identity(S)                    6 January 1993                    identity(S)


 Name

    identity - get or check uids or gids from program start

 Syntax


    cc  . . .  -lprot


    #include <sys/types.h>
    #include <sys/security.h>
    #include <sys/audit.h>
    #include <prot.h>

    void check_auth_parameters ()

    int is_starting_egid (gid)
    ushort gid;

    int is_starting_euid (uid)
    ushort uid;

    int is_starting_luid (uid)
    ushort uid;

    int is_starting_ruid (uid)
    ushort uid;

    int is_starting_rgid (gid)
    ushort gid;

    void set_auth_parameters (argc, argv)
    int argc;
    char *argv[];

    ushort starting_egid ()

    ushort starting_euid ()

    ushort starting_luid ()

    ushort starting_rgid ()

    ushort starting_ruid ()


 Description

    These routines provide a way to recall the IDs of a process at the time
    the program started.  They are useful when interrogating the invoking
    environment of a program after any setuid(S) or setgid(S) calls have been
    made so that the original environment can be captured.

    startingluid returns the login UID for the process as it was set in the
    beginning of the program.  The login UID is the immutable stamp for the
    process and accurately denotes the account under which the session is
    being run, regardless of subsequent setuid(S) calls.  startingruid
    returns the real UID for the process as it was set in the beginning of
    the program.  Similarly, startingeuid returns the effective UID,
    startingrgid returns the real GID, and startingegid returns the effec-
    tive GID, These IDs may not be the same as those returned by getluid(S),
    getuid(S), geteuid(S), getgid(S), or getegid(S), respectively, because
    intervening calls to setluid(S), setuid(S) or setgid(S) can change the
    latter set while the former set remains the same.

    The routine isstartingluid returns 1 if the argument is the same as the
    login UID at the time when setauthparameters was invoked, and 0 other-
    wise.  Similarly, isstartingruid returns 1 if the argument is the same
    as the real UID at the time when setauthparameters was invoked, and 0
    otherwise; isstartingeuid returns 1 if the argument is the same as the
    effective UID at the time when setauthparameters was invoked, and 0
    otherwise; isstartingrgid returns 1 if the argument is the same as the
    real GID at the time when setauthparameters was invoked, and 0 other-
    wise;  and isstartingegid returns 1 if the argument is the same as the
    effective GID at the time when setauthparameters was invoked, and 0
    otherwise.

    The setauthparameters routine is used to retain the IDs for future
    lookup.  It also tests the kernel to see if the C2 security features have
    been loaded.  If not, the program exists with an error message.  It
    should be called first in a program or there is a chance that it captures
    an environment different from the program beginning.  The two arguments
    are the argument count and vector with which the program was called.
    checkauthparameters verifies that setauthparameters has been previ-
    ously invoked.  If not, the program exits.  If so, nothing happens.

 Notes

    These routines only work as advertised when setauthparameters is called
    as the first item in main().

    setauthparameters resets the umask in the calling process to 077.

 See also

    getegid(S), geteuid(S), getgid(S), getuid(S)

 Standards conformance

    identity is an extension of AT&T System V provided by the Santa Cruz
    Operation.