v0.1.0 -- serve gemtext files

.gitignore

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+/docs/
+/lib/
+/bin/
+/.shards/
+*.dwarf

LICENSE

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+Copyright (c) 2022 Sutty
+
+The following license is modified from the MIT license and downloaded
+from <https://github.com/Laurelai/anti-fascist-mit-license> on
+2019-07-11.
+
+Anti-Fascist MIT License:
+
+The following conditions must be met by any person obtaining a copy of
+this software:
+
+- You MAY NOT be a fascist.
+- You MUST not financially support fascists.
+- You MUST not intentionally provide or knowingly provide through
+  inaction a platform for fascists to spread propaganda or organize.
+- You MUST not publicly voice support for fascists.
+- You MAY NOT be a member of any fascist organization, even if you are a
+  member to infiltrate for anti-fascist purposes.
+
+"Fascist" can be understood as any group or individual who promotes the
+political ideology of fascism.
+
+"Fascism" can be broken down into 11 ideological features as well as 8
+tactics that can form a fascist system in varying combinations, for the
+sake of simplicity and brevity the individual or organization in
+question must match to at least 5 features or tactics or a combination
+of the two determined by the individual licencer.
+
+Said licencer may provide a list if an individual or group matches to at
+least 5 features upon request from the individual or group in question.
+
+The ideological features are listed below.
+
+1. Hyper-nationalism.
+
+As defined as "The belief in the superiority of one's nation and of the
+paramount importance of advancing it."
+
+2. Militarism.
+
+As defined as "Advocating for an increase in military forces beyond what
+the real defense of a nation needs, more influence of the military upon
+the policies of the civilian government, and a preference for force as a
+solution over diplomacy for problems."
+
+3. Glorification of violence and readiness to use it in politics.
+
+As defined as "The belief that violence can be used to cleanse a
+tarnished nation, also by using violence to harm, intimidate or kill
+political oppoenents."
+
+4. Fetishization of youth.
+
+As defined as "Extolling the virtues of youth and making a special
+appeal to young people to join a cause or organization"
+
+5. Fetishization of masculinity.
+
+As defined as "Extolling the virtues of male authority or patriarchy and
+making a special appeal to men to be leaders of households and groups"
+
+6. Leader cult.
+
+As defined as "Creating an idealized, heroic, and worshipful image of a
+leader, often through unquestioning flattery and praise."
+
+7. Lost-golden-age syndrome.
+
+As defined as "Creating or promoting the idea that a nation had a lost
+or stolen golden age in the past that must be returned to"
+
+8. Self-definition by opposition.
+
+As defined as "Creating or promoting the idea that the group or
+individual is the only person or way who can fight real or imagined
+evils within a society."
+
+9. Mass mobilization and mass party.
+
+As defined as "Creating or promoting the creation of a populist group or
+party for the advancment of fascist tactics or features."
+
+10. Hierarchical party structure and tendency to purge the disloyal.
+
+As defined as "Removal of membership from a group for lacking absolute
+loyalty or lacking further usefulness to the group. Also having a
+hierarchical structure within the group itself."
+
+11. Theatricality.
+
+As defined as "Using spectacle to gain and keep the attention of those
+inside and outside of the group using speeches full of absolutes and or
+superlatives. Elaborate collective rituals (rallies) meant to reenforce
+loyalty within the group."
+
+Fascist tactics include
+
+1) Persecution of national minorities.
+2) Persecution of racial minorities.
+3) Persecution of religious minorities (Anti-Semitism, Islamophobia and others).
+4) Promotion of a type of national purity.
+5) Promotion of a state run by ideologically oriented corporate bodies.
+6) Persecution of gender or sexual minorities.
+7) Persecution of the disabled.
+8) Formation of extra-legal forces (brownshirts) to defend fascist values.
+
+Special criteria: Meeting only one point of the special criteria is
+enough to consider someone or a group to be fascist for the purposes of
+this licence.
+
+1. Promotion of any theories that state members of the jewish ethnicity
+   or faith control or largely control the world, finance, or other
+   global major power system.
+
+2. Denial of the holocaust or any other historically proven genocide.
+
+3. Promotion of ethnostates.
+
+4. Advocating for eugenics. Either positive or negative eugenics.
+   Promotion for the rights of abortion are not considered eugenics.
+
+5. Advocating for the removal of rights or legal protections from a
+   class or group of people.
+
+Former fascists: People or organizations who used to promote the
+political ideology of fascism but no longer do so must meet the
+following criterea to be able to use this software.
+
+1. Publicly disavow past fascist deeds and ideologies.
+
+2. Expose any and all known fascists former allies to the public.
+
+   A suggested route would be through the one peoples project
+   (onepeoplesproject.com).  If they can confirm you have done so that
+   will count as meeting condition two.
+
+3. Publicly destroy any and all fascist paraphenelia you have in your
+   posession including removal of tattoos and body markings
+   affiliated with fascist groups or gangs.
+
+ANTI-FASCIST-MIT LICENSE:
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+The above licence agreement conditions are met in full.
+
+The Anti-Fascist MIT License may only be used under the terms of the
+Anti-Fascist MIT License.
+
+Any modified versions of this software must also include the
+Anti-Fascist MIT Licence.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Makefile

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+PREFIX ?= /usr/local
+
+entry := src/gemini.cr
+sources := $(wildcard src/*/*.cr)
+
+gemini: $(entry) $(sources)
+	crystal build --release $<
+	strip --strip-all $@
+
+install: gemini
+	install -m 755 $< $(PREFIX)/bin/$<

README.md

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+# gemini
+
+This is a Gemini server for ad-hoc hosting.  It depends on a TLS
+termination service like Nginx or HAProxy.  This allow us to configure
+TLS like we need to and offload safety to a better reviewed project.
+
+## Installation
+
+```bash
+crystal build --release src/gemini.cr
+strip --strip-all ./gemini
+install -m 755 ./gemini /usr/local/bin/gemini
+# Or
+make gemini
+sudo make install
+```
+
+## Usage
+
+`gemini` runs on port 19650/tcp without security on.  Make sure to keep
+this port closed on your firewall, but open 1965/tcp for TLS
+connections.
+
+`gemini` expects to serve files from the directory it's run from, and
+serves several hosts under their own directory.
+
+```bash
+# Enter the directory you're hosting capsules from
+cd /srv/gemini
+# Create a directory for the capsule
+install -dm 750 -o user -g gemini gemini.sutty.coop.ar
+# Create a Gemtext file
+echo "Hi" > gemini.sutty.coop.ar/index.gmi
+# Run the server
+gemini
+```
+
+Configure your Nginx server to proxy Gemini requests to
+`gemini`. There's an example configuration on `contrib/`.
+
+To test your setup, visit <gemini://gemini.sutty.coop.ar>
+
+### Self-signed certificates
+
+The example configuration reuses the Let's Encrypt certificates we
+already issue at [Sutty](https://sutty.coop.ar/) for our sites.  If you
+want to use a self-signed certificate, GnuTLS provides the simplest way.
+
+```bash
+certtool --generate-privkey --outfile gemini.key
+certtool --generate-self-signed --load-privkey gemini.key --outfile gemini.crt
+```
+
+The only fields required are `CN` for your domain, and a certification
+duration in days, you can press Enter for everything else.
+
+## Development
+
+You'll need to install Crystal ~>1.2.2.
+
+[Gemini Specification v0.16.0](https://gemini.circumlunar.space/docs/specification.gmi)
+
+## Contributing
+
+```bash
+# 1. Fork it
+git clone https://gitea.sutty.coop.ar/Sutty/gemini.git
+cd gemini
+git remote rename origin upstream
+# 2. Work on your changes
+# [...]
+# 3. Send patches
+git format-patch upstream
+git send-email --to=f@sutty.coop.ar *.patch
+```

contrib/nginx.conf

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+# This requires the `stream` module.  This sections goes on the main
+# nginx.conf or at least outside the `http` section.  Run `nginx -t` to
+# test changes.
+stream {
+  server {
+    # Listen on port 1965, with mandatory TLS.
+    listen 1965 ssl;
+
+    # Run only these protocols.
+    ssl_protocols TLSv1.2 TLSv1.3;
+
+    # Other TLS options could go here.
+
+    # The variable $ssl_server_name dynamically loads a certificate for
+    # any domain name that points to this server.
+    # 
+    # No need to send the full chain since Gemini clients only want to
+    # validate the CommonName field.
+    ssl_certificate /etc/letsencrypt/live/$ssl_server_name/cert.pem;
+    ssl_certificate_key /etc/letsencrypt/live/$ssl_server_name/privkey.pem;
+
+    # After TLS session is started, proxy everything to `gemini`.
+    proxy_pass 127.0.0.1:19650;
+  }
+}

shard.yml

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+name: gemini
+version: 0.1.0
+
+authors:
+- f <f@sutty.coop.ar>
+
+targets:
+  gemini:
+    main: src/gemini.cr
+
+crystal: 1.2.2
+
+license: MIT-Antifa

src/gemini.cr

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+require "./gemini/server"
+
+module Gemini
+  class Error < ::ArgumentError; end
+end
+
+gemini = Gemini::Server.new(19650)
+gemini.start

src/gemini/request.cr

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+require "uri"
+
+# Processes a Gemini request
+class Gemini::Request
+  getter server : Server
+  getter connection : IO
+  getter uri : URI
+  getter path : Path
+  getter host : Path
+
+  def initialize(@server, @connection, uri : String)
+    @uri = URI.parse uri
+
+  if @uri.host.nil? || @uri.host.try(&.blank?)
+     raise Error.new("Host can't be empty")
+   end
+
+    @host = @server.pwd / Path[@uri.host || "doesnt_exist"]
+    @path = process_path
+  end
+
+  # Validates the request by raising exceptions
+  def validate!
+    unless host_exist?
+      raise Error.new("Missing host directory #{@uri.host} at #{Dir.current}, you may need to create and populate it")
+    end
+
+    if malicious_path?
+      raise Error.new("#{path} is outside served directory #{@host}")
+    end
+  end
+
+  def host_exist? : Bool
+    File.directory? @host
+  end
+
+  # Path must be inside served directory
+  def malicious_path? : Bool
+    !path.to_s.starts_with?(@host.to_s)
+  end
+
+  private def process_path : Path
+    path = (@host / Path[@uri.path]).normalize
+    path = path / Path["index.gmi"] if File.directory? path
+
+    path
+  end
+end

src/gemini/response.cr

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+
+# Gemini response
+class Gemini::Response
+  getter server : Server
+  getter connection : IO
+  getter request : Request
+
+  property status : Int32 = 20
+  property meta : String = "text/gemini"
+
+  def initialize(@server, @connection, @request)
+  end
+
+  # Send the file
+  def send : Nil
+    unless exists?
+      @status = 51
+      @meta = "Not found"
+    end
+
+    if removed?
+      @status = 52
+      @meta = "Gone"
+    end
+
+    @server.puts @connection, "#{@status} #{@meta}"
+
+    Log.info { "#{@request.host}: #{@status} #{@meta} #{@request.path}" }
+
+    send_file if @status == 20
+  end
+
+  def exists? : Bool
+    File.exists? @request.path
+  end
+
+  # Files can be specifically removed by appending .remove at the end.
+  def removed? : Bool
+    File.exists? "#{@request.path}.remove"
+  end
+
+  # Sends the file by copying its contents
+  private def send_file : Nil
+    IO.copy File.open(@request.path), @connection
+  end
+end

src/gemini/server.cr

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+require "socket"
+require "log"
+require "./request"
+require "./response"
+
+class Gemini::Server
+  getter server : TCPServer
+  getter port : Int32
+  getter pwd : Path
+
+  def initialize(@port : Int32 = 1965)
+    @server = TCPServer.new(@port)
+    @pwd = Path[Dir.current]
+
+    Log.info { "Gemini server started at port #{@port}" }
+  end
+
+  # Runs the server and starts waiting for connections
+  def start : Nil
+    while connection = @server.accept?
+      begin
+        uri = connection.gets
+
+        # Client must send URI first
+        unless uri.nil? || uri.blank?
+          request = Request.new(self, connection, uri)
+          response = Response.new(self, connection, request)
+
+          request.validate!
+
+          response.send
+        else
+          raise Error.new("URI is empty")
+        end
+      rescue ex
+        puts connection, "40 Error"
+        Log.error(exception: ex) { "Gemini::Error" }
+      end
+
+      # Always close the connection
+      connection.close
+    end
+  end
+
+  # Sends a message through the connection
+  def puts(connection : IO, message : String) : Nil
+    connection.puts message
+    connection.puts "\r\n"
+  end
+end