Link Search Menu Expand Document

Create a Tor Hidden Service

A simple example of creating and using a Tor Hidden Service.

Using SSH as an example, use any other name to be change the directory name.

  • Install Tor:
    sudo apt install tor
    
  • Edit the config file:
    sudo nano /etc/tor/torrc
    
  • Create a v3 onion address
    sharing the internal ssh port (22) on the custom port 8080 of the .onion service:
    HiddenServiceDir /var/lib/tor/ssh/
    HiddenServiceVersion 3
    HiddenServicePort 8080 127.0.0.1:22
    
  • Restart Tor:
    sudo systemctl restart tor
    
  • List the files in the directory
    $ sudo ls -la /var/lib/tor/ssh/
    total 12
    drwx------ 1 debian-tor debian-tor 136 Jan 30 07:09 .
    drwx------ 1 debian-tor debian-tor 826 Jan 31 00:00 ..
    drwx------ 1 debian-tor debian-tor   0 Feb 11  2020 authorized_clients
    -rw------- 1 debian-tor debian-tor  63 Jan 30 07:09 hostname
    -rwx------ 1 debian-tor debian-tor  64 Feb 11  2020 hs_ed25519_public_key
    -rwx------ 1 debian-tor debian-tor  96 Feb 11  2020 hs_ed25519_secret_key
    
  • Note the Hidden Service address:
    sudo cat /var/lib/tor/ssh/hostname
    
  • For ssh over Tor install Tor on your client
    • Linux:
      sudo apt install tor
      
    • On mobile can use Termux:
      pkg install tor
      

      run Tor in a different window:

      tor
      

      or in the background with:

      tor &
      
    • See this video for different Windows and MacOS: https://www.keepitsimplebitcoin.com/how-to-install-tor/
  • SSH over Tor
    in a Linux terminal use (set the custom port used for ssh):
    torify ssh username@HiddenServiceAddress.onion:8080
    
  • If there is a website hosted on your .onion service use the Tor Browser to open the address.

Add client authorization (Optional)

A simple example of requiring authentication credential in order to connect to the onion service

  • Install required packages:
    sudo apt install basez openssl
    
  • Generate key:
    openssl genpkey -algorithm x25519 -out /tmp/k1.prv.pem
    
  • Re-format key into base32 creating public and private keys:
    cat /tmp/k1.prv.pem | grep -v " PRIVATE KEY" | base64pem -d | tail --bytes=32 | base32 | sed 's/=//g' > /tmp/k1.prv.key
    openssl pkey -in /tmp/k1.prv.pem -pubout | grep -v " PUBLIC KEY" | base64pem -d | tail --bytes=32 | base32 | sed 's/=//g' > /tmp/k1.pub.key
    
  • Note the private key (client):
    cat /tmp/k1.prv.key
    
  • Note the public key: (server):
    cat /tmp/k1.pub.key
    
  • Server config:
    • Create .auth file:
       sudo nano /var/lib/tor/ssh/authorized_clients/alice.auth
      
    • Edit .auth file:
       descriptor:x25519:<base32-pub-key>
      
  • Client config for (choose one):
    • GUI service (thunderhub):
    • Headless service (ssh):
      • Edit the config file:
        ClientOnionAuthDir /var/lib/tor/onion_auth/
        
      • Create .auth_private file:
        sudo nano /var/lib/tor/onion_auth/bob-ssh.auth_private
        
      • Edit .auth_private file
        <56-char-onion-addr-without-.onion-part>:descriptor:x25519:<base32-priv-key>
        
  • Remove keys stored in /tmp:
    sudo rm -f /tmp/k1.pub.key /tmp/k1.prv.key /tmp/k1.prv.pem
    
  • Restart Tor to apply changes (server and client):
    sudo systemctl restart tor@default
    

Notes:

  • The SSL stripping attack is not applicable when the traffic does not leave the Tor network so usinga self-hosted Hidden Service in the Tor Browser is not at risk.
  • Always make sure that the clearnet site you open in the Tor Browser uses SSL encryption (HTTPS).

Sources: