# frozen_string_literal: true
#
# Author:: Bryan McLellan <btm@chef.io>
# Copyright:: Copyright (c) Chef Software Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

Ohai.plugin(:SSHHostKey) do
  provides "keys/ssh"
  depends "keys"

  def extract_keytype?(content)
    case content[0]
    when "ssh-dss"
      [ "dsa", nil ]
    when "ssh-rsa"
      [ "rsa", nil ]
    when /^ecdsa/
      [ "ecdsa", content[0] ]
    when "ssh-ed25519"
      [ "ed25519", nil ]
    else
      [ nil, nil ]
    end
  end

  collect_data do
    keys[:ssh] = Mash.new

    sshd_config = if file_exist?("/etc/ssh/sshd_config")
                    "/etc/ssh/sshd_config"
                  elsif file_exist?("/etc/sshd_config")
                    # Darwin
                    "/etc/sshd_config"
                  else
                    logger.trace("Plugin SSHHostKey: Failed to find sshd configuration file")
                    nil
                  end

    if sshd_config
      file_open(sshd_config) do |conf|
        conf.each_line do |line|
          if /^hostkey\s/i.match?(line)
            pub_file = "#{line.split[1]}.pub"
            content = file_read(pub_file).split
            key_type, key_subtype = extract_keytype?(content)
            keys[:ssh]["host_#{key_type}_public"] = content[1] unless key_type.nil?
            keys[:ssh]["host_#{key_type}_type"] = key_subtype unless key_subtype.nil?
          end
        end
      end
    end

    if keys[:ssh][:host_dsa_public].nil? && file_exist?("/etc/ssh/ssh_host_dsa_key.pub")
      keys[:ssh][:host_dsa_public] = file_read("/etc/ssh/ssh_host_dsa_key.pub").split[1]
    end

    if keys[:ssh][:host_rsa_public].nil? && file_exist?("/etc/ssh/ssh_host_rsa_key.pub")
      keys[:ssh][:host_rsa_public] = file_read("/etc/ssh/ssh_host_rsa_key.pub").split[1]
    end

    if keys[:ssh][:host_ecdsa_public].nil? && file_exist?("/etc/ssh/ssh_host_ecdsa_key.pub")
      content = file_read("/etc/ssh/ssh_host_ecdsa_key.pub")
      keys[:ssh][:host_ecdsa_public] = content.split[1]
      keys[:ssh][:host_ecdsa_type] = content.split[0]
    end

    if keys[:ssh][:host_ed25519_public].nil? && file_exist?("/etc/ssh/ssh_host_ed25519_key.pub")
      keys[:ssh][:host_ed25519_public] = file_read("/etc/ssh/ssh_host_ed25519_key.pub").split[1]
    end
  end
end