# RouterOS script: check-certificates
# Copyright (c) 2013-2018 Christian Hesse <mail@eworm.de>
#
# check for certificate validity

:global "identity";
:global "email-general-to";
:global "email-general-cc";

:local months ("jan","feb","mar","apr","may","jun","jul","aug","sep","oct","nov","dec");

:local currentdate [ / system clock get date ];

:local currentmonthstr [ :pick $currentdate 0 3 ];
:local currentday [ :pick $currentdate 4 6 ];
:local currentyear [ :pick $currentdate 7 11 ];
:local currentmonth ([ :find $months $currentmonthstr -1 ] + 1);
:local currentstamp ($currentyear * 365 + $currentmonth * 30 + $currentday);

:foreach cert in=[ / certificate find where !revoked ] do={
  :local certname [ / certificate get $cert name ];
  :local invaliddate [ / certificate get $cert invalid-after ];

  :if ([ :len $invaliddate ] > 0) do={
    :local invalidmonthstr [ :pick $invaliddate 0 3 ];
    :local invalidday [ :pick $invaliddate 4 6 ];
    :local invalidyear [ :pick $invaliddate 7 11 ];
    :local invalidmonth ([ :find $months $invalidmonthstr -1 ] + 1);
    :local invalidstamp ($invalidyear * 365 + invalidmonth * 30 + invalidday);

    :local remaining ($invalidstamp - $currentstamp);

    :if ($remaining < 15) do={
      :local commonname [ / certificate get $cert common-name ];
      :local fingerprint [ / certificate get $cert fingerprint ];
      :local invalidbefore [ / certificate get $cert invalid-before ];
      :local invalidafter [ / certificate get $cert invalid-after ];
      / tool e-mail send to=$"email-general-to" cc=$"email-general-cc" \
        subject=("[" . $identity . "] Certificate warning!") \
        body=("A certificate on " . $identity . " is about to expire.\n\n" . \
          "Certificate Name: " . $certname . "\n" . \
          "Common Name:      " . $commonname . "\n" . \
          "Fingerprint:      " . $fingerprint . "\n" . \
          "Validity:         " . $invalidbefore . " to " . $invalidafter);
      :log warning ("A certificate is about to expire within " . $remaining . " days: " . $certname);
    } else={
      :log debug ("The certificate " . $certname . " expires in " . $remaining . " days.");
    }
  } else={
    :log debug ("The certificate " . $certname . " is just a template.");
  }
}