Safely print cert string values in ronin cert-dump

[postmodern]

X509 certificate strings can contain newlines and other control characters. If a cert string contains non-printable characters (ex: str =~ /[^[:print:]]/) then display the string as quoted/escaped (ex: str = str.inspect). This should be done for all String values in the parsed Cert object.

def escape_string(string)
  if string =~ /[^[:print:]]/
    string.inspect
  else
    string
  end
end

References

• https://infosec.exchange/@ryanc/112455283652607072
• https://gist.githubusercontent.com/ryancdotorg/73f298821f57b56ec328181dfa9b9ade/raw/37444b84684315b19ef50f85d4453663cfafeb96/nsa.test.pem