A7000%2Fcallback&state=random_string
You should see there the authorization page where user is asked for permission to share their data. Once user approves, user is redirected to this url with an authorization code
: http://localhost:7000/callback?state=123456&code=the_code
Next, exchange the code to get the token with {code}
replaced by the code obtained in previous step. The http
tool used here is https://httpie.org
http -f -a client-id:client-secret http://localhost:7777/oauth/token grant_type=authorization_code code={code}
This should return an access token
that allows to get user info via the following command. Again, http
tool is used.
http http://localhost:7777/oauth/user_info 'Authorization:Bearer {token}'
Implicit flow
Similar to code flow, except for the the access token
which we we get back with the redirection.
For implicit flow, the url is
http://localhost:7777/oauth/authorize?client_id=client-id&state=123456&response_type=token&redirect_uri=http%3A%2F%2Flocalhost%3A7000%2Fcallback&state=random_string
OpenID and OAuth2 response_type & scope
According to the sharing web blog titled Diagrams of All The OpenID Connect Flows, we should pay attention to:
response_type
can be eithercode, token, id_token
or any combination of those attributes.scope
might containopenid
Below are the potential combinations that are taken into account in SL until now:
response_type=code
scope:
with `openid` in scope, return `id_token` at /token: OK
without: OK
response_type=token
scope:
with and without `openid`, nothing to do: OK
response_type=id_token
return `id_token` in /authorization endpoint
response_type=id_token token
return `id_token` in addition to `access_token` in /authorization endpoint
response_type=id_token code
return `id_token` in addition to `authorization_code` in /authorization endpoint
❤️ Contributors
Thanks go to these wonderful people:
![]() Dung Nguyen Van |
![]() Giuseppe Federico |
Ninh Dinh |
Tung Nguyen V. N. |
![]() Son Nguyen Kim |