/* 
   Unix SMB/Netbios implementation.
   Version 3.0
   handle NLTMSSP, server side

   Copyright (C) Andrew Tridgell      2001
   Copyright (C) Andrew Bartlett 2001-2003,2011

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "auth.h"
#include "../auth/ntlmssp/ntlmssp.h"
#include "ntlmssp_wrap.h"
#include "../librpc/gen_ndr/netlogon.h"
#include "../librpc/gen_ndr/dcerpc.h"
#include "../lib/tsocket/tsocket.h"
#include "auth/gensec/gensec.h"
#include "librpc/rpc/dcerpc.h"
#include "lib/param/param.h"

static NTSTATUS gensec_ntlmssp3_server_session_info(struct gensec_security *gensec_security,
					TALLOC_CTX *mem_ctx,
					struct auth_session_info **session_info)
{
	struct gensec_ntlmssp_context *gensec_ntlmssp =
		talloc_get_type_abort(gensec_security->private_data,
				      struct gensec_ntlmssp_context);
	NTSTATUS nt_status;

	nt_status = create_local_token(mem_ctx,
				       gensec_ntlmssp->server_info,
				       &gensec_ntlmssp->ntlmssp_state->session_key,
				       gensec_ntlmssp->ntlmssp_state->user,
				       session_info);
	if (!NT_STATUS_IS_OK(nt_status)) {
		DEBUG(10, ("create_local_token failed: %s\n",
			   nt_errstr(nt_status)));
		return nt_status;
	}

	return NT_STATUS_OK;
}

static NTSTATUS gensec_ntlmssp3_server_update(struct gensec_security *gensec_security,
					      TALLOC_CTX *out_mem_ctx,
					      struct tevent_context *ev,
					      const DATA_BLOB request,
					      DATA_BLOB *reply)
{
	NTSTATUS status;
	struct gensec_ntlmssp_context *gensec_ntlmssp =
		talloc_get_type_abort(gensec_security->private_data,
				      struct gensec_ntlmssp_context);

	status = ntlmssp_update(gensec_ntlmssp->ntlmssp_state, request, reply);
	if (NT_STATUS_IS_OK(status) ||
	    NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
		talloc_steal(out_mem_ctx, reply->data);
	}

	return status;
}

/**
 * Return the challenge as determined by the authentication subsystem 
 * @return an 8 byte random challenge
 */

static NTSTATUS auth_ntlmssp_get_challenge(const struct ntlmssp_state *ntlmssp_state,
					   uint8_t chal[8])
{
	struct gensec_ntlmssp_context *gensec_ntlmssp =
		(struct gensec_ntlmssp_context *)ntlmssp_state->callback_private;
	gensec_ntlmssp->auth_context->get_ntlm_challenge(
		gensec_ntlmssp->auth_context, chal);
	return NT_STATUS_OK;
}

/**
 * Some authentication methods 'fix' the challenge, so we may not be able to set it
 *
 * @return If the effective challenge used by the auth subsystem may be modified
 */
static bool auth_ntlmssp_may_set_challenge(const struct ntlmssp_state *ntlmssp_state)
{
	struct gensec_ntlmssp_context *gensec_ntlmssp =
		(struct gensec_ntlmssp_context *)ntlmssp_state->callback_private;
	struct auth_context *auth_context = gensec_ntlmssp->auth_context;

	return auth_context->challenge_may_be_modified;
}

/**
 * NTLM2 authentication modifies the effective challenge, 
 * @param challenge The new challenge value
 */
static NTSTATUS auth_ntlmssp_set_challenge(struct ntlmssp_state *ntlmssp_state, DATA_BLOB *challenge)
{
	struct gensec_ntlmssp_context *gensec_ntlmssp =
		(struct gensec_ntlmssp_context *)ntlmssp_state->callback_private;
	struct auth_context *auth_context = gensec_ntlmssp->auth_context;

	SMB_ASSERT(challenge->length == 8);

	auth_context->challenge = data_blob_talloc(auth_context,
						   challenge->data, challenge->length);

	auth_context->challenge_set_by = "NTLMSSP callback (NTLM2)";

	DEBUG(5, ("auth_context challenge set by %s\n", auth_context->challenge_set_by));
	DEBUG(5, ("challenge is: \n"));
	dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
	return NT_STATUS_OK;
}

/**
 * Check the password on an NTLMSSP login.  
 *
 * Return the session keys used on the connection.
 */

static NTSTATUS auth_ntlmssp_check_password(struct ntlmssp_state *ntlmssp_state, TALLOC_CTX *mem_ctx,
					    DATA_BLOB *session_key, DATA_BLOB *lm_session_key)
{
	struct gensec_ntlmssp_context *gensec_ntlmssp =
		(struct gensec_ntlmssp_context *)ntlmssp_state->callback_private;
	struct auth_usersupplied_info *user_info = NULL;
	NTSTATUS nt_status;
	bool username_was_mapped;

	/* the client has given us its machine name (which we otherwise would not get on port 445).
	   we need to possibly reload smb.conf if smb.conf includes depend on the machine name */

	set_remote_machine_name(gensec_ntlmssp->ntlmssp_state->client.netbios_name, True);

	/* setup the string used by %U */
	/* sub_set_smb_name checks for weird internally */
	sub_set_smb_name(gensec_ntlmssp->ntlmssp_state->user);

	lp_load(get_dyn_CONFIGFILE(), false, false, true, true);

	nt_status = make_user_info_map(&user_info,
				       gensec_ntlmssp->ntlmssp_state->user,
				       gensec_ntlmssp->ntlmssp_state->domain,
				       gensec_ntlmssp->ntlmssp_state->client.netbios_name,
				       gensec_get_remote_address(gensec_ntlmssp->gensec_security),
	                               gensec_ntlmssp->ntlmssp_state->lm_resp.data ? &gensec_ntlmssp->ntlmssp_state->lm_resp : NULL,
	                               gensec_ntlmssp->ntlmssp_state->nt_resp.data ? &gensec_ntlmssp->ntlmssp_state->nt_resp : NULL,
				       NULL, NULL, NULL,
				       AUTH_PASSWORD_RESPONSE);

	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	user_info->logon_parameters = MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT | MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT;

	nt_status = gensec_ntlmssp->auth_context->check_ntlm_password(gensec_ntlmssp->auth_context,
									  user_info, &gensec_ntlmssp->server_info);

	username_was_mapped = user_info->was_mapped;

	free_user_info(&user_info);

	if (!NT_STATUS_IS_OK(nt_status)) {
		nt_status = do_map_to_guest_server_info(nt_status,
							&gensec_ntlmssp->server_info,
							gensec_ntlmssp->ntlmssp_state->user,
							gensec_ntlmssp->ntlmssp_state->domain);
		return nt_status;
	}

	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	gensec_ntlmssp->server_info->nss_token |= username_was_mapped;

	/* Clear out the session keys, and pass them to the caller.
	 * They will not be used in this form again - instead the
	 * NTLMSSP code will decide on the final correct session key,
	 * and supply it to create_local_token() */
	if (gensec_ntlmssp->server_info->session_key.length) {
		DEBUG(10, ("Got NT session key of length %u\n",
			(unsigned int)gensec_ntlmssp->server_info->session_key.length));
		*session_key = gensec_ntlmssp->server_info->session_key;
		talloc_steal(mem_ctx, gensec_ntlmssp->server_info->session_key.data);
		gensec_ntlmssp->server_info->session_key = data_blob_null;
	}
	if (gensec_ntlmssp->server_info->lm_session_key.length) {
		DEBUG(10, ("Got LM session key of length %u\n",
			(unsigned int)gensec_ntlmssp->server_info->lm_session_key.length));
		*lm_session_key = gensec_ntlmssp->server_info->lm_session_key;
		talloc_steal(mem_ctx, gensec_ntlmssp->server_info->lm_session_key.data);
		gensec_ntlmssp->server_info->lm_session_key = data_blob_null;
	}
	return nt_status;
}

NTSTATUS auth_generic_prepare(const struct tsocket_address *remote_address,
			      struct auth_generic_state **auth_ntlmssp_state)
{
	struct auth_context *auth_context;
	struct auth_generic_state *ans;
	NTSTATUS nt_status;

	ans = talloc_zero(NULL, struct auth_generic_state);
	if (!ans) {
		DEBUG(0,("auth_ntlmssp_start: talloc failed!\n"));
		return NT_STATUS_NO_MEMORY;
	}

	nt_status = make_auth_context_subsystem(talloc_tos(), &auth_context);
	if (!NT_STATUS_IS_OK(nt_status)) {
		TALLOC_FREE(ans);
		return nt_status;
	}

	ans->auth_context = talloc_steal(ans, auth_context);

	if (auth_context->prepare_gensec) {
		nt_status = auth_context->prepare_gensec(ans,
							 &ans->gensec_security);
		if (!NT_STATUS_IS_OK(nt_status)) {
			TALLOC_FREE(ans);
			return nt_status;
		}
		*auth_ntlmssp_state = ans;
		return NT_STATUS_OK;
	} else {
		struct gensec_settings *gensec_settings;
		struct loadparm_context *lp_ctx;

		lp_ctx = loadparm_init_s3(ans, loadparm_s3_context());
		if (lp_ctx == NULL) {
			DEBUG(10, ("loadparm_init_s3 failed\n"));
			TALLOC_FREE(ans);
			return NT_STATUS_INVALID_SERVER_STATE;
		}

		gensec_settings = lpcfg_gensec_settings(ans, lp_ctx);
		if (lp_ctx == NULL) {
			DEBUG(10, ("lpcfg_gensec_settings failed\n"));
			TALLOC_FREE(ans);
			return NT_STATUS_NO_MEMORY;
		}

		nt_status = gensec_server_start(ans, gensec_settings,
						NULL, &ans->gensec_security);

		if (!NT_STATUS_IS_OK(nt_status)) {
			TALLOC_FREE(ans);
			return nt_status;
		}
		talloc_unlink(ans, lp_ctx);
		talloc_unlink(ans, gensec_settings);
	}

	nt_status = gensec_set_remote_address(ans->gensec_security,
					      remote_address);
	if (!NT_STATUS_IS_OK(nt_status)) {
		TALLOC_FREE(ans);
		return nt_status;
	}

	*auth_ntlmssp_state = ans;
	return NT_STATUS_OK;
}

static NTSTATUS gensec_ntlmssp3_server_start(struct gensec_security *gensec_security)
{
	NTSTATUS nt_status;
	bool is_standalone;
	const char *netbios_name;
	const char *netbios_domain;
	const char *dns_name;
	char *dns_domain;
	struct gensec_ntlmssp_context *gensec_ntlmssp;

	if ((enum server_role)lp_server_role() == ROLE_STANDALONE) {
		is_standalone = true;
	} else {
		is_standalone = false;
	}

	netbios_name = lp_netbios_name();
	netbios_domain = lp_workgroup();
	/* This should be a 'netbios domain -> DNS domain' mapping */
	dns_domain = get_mydnsdomname(talloc_tos());
	if (dns_domain) {
		strlower_m(dns_domain);
	}
	dns_name = get_mydnsfullname();

	nt_status = gensec_ntlmssp_start(gensec_security);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	gensec_ntlmssp =
		talloc_get_type_abort(gensec_security->private_data,
				      struct gensec_ntlmssp_context);

	nt_status = ntlmssp_server_start(gensec_ntlmssp,
					 is_standalone,
					 netbios_name,
					 netbios_domain,
					 dns_name,
					 dns_domain,
					 &gensec_ntlmssp->ntlmssp_state);
	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	gensec_ntlmssp->ntlmssp_state->callback_private = gensec_ntlmssp;

	gensec_ntlmssp->ntlmssp_state->get_challenge = auth_ntlmssp_get_challenge;
	gensec_ntlmssp->ntlmssp_state->may_set_challenge = auth_ntlmssp_may_set_challenge;
	gensec_ntlmssp->ntlmssp_state->set_challenge = auth_ntlmssp_set_challenge;
	gensec_ntlmssp->ntlmssp_state->check_password = auth_ntlmssp_check_password;

	if (gensec_ntlmssp->gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
		gensec_ntlmssp->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
	}
	if (gensec_ntlmssp->gensec_security->want_features & GENSEC_FEATURE_SIGN) {
		gensec_ntlmssp->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
	}
	if (gensec_ntlmssp->gensec_security->want_features & GENSEC_FEATURE_SEAL) {
		gensec_ntlmssp->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
		gensec_ntlmssp->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
	}

	return NT_STATUS_OK;
}

static const char *gensec_ntlmssp3_server_oids[] = {
	GENSEC_OID_NTLMSSP,
	NULL
};

static const struct gensec_security_ops gensec_ntlmssp3_server_ops = {
	.name		= "ntlmssp3_server",
	.sasl_name	= GENSEC_SASL_NAME_NTLMSSP, /* "NTLM" */
	.auth_type	= DCERPC_AUTH_TYPE_NTLMSSP,
	.oid            = gensec_ntlmssp3_server_oids,
	.server_start   = gensec_ntlmssp3_server_start,
	.magic 	        = gensec_ntlmssp_magic,
	.update 	= gensec_ntlmssp3_server_update,
	.sig_size	= gensec_ntlmssp_sig_size,
	.sign_packet	= gensec_ntlmssp_sign_packet,
	.check_packet	= gensec_ntlmssp_check_packet,
	.seal_packet	= gensec_ntlmssp_seal_packet,
	.unseal_packet	= gensec_ntlmssp_unseal_packet,
	.wrap           = gensec_ntlmssp_wrap,
	.unwrap         = gensec_ntlmssp_unwrap,
	.session_key	= gensec_ntlmssp_session_key,
	.session_info   = gensec_ntlmssp3_server_session_info,
	.have_feature   = gensec_ntlmssp_have_feature,
	.enabled        = true,
	.priority       = GENSEC_NTLMSSP
};

NTSTATUS auth_generic_start(struct auth_generic_state *auth_ntlmssp_state, const char *oid)
{
	struct gensec_ntlmssp_context *gensec_ntlmssp;
	NTSTATUS status;

	if (auth_ntlmssp_state->auth_context->gensec_start_mech_by_oid) {
		return auth_ntlmssp_state->auth_context->gensec_start_mech_by_oid(
				auth_ntlmssp_state->gensec_security, oid);
	}

	if (strcmp(oid, GENSEC_OID_NTLMSSP) != 0) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}

	status = gensec_start_mech_by_ops(auth_ntlmssp_state->gensec_security,
					  &gensec_ntlmssp3_server_ops);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	gensec_ntlmssp =
		talloc_get_type_abort(auth_ntlmssp_state->gensec_security->private_data,
				      struct gensec_ntlmssp_context);

	gensec_ntlmssp->auth_context = talloc_move(gensec_ntlmssp, &auth_ntlmssp_state->auth_context);

	return NT_STATUS_OK;
}

NTSTATUS auth_generic_authtype_start(struct auth_generic_state *auth_ntlmssp_state,
				     uint8_t auth_type, uint8_t auth_level)
{
	struct gensec_ntlmssp_context *gensec_ntlmssp;
	NTSTATUS status;

	if (auth_ntlmssp_state->auth_context->gensec_start_mech_by_authtype) {
		return auth_ntlmssp_state->auth_context->gensec_start_mech_by_authtype(
				auth_ntlmssp_state->gensec_security,
				auth_type, auth_level);
	}

	if (auth_type != DCERPC_AUTH_TYPE_NTLMSSP) {
		/* The caller will then free the auth_ntlmssp_state,
		 * undoing what was done in auth_generic_prepare().
		 *
		 * We can't do that logic here, as
		 * auth_ntlmssp_want_feature() may have been called in
		 * between.
		 */
		return NT_STATUS_NOT_IMPLEMENTED;
	}

	gensec_want_feature(auth_ntlmssp_state->gensec_security,
			    GENSEC_FEATURE_DCE_STYLE);
	gensec_want_feature(auth_ntlmssp_state->gensec_security,
			    GENSEC_FEATURE_ASYNC_REPLIES);
	if (auth_level == DCERPC_AUTH_LEVEL_INTEGRITY) {
		gensec_want_feature(auth_ntlmssp_state->gensec_security,
				    GENSEC_FEATURE_SIGN);
	} else if (auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
		gensec_want_feature(auth_ntlmssp_state->gensec_security,
				    GENSEC_FEATURE_SIGN);
		gensec_want_feature(auth_ntlmssp_state->gensec_security,
				    GENSEC_FEATURE_SEAL);
	} else if (auth_level == DCERPC_AUTH_LEVEL_CONNECT) {
		/* Default features */
	} else {
		DEBUG(2,("auth_level %d not supported in DCE/RPC authentication\n",
			 auth_level));
		return NT_STATUS_INVALID_PARAMETER;
	}

	status = gensec_start_mech_by_ops(auth_ntlmssp_state->gensec_security,
					  &gensec_ntlmssp3_server_ops);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	gensec_ntlmssp =
		talloc_get_type_abort(auth_ntlmssp_state->gensec_security->private_data,
				      struct gensec_ntlmssp_context);

	gensec_ntlmssp->auth_context = talloc_move(gensec_ntlmssp, &auth_ntlmssp_state->auth_context);

	return NT_STATUS_OK;
}