/* $Id$
 *
 * Internal support functions for the wallet client.
 *
 * Written by Russ Allbery <rra@stanford.edu>
 * Copyright 2007, 2008 Board of Trustees, Leland Stanford Jr. University
 *
 * See LICENSE for licensing terms.
 */

#ifndef CLIENT_INTERNAL_H
#define CLIENT_INTERNAL_H 1

#include <portable/macros.h>

#include <krb5.h>
#include <sys/types.h>

/* Forward declarations to avoid unnecessary includes. */
struct remctl;

BEGIN_DECLS

/*
 * Given a Kerberos context and a principal name, obtain Kerberos credentials
 * for that principal and store them in a memory cache for use by later
 * operations.
 */
void kinit(krb5_context, const char *principal);

/*
 * Given a remctl object, run a remctl command.  If data is non-NULL, saves
 * the standard output from the command into data with the length in length.
 * Otherwise, prints it to standard output.  Either way, prints standard error
 * output and errors to standard error and returns the exit status or 255 for
 * a remctl internal error.
 */
int run_command(struct remctl *, const char **command, char **data,
                size_t *length);

/*
 * Check whether an object exists using the exists wallet interface.  Returns
 * true if it does, false if it doesn't, and dies on remctl errors.
 */
int object_exists(struct remctl *, const char *prefix, const char *type,
                  const char *name);

/* Attempt autocreation of an object.  Dies if autocreation fails. */
void object_autocreate(struct remctl *, const char *prefix, const char *type,
                       const char *name);

/*
 * Given a remctl object, the type for the wallet interface, object type,
 * object name, and a file (which may be NULL), send a wallet get command and
 * write the results to the provided file.  If the file is NULL, write the
 * results to standard output instead.  Returns 0 on success and an exit
 * status on failure.
 */
int get_file(struct remctl *, const char *prefix, const char *type,
             const char *name, const char *file);

/*
 * Given a remctl object, the Kerberos context, the type for the wallet
 * interface, the name of a keytab object, and a file name, call the correct
 * wallet commands to download a keytab and write it to that file.  If srvtab
 * is not NULL, write a srvtab based on the keytab after a successful
 * download.
 */
int get_keytab(struct remctl *, krb5_context, const char *type,
               const char *name, const char *file, const char *srvtab);

/*
 * Given a filename, some data, and a length, write that data to the given
 * file with error checking, overwriting any existing contents.
 */
void overwrite_file(const char *name, const void *data, size_t length);

/*
 * Given a filename, some data, and a length, write that data to the given
 * file safely and atomically by creating file.new, writing the data, linking
 * file to file.bak, and then renaming file.new to file.
 */
void write_file(const char *name, const void *data, size_t length);

/*
 * Given a Kerberos context, a srvtab file, the Kerberos v5 principal, and the
 * keytab file, write a srvtab file for the corresponding Kerberos v4
 * principal.
 */
void write_srvtab(krb5_context, const char *srvtab, const char *principal,
                  const char *keytab);

/*
 * Read all of a file into memory and return the contents as a newly allocated
 * string.  Handles a file name of "-" to mean standard input.  Dies on any
 * failure.  This will need modification later when we want to handle nul
 * characters.
 */
char *read_file(const char *);

END_DECLS

#endif /* !CLIENT_INTERNAL_H */