From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michael Tremer <michael.tremer@ipfire.org>
To: development@lists.ipfire.org
Subject: Re: validfqdn
Date: Thu, 13 Dec 2018 16:36:48 +0000
Message-ID: <08830C86-C35B-492D-BF8C-9BF9C772FA78@ipfire.org>
In-Reply-To: <pus370$nkt$1@tuscan3.grantura.co.uk>
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Hello Bob,

Thank you for submitting your patch.

> On 12 Dec 2018, at 22:48, Bob Brewer <ipfire-devel(a)grantura.co.uk> wrote:
>=20
> I am porting the old ipcop addon 'Banish' to IPFire and during testing have=
=20
> found a problem in general-functions.pl which causes validfqdn to return 1 =

> when testing valid and invalid ip addresses when it should return 0.=20

What does the add-on do? I could not find an old version for IPCop on the Int=
ernet=E2=80=A6

> As this is not a problem with IPCop 2 a comparison of the validfqdn section=
=20
> in IPFire's general-functions.pl shows a missing segment that checks the TL=
D=20
> can only be a-z or A-Z.

What requires this change?

I do not know of any ASCII TLDs that have numbers, but there is no reason tha=
t they can=E2=80=99t in the future. Furthermore, we have some non-ASCII TLDs =
which will have to be encoded into ASCII using the puny-codes. That will resu=
lt in something like this:

XN--FHBEI
XN--FIQ228C5HS
XN--FIQ64B
XN--FIQS8S
XN=E2=80=94FIQZ9S

This is just a couple of random TLDs I picked from here:

  http://data.iana.org/TLD/tlds-alpha-by-domain.txt

I assume that those will no longer be usable after your patch. Can you confir=
m that?

Best,
-Michael

> Applying the patch below to general-functions.pl corrects the problem with =

> my Banish port and I haven't found any problems affecting IPFire's=20
> operation.
>=20
> Regards
>=20
> Rob
>=20
> --- /tmp/general-functions.pl   2018-09-19 10:32:37.000000000 +0100
> +++ /tmp/general-functions.pl.new       2018-12-12 22:13:37.394653609 +0000
> @@ -666,9 +666,13 @@
> }
>=20
> sub validfqdn
> +# modified to add addition test to confirm TL is only a-z or A-Z
> +# as per ipcop rwb 12/12/18
> +
> {
>        my $part;
> -
> +        my $tld;
> +    =20
>        # Checks a fully qualified domain name against RFC1035
>         my $fqdn =3D $_[0];
>        my @parts =3D split (/\./, $fqdn);        # Split hostname at the '.'
> @@ -689,7 +693,14 @@
>                # Last character can only be a letter or a digit
>                if (substr ($part, -1, 1) !~ /^[a-zA-Z0-9]*$/) {
>                        return 0;}
> -       }
> +           # Store for additional check on TLD
> +           $tld =3D $part;
> +        }=20
> +
> +        # TLD valid characters are a-z, A-Z
> +        if ($tld !~ /^[a-zA-Z]*$/) {
> +        return 0;
> +        }
>        return 1;
> }
>=20


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