9:17 a.m.
Thanks for your fast response.
It fails in edge, and firefox too, so unfortunately not just chrome.
I agree with you that the IIS server is violating the spec - it should
never attempt to send UTF-8 encoded characters in the header, but it does
so anyway and it works with chome, firefox and edge when using http1.1
(they must autodetect the utf-8 encoding) - but with http/2 it fails on the
transport level somewhere.
I guess that undertow should not really try to guess a codepage and encode
it different, so there is probably not anything else to do - I just wanted
to check if there could be another bug that caused the protocol violation
error, or if you know of the http/2 spec mentioning anything about this, or
if undertow did something special with non-ascii characters.
I'll try encoding the header if I detect non-ascii characters in it and see
how it goes...
Below is the information from a trace in my proxy - sorry for the image,
but it doesn't cut'n paste well - the odd characters in the
Content-Disposition field are UTF-8 encoded version of of the danish letter
"å" (å in html)
2018-07-05 3:10 GMT+02:00 Stuart Douglas <sdouglas(a)redhat.com>:
On Wed, Jul 4, 2018 at 6:15 PM Kim Rasmussen <kr(a)asseco.dk> wrote:
> Hi,
>
> I have a setup where I have my own variant of a ProxyHandler within
> undertow.
> In one case, I proxy requests towards an IIS running MailEnable - if I
> try to download a webmail attachment where the filename contains non-ascii
> characters, MailEnable sends the filename in UTF-8 characters in the HTTP
> header.
>
> I guess this is kinda a violation of the HTTP protocol, but thats how it
> is.
>
> When I run my undertow proxy using HTTP1.1 between the browser and
> undertow, everything works as expected - the browser detects and supports
> UTF-8 characters in the filename in the HTTP headers.
> But, if I run HTTP/2 between the browser and undertow, using Chrome I am
> getting an SPDY_PROTOCOL_ERROR displayed within chrome.
>
Does it work with other browsers? Its possible that we have a bug in how
we handle this, but I think it is more likely that chrome is just being
more strict with HTTP/2 and enforcing the spec.
>
> So, I guess that it is because Chrome chokes on the UTF-8 characters in
> the HTTP/2 headers - I tried digging into the spec but I cannot really find
> anything mentioned there regarding restrictions on header content - just on
> header naming.
>
https://tools.ietf.org/html/rfc7230
" Historically, HTTP has allowed field content with text in the
ISO-8859-1 charset [ISO-8859-1], supporting other charsets only
through use of [RFC2047] encoding. In practice, most HTTP header
field values use only a subset of the US-ASCII charset [USASCII].
Newly defined header fields SHOULD limit their field values to
US-ASCII octets. A recipient SHOULD treat other octets in field
content (obs-text) as opaque data."
>
> Any suggestions ? I could of course strip the invalid characters from the
> response header before forwarding them but wanted to check if there is a
> better way first....
>
Maybe you could use RFC2047 encoding, although I don't think it is
particularly widely used, but I guess chrome probably supports it.
Looking at our HTTP/2 encoder it does not attempt to deal with UTF-8 at
all, it just casts the character to a byte, so we would not be encoding the
characters properly anyway, but I am not sure if it matters as I don't
think the browser would treat them as UTF-8 anyway.
Stuart
>
> --
> Med venlig hilsen / Best regards
>
> *Kim Rasmussen*
> Partner, IT Architect
>
> *Asseco Denmark A/S*
> Kronprinsessegade 54
>
<https://maps.google.com/?q=Kronprinsessegade+54+DK-1306+Copenhagen&en...
> DK-1306 Copenhagen
>
<https://maps.google.com/?q=Kronprinsessegade+54+DK-1306+Copenhagen&en...
> K
> Mobile: +45 26 16 40 23
> Ph.: +45 33 36 46 60
> Fax: +45 33 36 46 61
>
> https://ceptor.io
> https://asseco.dk
>
>
> _______________________________________________
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> undertow-dev(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/undertow-dev
--
Med venlig hilsen / Best regards
*Kim Rasmussen*
Partner, IT Architect
*Asseco Denmark A/S*
Kronprinsessegade 54
DK-1306 Copenhagen K
Mobile: +45 26 16 40 23
Ph.: +45 33 36 46 60
Fax: +45 33 36 46 61
https://ceptor.io
https://asseco.dk
