Feat: ssl_supported_protocols (TLSv1.3)

.travis.yml

@@ -1,2 +1,8 @@
 import:
-- logstash-plugins/.ci:travis/travis.yml@1.x
+ - logstash-plugins/.ci:travis/defaults.yml@1.x
+ - logstash-plugins/.ci:travis/exec.yml@1.x
+
+env:
+ jobs:
+ - ELASTIC_STACK_VERSION=8.x
+ - SNAPSHOT=true ELASTIC_STACK_VERSION=8.x

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 6.1.0
+ - Feat: ssl_supported_protocols (TLSv1.3) [#47](https://github.com/logstash-plugins/logstash-output-tcp/pull/47)
+ - Fix: close server and client sockets on plugin close
+
 ## 6.0.2
  - Fix: unable to start with password protected key [#45](https://github.com/logstash-plugins/logstash-output-tcp/pull/45)
 

docs/index.asciidoc

@@ -45,6 +45,7 @@ This plugin supports the following configuration options plus the <<plugins-{typ
 | <<plugins-{type}s-{plugin}-ssl_enable>> |<<boolean,boolean>>|No
 | <<plugins-{type}s-{plugin}-ssl_key>> |a valid filesystem path|No
 | <<plugins-{type}s-{plugin}-ssl_key_passphrase>> |<<password,password>>|No
+| <<plugins-{type}s-{plugin}-ssl_supported_protocols>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-ssl_verify>> |<<boolean,boolean>>|No
 |=======================================================================
 
@@ -130,6 +131,20 @@ SSL key path
 
 SSL key passphrase
 
+[id="plugins-{type}s-{plugin}-ssl_supported_protocols"]
+===== `ssl_supported_protocols`
+
+ * Value type is <<string,string>>
+ * Allowed values are: `'TLSv1.1'`, `'TLSv1.2'`, `'TLSv1.3'`
+ * Default depends on the JDK being used. With up-to-date Logstash, the default is `['TLSv1.2', 'TLSv1.3']`.
+ `'TLSv1.1'` is not considered secure and is only provided for legacy applications.
+
+List of allowed SSL/TLS versions to use when establishing a secure connection.
+
+NOTE: If you configure the plugin to use `'TLSv1.1'` on any recent JVM, such as the one packaged with Logstash,
+the protocol is disabled by default and needs to be enabled manually by changing `jdk.tls.disabledAlgorithms` in
+the *$JDK_HOME/conf/security/java.security* configuration file. That is, `TLSv1.1` needs to be removed from the list.
+
 [id="plugins-{type}s-{plugin}-ssl_verify"]
 ===== `ssl_verify` 
 

lib/logstash/outputs/tcp.rb

@@ -51,38 +51,43 @@ class LogStash::Outputs::Tcp < LogStash::Outputs::Base
  # SSL key passphrase
  config :ssl_key_passphrase, :validate => :password, :default => nil
 
+ # NOTE: the default setting [] uses SSL engine defaults
+ config :ssl_supported_protocols, :validate => ['TLSv1.1', 'TLSv1.2', 'TLSv1.3'], :default => [], :list => true
+
  class Client
- public
+
  def initialize(socket, logger)
  @socket = socket
  @logger = logger
  @queue = Queue.new
  end
 
- public
  def run
  loop do
  begin
  @socket.write(@queue.pop)
  rescue => e
- @logger.warn("tcp output exception", :socket => @socket,
- :exception => e)
+ log_warn 'socket write failed:', e, socket: (@socket ? @socket.to_s : nil)
  break
  end
  end
  end # def run
 
- public
  def write(msg)
  @queue.push(msg)
  end # def write
+
+ def close
+ @socket.close
+ rescue => e
+ log_warn 'socket close failed:', e, socket: (@socket ? @socket.to_s : nil)
+ end
  end # class Client
 
- private
  def setup_ssl
  require "openssl"
 
- @ssl_context = OpenSSL::SSL::SSLContext.new
+ @ssl_context = new_ssl_context
  if @ssl_cert
  @ssl_context.cert = OpenSSL::X509::Certificate.new(File.read(@ssl_cert))
  if @ssl_key
@@ -104,50 +109,66 @@ def setup_ssl
  @ssl_context.cert_store = @cert_store
  @ssl_context.verify_mode = OpenSSL::SSL::VERIFY_PEER|OpenSSL::SSL::VERIFY_FAIL_IF_NO_PEER_CERT
  end
- end # def setup_ssl
 
- public
+ @ssl_context.min_version = :TLS1_1 # not strictly required - JVM should have disabled TLSv1
+ if ssl_supported_protocols.any?
+ disabled_protocols = ['TLSv1.1', 'TLSv1.2', 'TLSv1.3'] - ssl_supported_protocols
+ unless OpenSSL::SSL.const_defined? :OP_NO_TLSv1_3 # work-around JRuby-OpenSSL bug - missing constant
+ @ssl_context.max_version = :TLS1_2 if disabled_protocols.delete('TLSv1.3')
+ end
+ # mapping 'TLSv1.2' -> OpenSSL::SSL::OP_NO_TLSv1_2
+ disabled_protocols.map! { |v| OpenSSL::SSL.const_get "OP_NO_#{v.sub('.', '_')}" }
+ @ssl_context.options = disabled_protocols.inject(@ssl_context.options) { |options, op_no| options | op_no }
+ end
+ @ssl_context
+ end
+ private :setup_ssl
+
+ # @note to be able to hook up into #ssl_context from tests
+ def new_ssl_context
+ OpenSSL::SSL::SSLContext.new
+ end
+ private :new_ssl_context
+
+ # @overload Base#register
  def register
  require "socket"
  require "stud/try"
- if @ssl_enable
- setup_ssl
- end # @ssl_enable
+ @closed = Concurrent::AtomicBoolean.new(false)
+ setup_ssl if @ssl_enable
 
  if server?
  @logger.info("Starting tcp output listener", :address => "#{@host}:#{@port}")
  begin
  @server_socket = TCPServer.new(@host, @port)
  rescue Errno::EADDRINUSE
- @logger.error("Could not start TCP server: Address in use",
- :host => @host, :port => @port)
+ @logger.error("Could not start tcp server: Address in use", host: @host, port: @port)
  raise
  end
  if @ssl_enable
  @server_socket = OpenSSL::SSL::SSLServer.new(@server_socket, @ssl_context)
  end # @ssl_enable
- @client_threads = []
+ @client_threads = Concurrent::Array.new
 
  @accept_thread = Thread.new(@server_socket) do |server_socket|
  loop do
+ break if @closed.value
  Thread.start(server_socket.accept) do |client_socket|
  # monkeypatch a 'peer' method onto the socket.
  client_socket.instance_eval { class << self; include ::LogStash::Util::SocketPeer end }
- @logger.debug("Accepted connection", :client => client_socket.peer,
- :server => "#{@host}:#{@port}")
+ @logger.debug("accepted connection", client: client_socket.peer, server: "#{@host}:#{@port}")
  client = Client.new(client_socket, @logger)
  Thread.current[:client] = client
  @client_threads << Thread.current
- client.run
+ client.run unless @closed.value
  end
  end
  end
 
  @codec.on_event do |event, payload|
- @client_threads.each do |client_thread|
+ @client_threads.select(&:alive?).each do |client_thread|
  client_thread[:client].write(payload)
  end
- @client_threads.reject! {|t| !t.alive? }
  end
  else
  client_socket = nil
@@ -163,18 +184,35 @@ def register
  # Now send the payload
  client_socket.syswrite(payload) if w.any?
  rescue => e
- @logger.warn("tcp output exception", :host => @host, :port => @port,
- :exception => e, :backtrace => e.backtrace)
+ log_warn "client socket failed:", e, host: @host, port: @port, socket: (client_socket ? client_socket.to_s : nil)
  client_socket.close rescue nil
  client_socket = nil
  sleep @reconnect_interval
  retry
  end
  end
  end
- end # def register
+ end
+
+ # @overload Base#receive
+ def receive(event)
+ @codec.encode(event)
+ end
+
+ # @overload Base#close
+ def close
+ @closed.make_true
+ @server_socket.close rescue nil if @server_socket
+
+ return unless @client_threads
+ @client_threads.each do |thread|
+ client = thread[:client]
+ client.close rescue nil if client
+ end
+ end
 
  private
+
  def connect
  begin
  client_socket = TCPSocket.new(@host, @port)
@@ -183,29 +221,36 @@ def connect
  begin
  client_socket.connect
  rescue OpenSSL::SSL::SSLError => ssle
- @logger.error("SSL Error", :exception => ssle, :backtrace => ssle.backtrace)
+ log_error 'connect ssl failure:', ssle, backtrace: false
  # NOTE(mrichar1): Hack to prevent hammering peer
  sleep(5)
  raise
  end
  end
  client_socket.instance_eval { class << self; include ::LogStash::Util::SocketPeer end }
- @logger.debug("Opened connection", :client => "#{client_socket.peer}")
+ @logger.debug("opened connection", :client => client_socket.peer)
  return client_socket
- rescue StandardError => e
- @logger.error("Failed to connect: #{e.message}", :exception => e.class, :backtrace => e.backtrace)
+ rescue => e
+ log_error 'failed to connect:', e
  sleep @reconnect_interval
  retry
  end
  end # def connect
 
- private
  def server?
  @mode == "server"
  end # def server?
 
- public
- def receive(event)
- @codec.encode(event)
- end # def receive
+ def log_warn(msg, e, backtrace: @logger.debug?, **details)
+ details = details.merge message: e.message, exception: e.class
+ details[:backtrace] = e.backtrace if backtrace
+ @logger.warn(msg, details)
+ end
+
+ def log_error(msg, e, backtrace: @logger.info?, **details)
+ details = details.merge message: e.message, exception: e.class
+ details[:backtrace] = e.backtrace if backtrace
+ @logger.error(msg, details)
+ end
+
 end # class LogStash::Outputs::Tcp

logstash-output-tcp.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
  s.name = 'logstash-output-tcp'
- s.version = '6.0.2'
+ s.version = '6.1.0'
  s.licenses = ['Apache License (2.0)']
  s.summary = "Writes events over a TCP socket"
  s.description = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"
@@ -21,11 +21,14 @@ Gem::Specification.new do |s|
 
  # Gem dependencies
  s.add_runtime_dependency "logstash-core-plugin-api", ">= 1.60", "<= 2.99"
-
+ s.add_runtime_dependency 'logstash-core', '>= 8.1.0'
  s.add_runtime_dependency 'logstash-codec-json'
  s.add_runtime_dependency 'stud'
 
+ s.add_runtime_dependency 'jruby-openssl', '>= 0.12.2' # 0.12 supports TLSv1.3
+
  s.add_development_dependency 'logstash-devutils'
+ s.add_development_dependency 'logstash-codec-plain'
  s.add_development_dependency 'flores'
 end