From 0b7da43da0bd5c7e0986854cda63103f082a26ee Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Thu, 18 Mar 2010 09:14:40 +0100
Subject: s3:smbd: add an option to skip signings checks srv_check_sign_mac for
 trusted channels

metze
---
 source3/smbd/process.c |  2 +-
 source3/smbd/signing.c | 24 +++++++++++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

(limited to 'source3/smbd')

diff --git a/source3/smbd/process.c b/source3/smbd/process.c
index f467587ab0..09d00a3be8 100644
--- a/source3/smbd/process.c
+++ b/source3/smbd/process.c
@@ -352,7 +352,7 @@ static NTSTATUS receive_smb_talloc(TALLOC_CTX *mem_ctx,	int fd,
 	}
 
 	/* Check the incoming SMB signature. */
-	if (!srv_check_sign_mac(smbd_server_conn, *buffer, seqnum)) {
+	if (!srv_check_sign_mac(smbd_server_conn, *buffer, seqnum, false)) {
 		DEBUG(0, ("receive_smb: SMB Signature verification failed on "
 			  "incoming packet!\n"));
 		return NT_STATUS_INVALID_NETWORK_RESPONSE;
diff --git a/source3/smbd/signing.c b/source3/smbd/signing.c
index 9b5e3452f9..f8162d8778 100644
--- a/source3/smbd/signing.c
+++ b/source3/smbd/signing.c
@@ -28,13 +28,35 @@
 ************************************************************/
 
 bool srv_check_sign_mac(struct smbd_server_connection *conn,
-			const char *inbuf, uint32_t *seqnum)
+			const char *inbuf, uint32_t *seqnum,
+			bool trusted_channel)
 {
 	/* Check if it's a non-session message. */
 	if(CVAL(inbuf,0)) {
 		return true;
 	}
 
+	if (trusted_channel) {
+		NTSTATUS status;
+
+		if (smb_len(inbuf) < (smb_ss_field + 8 - 4)) {
+			DEBUG(1,("smb_signing_check_pdu: Can't check signature "
+				 "on short packet! smb_len = %u\n",
+				 smb_len(inbuf)));
+			return false;
+		}
+
+		status = NT_STATUS(IVAL(inbuf, smb_ss_field + 4));
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(1,("smb_signing_check_pdu: trusted channel passed %s\n",
+				 nt_errstr(status)));
+			return false;
+		}
+
+		*seqnum = IVAL(inbuf, smb_ss_field);
+		return true;
+	}
+
 	*seqnum = smb_signing_next_seqnum(conn->smb1.signing_state, false);
 	return smb_signing_check_pdu(conn->smb1.signing_state,
 				     (const uint8_t *)inbuf,
-- 
cgit