#ifndef WH_KEYFILES_H_7ba76961_
#define WH_KEYFILES_H_7ba76961_

/* This file is in the public domain. */

#include <stdio.h>
#include <sys/socket.h>

/*
 * This typedef is here, before we #include "algs.h", to work around an
 *  annoying issue.  We include algs.h which includes userauth.h which
 *  includes us because it (userauth.h) uses AK_CMD_LIST.  If we leave
 *  this typedef until after we include algs.h, then, when userauth.h
 *  uses AK_CMD_LIST, the typedef is not yet in effect and it produces
 *  an error.
 *
 * There is probably a better way to fix this.  I welcome suggestions.
 */
typedef struct ak_cmd_list AK_CMD_LIST;

#include "str.h"
#include "algs.h"

extern int load_key_pair( const char *, const char *,
			  void **, int *, HKALG **,
			  void **, int *, char **,
			  char *, FILE *);
extern int load_key_pair_stdio( FILE *, const char *, FILE *, const char *,
				void **, int *, HKALG **,
				void **, int *, char **,
				char *, FILE *);
extern int load_key_pub_string( const char *, const char *,
				void **, int *, HKALG **,
				char **, char *, FILE *);
extern void write_key( HKALG *,      const char *, void *, int,
		       const char *, const char *, void *, int );
extern int write_pub_to_fd(const char *, const char *, int, HKALG *, const void *, int, const char *);
extern int write_priv_to_fd(const char *, const char *, int, const void *, int);
extern int brief_pub_to_fd(const char *, const char *, int, HKALG *, const char *);
extern int key_files_exist(const char *, const char *);

/*
 * Authorized-keys file reading.
 *
 * read_authkeys_file(fn,cb) reads file fn, calling cb for each key or
 *  clause found.  The AK * passed to the callback goes invalid as soon
 *  as the callback returns.
 *
 * ak_nkeys(ak) and ak_key(ak,n) retrieve the number of keys in a
 *  clause and the Nth key for a given N.  Keys are returned as
 *  pointers to AK_KEY structs; these returned pointers must not be
 *  freed, and go invalid as soon as the AK * argument does.
 *
 * ak_ip_ok(ak,sa,salen) tests whether a given client address is
 *  acceptable according to the clientip clauses present, if any, in
 *  the clause.  The return value can be AK_IP_ALLOW, AK_IP_DENY, or
 *  AK_IP_SKIP; ALLOW and DENY have the obvious meanings, while SKIP
 *  means that the clause should be skipped, as if the key did not
 *  match.  (It is up to the caller to check whether the key matches.)
 *
 * ak_cmd_list_get(ak) returns an AK_CMD_LIST * which is used to check
 *  acceptability of a proposed command.  This pointer's validity does
 *  survive termination of the enclosing read_authkeys_file callback;
 *  it must be freed with ak_cmd_list_done(akcl) when it's no longer
 *  needed.
 *
 * ak_cmd_list_ok(akcl,cmd,cmdlen,tty) checks a proposed command.  It
 *  takes the AK_CMD_LIST *, the proposed command line (as a
 *  pointer-and-length), and a boolean indicating whether the client
 *  has requested a pseudo-tty (true=yes).  Return value is zero for
 *  "not acceptable" and nonzero for "acceptable".  To check a proposed
 *  interactive shell session, pass a nil pointer for the command
 *  buffer and AKCL_SHELL for the length.
 *
 * ak_cmd_list_override(akcl) indicates whether the client-specified
 *  command is to be overridden.  If `override' was used in the clause,
 *  this returns a ROSTR containing the specified command.  (The memory
 *  pointed to by the ROSTR is valid until ak_cmd_list_done() is called
 *  on the AK_CMD_LIST *.)  If `override' was not used, the returned
 *  ROSTR has length zero and a nil data pointer.
 *
 * ak_cmd_list_done(akcl) frees up any memory held by the AK_CMD_LIST.
 *  As mentioned above under ak_cmd_list_get(), it must be called when
 *  the AK_CMD_LIST is no longer needed to avoid leaking memory.  (If
 *  ak_cmd_list_get returns nil, no ak_cmd_list_done call is needed,
 *  though it is still permitted.)
 */
typedef enum {
	  AK_IP_ALLOW = 1,
	  AK_IP_DENY,
	  AK_IP_SKIP,
	  } AK_IP_OK_RV;
typedef struct ak AK;
typedef struct ak_key AK_KEY;
struct ak_key {
  HKALG *alg;
  ROSTR blob;
  const char *comment;
  } ;
extern int read_authkeys_file(const char *, int (*)(AK *));
extern int ak_nkeys(AK *);
extern const AK_KEY *ak_key(AK *, int);
extern AK_IP_OK_RV ak_ip_ok(AK *, const struct sockaddr *, int);
extern AK_CMD_LIST *ak_cmd_list_get(AK *);
#define AKCL_SHELL (-10001)
extern int ak_cmd_list_ok(AK_CMD_LIST *, const char *, int, int);
extern ROSTR ak_cmd_list_override(AK_CMD_LIST *);
extern void ak_cmd_list_done(AK_CMD_LIST *);

#endif