Failed NPN Negotiation

[Jeremy Payne]

ERROR: failed to find registered SSL endpoint for ''

ATS 6.1.1
Built against RHEL-openssl 1.0.1e-fips


Has anyone identified any legacy/broken clients out in the wild that may be
responsible for causing these errors ?
I cant seem to generate the same error using openssl:

openssl s_client -connect ip:port -nextprotoneg ''

If I pass an empty list, ATS just returns a list of supported protocols and
closes the TLS connection. Which is per spec(if i read correctly).

The request must be flawed some other way for ATS to generate this error.
I can't run debug or packet capture on these machines since they are in
production
The error seems somewhat innocent.. I am guessing what I may find is that
these
errors are caused by some broken/incomplete client/TLS implementation. I
am leaning towards
this being something amiss with early implementations of boringssl.

However, while I am testing some older clients I am putting this out to the
community.
Maybe someone here has already identified some broken clients or identified
a general area
causing these errors to generate.

Thanks!

[Bryan Call]

I looked through our produciton logs on all our servers (a lot of servers) and I am seeing this too once in awhile. It shouldn’t print the log unless len > 0, but from the logs it looks like the length is 0.

It might be helpful to also print len to see what the value is. Can you please file an issue on this?

Link to issues:
https://github.com/apache/trafficserver/issues <https://github.com/apache/trafficserver/issues>

Thank you,

-Bryan

Post by Jeremy Payne
ERROR: failed to find registered SSL endpoint for ''
ATS 6.1.1
Built against RHEL-openssl 1.0.1e-fips
Has anyone identified any legacy/broken clients out in the wild that may be responsible for causing these errors ?
openssl s_client -connect ip:port -nextprotoneg ''
If I pass an empty list, ATS just returns a list of supported protocols and closes the TLS connection. Which is per spec(if i read correctly).
The request must be flawed some other way for ATS to generate this error.
I can't run debug or packet capture on these machines since they are in production
The error seems somewhat innocent.. I am guessing what I may find is that these
errors are caused by some broken/incomplete client/TLS implementation. I am leaning towards
this being something amiss with early implementations of boringssl.
However, while I am testing some older clients I am putting this out to the community.
Maybe someone here has already identified some broken clients or identified a general area
causing these errors to generate.
Thanks!

[Jeremy Payne]

ok.. so here is my best guess as to whats going on with regards to this
error with the 'empty' protocol list...
it looks like the 'rogue' client is possibly sending a \0 or some other
'garbage' non-printable character(s) as
a protocol. this is the reason why len > 0, but the requested protocol
appears to be 'empty'

Post by Bryan Call
I looked through our produciton logs on all our servers (a lot of servers)
and I am seeing this too once in awhile. It shouldn’t print the log unless
len > 0, but from the logs it looks like the length is 0.
It might be helpful to also print len to see what the value is. Can you
please file an issue on this?
https://github.com/apache/trafficserver/issues
Thank you,
-Bryan
ERROR: failed to find registered SSL endpoint for ''
ATS 6.1.1
Built against RHEL-openssl 1.0.1e-fips
Has anyone identified any legacy/broken clients out in the wild that may
be responsible for causing these errors ?
openssl s_client -connect ip:port -nextprotoneg ''
If I pass an empty list, ATS just returns a list of supported protocols
and closes the TLS connection. Which is per spec(if i read correctly).
The request must be flawed some other way for ATS to generate this error.
I can't run debug or packet capture on these machines since they are in production
The error seems somewhat innocent.. I am guessing what I may find is that these
errors are caused by some broken/incomplete client/TLS implementation. I
am leaning towards
this being something amiss with early implementations of boringssl.
However, while I am testing some older clients I am putting this out to the community.
Maybe someone here has already identified some broken clients or identified a general area
causing these errors to generate.
Thanks!

[Alan Carroll]

Yes, that makes sense. If it's just a a null then you'd get that particular error message.


On Friday, May 5, 2017, 3:00:49 PM CDT, Jeremy Payne <***@gmail.com> wrote:ok.. so here is my best guess as to whats going on with regards to this error with the 'empty' protocol list...it looks like the 'rogue' client is possibly sending a \0 or some other 'garbage' non-printable character(s) as a protocol.  this is the reason why len > 0, but the requested protocol appears to be 'empty'


On Wed, May 3, 2017 at 3:08 PM, Bryan Call <***@apache.org> wrote:

I looked through our produciton logs on all our servers (a lot of servers) and I am seeing this too once in awhile.  It shouldn’t print the log unless len > 0, but from the logs it looks like the length is 0.
It might be helpful to also print len to see what the value is.  Can you please file an issue on this?
Link to issues:https://github.com/apache/ trafficserver/issues
Thank you,
-Bryan

On May 3, 2017, at 12:23 PM, Jeremy Payne <***@gmail.com> wrote:
ERROR: failed to find registered SSL endpoint for ''
ATS 6.1.1Built against RHEL-openssl 1.0.1e-fips

Has anyone identified any legacy/broken clients out in the wild that may be responsible for causing these errors ?I cant seem to generate the same error using openssl:
openssl s_client  -connect ip:port  -nextprotoneg ''

If I pass an empty list, ATS just returns a list of supported protocols and closes the TLS connection. Which is per spec(if i read correctly). 
The request must be flawed some other way for ATS to generate this error. 
I can't run debug or packet capture on these machines since they are in productionThe error seems somewhat innocent.. I am guessing what I may find is that theseerrors are caused by some broken/incomplete client/TLS implementation.  I am leaning towards
this being something amiss with early implementations of boringssl. 
However, while I am testing some older clients I am putting this out to the community.Maybe someone here has already identified some broken clients or identified a general areacausing these errors to generate.
Thanks!