/*
 * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _SSH_GSS_H
#define _SSH_GSS_H

#ifdef GSSAPI

#include "kex.h"
#include "buffer.h"

#include <gssapi/gssapi.h>

#ifdef KRB5
#ifndef HEIMDAL
#include <gssapi/gssapi_generic.h>

/* MIT Kerberos doesn't seem to define GSS_NT_HOSTBASED_SERVICE */
#ifndef GSS_C_NT_HOSTBASED_SERVICE
#define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
#endif /* GSS_C_NT_... */
#endif /* !HEIMDAL */
#endif /* KRB5 */

/* draft-ietf-secsh-gsskeyex-03 */
#define SSH2_MSG_KEXGSS_INIT				30
#define SSH2_MSG_KEXGSS_CONTINUE 			31
#define SSH2_MSG_KEXGSS_COMPLETE 			32
#define SSH2_MSG_KEXGSS_HOSTKEY				33
#define SSH2_MSG_KEXGSS_ERROR				34
#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE     		60
#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN        		61
#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE	63    
#define SSH2_MSG_USERAUTH_GSSAPI_ERROR			64  
#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK			65

#define KEX_GSS_SHA1					"gss-group1-sha1-"

typedef struct {
        char *filename;
        char *envvar;
        char *envval;
        void *data;
} ssh_gssapi_ccache;

typedef struct {
	gss_buffer_desc name;
	gss_cred_id_t   creds;
	struct ssh_gssapi_mech_struct *mech;
	ssh_gssapi_ccache store;
} ssh_gssapi_client;

typedef struct ssh_gssapi_mech_struct {
        char *enc_name;
        char *name;
        gss_OID_desc oid;
	int (*dochild) (ssh_gssapi_client *);
	int (*userok) (ssh_gssapi_client *, char *);
	int (*localname) (ssh_gssapi_client *, char **);
	void (*storecreds) (ssh_gssapi_client *);
} ssh_gssapi_mech;



typedef struct {
	OM_uint32	major; /* both */
	OM_uint32	minor; /* both */
	gss_ctx_id_t	context; /* both */
	gss_name_t	name; /* both */
	gss_OID		oid; /* client */
	gss_cred_id_t	creds; /* server */
	gss_name_t	client; /* server */
	gss_cred_id_t	client_creds; /* server */
} Gssctxt;

extern ssh_gssapi_mech *supported_mechs[];

char *ssh_gssapi_mechanisms(char *host);
char *ssh_gssapi_client_mechanisms(char *host);
gss_OID ssh_gssapi_client_id_kex(Gssctxt *ctx, char *name);
int  ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len);
void ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len);
void ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid);
void ssh_gssapi_supported_oids(gss_OID_set *oidset);
ssh_gssapi_mech *ssh_gssapi_get_ctype(Gssctxt *ctxt);

OM_uint32 ssh_gssapi_import_name(Gssctxt *ctx, const char *host);
OM_uint32 ssh_gssapi_acquire_cred(Gssctxt *ctx);
OM_uint32 ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds,
			      gss_buffer_desc *recv_tok, 
			      gss_buffer_desc *send_tok, OM_uint32 *flags);
OM_uint32 ssh_gssapi_accept_ctx(Gssctxt *ctx,
				gss_buffer_desc *recv_tok,
				gss_buffer_desc *send_tok,
				OM_uint32 *flags);
OM_uint32 ssh_gssapi_getclient(Gssctxt *ctx,
				ssh_gssapi_mech **mech,
				gss_buffer_desc *name,
				gss_cred_id_t *creds);
void ssh_gssapi_error(Gssctxt *ctx);
char *ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *maj, OM_uint32 *min);
void ssh_gssapi_build_ctx(Gssctxt **ctx);
void ssh_gssapi_delete_ctx(Gssctxt **ctx);
OM_uint32 ssh_gssapi_server_ctx(Gssctxt **ctx,gss_OID oid);

int ssh_gssapi_check_mechanism(gss_OID oid, char *host);

/* In the server */
gss_OID ssh_gssapi_server_id_kex(char *name);
int ssh_gssapi_userok(char *name);
int ssh_gssapi_localname(char **name);
void ssh_gssapi_server(Kex *kex, Buffer *client_kexinit, 
		       Buffer *server_kexinit);

OM_uint32 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *buffer, 
					gss_buffer_desc *hash);

void ssh_gssapi_do_child(char ***envp, u_int *envsizep);                 
void ssh_gssapi_cleanup_creds(void *ignored);
void ssh_gssapi_storecreds();
char *ssh_gssapi_server_mechanisms();
#endif /* GSSAPI */

#endif /* _SSH_GSS_H */