Features

• Supports only IKEv2 with strong crypto: AES-GCM, SHA2, and P-256
• Generates Apple profiles to auto-configure iOS and macOS devices
• Includes a helper script to add and remove users
• Blocks ads with a local DNS resolver (optional)
• Sets up limited SSH users for tunneling traffic (optional)
• Based on current versions of Ubuntu and strongSwan
• Installs to DigitalOcean, Amazon EC2, Microsoft Azure, Google Compute Engine, or your own server

Anti-features

• Does not support legacy cipher suites or protocols like L2TP, IKEv1, or RSA
• Does not install Tor, OpenVPN, or other risky servers
• Does not depend on the security of TLS
• Does not require client software on most platforms
• Does not claim to provide anonymity or censorship avoidance
• Does not claim to protect you from the FSB, MSS, DGSE, or FSM

Deploy the Algo Server
The easiest way to get an Algo server running is to let it set up a new virtual machine in the cloud for you.

1. Setup an account on a cloud hosting provider. Algo supports DigitalOcean (most user friendly), Amazon EC2, Google Compute Engine, and Microsoft Azure.
   
2. Download Algo. Unzip it in a convenient location on your local machine.
   
3. Install Algo's core dependencies. Open the Terminal. The python interpreter you use to deploy Algo must be python2. If you don't know what this means, you're probably fine. cd into the algo-master directory where you unzipped Algo, then run:
   
   • macOS:

     $ python -m ensurepip --user
      $ python -m pip install --user --upgrade virtualenv

   • Linux (deb-based):

     $ sudo apt-get update && sudo apt-get install \
          build-essential \
          libssl-dev \
          libffi-dev \
          python-dev \
          python-pip \
          python-setuptools \
          python-virtualenv -y

   • Linux (rpm-based): See the Pre-Install Documentation for RedHat/CentOS 6.x
   • Windows: See the Windows documentation
4. Install Algo's remaining dependencies. Use the same Terminal window as the previous step and run:
   

   $ python -m virtualenv env && source env/bin/activate && python -m pip install -U pip && python -m pip install -r requirements.txt

   On macOS, you may be prompted to install cc. You should press accept if so.
   
5. List the users to create. Open config.cfg in your favorite text editor. Specify the users you wish to create in the users list.
   
6. Start the deployment. Return to your terminal. In the Algo directory, run ./algo and follow the instructions. There are several optional features available. None are required for a fully functional VPN server. These optional features are described in greater detail in deploy-from-ansible.md.
   

That's it! You will get the message below when the server deployment process completes. You now have an Algo server on the internet. Take note of the p12 (user certificate) password in case you need it later.
You can now setup clients to connect it, e.g. your iPhone or laptop. Proceed to Configure the VPN Clients below.

        "\"#----------------------------------------------------------------------#\"",
         "\"#                          Congratulations!                            #\"",
         "\"#                     Your Algo server is running.                     #\"",
         "\"#    Config files and certificates are in the ./configs/ directory.    #\"",
         "\"#              Go to https://whoer.net/ after connecting               #\"",
         "\"#        and ensure that all your traffic passes through the VPN.      #\"",
         "\"#                    Local DNS resolver 172.16.0.1                     #\"",
         "\"#                The p12 and SSH keys password is XXXXXXXX             #\"",
         "\"#----------------------------------------------------------------------#\"",

Configure the VPN Clients
Certificates and configuration files that users will need are placed in the configs directory. Make sure to secure these files since many contain private keys. All files are saved under a subdirectory named with the IP address of your new Algo VPN server.

Apple Devices
Send users their Apple Profile. Find the corresponding mobileconfig (Apple Profile) for each user and send it to them over AirDrop or other secure means. Apple Configuration Profiles are all-in-one configuration files for iOS and macOS devices. On macOS, double-clicking a profile to install it will fully configure the VPN. On iOS, users are prompted to install the profile as soon as the AirDrop is accepted.
Turn on the VPN. On iOS, connect to the VPN by opening Settings and clicking the toggle next to "VPN" near the top of the list. On macOS, connect to the VPN by opening System Preferences -> Network, finding Algo VPN in the left column and clicking "Connect." On macOS, check "Show VPN status in menu bar" to easily connect and disconnect from the menu bar.
Managing On-Demand VPNs. If you enabled "On Demand", the VPN will connect automatically whenever it is able. On iOS, you can turn off "On Demand" by clicking the (i) next to the entry for Algo VPN and toggling off "Connect On Demand." On macOS, you can turn off "On Demand" by opening the Network Preferences, finding Algo VPN in the left column, and unchecking the box for "Connect on demand."

Android Devices
No version of Android supports IKEv2. Install the strongSwan VPN Client for Android 4 and newer. Import the corresponding user.p12 certificate to your device. See the Android setup instructions for more a more detailed walkthrough.

Windows 10
Copy your PowerShell script windows_{username}.ps1 and p12 certificate {username}.p12 to the Windows client and run the following command as Administrator to configure the VPN connection.

powershell -ExecutionPolicy ByPass -File windows_{username}.ps1 Add

For a manual installation, see the Windows setup instructions.

Linux Network Manager Clients (e.g., Ubuntu, Debian, or Fedora Desktop)
Network Manager does not support AES-GCM. In order to support Linux Desktop clients, choose the "compatible" cryptography during the deploy process and use at least Network Manager 1.4.1. See Issue #263 for more information.

Linux strongSwan Clients (e.g., OpenWRT, Ubuntu Server, etc.)
Install strongSwan, then copy the included ipsec_user.conf, ipsec_user.secrets, user.crt (user certificate), and user.key (private key) files to your client device. These will require customization based on your exact use case. These files were originally generated with a point-to-point OpenWRT-based VPN in mind.

Ubuntu Server 16.04 example

1. sudo apt-get install strongswan strongswan-plugin-openssl: install strongSwan
2. /etc/ipsec.d/certs: copy <name>.crt from algo-master/configs/<server_ip>/pki/certs/<name>.crt
3. /etc/ipsec.d/private: copy <name>.key from algo-master/configs/<server_ip>/pki/private/<name>.key
4. /etc/ipsec.d/cacerts: copy cacert.pem from algo-master/configs/<server_ip>/pki/cacert.pem
5. /etc/ipsec.secrets: add your user.key to the list, e.g. <server_ip> : ECDSA <name>.key
6. /etc/ipsec.conf: add the connection from ipsec_user.conf and ensure leftcert matches the <name>.crt filename
7. sudo ipsec restart: pick up config changes
8. sudo ipsec up <conn-name>: start the ipsec tunnel
9. sudo ipsec down <conn-name>: shutdown the ipsec tunnel

One common use case is to let your server access your local LAN without going through the VPN. Set up a passthrough connection by adding the following to /etc/ipsec.conf:

conn lan-passthrough
 leftsubnet=192.168.1.1/24 # Replace with your LAN subnet
 rightsubnet=192.168.1.1/24 # Replac with your LAND subnet
 authby=never # No authentication necessary
 type=pass # passthrough
 auto=route # no need to ipsec up lan-passthrough

Other Devices
Depending on the platform, you may need one or multiple of the following files.

• cacert.pem: CA Certificate
• user.mobileconfig: Apple Profile
• user.p12: User Certificate and Private Key (in PKCS#12 format)
• user.sswan: Android strongSwan Profile
• ipsec_user.conf: strongSwan client configuration
• ipsec_user.secrets: strongSwan client configuration
• windows_user.ps1: Powershell script to help setup a VPN connection on Windows

Setup an SSH Tunnel
If you turned on the optional SSH tunneling role, then local user accounts will be created for each user in config.cfg and SSH authorized_key files for them will be in the configs directory (user.ssh.pem). SSH user accounts do not have shell access, cannot authenticate with a password, and only have limited tunneling options (e.g., ssh -N is required). This ensures that SSH users have the least access required to setup a tunnel and can perform no other actions on the Algo server.
Use the example command below to start an SSH tunnel by replacing user and ip with your own. Once the tunnel is setup, you can configure a browser or other application to use 127.0.0.1:1080 as a SOCKS proxy to route traffic through the Algo server.
ssh -D 127.0.0.1:1080 -f -q -C -N user@ip -i configs/ip_user.ssh.pem

SSH into Algo Server
To SSH into the Algo server for administrative purposes you can use the example command below by replacing ip with your own:
ssh root@ip -i ~/.ssh/algo.pem
If you find yourself regularly logging into Algo then it will be useful to load your Algo ssh key automatically. Add the following snippet to the bottom of ~/.bash_profile to add it to your shell environment permanently.
ssh-add ~/.ssh/algo > /dev/null 2>&1
Note the admin username is ubuntu instead of root on providers other than Digital Ocean.

Adding or Removing Users
If you chose the save the CA certificate during the deploy process, then Algo's own scripts can easily add and remove users from the VPN server.

1. Update the users list in your config.cfg
2. Open a terminal, cd to the algo directory, and activate the virtual environment with source env/bin/activate
3. Run the command: ./algo update-users

After this process completes, the Algo VPN server will contains only the users listed in the config.cfg file.