/*++ /* 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); }