s3-rpcserver: fix security level check for DsRGetForestTrustInformation

Harmonize _netr_DsRGetForestTrustInformation with source4/ logic which
didn't change since DCE RPC channel refactoring.

With the current code we return RPC faul as can be seen in the logs:

2019/12/11 17:12:55.463081,  1, pid=20939, effective(1284200000, 1284200000), real(1284200000, 0), class=rpc_parse] ../librpc/ndr/ndr.c:471(ndr_print_function_debug)
       netr_DsRGetForestTrustInformation: struct netr_DsRGetForestTrustInformation
          in: struct netr_DsRGetForestTrustInformation
              server_name              : *
                  server_name              : '\\some-dc.example.com'
              trusted_domain_name      : NULL
              flags                    : 0x00000000 (0)
[2019/12/11 17:12:55.463122,  4, pid=20939, effective(1284200000, 1284200000), real(1284200000, 0), class=rpc_srv] ../source3/rpc_server/srv_pipe.c:1561(api_rpcTNP)
  api_rpcTNP: fault(5) return.

This is due to this check in processing a request:
        if (!(p->pipe_bound && (p->auth.auth_type != DCERPC_AUTH_TYPE_NONE)
                       && (p->auth.auth_level != DCERPC_AUTH_LEVEL_NONE))) {
                p->fault_state = DCERPC_FAULT_ACCESS_DENIED;
                return WERR_ACCESS_DENIED;
        }

and since we get AuthZ response,

  Successful AuthZ: [netlogon,ncacn_np] user [EXAMPLE]\[admin] [S-1-5-21-1234567-890123456-500] at [Wed, 11 Dec 2019 17:12:55.461164 UTC]
  Remote host [ipv4:Y.Y.Y.Y:59017] local host [ipv4:X.X.X.X:445]
[2019/12/11 17:12:55.461584,  4, pid=20939, effective(0, 0), real(0, 0)] ../lib/audit_logging/audit_logging.c:141(audit_log_json)
  JSON Authorization: {"timestamp": "2019-12-11T17:12:55.461491+0000",
   "type": "Authorization", "Authorization": {"version": {"major": 1, "minor": 1},
   "localAddress": "ipv4:X.X.X.X:445", "remoteAddress": "ipv4:Y.Y.Y.Y:59017",
   "serviceDescription": "netlogon", "authType": "ncacn_np",
   "domain": "EXAMPLE", "account": "admin", "sid": "S-1-5-21-1234567-890123456-500",
   "sessionId": "c5a2386f-f2cc-4241-9a9e-d104cf5859d5", "logonServer": "SOME-DC",
   "transportProtection": "SMB", "accountFlags": "0x00000010"}}

this means we are actually getting anonymous DCE/RPC access to netlogon
on top of authenticated SMB connection. In such case we have exactly
auth_type set to DCERPC_AUTH_TYPE_NONE and auth_level set to
DCERPC_AUTH_LEVEL_NONE in the pipe->auth. Thus, returning an error.

Update the code to follow the same security level check as in s4 variant
of the call.

Signed-off-by: Alexander Bokovoy <ab@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
Autobuild-User(master): Günther Deschner <gd@samba.org>
Autobuild-Date(master): Mon Jan 13 15:05:28 UTC 2020 on sn-devel-184

diff --git a/source3/rpc_server/netlogon/srv_netlog_nt.c b/source3/rpc_server/netlogon/srv_netlog_nt.c
index cbbf9feedc7b4789b210e4e5985d0195a70cd430..52b17c10e611676b4145af9f7231141cf3ee2868 100644 (file)
--- a/source3/rpc_server/netlogon/srv_netlog_nt.c
+++ b/source3/rpc_server/netlogon/srv_netlog_nt.c
@@ -2451,10 +2451,10 @@ WERROR _netr_DsRGetForestTrustInformation(struct pipes_struct *p,
 {
        NTSTATUS status;
        struct lsa_ForestTrustInformation *info, **info_ptr;
+       enum security_user_level security_level;
 
-       if (!(p->pipe_bound && (p->auth.auth_type != DCERPC_AUTH_TYPE_NONE)
-                      && (p->auth.auth_level != DCERPC_AUTH_LEVEL_NONE))) {
-               p->fault_state = DCERPC_FAULT_ACCESS_DENIED;
+       security_level = security_session_user_level(p->session_info, NULL);
+       if (security_level < SECURITY_USER) {
                return WERR_ACCESS_DENIED;
        }