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/*++
/* NAME
/* open_as 3
/* SUMMARY
/* open file as user
/* SYNOPSIS
/* #include <fcntl.h>
/* #include <open_as.h>
/*
/* int open_as(path, flags, mode, euid, egid)
/* const char *path;
/* int mode;
/* uid_t euid;
/* gid_t egid;
/* DESCRIPTION
/* open_as() opens the named \fIpath\fR with the named \fIflags\fR
/* and \fImode\fR, and with the effective rights specified by \fIeuid\fR
/* and \fIegid\fR. A -1 result means the open failed.
/* DIAGNOSTICS
/* Fatal error: no permission to change privilege level.
/* SEE ALSO
/* set_eugid(3) switch effective rights
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <fcntl.h>
#include <unistd.h>
/* Utility library. */
#include "msg.h"
#include "set_eugid.h"
#include "open_as.h"
/* open_as - open file as user */
int open_as(const char *path, int flags, int mode, uid_t euid, gid_t egid)
{
uid_t saved_euid = geteuid();
gid_t saved_egid = getegid();
int fd;
/*
* Switch to the target user privileges.
*/
set_eugid(euid, egid);
/*
* Open that file.
*/
fd = open(path, flags, mode);
/*
* Restore saved privileges.
*/
set_eugid(saved_euid, saved_egid);
return (fd);
}
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