From 31ea01b83b8bb3075e62c1ed43d116bc96ce9f28 Mon Sep 17 00:00:00 2001 From: Arvid Requate Date: Thu, 6 Aug 2015 15:00:25 +0200 Subject: [PATCH] s4:rpc_server/netlogon: Fix for NetApp This patch fixes an issue where NetApp filers joined to a Samba/ADDC cannot resolve SIDs. Without this patch the issue can only be avoided by setting "allow nt4 crypto = yes" in smb.conf. The issue is triggered by NetApp filers in three steps: 1. The client calls netr_ServerReqChallenge to set up challenge tokens 2. Next it calls netr_ServerAuthenticate2 with NETLOGON_NEG_STRONG_KEYS set to 0. Native AD and Samba respond to this with NT_STATUS_DOWNGRADE_DETECTED. At this point Samba throws away the challenge token negotiated in the first step. 3. Next the client calls netr_ServerAuthenticate2 again, this time with NETLOGON_NEG_STRONG_KEYS set to 1. Samba returns NT_STATUS_ACCESS_DENIED as it has lost track of the challenge and denies logon with the message No challenge requested by client [CLNT1/CLNT1$], cannot authenticate Git commit 321ebc99b5a00f82265aee741a48aa84b214d6e8 introduced a workaround for a different but related issue. This patch makes a minor adjustment to that commit to delay flushing the cached challenge until it's clear that we are not in a NT_STATUS_DOWNGRADE_DETECTED situation. Signed-off-by: Arvid Requate --- source4/rpc_server/netlogon/dcerpc_netlogon.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/source4/rpc_server/netlogon/dcerpc_netlogon.c b/source4/rpc_server/netlogon/dcerpc_netlogon.c index b47ccf4..49b5b2f 100644 --- a/source4/rpc_server/netlogon/dcerpc_netlogon.c +++ b/source4/rpc_server/netlogon/dcerpc_netlogon.c @@ -172,17 +172,6 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3(struct dcesrv_call_state *dce_ca } } - /* - * At this point we can cleanup the cache entry, - * if we fail the client needs to call netr_ServerReqChallenge - * again. - * - * Note: this handles global_challenge_table == NULL - * and also a non existing record just fine. - */ - memcache_delete(global_challenge_table, - SINGLETON_CACHE, challenge_key); - server_flags = NETLOGON_NEG_ACCOUNT_LOCKOUT | NETLOGON_NEG_PERSISTENT_SAMREPL | NETLOGON_NEG_ARCFOUR | @@ -229,6 +218,17 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3(struct dcesrv_call_state *dce_ca } /* + * At this point we can cleanup the cache entry, + * if we fail the client needs to call netr_ServerReqChallenge + * again. + * + * Note: this handles global_challenge_table == NULL + * and also a non existing record just fine. + */ + memcache_delete(global_challenge_table, + SINGLETON_CACHE, challenge_key); + + /* * According to Microsoft (see bugid #6099) * Windows 7 looks at the negotiate_flags * returned in this structure *even if the -- 2.1.4