crypto/tls: does not support renegotiation #5742

rogpeppe · 2013-06-20T16:01:36Z

We would like to use net/http to talk to Microsoft Azure services, but
their servers force a TLS renegotiation, which crypto/tls
does not currently support.

bradfitz · 2013-06-20T18:21:05Z

Comment 1:

Owner changed to @agl.

Status changed to Accepted.

agl · 2013-06-20T18:22:07Z

Comment 2:

Really don't ever want to support this. TLS renegotiation is a huge mess.

rogpeppe · 2013-06-21T06:34:50Z

Comment 3:

> Really don't ever want to support this. TLS renegotiation is a huge mess.
That's a pity, although I do understand. It seems we're ending up using
http://godoc.org/github.com/andelf/go-curl which is a) a pretty messy package and b) a
cgo dependency we could do without.
Have you got a suggestion for a neater way around the issue, by any chance?

rsc · 2013-11-27T18:45:42Z

Comment 4:

Labels changed: added go1.3maybe.

rsc · 2013-12-04T01:29:04Z

Comment 5:

Labels changed: added release-none, removed go1.3maybe.

rsc · 2013-12-04T01:47:02Z

Comment 6:

Labels changed: added repo-main.

gopherbot · 2014-01-09T19:43:41Z

Comment 7 by otto.bretz:

Fixed by https://code.google.com/p/go/source/detail?r=f1e918132139?

mikioh · 2014-01-10T01:12:52Z

Comment 8:

This issue was updated by revision 779ef7b.

gopherbot · 2014-04-07T23:22:59Z

Comment 9 by salmodan:

I am creating a Packer plugin for the Microsoft Azure services but I am getting a "local
error: no renegotiation" error message when I make the client.Do(req)   after setting up
the transport to use my client certificate.  I am using Go version 1.2.1.  Am I
understanding this issue correctly in that 1.2.1 is not be able to to talk to Microsoft
Azure services?  Is my only choice to compile a new dev version of Go?  Are there any
newer binaries available?

agl · 2014-04-07T23:28:21Z

Comment 10:

salmodan: there is no published version of the code that does the weird renegotiation
dance that Azure needs. I wrote a patch for some folks who needed it, but it didn't make
Go 1.3. I do think, at this point, that supporting Azure is sufficiently compelling for
1.4 however.

Labels changed: added release-go1.4, removed priority-triage, release-none.

lukescott · 2014-04-08T00:21:51Z

Comment 11:

Is there a reason why this wasn't included in 1.3 when it was reviewed well before the
feature freeze? This occurs with FirstData's payment gateway API. Is there anything
wrong with the patch itself? Is there a better way to address this issue?

agl · 2014-04-09T00:11:17Z

Comment 12:

luke@webconnex.com: what patch do you think was reviewed before the freeze? I may have
missed one.
In general, sites that do this are mistaken and the solution is a hack which is why I've
resisted doing it. This form of authentication is also broken by triple-handshake
attacks[1] and the fix for that hasn't gone through the IETF yet.
It needs careful thought in order to minimise the amount of disruption to the code while
supporting these needs.
[1] https://secure-resumption.com/

gopherbot · 2014-07-25T01:24:49Z

Comment 13 by Hope2BelieveIn:

"I wrote a patch for some folks who needed it".
Can you please give a link to your patch?

gopherbot · 2014-07-25T01:28:44Z

Comment 14 by Hope2BelieveIn:

agl@golang.org: "I wrote a patch for some folks who needed it"
Can you please give a link to this patch?

rsc · 2014-09-15T16:04:12Z

Comment 15:

Too late for 1.4.

Labels changed: added release-go1.5, removed release-go1.4.

gopherbot · 2014-11-20T20:17:34Z

Comment 16 by thegroff:

Will it be too late for 1.5 too? #7 patch has been sitting there for a year. Is there a
problem with the patch?

minux · 2014-11-20T23:03:33Z

Comment 17:

what #7 mentioned is a commit that is in 1.4.
the reason this issue is not closed by that
commit is that we still need client support,
but the secure solution hasn't been made into
official RFC yet.
To summarize, there is no unreviewed pending
patch for this issue, and before the RFC come
out, we can't do anything about the client
side of the issue. (agl explained why he didn't
want to implement a workaround in #12)

rsc · 2014-12-09T15:28:33Z

https://github.com/MSOpenTech/azure-sdk-for-go includes a forked copy of net/http because they needed to be able to talk to Azure servers. Is it possible to support only the limited behavior of the Azure services without getting into the entire TLS renegotiation mess?

agl · 2016-04-26T21:55:58Z

https://go-review.googlesource.com/#/c/22475/ may address this bug, but the primary use case is HTTPS servers which do the Microsoft trick of renegotiating a connection to add client certificates and I don't have any.

Can any interested party here either point me at such a server (with or without a test certificate to authenticate with) or test that patch themselves?

gopherbot · 2016-04-26T22:00:34Z

CL https://golang.org/cl/22475 mentions this issue.

ahmetb · 2016-04-26T22:19:26Z

@agl reaching out to you via email to provide an endpoint and certs.

agl · 2016-04-26T23:15:27Z

@ahmetalpbalkan thank you!

ahmetb · 2016-04-26T23:28:32Z

@agl thanks for confirming the fix and thanks for the patch.

hoenirvili · 2016-04-27T08:50:56Z

So this is resolved?

rsc · 2016-04-28T15:52:06Z

There is a CL out that I expect to be in Go 1.7. This bug will be closed when the CL is committed to Git, but you'll have to wait for Go 1.7 to use it (unless you run from the Git master branch, which can be unstable at times and is not recommended for production code).

ottob · 2016-04-28T17:55:10Z

The patch works fine for me. Huge thanks to @agl!

hoenirvili · 2016-04-28T18:52:41Z

Thanks for clarifying @rsc, and thanks @agl again for the patch.

ghost · 2016-07-08T12:46:56Z

Has anyone tested this with the Go 1.7 RC?

bradfitz · 2016-07-08T15:36:32Z

@aidylewis, @ottob above said he had tested this.

ahmetb · 2016-08-09T04:35:37Z

Also verified this with go1.7rc6 in azure-sdk-for-go.

elimisteve · 2017-01-20T06:36:18Z

Just to be explicit to future readers: this feature has been merged into master, and you can use it by setting the Renegotiation field in your *tls.Config to tls.RenegotiateFreelyAsClient:

config := &tls.Config{
    Renegotiation: tls.RenegotiateFreelyAsClient,
}

Integralist · 2017-01-20T07:02:42Z

Thanks @elimisteve :-)

hoenirvili · 2017-01-20T08:26:08Z

@elimisteve Cheers mate !

ghost · 2017-01-20T10:58:53Z

@Integralist Does that solve the Vegeta issue or is it a different app?

Integralist · 2017-01-21T08:56:21Z

@aidylewis Different app I think? Can't remember now. It was the team's own CLI app interacting with internal BBC service behind self-signed cert that was the issue iirc

Issue golang/go#5742 resolved.

This change adds Config.Renegotiation which controls whether a TLS client will accept renegotiation requests from a server. This is used, for example, by some web servers that wish to “add” a client certificate to an HTTPS connection. This is disabled by default because it significantly complicates the state machine. Originally, handshakeMutex was taken before locking either Conn.in or Conn.out. However, if renegotiation is permitted then a handshake may be triggered during a Read() call. If Conn.in were unlocked before taking handshakeMutex then a concurrent Read() call could see an intermediate state and trigger an error. Thus handshakeMutex is now locked after Conn.in and the handshake functions assume that Conn.in is locked for the duration of the handshake. Additionally, handshakeMutex used to protect Conn.out also. With the possibility of renegotiation that's no longer viable and so writeRecordLocked has been split off. Fixes golang#5742. Change-Id: I935914db1f185d507ff39bba8274c148d756a1c8 Reviewed-on: https://go-review.googlesource.com/22475 Run-TryBot: Adam Langley <agl@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>

rogpeppe added accepted labels Nov 20, 2014

wheelcomplex mentioned this issue Dec 9, 2014

crypto/tls: remote error: handshake failure #8608

Closed

bradfitz modified the milestone: Go1.5 Dec 16, 2014

bradfitz removed the release-go1.5 label Dec 16, 2014

christophershirk mentioned this issue Feb 1, 2015

net/smtp: STARTTLS with server certificate hash pinning #9451

Closed

sthulb mentioned this issue Mar 19, 2015

Docker Registry SSL CA cert failing to be read moby/moby#9118

Closed

rsc removed accepted labels Apr 14, 2015

ahmetb mentioned this issue Apr 26, 2016

Eliminate stdlib forks living at core/ Azure/azure-sdk-for-go#90

Closed

gopherbot closed this as completed in af125a5 Apr 28, 2016

Persistent13 mentioned this issue Jul 5, 2016

Caddy 502 Bad Gateway; No Issue from Other Sources caddyserver/caddy#911

Closed

vincepri mentioned this issue Aug 9, 2016

EOF Reading rows in TLS mode jackc/pgx#103

Closed

jimmidyson mentioned this issue Sep 15, 2016

Consider supporting TLS renegotiation prometheus/prometheus#1998

Closed

wxbit mentioned this issue Sep 27, 2016

Add support to TLS renegotiation syncthing/syncthing#3629

Closed

MLauper pushed a commit to MLauper/go-pulp that referenced this issue Feb 7, 2017

Switch to default http and tls module.

052a169

Issue golang/go#5742 resolved.

bradfitz mentioned this issue Jul 19, 2017

x/build: rewrite Hg hashes in issue tracker #21088

Open

golang locked and limited conversation to collaborators Jan 21, 2018

gopherbot added the FrozenDueToAge label Jan 21, 2018

rsc unassigned agl Jun 22, 2022

crypto/tls: does not support renegotiation #5742

crypto/tls: does not support renegotiation #5742

Comments

rogpeppe commented Jun 20, 2013

bradfitz commented Jun 20, 2013

agl commented Jun 20, 2013

rogpeppe commented Jun 21, 2013

rsc commented Nov 27, 2013

rsc commented Dec 4, 2013

rsc commented Dec 4, 2013

gopherbot commented Jan 9, 2014

mikioh commented Jan 10, 2014

gopherbot commented Apr 7, 2014

agl commented Apr 7, 2014

lukescott commented Apr 8, 2014

agl commented Apr 9, 2014

gopherbot commented Jul 25, 2014

gopherbot commented Jul 25, 2014

rsc commented Sep 15, 2014

gopherbot commented Nov 20, 2014

minux commented Nov 20, 2014

rsc commented Dec 9, 2014

agl commented Apr 26, 2016

gopherbot commented Apr 26, 2016

ahmetb commented Apr 26, 2016

agl commented Apr 26, 2016

ahmetb commented Apr 26, 2016 • edited by bradfitz

hoenirvili commented Apr 27, 2016

rsc commented Apr 28, 2016

ottob commented Apr 28, 2016

hoenirvili commented Apr 28, 2016

ghost commented Jul 8, 2016

bradfitz commented Jul 8, 2016

ahmetb commented Aug 9, 2016

elimisteve commented Jan 20, 2017

Integralist commented Jan 20, 2017

hoenirvili commented Jan 20, 2017

ghost commented Jan 20, 2017

Integralist commented Jan 21, 2017

ahmetb commented Apr 26, 2016 •

edited by bradfitz