/* 
   Unix SMB/CIFS implementation.

   dcerpc schannel operations

   Copyright (C) Andrew Tridgell 2004
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"
#include "auth/auth.h"
#include "libcli/composite/composite.h"
#include "libcli/auth/proto.h"


struct schannel_key_state {
	struct dcerpc_pipe *pipe;
	struct dcerpc_pipe *pipe2;
	struct dcerpc_binding *binding;
	struct cli_credentials *credentials;
	struct creds_CredentialState *creds;
	uint32_t negotiate_flags;
	struct netr_Credential credentials1;
	struct netr_Credential credentials2;
	struct netr_Credential credentials3;
	struct netr_ServerReqChallenge r;
	struct netr_ServerAuthenticate2 a;
	const struct samr_Password *mach_pwd;
};


static void continue_secondary_connection(struct composite_context *ctx);
static void continue_bind_auth_none(struct composite_context *ctx);
static void continue_srv_challenge(struct rpc_request *req);
static void continue_srv_auth2(struct rpc_request *req);


static void continue_epm_map_binding(struct composite_context *ctx)
{
	struct composite_context *c;
	struct schannel_key_state *s;
	struct composite_context *sec_conn_req;

	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct schannel_key_state);

	c->status = dcerpc_epm_map_binding_recv(ctx);
	if (!composite_is_ok(c)) {
		DEBUG(0,("Failed to map DCERPC/TCP NCACN_NP pipe for '%s' - %s\n",
			 DCERPC_NETLOGON_UUID, nt_errstr(c->status)));
		return;
	}

	sec_conn_req = dcerpc_secondary_connection_send(c, s->pipe, &s->pipe2,
							s->binding);
	if (composite_nomem(sec_conn_req, c)) return;

	composite_continue(c, sec_conn_req, continue_secondary_connection, c);
}


static void continue_secondary_connection(struct composite_context *ctx)
{
	struct composite_context *c;
	struct schannel_key_state *s;
	struct composite_context *auth_none_req;

	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct schannel_key_state);

	c->status = dcerpc_secondary_connection_recv(ctx);
	if (!composite_is_ok(c)) return;

	auth_none_req = dcerpc_bind_auth_none_send(c, s->pipe2, &dcerpc_table_netlogon);
	if (composite_nomem(auth_none_req, c)) return;

	composite_continue(c, auth_none_req, continue_bind_auth_none, c);
}


static void continue_bind_auth_none(struct composite_context *ctx)
{
	struct composite_context *c;
	struct schannel_key_state *s;
	struct rpc_request *srv_challenge_req;

	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct schannel_key_state);
	
	c->status = dcerpc_bind_auth_none_recv(ctx);
	if (!composite_is_ok(c)) {
		talloc_free(s->pipe2);
		return;
	}

	s->r.in.server_name   = talloc_asprintf(c, "\\\\%s", dcerpc_server_name(s->pipe));
	if (composite_nomem(s->r.in.server_name, c)) return;
	s->r.in.computer_name = cli_credentials_get_workstation(s->credentials);
	s->r.in.credentials   = &s->credentials1;
	s->r.out.credentials  = &s->credentials2;

	generate_random_buffer(s->credentials1.data, sizeof(s->credentials1.data));

	/*
	  request a netlogon challenge
	*/

	srv_challenge_req = dcerpc_netr_ServerReqChallenge_send(s->pipe2, c, &s->r);
	if (composite_nomem(srv_challenge_req, c)) return;

	composite_continue_rpc(c, srv_challenge_req, continue_srv_challenge, c);
}


static void continue_srv_challenge(struct rpc_request *req)
{
	struct composite_context *c;
	struct schannel_key_state *s;
	struct rpc_request *srv_auth2_req;

	c = talloc_get_type(req->async.private, struct composite_context);
	s = talloc_get_type(c->private_data, struct schannel_key_state);

	c->status = dcerpc_ndr_request_recv(req);
	if (!composite_is_ok(c)) return;

	/*
	  authenticate on the netlogon pipe
	*/

	s->mach_pwd = cli_credentials_get_nt_hash(s->credentials, c);

	creds_client_init(s->creds, &s->credentials1, &s->credentials2,
			  s->mach_pwd, &s->credentials3, s->negotiate_flags);

	s->a.in.server_name      = s->r.in.server_name;
	s->a.in.account_name     = cli_credentials_get_username(s->credentials);
	s->a.in.secure_channel_type =
		cli_credentials_get_secure_channel_type(s->credentials);
	s->a.in.computer_name    = cli_credentials_get_workstation(s->credentials);
	s->a.in.negotiate_flags  = &s->negotiate_flags;
	s->a.in.credentials      = &s->credentials3;
	s->a.out.negotiate_flags = &s->negotiate_flags;
	s->a.out.credentials     = &s->credentials3;

	srv_auth2_req = dcerpc_netr_ServerAuthenticate2_send(s->pipe2, c, &s->a);
	if (composite_nomem(srv_auth2_req, c)) return;

	composite_continue_rpc(c, srv_auth2_req, continue_srv_auth2, c);
}


static void continue_srv_auth2(struct rpc_request *req)
{
	struct composite_context *c;
	struct schannel_key_state *s;

	c = talloc_get_type(req->async.private, struct composite_context);
	s = talloc_get_type(c->private_data, struct schannel_key_state);

	c->status = dcerpc_ndr_request_recv(req);
	if (!composite_is_ok(c)) return;

	if (!creds_client_check(s->creds, s->a.out.credentials)) {
		composite_error(c, NT_STATUS_UNSUCCESSFUL);
		return;
	}

	cli_credentials_set_netlogon_creds(s->credentials, s->creds);
	talloc_free(s->pipe2);
	
	composite_done(c);
}


/*
  initiate getting a schannel key using a netlogon challenge on a secondary pipe
*/
struct composite_context *dcerpc_schannel_key_send(TALLOC_CTX *mem_ctx,
						   struct dcerpc_pipe *p,
						   struct cli_credentials *credentials)
{
	struct composite_context *c;
	struct schannel_key_state *s;
	struct composite_context *epm_map_req;
	
	c = talloc_zero(mem_ctx, struct composite_context);
	if (c == NULL) return NULL;

	s = talloc_zero(c, struct schannel_key_state);
	if (composite_nomem(s, c)) return c;

	c->state = COMPOSITE_STATE_IN_PROGRESS;
	c->private_data = s;
	c->event_ctx = p->conn->event_ctx;

	s->pipe        = p;
	s->credentials = credentials;

	s->creds = talloc(c, struct creds_CredentialState);
	if (composite_nomem(s->creds, c)) return c;

	if (s->pipe->conn->flags & DCERPC_SCHANNEL_128) {
		s->negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
	} else {
		s->negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
	}

	s->binding = talloc(c, struct dcerpc_binding);
	if (composite_nomem(s->binding, c)) return c;

	*s->binding = *s->pipe->binding;

	epm_map_req = dcerpc_epm_map_binding_send(c, s->binding,
						  &dcerpc_table_netlogon,
						  s->pipe->conn->event_ctx);
	if (composite_nomem(epm_map_req, c)) return c;

	composite_continue(c, epm_map_req, continue_epm_map_binding, c);
	return c;
}


NTSTATUS dcerpc_schannel_key_recv(struct composite_context *c)
{
	NTSTATUS status = composite_wait(c);
	
	talloc_free(c);
	return status;
}


struct auth_schannel_state {
	struct dcerpc_pipe *pipe;
	struct cli_credentials *credentials;
	const struct dcerpc_interface_table *table;
	uint8_t auth_level;
};


static void continue_bind_auth(struct composite_context *ctx);


static void continue_schannel_key(struct composite_context *ctx)
{
	struct composite_context *auth_req;
	struct composite_context *c = talloc_get_type(ctx->async.private_data,
						      struct composite_context);
	struct auth_schannel_state *s = talloc_get_type(c->private_data,
							struct auth_schannel_state);

	c->status = dcerpc_schannel_key_recv(ctx);
	if (!composite_is_ok(c)) {
		DEBUG(1, ("Failed to setup credentials for account %s: %s\n",
			  cli_credentials_get_username(s->credentials), nt_errstr(c->status)));
		return;
	}

	auth_req = dcerpc_bind_auth_send(c, s->pipe, s->table, s->credentials, 
					 DCERPC_AUTH_TYPE_SCHANNEL, s->auth_level,
					 NULL);
	if (composite_nomem(auth_req, c)) return;
	
	composite_continue(c, auth_req, continue_bind_auth, c);
}


static void continue_bind_auth(struct composite_context *ctx)
{
	struct composite_context *c = talloc_get_type(ctx->async.private_data,
						      struct composite_context);

	c->status = dcerpc_bind_auth_recv(ctx);
	if (!composite_is_ok(c)) return;

	composite_done(c);
}


struct composite_context *dcerpc_bind_auth_schannel_send(TALLOC_CTX *tmp_ctx, 
							 struct dcerpc_pipe *p,
							 const struct dcerpc_interface_table *table,
							 struct cli_credentials *credentials,
							 uint8_t auth_level)
{
	struct composite_context *c;
	struct auth_schannel_state *s;
	struct composite_context *schan_key_req;

	c = talloc_zero(tmp_ctx, struct composite_context);
	if (c == NULL) return NULL;
	
	s = talloc_zero(c, struct auth_schannel_state);
	if (composite_nomem(s, c)) return c;
	
	c->state = COMPOSITE_STATE_IN_PROGRESS;
	c->private_data = s;
	c->event_ctx = p->conn->event_ctx;

	s->pipe        = p;
	s->credentials = credentials;
	s->table       = table;
	s->auth_level  = auth_level;

	schan_key_req = dcerpc_schannel_key_send(c, p, credentials);
	if (composite_nomem(schan_key_req, c)) return c;

	composite_continue(c, schan_key_req, continue_schannel_key, c);
	return c;
}


NTSTATUS dcerpc_bind_auth_schannel_recv(struct composite_context *c)
{
	NTSTATUS status = composite_wait(c);
	
	talloc_free(c);
	return status;
}


NTSTATUS dcerpc_bind_auth_schannel(TALLOC_CTX *tmp_ctx, 
				   struct dcerpc_pipe *p,
				   const struct dcerpc_interface_table *table,
				   struct cli_credentials *credentials,
				   uint8_t auth_level)
{
	struct composite_context *c;

	c = dcerpc_bind_auth_schannel_send(tmp_ctx, p, table, credentials,
					   auth_level);
	return dcerpc_bind_auth_schannel_recv(c);
}