Re: The scheme https s not consistent with the TLS enabled setting (Re: [ANN] Apache Tomcat 11.0.22 Available)

Mark,

On 5/26/26 1:34 PM, Mark Thomas wrote:
> On 12/05/2026 14:40, Mark Thomas wrote:
>> On 12/05/2026 14:15, Rémy Maucherat wrote:
>>> On Tue, May 12, 2026 at 1:46 PM Mark Thomas <[email protected]> wrote:
>>>>
>>>> On 12/05/2026 09:36, Thomas Meyer wrote:
>>>>>
>>>>> Zitat von Mark Thomas <[email protected]>:
>>>>>
>>>>> Hi,
>>>>>
>>>>>> - Various HTTP/2 validation improvements and a broader change to use
>>>>>>    stream resets rather than connection closures where appropriate.
>>>>>
>>>>> After upgrading our applications to tomcat 11.0.22 we see only
>>>>> connection errors 503 for our setup.
>>>>>
>>>>> We do run Tomcat behind istio/envoy proxy and tomcat uses h2c mode.
>>>>> Istio Service mash handles TLS and Tomcat speaks clear text http2.
>>>>>
>>>>> We see those error messages in our logs: "Connection [{0}], Stream
>>>>> [{1}], The scheme [{2}] is not consistent with the TLS enabled setting
>>>>> of [{3}]"
>>>>>
>>>>> which seems to come from this change:
>>>>> https://github.com/apache/tomcat/commit/96817a0
>>>>>
>>>>> Bug or feature?
>>>>
>>>> Hmm. The change was intentional. The motivation was a security review
>>>> that highlighted that clients could connect over h2c to a resource that
>>>> required TLS. We rejected that as a vulnerability since the attacker 
>>>> can
>>>> only harm their own privacy but we did opt to fix the behaviour to
>>>> protect users from client side error / misconfiguration.
>>>>
>>>> I think the change is consistent with RFC 9113 but there is a reference
>>>> to RFC 9112 3.3 which in turn references a "trusted gateway" which is
>>>> the case you describe. However, Tomcat currently has no way to 
>>>> determine
>>>> (without additional configuration) if an HTTP/2 request is from a
>>>> trusted gateway or not.
>>>>
>>>> Tomcat normally uses the RemoteIpValve in situations where the
>>>> application needs to see the protocol used by the client 
>>>> irrespective of
>>>> the protocol used between the proxy and Tomcat.
>>>>
>>>> How practical is it to configure your proxy to use http for :scheme and
>>>> have it set the X-Forwarded-Proto header? You'd also need to configure
>>>> the RemoteIpValve Tomcat on Tomcat?
>>>>
>>>> Another solution would be to use h2 rather than h2c between the proxy
>>>> and Tomcat.
>>>>
>>>> On balance I'm leaning towards the new behaviour of requiring some
>>>> explicit configuration if proxying secure traffic over h2c. I'll note
>>>> that if you proxy over http you'll need similar configuration although
>>>> AJP (which only supports clear text) will allow this without further
>>>> configuration.
>>>>
>>>> All that said, I am open to being convinced to either revert the new
>>>> behaviour or make it optional.
>>>
>>> We (kind of) allow this in a way: the connector has a secure flag
>>> where it can be configured to say it is supposed to be secure. That is
>>> why you have to configure both sslenabled and secure on the connector
>>> when actually enabling a secure setup.
>>
>> True. Although those only apply to HTTP and can only be used to force 
>> http to be treated as https.
>>
>> RemoteIpValve is arguably a better, more generic solution.
>>
>> You got me thinking about maybe removing those settings from the 
>> Connector.
> 
> It has been a couple of weeks without any further comment. With the June 
> release window approaching now would be the time to make a case 
> adjusting this behaviour. Options include:
> 
> - do nothing (keep the new behaviour)
> - revert the change
> - make the change optional (with a configuration option - TBD)
> - remove the secure and scheme settings entirely (and use RemoteIpValve)
> - something else
> 
> I don't think I have strong views on any particular option. Do nothing 
> is my default option but only because I can;t see a strong argument for 
> on option over any of the others.

+1 for "no additional changes".

I think RemoteIPValve is the correct maneuver, here.

-chris