Atlas

the launch rocket of the gemini capsule

• C# / NET 8
• zero dependencies
• Linux and Windows - x86, x64 and ARM

Features

• Docker Support
• Automatic certificate generation
• Analythics
• Server-side animations on supported clients (eg. Lagrange) DEMO: gemini://her.st/
• Built-in special tokens (see below)
• vhosts
  • Per Location Configuration
    • directory listing
  • JSON config file
• Configurable Default Mime Types
• tsv Mimetype map
• gemini:// with titan:// file uploads*
• spartan:// file uploads and downloads*
• CGI interface compatible with jetforce
  • CGI streaming (for things like gemini://chat.mozz.us/)

*Still WIP

Built-in Special Tokens

Token	Replaced With
%%{sub}%%	Gemini: Subject Name of the Client Cert (without CN=) - if any - otherwise 'Anon'. For Spartan it always returns 'Spartan'
%%{host}%%	FQDN - eg: her.st
%%{path}%%	requested path - eg: /index.gmi
%%{scheme}%%	protocol of request - eg: spartan / gemini
%%{date}%%	YYYY-MM-DD - eg: 2024-03-30
%%{time}%%	HH:mm:ss - eg: 21:04:25
%%{datetime}%%	YYYY-MM-DD HH-mm-ss - eg: 2024-03-30 21:04:25
%%{rendertime}%%	Milliseconds - eg: 0.59
%%{ls}%%	Create Directory Index

Example

Gemtext	Rendered
Sub: %%{sub}%%	Sub: Alumniminium
Host: %%{host}%%	Host: localhost
Path: %%{path}%%	Path: /index.gmi
Scheme: %%{scheme}%%	Scheme: gemini
Date: %%{date}%%	Date: 2024-04-01
Time: %%{time}%%	Time: 11:32:41
Datetime: %%{datetime}%%	Datetime: 2024-04-01 11:32:41
Render Time: %%{rendertime}%%	Render Time: 4564.80
%%{ls}%%	=> gemini://localhost//index.gmi 2024-04-01 | 0.00mb | index.gmi
	=> gemini://localhost//localhost.pfx 2024-03-30 | 0.00mb | localhost.pfx

Atlas Statistics

You can always access Atlas Stats on the following URL: gemini://yourserver.tld/atlas.stats

Roadmap (in no particular order)

• FastCGI
• Use single Docker volume
• Caching
• certificate validation DONE IN v0.3 (April 1st 2024)
• rate limiting
• proper networking with SocketAsyncEventArgs
• Inline Server Sided Scripts using %%{exec scriptname}%%
• Assign "Owner" Cert in Capsule config to allow editing of files via TITAN:// in-client

Sample configuration with all options

A minimal config file will be autogenerated if none is found. this one is just an advanced example

{
  "GeminiPort": 1965,
  "SpartanPort": 300,

  "SlowMode": true, // animations, currently only for gemini
  "SlowModeMaxMilliSeconds": 2000, // max time for animations in ms

  "Capsules": {
    
    "allsafe.net": {
      "AbsoluteRootPath": "/srv/gemini/allsafe.net/",
      "AbsoluteTlsCertPath": "/srv/gemini/allsafe.net/allsafe.net.pfx",
      "FQDN": "allsafe.net",
      "Index": "index.gmi",

      "Locations": 
      [
        {
          "AbsoluteRootPath": "/srv/gemini/allsafe.net/",
          "Index": "index.gmi",
        }
      ]

    },

    "evilcorp.net": {
      "FQDN": "evilcorp.net",
      "AbsoluteRootPath": "/srv/gemini/evilcorp.net/",
      "AbsoluteTlsCertPath": "",// will be automatically created and placed at AbsoluteRootPath/FQDN.pfx
      "Index": "index.gmi",
      "MaxUploadSize": 4194304, // global max upload size (bytes)
      
      "Locations": [
        {
          "AbsoluteRootPath": "/srv/gemini/evilcorp.net/",
          "Index": "index.gmi",
        },

        {
          "AbsoluteRootPath": "/srv/gemini/evilcorp.net/cgi/",
          "Index": "script.csx",
          "CGI": true,
          "RequireClientCert": true,  // disables access for spartan protocol due to lack of support
        },

        {
          "AbsoluteRootPath": "/srv/gemini/evilcorp.net/textfiles/",
          "Index": "index.gmi",
          "DirectoryListing": true, 
          "AllowFileUploads": true, // public Titan/Spartan  uploads in this location
          "MaxUploadSize": 100000, // override max upload size (bytes)
          "DefaultMimeType": "text/plain", // default mimetype for files without or unknown extension

          "AllowedMimeTypes": {
            "text/*": { // whitelist all text files
              "MaxSizeBytes": 1048576 // override max upload size for text files
            },
          }
        }
      ]

    }

  }
}

CGI Interface

The CGI interface provides the following environment variables:

Variable	Description	Default
DOTNET_CLI_HOME	Required for .NET assemblies to execute	~/.dotnet
GATEWAY_INTERFACE	CGI Version	CGI/1.1
SERVER_PROTOCOL	Either Gemini or Spartan	GEMINI / SPARTAN
SERVER_PORT	Gemini or Spartan Port according to config.json	1965 / 300
SERVER_SOFTWARE	atlas/version string	atlas/0.2b
URL	URL of the Request	gemini://evil.corp/cgi/binary?queryString=value#fragment&token
SCRIPT_NAME	the CGI script name	binary
PATH_INFO	See CGI documentation	Hopefully correct
QUERY_STRING	Query from the URL	?queryString=value#fragment&token
SERVER_NAME	the FQDN of the vhost	evil.corp
REMOTE_HOST	The IP of the client sending the request	127.0.0.1
REMOTE_ADDR	as above	as above
TLS_VERSION	Gemini Only	1.3
REMOTE_USER	TLS Cert Subject without CN=	trbl
TLS_CLIENT_SUBJECT	as above	as above
TLS_CLIENT_VALID	Certificate is not expired	true
TLS_CLIENT_TRUSTED	Certificate issued by atlas	false
TLS_CLIENT_HASH	The Certificate Thumbprint	0baf2asdb23i02..
TLS_CLIENT_NOT_BEFORE	Certificate Valid From Time	08/28/2022 18:26:30
TLS_CLIENT_NOT_AFTER	Certificate Valid To Time	08/28/3000 18:26:30
TLS_CLIENT_SERIAL_NUMBER	The Certificate Serial Number
AUTH_TYPE	CERTIFICATE or NONE	NONE

sample CGI script

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