source: rtems/cpukit/librpc/src/rpc/auth_unix.c @ e5fc1df

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";*/
/*static char *sccsid = "from: @(#)auth_unix.c  2.2 88/08/01 4.0 RPCSRC";*/
static char *rcsid = "$FreeBSD: src/lib/libc/rpc/auth_unix.c,v 1.12 1999/12/29 05:04:16 peter Exp $";
#endif

/*
 * auth_unix.c, Implements UNIX style authentication parameters.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * The system is very weak.  The client uses no encryption for it's
 * credentials and only sends null verifiers.  The server sends backs
 * null verifiers or optionally a verifier that suggests a new short hand
 * for the credentials.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <sys/param.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_unix.h>

/*
 * Unix authenticator operations vector
 */
static void     authunix_nextverf();
static bool_t   authunix_marshal();
static bool_t   authunix_validate();
static bool_t   authunix_refresh();
static void     authunix_destroy();

static struct auth_ops auth_unix_ops = {
        authunix_nextverf,
        authunix_marshal,
        authunix_validate,
        authunix_refresh,
        authunix_destroy
};

/*
 * This struct is pointed to by the ah_private field of an auth_handle.
 */
struct audata {
        struct opaque_auth      au_origcred;    /* original credentials */
        struct opaque_auth      au_shcred;      /* short hand cred */
        u_long                  au_shfaults;    /* short hand cache faults */
        char                    au_marshed[MAX_AUTH_BYTES];
        u_int                   au_mpos;        /* xdr pos at end of marshed */
};
#define AUTH_PRIVATE(auth)      ((struct audata *)auth->ah_private)

static void marshal_new_auth();

/*
 * This goop is here because some servers refuse to accept a
 * credential with more than some number (usually 8) supplementary
 * groups.  Blargh!
 */
static int authunix_maxgrouplist = 0;

void
set_rpc_maxgrouplist(int num)
{
        authunix_maxgrouplist = num;
}

/*
 * Create a unix style authenticator.
 * Returns an auth handle with the given stuff in it.
 */
AUTH *
authunix_create(machname, uid, gid, len, aup_gids)
        char *machname;
        int uid;
        int gid;
        register int len;
        int *aup_gids;
{
        struct authunix_parms aup;
        char mymem[MAX_AUTH_BYTES];
        struct timeval now;
        XDR xdrs;
        register AUTH *auth;
        register struct audata *au;

        /*
         * Allocate and set up auth handle
         */
        auth = (AUTH *)mem_alloc(sizeof(*auth));
#ifndef _KERNEL
        if (auth == NULL) {
                (void)fprintf(stderr, "authunix_create: out of memory\n");
                return (NULL);
        }
#endif
        au = (struct audata *)mem_alloc(sizeof(*au));
#ifndef _KERNEL
        if (au == NULL) {
                (void)fprintf(stderr, "authunix_create: out of memory\n");
                return (NULL);
        }
#endif
        auth->ah_ops = &auth_unix_ops;
        auth->ah_private = (caddr_t)au;
        auth->ah_verf = au->au_shcred = _null_auth;
        au->au_shfaults = 0;

        /*
         * fill in param struct from the given params
         */
        (void)gettimeofday(&now,  (struct timezone *)0);
        aup.aup_time = now.tv_sec;
        aup.aup_machname = machname;
        aup.aup_uid = uid;
        aup.aup_gid = gid;
        /* GW: continuation of max group list hack */
        if(authunix_maxgrouplist != 0) {
                aup.aup_len = ((len < authunix_maxgrouplist) ? len
                               : authunix_maxgrouplist);
        } else {
                aup.aup_len = (u_int)len;
        }
        aup.aup_gids = aup_gids;

        /*
         * Serialize the parameters into origcred
         */
        xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
        if (! xdr_authunix_parms(&xdrs, &aup))
                abort();
        au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
        au->au_origcred.oa_flavor = AUTH_UNIX;
#ifdef _KERNEL
        au->au_origcred.oa_base = mem_alloc((u_int) len);
#else
        if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
                (void)fprintf(stderr, "authunix_create: out of memory\n");
                return (NULL);
        }
#endif
        memcpy(au->au_origcred.oa_base, mymem, (u_int)len);

        /*
         * set auth handle to reflect new cred.
         */
        auth->ah_cred = au->au_origcred;
        marshal_new_auth(auth);
        return (auth);
}

/*
 * Returns an auth handle with parameters determined by doing lots of
 * syscalls.
 */
AUTH *
authunix_create_default()
{
        register int len;
        char machname[MAX_MACHINE_NAME + 1];
        register int uid;
        register int gid;
        int gids[NGRPS];
        int i;
        gid_t real_gids[NGROUPS];

        if (gethostname(machname, MAX_MACHINE_NAME) == -1)
                abort();
        machname[MAX_MACHINE_NAME] = 0;
        uid = (int)geteuid();
        gid = (int)getegid();
        if ((len = getgroups(NGROUPS, real_gids)) < 0)
                abort();
        if(len > NGRPS) len = NGRPS; /* GW: turn `gid_t's into `int's */
        for(i = 0; i < len; i++) {
                gids[i] = (int)real_gids[i];
        }
        return (authunix_create(machname, uid, gid, len, gids));
}

/*
 * authunix operations
 */

static void
authunix_nextverf(auth)
        AUTH *auth;
{
        /* no action necessary */
}

static bool_t
authunix_marshal(auth, xdrs)
        AUTH *auth;
        XDR *xdrs;
{
        register struct audata *au = AUTH_PRIVATE(auth);

        return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
}

static bool_t
authunix_validate(auth, verf)
        register AUTH *auth;
        struct opaque_auth verf;
{
        register struct audata *au;
        XDR xdrs;

        if (verf.oa_flavor == AUTH_SHORT) {
                au = AUTH_PRIVATE(auth);
                xdrmem_create(&xdrs, verf.oa_base, verf.oa_length, XDR_DECODE);

                if (au->au_shcred.oa_base != NULL) {
                        mem_free(au->au_shcred.oa_base,
                            au->au_shcred.oa_length);
                        au->au_shcred.oa_base = NULL;
                }
                if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
                        auth->ah_cred = au->au_shcred;
                } else {
                        xdrs.x_op = XDR_FREE;
                        (void)xdr_opaque_auth(&xdrs, &au->au_shcred);
                        au->au_shcred.oa_base = NULL;
                        auth->ah_cred = au->au_origcred;
                }
                marshal_new_auth(auth);
        }
        return (TRUE);
}

static bool_t
authunix_refresh(auth)
        register AUTH *auth;
{
        register struct audata *au = AUTH_PRIVATE(auth);
        struct authunix_parms aup;
        struct timeval now;
        XDR xdrs;
        register int stat;

        if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
                /* there is no hope.  Punt */
                return (FALSE);
        }
        au->au_shfaults ++;

        /* first deserialize the creds back into a struct authunix_parms */
        aup.aup_machname = NULL;
        aup.aup_gids = (int *)NULL;
        xdrmem_create(&xdrs, au->au_origcred.oa_base,
            au->au_origcred.oa_length, XDR_DECODE);
        stat = xdr_authunix_parms(&xdrs, &aup);
        if (! stat)
                goto done;

        /* update the time and serialize in place */
        (void)gettimeofday(&now, (struct timezone *)0);
        aup.aup_time = now.tv_sec;
        xdrs.x_op = XDR_ENCODE;
        XDR_SETPOS(&xdrs, 0);
        stat = xdr_authunix_parms(&xdrs, &aup);
        if (! stat)
                goto done;
        auth->ah_cred = au->au_origcred;
        marshal_new_auth(auth);
done:
        /* free the struct authunix_parms created by deserializing */
        xdrs.x_op = XDR_FREE;
        (void)xdr_authunix_parms(&xdrs, &aup);
        XDR_DESTROY(&xdrs);
        return (stat);
}

static void
authunix_destroy(auth)
        register AUTH *auth;
{
        register struct audata *au = AUTH_PRIVATE(auth);

        mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);

        if (au->au_shcred.oa_base != NULL)
                mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);

        mem_free(auth->ah_private, sizeof(struct audata));

        if (auth->ah_verf.oa_base != NULL)
                mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);

        mem_free((caddr_t)auth, sizeof(*auth));
}

/*
 * Marshals (pre-serializes) an auth struct.
 * sets private data, au_marshed and au_mpos
 */
static void
marshal_new_auth(auth)
        register AUTH *auth;
{
        XDR             xdr_stream;
        register XDR    *xdrs = &xdr_stream;
        register struct audata *au = AUTH_PRIVATE(auth);

        xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
        if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
            (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
                perror("auth_none.c - Fatal marshalling problem");
        } else {
                au->au_mpos = XDR_GETPOS(xdrs);
        }
        XDR_DESTROY(xdrs);
}