Mini TOTP auth server

Intended to work with Nginx auth_request

Uses Micronaut framework

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Docker

Available on docker hub

sudo docker run \
    -d \
    --restart unless-stopped \
    --name totpauthserver \
    -p 127.0.0.1:8082:8080 \
    -v /etc/totp-auth-server:/etc/totp-auth-server \
    5mrd/totpauthserver:latest

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Warning

Do not expose the server port, TOTP secret deleting and adding is not authenticated.

When using docker, to prevent exposing the port, use 127.0.0.1:xxxx:xxxx to bind the port instead of xxxx:xxxx
otherwise docker will expose automatically.

Secrets cannot be viewed via http and must be inspected in secrets.json.

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Environment variables

Variable RUNNING_DOCKERIZED=true must exist to detect docker

• To change the location of the secrets save file, change SECRETFOLDER variable to the parent folder of the json.

  Example: SECRETFOLDER=/etc/newfolder

• To change the default port from 8082, set the MICRONAUT_SERVER_PORT variable.

  Example: MICRONAUT_SERVER_PORT=9090

• To change the default auth token TTL from 300s, set TOKENTTL in seconds.

  Example: TOKENTTL=100

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Cookie format is authtoken-someId

Each secret ID has its own cookie.

TOTP secrets are saved under unique IDs, which are also used as usernames. TOTP secrets are saved in a json file.

All secrets are loaded in memory at startup. Any changes to secrets.json must be loaded with /totp/reload/{logoutAll}

If secrets.json becomes corrupted or inaccessible, certain functions such as saving or deleting secrets becomes disabled. Any issues have to be fixed manually. When any issues are fixed, the reload endpoint can be called.

Default locations:

• Windows: C:\ProgramData\totpauthserver\secrets.json - %ALLUSERSPROFILE%
• Linux: /etc/totpauthserver/secrets.json

The /login endpoint has a simple rate limiter to prevent brute force attacks, based on IP.
The limiter is OFF if there isnt an X-Forwarded-For header found!

Most requests (Internal and external) are logged in console & log. It includes: time, external IP (if found in header), path.
Endpoints such as /auth/verify are not logged due to constant use.

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/logs/{amount} Shows selected number of last logs

/auth/loginpage Serves login page

/auth/login Login POST endpoint - POST params id and totp

/totp/list List available IDs

/totp/save/{id}/{ttl}/{secret} Save TOTP secret under an ID, with seconds TTL

/totp/delete/{id} Delete a TOTP secret via ID

/totp/new Generate TOTP secret

/auth/logout/{id} Logs client out of specific ID
Separate IDs with comma

/totp/reload/{logout} Reloads secrets from the file, with logout all users option (boolean)

Below endpoints return 200 "ok" or 401 "unauthorized" (or 400 if input is invalid)

/auth/verify/{id} Authenticate a client token (via cookie)
To allow multiple IDs on an endpoint, separate with comma

/auth/verify/{id}/{token} Authenticate a client token

/totp/verify/{id}/{code} Verify a TOTP code

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Nginx config example

Server accessible on port 8082

Change the internal /authrequest endpoint to contain the appropriate totp ID for your authenticated service, so that only the correct TOTP can be used to log in.

X-Forwarded-For header must be present for rate limiting.
If it isnt present, rate limiting will be disabled.

server {

    listen 8443 ssl;
	
    # other configuration ...
    
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    

    location /tas/auth/login {
        auth_request off;
        proxy_pass http://127.0.0.1:8082/auth/login;
    }

    location /tas/totp/list {
        auth_request off;
        proxy_pass http://127.0.0.1:8082/totp/list;
    }

    location = /authrequest {
        internal;
        proxy_pass http://127.0.0.1:8082/auth/verify/exampleId,otherId;  # App-specific ID
        proxy_set_header Content-Length "";
        proxy_pass_request_body off;
        proxy_set_header Cookie $http_cookie;
    }

    location /unauthorized {
        internal;
        proxy_pass http://127.0.0.1:8082/auth/loginpage;
    }

    location /myLogoutPath {
        auth_request /authrequest;
        error_page 401 403 =200 /unauthorized;
        proxy_pass http://127.0.0.1:8082/auth/logout/exampleId,otherId;  # App-specific ID
    }

    location / {
        auth_request /authrequest;
        error_page 401 403 =200 /unauthorized;
        proxy_pass http://127.0.0.1:5800/;
    }
}

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