netlogon: Implement SendToSam along with its winbind forwarding

This allows you to forward bad password count resets to 0. Currently,
there is a missing access check for the RODC to ensure it only applies
to cached users (msDS-Allowed-Password-Replication-Group).

(further patches still need to address forcing a RWDC contact)

Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

2 files changed, 271 insertions, 0 deletions

diff --git a/libcli/auth/netlogon_creds_cli.c b/libcli/auth/netlogon_creds_cli.c
index ff30354d60e..fcab81491c6 100644
--- a/libcli/auth/netlogon_creds_cli.c
+++ b/libcli/auth/netlogon_creds_cli.c
@@ -31,6 +31,7 @@
 #include "../libcli/auth/schannel.h"
 #include "../librpc/gen_ndr/ndr_schannel.h"
 #include "../librpc/gen_ndr/ndr_netlogon_c.h"
+#include "../librpc/gen_ndr/ndr_netlogon.h"
 #include "../librpc/gen_ndr/server_id.h"
 #include "netlogon_creds_cli.h"
 #include "source3/include/messages.h"
@@ -3415,3 +3416,262 @@ NTSTATUS netlogon_creds_cli_GetForestTrustInformation(
 	TALLOC_FREE(frame);
 	return status;
 }
+
+struct netlogon_creds_cli_SendToSam_state {
+	struct tevent_context *ev;
+	struct netlogon_creds_cli_context *context;
+	struct dcerpc_binding_handle *binding_handle;
+
+	char *srv_name_slash;
+	enum dcerpc_AuthType auth_type;
+	enum dcerpc_AuthLevel auth_level;
+
+	DATA_BLOB opaque;
+
+	struct netlogon_creds_CredentialState *creds;
+	struct netlogon_creds_CredentialState tmp_creds;
+	struct netr_Authenticator req_auth;
+	struct netr_Authenticator rep_auth;
+};
+
+static void netlogon_creds_cli_SendToSam_cleanup(struct tevent_req *req,
+								 NTSTATUS status);
+static void netlogon_creds_cli_SendToSam_locked(struct tevent_req *subreq);
+
+struct tevent_req *netlogon_creds_cli_SendToSam_send(TALLOC_CTX *mem_ctx,
+						     struct tevent_context *ev,
+						     struct netlogon_creds_cli_context *context,
+						     struct dcerpc_binding_handle *b,
+						     struct netr_SendToSamBase *message)
+{
+	struct tevent_req *req;
+	struct netlogon_creds_cli_SendToSam_state *state;
+	struct tevent_req *subreq;
+	enum ndr_err_code ndr_err;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct netlogon_creds_cli_SendToSam_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->ev = ev;
+	state->context = context;
+	state->binding_handle = b;
+
+	state->srv_name_slash = talloc_asprintf(state, "\\\\%s",
+						context->server.computer);
+	if (tevent_req_nomem(state->srv_name_slash, req)) {
+		return tevent_req_post(req, ev);
+	}
+
+	ndr_err = ndr_push_struct_blob(&state->opaque, mem_ctx, message,
+				       (ndr_push_flags_fn_t)ndr_push_netr_SendToSamBase);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		NTSTATUS status = ndr_map_error2ntstatus(ndr_err);
+		tevent_req_nterror(req, status);
+		return tevent_req_post(req, ev);
+	}
+
+	dcerpc_binding_handle_auth_info(state->binding_handle,
+					&state->auth_type,
+					&state->auth_level);
+
+	subreq = netlogon_creds_cli_lock_send(state, state->ev,
+					      state->context);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+
+	tevent_req_set_callback(subreq,
+				netlogon_creds_cli_SendToSam_locked,
+				req);
+
+	return req;
+}
+
+static void netlogon_creds_cli_SendToSam_cleanup(struct tevent_req *req,
+							 NTSTATUS status)
+{
+	struct netlogon_creds_cli_SendToSam_state *state =
+		tevent_req_data(req,
+		struct netlogon_creds_cli_SendToSam_state);
+
+	if (state->creds == NULL) {
+		return;
+	}
+
+	if (!NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_ACCESS_DENIED) &&
+	    !NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) &&
+	    !NT_STATUS_EQUAL(status, NT_STATUS_DOWNGRADE_DETECTED) &&
+	    !NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED) &&
+	    !NT_STATUS_EQUAL(status, NT_STATUS_RPC_SEC_PKG_ERROR)) {
+		TALLOC_FREE(state->creds);
+		return;
+	}
+
+	netlogon_creds_cli_delete(state->context, &state->creds);
+}
+
+static void netlogon_creds_cli_SendToSam_done(struct tevent_req *subreq);
+
+static void netlogon_creds_cli_SendToSam_locked(struct tevent_req *subreq)
+{
+	struct tevent_req *req =
+		tevent_req_callback_data(subreq,
+		struct tevent_req);
+	struct netlogon_creds_cli_SendToSam_state *state =
+		tevent_req_data(req,
+		struct netlogon_creds_cli_SendToSam_state);
+	NTSTATUS status;
+
+	status = netlogon_creds_cli_lock_recv(subreq, state,
+					      &state->creds);
+	TALLOC_FREE(subreq);
+	if (tevent_req_nterror(req, status)) {
+		return;
+	}
+
+	if (state->auth_type == DCERPC_AUTH_TYPE_SCHANNEL) {
+		switch (state->auth_level) {
+		case DCERPC_AUTH_LEVEL_INTEGRITY:
+		case DCERPC_AUTH_LEVEL_PRIVACY:
+			break;
+		default:
+			tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
+			return;
+		}
+	} else {
+		uint32_t tmp = state->creds->negotiate_flags;
+
+		if (tmp & NETLOGON_NEG_AUTHENTICATED_RPC) {
+			/*
+			 * if DCERPC_AUTH_TYPE_SCHANNEL is supported
+			 * it should be used, which means
+			 * we had a chance to verify no downgrade
+			 * happened.
+			 *
+			 * This relies on netlogon_creds_cli_check*
+			 * being called before, as first request after
+			 * the DCERPC bind.
+			 */
+			tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
+			return;
+		}
+	}
+
+	/*
+	 * we defer all callbacks in order to cleanup
+	 * the database record.
+	 */
+	tevent_req_defer_callback(req, state->ev);
+
+	state->tmp_creds = *state->creds;
+	netlogon_creds_client_authenticator(&state->tmp_creds,
+					    &state->req_auth);
+	ZERO_STRUCT(state->rep_auth);
+
+	if (state->tmp_creds.negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
+		netlogon_creds_aes_encrypt(&state->tmp_creds,
+					   state->opaque.data,
+					   state->opaque.length);
+	} else {
+		netlogon_creds_arcfour_crypt(&state->tmp_creds,
+					     state->opaque.data,
+					     state->opaque.length);
+	}
+
+	subreq = dcerpc_netr_NetrLogonSendToSam_send(state, state->ev,
+						     state->binding_handle,
+						     state->srv_name_slash,
+						     state->tmp_creds.computer_name,
+						     &state->req_auth,
+						     &state->rep_auth,
+						     state->opaque.data,
+						     state->opaque.length);
+	if (tevent_req_nomem(subreq, req)) {
+		status = NT_STATUS_NO_MEMORY;
+		netlogon_creds_cli_SendToSam_cleanup(req, status);
+		return;
+	}
+
+	tevent_req_set_callback(subreq,
+				netlogon_creds_cli_SendToSam_done,
+				req);
+}
+
+static void netlogon_creds_cli_SendToSam_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req =
+		tevent_req_callback_data(subreq,
+		struct tevent_req);
+	struct netlogon_creds_cli_SendToSam_state *state =
+		tevent_req_data(req,
+		struct netlogon_creds_cli_SendToSam_state);
+	NTSTATUS status;
+	NTSTATUS result;
+	bool ok;
+
+	status = dcerpc_netr_NetrLogonSendToSam_recv(subreq, state, &result);
+	TALLOC_FREE(subreq);
+	if (tevent_req_nterror(req, status)) {
+		netlogon_creds_cli_SendToSam_cleanup(req, status);
+		return;
+	}
+
+	ok = netlogon_creds_client_check(&state->tmp_creds,
+					 &state->rep_auth.cred);
+	if (!ok) {
+		status = NT_STATUS_ACCESS_DENIED;
+		tevent_req_nterror(req, status);
+		netlogon_creds_cli_SendToSam_cleanup(req, status);
+		return;
+	}
+
+	*state->creds = state->tmp_creds;
+	status = netlogon_creds_cli_store(state->context,
+					  &state->creds);
+
+	if (tevent_req_nterror(req, status)) {
+		netlogon_creds_cli_SendToSam_cleanup(req, status);
+		return;
+	}
+
+	/*
+	 * Creds must be stored before we send back application errors
+	 * e.g. NT_STATUS_NOT_IMPLEMENTED
+	 */
+	if (tevent_req_nterror(req, result)) {
+		netlogon_creds_cli_SendToSam_cleanup(req, result);
+		return;
+	}
+
+	tevent_req_done(req);
+}
+
+NTSTATUS netlogon_creds_cli_SendToSam(struct netlogon_creds_cli_context *context,
+				      struct dcerpc_binding_handle *b,
+				      struct netr_SendToSamBase *message)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	struct tevent_context *ev;
+	struct tevent_req *req;
+	NTSTATUS status = NT_STATUS_OK;
+
+	ev = samba_tevent_context_init(frame);
+	if (ev == NULL) {
+		goto fail;
+	}
+	req = netlogon_creds_cli_SendToSam_send(frame, ev, context, b, message);
+	if (req == NULL) {
+		goto fail;
+	}
+	if (!tevent_req_poll_ntstatus(req, ev, &status)) {
+		goto fail;
+	}
+
+	/* Ignore the result */
+ fail:
+	TALLOC_FREE(frame);
+	return status;
+}
diff --git a/libcli/auth/netlogon_creds_cli.h b/libcli/auth/netlogon_creds_cli.h
index 949e03bd460..7c737dd920a 100644
--- a/libcli/auth/netlogon_creds_cli.h
+++ b/libcli/auth/netlogon_creds_cli.h
@@ -181,4 +181,15 @@ NTSTATUS netlogon_creds_cli_GetForestTrustInformation(
 			TALLOC_CTX *mem_ctx,
 			struct lsa_ForestTrustInformation **forest_trust_info);
 
+struct tevent_req *netlogon_creds_cli_SendToSam_send(TALLOC_CTX *mem_ctx,
+						     struct tevent_context *ev,
+						     struct netlogon_creds_cli_context *context,
+						     struct dcerpc_binding_handle *b,
+						     struct netr_SendToSamBase *message);
+
+NTSTATUS netlogon_creds_cli_SendToSam(
+				struct netlogon_creds_cli_context *context,
+				struct dcerpc_binding_handle *b,
+				struct netr_SendToSamBase *message);
+
 #endif /* NETLOGON_CREDS_CLI_H */