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Fix disconnect_expired_cert when Kube Identity forwarding is used #24913

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Merged
tigrato merged 2 commits into from
Apr 24, 2023
Merged

Fix disconnect_expired_cert when Kube Identity forwarding is used #24913

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4f44751
Fix `disconnect_expired_cert` not being respected for Kube
tigrato Apr 20, 2023
1cbc54b
fix test
tigrato Apr 20, 2023
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28 changes: 8 additions & 20 deletions lib/kube/proxy/forwarder.go
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Original file line number Diff line number Diff line change
Expand Up @@ -88,7 +88,6 @@ import (
"github.com/gravitational/teleport/lib/services"
"github.com/gravitational/teleport/lib/srv"
"github.com/gravitational/teleport/lib/sshca"
"github.com/gravitational/teleport/lib/tlsca"
"github.com/gravitational/teleport/lib/utils"
)

Expand Down Expand Up @@ -548,31 +547,20 @@ func (f *Forwarder) authenticate(req *http.Request) (*authContext, error) {
if err != nil {
return nil, authz.ConvertAuthorizerError(ctx, f.log, err)
}
peers := req.TLS.PeerCertificates
if len(peers) > 1 {
// when turning intermediaries on, don't forget to verify
// https://github.com/kubernetes/kubernetes/pull/34524/files#diff-2b283dde198c92424df5355f39544aa4R59
return nil, trace.AccessDenied("access denied: intermediaries are not supported")
}
if len(peers) == 0 {
return nil, trace.AccessDenied("access denied: only mutual TLS authentication is supported")
}
clientCert := peers[0]
clientIdentity, err := tlsca.FromSubject(clientCert.Subject, clientCert.NotAfter)
if err != nil {
return nil, trace.Wrap(err)
}

// kubeResource is the Kubernetes Resource the request is targeted at.
// Currently only supports Pods and it includes the pod name and namespace.
kubeResource := getPodResourceFromRequest(req.RequestURI)
authContext, err := f.setupContext(ctx, *userContext, req, isRemoteUser, clientIdentity, kubeResource)
authContext, err := f.setupContext(ctx, *userContext, req, isRemoteUser, kubeResource)
if err != nil {
f.log.WithError(err).Warn("Unable to setup context.")
if trace.IsAccessDenied(err) {
if kubeResource != nil {
return nil, trace.AccessDenied(
kubeResourceDeniedAccessMsg(
clientIdentity.Username,
// return the unmapped username to the client, otherwise for leaf
// clusters the client will see the "remote-username".
userContext.UnmappedIdentity.GetIdentity().Username,
req.Method,
kubeResource,
),
Expand Down Expand Up @@ -754,7 +742,7 @@ func (f *Forwarder) formatStatusResponseError(rw http.ResponseWriter, respErr er
}
}

func (f *Forwarder) setupContext(ctx context.Context, authCtx authz.Context, req *http.Request, isRemoteUser bool, clientIdentity *tlsca.Identity, kubeResource *types.KubernetesResource) (*authContext, error) {
func (f *Forwarder) setupContext(ctx context.Context, authCtx authz.Context, req *http.Request, isRemoteUser bool, kubeResource *types.KubernetesResource) (*authContext, error) {
ctx, span := f.cfg.tracer.Start(
ctx,
"kube.Forwarder/setupContext",
Expand Down Expand Up @@ -955,8 +943,8 @@ func (f *Forwarder) setupContext(ctx context.Context, authCtx authz.Context, req
recordingConfig: recordingConfig,
kubeClusterName: kubeCluster,
kubeResource: kubeResource,
certExpires: clientIdentity.Expires,
disconnectExpiredCert: srv.GetDisconnectExpiredCertFromIdentity(roles, authPref, clientIdentity),
certExpires: identity.Expires,
disconnectExpiredCert: srv.GetDisconnectExpiredCertFromIdentity(roles, authPref, &identity),
teleportCluster: teleportClusterClient{
name: teleportClusterName,
remoteAddr: utils.NetAddr{AddrNetwork: "tcp", Addr: req.RemoteAddr},
Expand Down
2 changes: 1 addition & 1 deletion lib/kube/proxy/forwarder_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -751,6 +751,7 @@ func TestAuthenticate(t *testing.T) {
RouteToCluster: tt.routeToCluster,
KubernetesCluster: tt.kubernetesCluster,
ActiveRequests: tt.activeRequests,
Expires: certExpiration,
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@zmb3 zmb3 Apr 20, 2023

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If I add this line, but don't add the fixes above, the test still passes.

This makes me think we don't actually have a test that verifies this behavior is correct.

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@tigrato tigrato Apr 20, 2023

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That was a nice catch although the test was correct. I didn't remove the expiration from the certificate and it was picking that value.
Fixed by 1cbc54b

}),
}
authorizer := mockAuthorizer{ctx: &authCtx}
Expand All @@ -769,7 +770,6 @@ func TestAuthenticate(t *testing.T) {
CommonName: username,
Organization: []string{"example"},
},
NotAfter: certExpiration,
},
},
},
Expand Down