HTTP SSL Certificate Checker

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::Tcp
  include Msf::Auxiliary::WmapScanSSL
  include Msf::Auxiliary::Scanner
  include Msf::Auxiliary::Report

  def initialize
    super(
      'Name'        => 'HTTP SSL Certificate Checker',
      'Author'      => 'nebulus',
      'License'     => MSF_LICENSE,
      'Description' => %q{
          This module will check the certificate of the specified web servers
        to ensure the subject and issuer match the supplied pattern and that the certificate
        is not expired.
      }
    )

    register_options(
      [
        Opt::RPORT(443),
        OptRegexp.new('ISSUER', [ true,  "Show a warning if the Issuer doesn't match this regex", '.*']),
        OptBool.new('SHOWALL', [ false, "Show all certificates (issuer,time) regardless of match", false]),
      ])
  end

  # Fingerprint a single host
  def run_host(ip)

    connect(true, {"SSL" => true}) #Force SSL
    cert  = OpenSSL::X509::Certificate.new(sock.peer_cert)
    disconnect

    if(not cert)
      print_status("#{ip} No certificate subject or CN found")
      return
    end
    sub = cert.subject.to_a

    before = Time.parse("#{cert.not_before}")
    after = Time.parse("#{cert.not_after}")

    now = Time.now
    a = now <=> before
    b = now <=> after

    vhostn = 'EMPTY'
    sub.each do |n|
      if n[0] == 'CN'
        vhostn = n[1]
      end
    end

    if cert.issuer.to_s !~ /#{datastore['ISSUER'].source}/n
      print_good("#{ip} - '#{vhostn}' : #{cert.issuer} (BAD ISSUER)" )
    elsif datastore['SHOWALL']
      # show verbose as status
      print_status("#{ip} - '#{vhostn}' : #{cert.issuer}")
    end

    if ( a < 1 or b > 0 )
      print_good("#{ip} - '#{vhostn}' : '" + before.to_s + "' - '" + after.to_s + "' (EXPIRED)'")
    elsif
      # show verbose as status
      print_status("#{ip} - '#{vhostn}' : '" + before.to_s + "' - '" + after.to_s + "'")
    end

    report_note(
      :host	=> ip,
      :port	=> rport,
      :proto  => 'tcp',
      :type	=> 'http.vhost',
      :data	=> {:name => vhostn}
    ) if vhostn

    # Store the SSL certificate itself
    report_note(
      :host	=> ip,
      :proto  => 'tcp',
      :port	=> rport,
      :type	=> 'ssl.certificate',
      :data	=> {
        :cn        => vhostn,
        :subject   => cert.subject.to_a,
        :algorithm => cert.signature_algorithm

      }
    ) if vhostn

    # Update the server hostname if necessary
    if vhostn !~ /localhost|snakeoil/i
      report_host(
        :host => ip,
        :name => vhostn
      )
    end


  rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
  rescue ::Timeout::Error, ::Errno::EPIPE
  rescue ::OpenSSL::SSL::SSLError => e
    return if(e.to_s.match(/^SSL_connect /) ) # strange errors / exception if SSL connection aborted
  rescue ::Exception => e
    return if(e.to_s =~ /execution expired/)
    print_error("Error: '#{ip}' '#{e.class}' '#{e}' '#{e.backtrace}'")
  end
end