Don't sign NTP packets to disabled accounts

(As this would allow an offline attack on their password)

Andrew Bartlett
(This used to be commit e28481fc0976231c6f4cb7a5f7c7708f4becdb18)

1 files changed, 10 insertions, 1 deletions

diff --git a/source4/ntp_signd/ntp_signd.c b/source4/ntp_signd/ntp_signd.c
index fdd97e475c..c1ac7dbcf4 100644
--- a/source4/ntp_signd/ntp_signd.c
+++ b/source4/ntp_signd/ntp_signd.c
@@ -123,9 +123,10 @@ static NTSTATUS ntp_signd_recv(void *private, DATA_BLOB wrapped_input)
 	struct signed_reply signed_reply;
 	enum ndr_err_code ndr_err;
 	struct ldb_result *res;
-	const char *attrs[] = { "unicodePwd", NULL };
+	const char *attrs[] = { "unicodePwd", "userAccountControl", NULL };
 	struct MD5Context ctx;
 	struct samr_Password *nt_hash;
+	uint32_t user_account_control;
 	int ret;
 
 	NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
@@ -184,6 +185,14 @@ static NTSTATUS ntp_signd_recv(void *private, DATA_BLOB wrapped_input)
 		return signing_failure(ntp_signdconn, sign_request.packet_id);
 	}
 
+	user_account_control = ldb_msg_find_attr_as_uint(res->msgs[0], "userAccountControl", 0);
+
+	if (user_account_control & UF_ACCOUNTDISABLE) {
+		DEBUG(1, ("Account for SID [%s] is disabled\n", dom_sid_string(tmp_ctx, sid)));
+		talloc_free(tmp_ctx);
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
 	nt_hash = samdb_result_hash(tmp_ctx, res->msgs[0], "unicodePwd");
 	if (!nt_hash) {
 		DEBUG(1, ("No unicodePwd found on record of SID %s for NTP signing\n", dom_sid_string(tmp_ctx, sid)));