[squid-users] IPv6 and syntax?

Walter H. Walter.H at mathemainzel.info
Sat May 16 06:22:04 UTC 2015


On 16.05.2015 01:41, Amos Jeffries wrote:
> On 16/05/2015 6:14 a.m., Walter H. wrote:
>> Hello,
>>
>> is IPv6 somewhat similar to IPv4?
> Somewhat, yes.
I just wondered because of the "different" behaviour;
>> e.g.
>>
>> I would write
>>
>> acl block_ipv4_range dst  84.84.84.0/24
>> deny_info errorpage block_ipv4_range
>> http_access deny block_ipv4_range
>>
>> to block any hosts within this IPv4 range
> Taking a step asside, that is not quite what those rules do. They block
> access from anywhere *to* the IP address range (TCP/IP packet
> destination on the request messages).
>
yes this should be the intention, that you get an error (in this case 
the errorpage) when
you have e.g.  http://84.84.84.2/ or https://84.84.84.2/ as URL in your 
browser ...
> If you were trying to prevent those hosts themselves from accessing
> anything through the proxy you need the "src" ACL type.
I know;
>> how would be the syntax for blocking any hosts within a specific IPv6
>> subnet
>> e.g. [2408:8000::]/24
> FYI the [] syntax is URL format - for uses when a port may exist. So the
> ':' between IP:port dont get confused.
>
I noticed the difference, but wondered why e.g. /etc/hosts.deny contains 
this:
sshd: [2408:8000::]/24

>> should it be this?
>>
>> acl block_ipv6_subnet dst 2408:8000::/24
>> deny_info errorpage block_ipv6_subnet
>> http_access deny block_ipv6_subnet
> Yes. Though the /N CIDR range is probably different. An IPv4 /24 is
> equivalent to an IPv6 /52  (255 separate pieces of hardware with a
> mandatory /64 each).
>
why I'm asking, because; when having both sections in squid.conf and 
doing SSL-bump
you get a different reaction in the browser:

https://84.84.84.22/
brings the 'errorpage' as expected
the generated certificate has the IP-address (84.84.84.22) as its common 
name;

but
https://[2408:8000::3]/
behaves different in various browsers:

- IE 7: brings a certificate error, when accepting you get the errorpage
            the generated certificate has the IP-address 2408:8000::3 as 
its common name

- later FF (17+) do nothing, older FF (3.6) bring
        "The proxy server is refusing connections
        Firefox is configured to use a proxy server that is refusing 
connections."

- Chrome 42 brings ' Your connection is not private' and 
NET::ERR_CERT_COMMON_NAME_INVALID
      when clicking advanced and proceed with warning you get the errorpage
            the generated certificate has the IP-address 2408:8000::3 as 
its common name

trying https://[2408:8000:0:0:0:0:0:3]/  does an automatic reduction to 
https://[2408:8000::3]/ by the browser

does it seem to be problematic, when having an TLS-server with an IPv6 
address only without DNS, because of the comm name?

Thanks,
Walter

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