TLS ping host and port. 🔑

.gitignore

@@ -0,0 +1,61 @@
+# Created by https://www.toptal.com/developers/gitignore/api/ruby
+# Edit at https://www.toptal.com/developers/gitignore?templates=ruby
+
+### Ruby ###
+*.gem
+*.rbc
+/.config
+/coverage/
+/InstalledFiles
+/pkg/
+/spec/reports/
+/spec/examples.txt
+/test/tmp/
+/test/version_tmp/
+/tmp/
+
+# Used by dotenv library to load environment variables.
+# .env
+
+# Ignore Byebug command history file.
+.byebug_history
+
+## Specific to RubyMotion:
+.dat*
+.repl_history
+build/
+*.bridgesupport
+build-iPhoneOS/
+build-iPhoneSimulator/
+
+## Specific to RubyMotion (use of CocoaPods):
+#
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+# vendor/Pods/
+
+## Documentation cache and generated files:
+/.yardoc/
+/_yardoc/
+/doc/
+/rdoc/
+
+## Environment normalization:
+/.bundle/
+/vendor/bundle
+/lib/bundler/man/
+
+# for a library or gem, you might want to ignore these files since the code is
+# intended to run in multiple environments; otherwise, check them in:
+Gemfile.lock
+.ruby-version
+.ruby-gemset
+
+# unless supporting rvm < 1.11.0 or doing something fancy, ignore this:
+.rvmrc
+
+# Used by RuboCop. Remote config files pulled in from inherit_from directive.
+# .rubocop-https?--*
+
+# End of https://www.toptal.com/developers/gitignore/api/ruby

.rspec

@@ -0,0 +1 @@
+--require spec_helper

.rubocop.yml

@@ -0,0 +1,24 @@
+---
+require:
+  - rubocop-rspec
+  - rubocop-rake
+  - rubocop-performance
+
+AllCops:
+  NewCops: enable
+
+Style/NegatedIf:
+  Enabled: false
+
+Metrics/MethodLength:
+  CountAsOne:
+    - 'array'
+    - 'hash'
+    - 'heredoc'
+  Max: 25
+
+Metrics/AbcSize:
+  CountRepeatedAttributes: false
+
+Style/Documentation:
+  Enabled: false

Gemfile

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+source 'https://rubygems.org'
+gemspec
+
+group :development, :test do
+  gem 'rake'
+
+  gem 'pry'
+  gem 'pry-byebug'
+  gem 'pry-doc'
+  gem 'pry-rescue'
+
+  gem 'rspec'
+
+  gem 'rubocop'
+  gem 'rubocop-performance'
+  gem 'rubocop-rake'
+  gem 'rubocop-rspec'
+
+  gem 'simplecov'
+end

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Tobias Schäfer
+
+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 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.

README.md

@@ -0,0 +1,52 @@
+# tls-ping
+
+TLS ping host and port.
+
+## Introduction
+
+**tls-ping** connects to a given host and port and validates the TLS connection
+and certificate.
+
+## Installation
+
+```bash
+gem build
+version=$(ruby -Ilib -e 'require "tls/ping"; puts TLS::Ping::VERSION')
+gem install tls-ping-${version}.gem
+```
+
+## Usage
+
+```bash
+$ tls-ping github.com 443
+> github.com:443
+   [ OK ] /CN=github.com
+```
+
+For further information about the command line tool `tls-ping` see the following
+help output.
+
+```bash
+Usage:
+    tls-ping [OPTIONS] HOST PORT
+
+Parameters:
+    HOST                     hostname to ping
+    PORT                     port to ping
+
+Options:
+    -s, --starttls           use STARTTLS
+    -t, --timeout SECONDS    timeout in seconds (default: 5)
+    -q, --quiet              suppress output
+    -h, --help               print help
+    -m, --man                show manpage
+    -v, --version            show version
+```
+
+## License
+
+[MIT License](https://spdx.org/licenses/MIT.html)
+
+## Is it any good?
+
+[Yes.](https://news.ycombinator.com/item?id=3067434)

Rakefile

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
+require 'rubocop/rake_task'
+
+FileList['tasks/**/*.rake'].each { |f| import(f) }
+
+RSpec::Core::RakeTask.new(:rspec)
+RuboCop::RakeTask.new
+
+desc "Run tasks 'rubocop' by default."
+task default: %w[rubocop]

bin/tls-ping

@@ -0,0 +1,6 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'tls/ping/app'
+
+TLS::Ping::App::Command.run

lib/tls.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative 'tls/ping'
+
+# :nodoc:
+module TLS
+  class << self
+    def ping(...)
+      TLS::Ping.new(...).succeeded!
+    end
+  end
+end

lib/tls/ping.rb

@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'openssl'
+require 'socket'
+require 'timeout'
+
+module TLS
+  class Ping
+    VERSION = '0.1.0'
+
+    attr_reader :error, :peer_cert
+
+    def initialize(host, port, starttls: false, timeout: 5)
+      @host = host
+      @port = port
+      @starttls = starttls
+      @timeout = timeout
+
+      execute
+    end
+
+    def succeeded?
+      @error.nil?
+    end
+
+    def succeeded!
+      raise @error if @error
+    end
+
+    private
+
+    def execute
+      socket = Timeout.timeout(@timeout) do
+        socket = TCPSocket.new(@host, @port)
+        socket.timeout = @timeout
+        socket
+      end
+
+      starttls(socket) if @starttls
+
+      tls_socket = OpenSSL::SSL::SSLSocket.new(socket, tls_ctx)
+      tls_socket.hostname = @host
+      tls_socket.connect
+    rescue StandardError => e
+      @error = e
+    ensure
+      @peer_cert = tls_socket&.peer_cert || tls_socket&.peer_cert_chain&.first
+      tls_socket&.close
+      socket&.close
+    end
+
+    def tls_ctx
+      OpenSSL::SSL::SSLContext.new.tap do |ctx|
+        store = OpenSSL::X509::Store.new
+        store.set_default_paths
+
+        ctx.verify_mode = OpenSSL::SSL::VERIFY_PEER
+        ctx.cert_store = store
+        ctx.timeout = @timeout
+      end
+    end
+
+    def starttls(socket)
+      return if !@starttls
+
+      socket.gets
+      socket.write("EHLO tls.ping\r\n")
+
+      loop do
+        break if socket.gets.start_with?('250 ')
+      end
+
+      socket.write("STARTTLS\r\n")
+      socket.gets
+    end
+  end
+end

lib/tls/ping/app.rb

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+require_relative 'app/base'
+require_relative '../../tls'
+
+module TLS
+  class Ping
+    module App
+      class Command < TLS::Ping::App::BaseCommand
+        parameter 'HOST', 'hostname to ping'
+        parameter 'PORT', 'port to ping'
+        option ['-s', '--starttls'], :flag, 'use STARTTLS'
+        option ['-t', '--timeout'], 'SECONDS', 'timeout in seconds', default: 5
+        option ['-q', '--quiet'], :flag, 'suppress output'
+
+        PING_OK = 0
+        PING_FAIL = 1
+        PING_UNKNOWN = 255
+
+        def execute
+          header
+          code, reason = action
+          result(code, reason:)
+
+          exit(code)
+        end
+
+        private
+
+        def header
+          return if quiet?
+
+          puts "> #{host}:#{port}" if !quiet?
+        end
+
+        def action
+          ping = TLS::Ping.new(
+            host,
+            port,
+            starttls: starttls?,
+            timeout: timeout.to_f
+          )
+          ping.succeeded!
+
+          reason = ping.peer_cert.subject.to_s
+          [PING_OK, reason]
+        rescue OpenSSL::SSL::SSLError => e
+          reason = e.message.split(': ').last.capitalize
+          [PING_FAIL, reason]
+        rescue StandardError
+          [PING_UNKNOWN]
+        end
+
+        def result(code, reason: nil)
+          return if quiet?
+
+          status = {
+            PING_OK => Pastel.new.green.bold('OK'),
+            PING_FAIL => Pastel.new.red.bold('FAIL'),
+            PING_UNKNOWN => Pastel.new.yellow.bold('UNKNOWN')
+          }[code]
+
+          info = "   [ #{status} ]"
+          info += " #{reason}" if reason
+
+          puts info
+        end
+      end
+    end
+  end
+end