# -*- ruby -*-
# $Id: check_user.rb,v 1.3 2001/08/03 23:43:24 ttate Exp $

require "pam"

def pam_conv(msgs, data)
  ret = []

  msgs.each{|msg|
    case msg.msg_style
    when PAM::PAM_PROMPT_ECHO_ON
      printf(msg.msg)
      if( str = $stdin.gets )
	str.chomp!
      end
      ret.push(PAM::Response.new(str,0))
    when PAM::PAM_PROMPT_ECHO_OFF
      printf(msg.msg)
      `stty -echo`
      begin
	if( str = $stdin.gets )
	  str.chomp!
	end
      ensure
	`stty echo`
      end
      ret.push(PAM::Response.new(str, 0))
    else
      # unexpected, bug?
      ret.push(PAM::Response.new(nil, 0))
    end
  }

  ret
end

if( ARGV[0] && ARGV[1] )
  service = ARGV[0]
  user    = ARGV[1]
else
  print("usage:\n #{$0} <service> <user>\n")
  exit(1)
end
conv = proc{|msg| pam_conv(msg)}
conv_data = user

PAM.start(service, user, :pam_conv, conv_data){|pam|
  print("PAM_RUSER   = ", pam.get_item(PAM::PAM_RUSER), "\n")
  print("PAM_RHOST   = ", pam.get_item(PAM::PAM_RHOST), "\n")
  print("PAM_USER    = ", pam.get_item(PAM::PAM_USER), "\n")
  print("PAM_SERVICE = ", pam.get_item(PAM::PAM_SERVICE), "\n")
  print("PAM_CONV    = ", pam.get_item(PAM::PAM_CONV).inspect, "\n")
  begin
    pam.authenticate(0)
  rescue PAM::PAM_USER_UNKNOWN
    print("unknown user: #{pam.get_item(PAM::PAM_USER)}\n")
    exit(1)
  rescue PAM::PAM_AUTH_ERR
    print("authentication error: #{pam.get_item(PAM::PAM_USER)}\n")
    exit(1)
  rescue PAM::PAMError
    print("error code = #{pam.status}\n")
    exit(1)
  end

  begin
    pam.acct_mgmt(0)
    pam.open_session
  rescue PAM::PAMError
    printf("you can't access.\n")
    exit(1)
  ensure
    pam.close_session
  end

  print("\n",
	"authenticated!\n")
}