CVE-2020-1472(ZeroLogon): libcli/auth: make use of netlogon_creds_random_challenge...

This will avoid getting rejected by the server if we generate
a weak challenge.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14497

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>

diff --git a/libcli/auth/netlogon_creds_cli.c b/libcli/auth/netlogon_creds_cli.c
index 407cb471cbcc93817d7b2cdab3934a1848425f0f..12cb3149ff607feeba4837a11157d56d2129aef5 100644 (file)
--- a/libcli/auth/netlogon_creds_cli.c
+++ b/libcli/auth/netlogon_creds_cli.c
@@ -1177,8 +1177,7 @@ static void netlogon_creds_cli_auth_challenge_start(struct tevent_req *req)
 
        TALLOC_FREE(state->creds);
 
-       generate_random_buffer(state->client_challenge.data,
-                              sizeof(state->client_challenge.data));
+       netlogon_creds_random_challenge(&state->client_challenge);
 
        subreq = dcerpc_netr_ServerReqChallenge_send(state, state->ev,
                                                state->binding_handle,