libnsl/rpc/auth_sys.c

	auth_sys.c revision 61961e0f20c7637a3846bb39786bb9dffa91dfb9
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * Portions of this source code were derived from Berkeley
 * 4.3 BSD under license from the Regents of the University of
 * California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * auth_sys.c, Implements UNIX (system) style authentication parameters.
 *
 * The system is very weak.  The client uses no encryption for its
 * 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 "mt.h"
#include "rpc_mt.h"
#include <stdio.h>
#include <syslog.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_sys.h>
#include <synch.h>

extern int gethostname(char *, int);
extern bool_t xdr_opaque_auth(XDR *, struct opaque_auth *);

static struct auth_ops *authsys_ops(void);

/*
 * 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 */
    uint_t          au_shfaults;    /* short hand cache faults */
    char            au_marshed[MAX_AUTH_BYTES];
    uint_t          au_mpos;    /* xdr pos at end of marshed */
};
#define AUTH_PRIVATE(auth)  ((struct audata *)auth->ah_private)

static void marshal_new_auth();

static const char auth_sys_str[] = "%s : %s";
static const char authsys_create_str[] = "authsys_create";
static const char __no_mem_auth[] = "out of memory";

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

    /*
     * Allocate and set up auth handle
     */
    auth = malloc(sizeof (*auth));
    if (auth == NULL) {
        (void) syslog(LOG_ERR, auth_sys_str, authsys_create_str,
            __no_mem_auth);
        return (NULL);
    }
    au = malloc(sizeof (*au));
    if (au == NULL) {
        (void) syslog(LOG_ERR, auth_sys_str, authsys_create_str,
            __no_mem_auth);
        free(auth);
        return (NULL);
    }
    auth->ah_ops = authsys_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 = (char *)machname;
    aup.aup_uid = uid;
    aup.aup_gid = gid;
    aup.aup_len = (uint_t)len;
    aup.aup_gids = (gid_t *)aup_gids;

    /*
     * Serialize the parameters into origcred
     */
    xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
    if (!xdr_authsys_parms(&xdrs, &aup)) {
        (void) syslog(LOG_ERR, auth_sys_str, authsys_create_str,
            ":  xdr_authsys_parms failed");
        return (NULL);
    }
    au->au_origcred.oa_length = XDR_GETPOS(&xdrs);
    au->au_origcred.oa_flavor = AUTH_SYS;
    if ((au->au_origcred.oa_base = malloc(au->au_origcred.oa_length)) ==
                                    NULL) {
        (void) syslog(LOG_ERR, auth_sys_str, authsys_create_str,
            __no_mem_auth);
        free(au);
        free(auth);
        return (NULL);
    }
    (void) memcpy(au->au_origcred.oa_base, mymem,
                    (size_t)au->au_origcred.oa_length);

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

/*
 * authsys_create_default is a public interface.
 *
 * Returns an auth handle with parameters determined by doing lots of
 * syscalls.
 */

static const char authsys_def_str[] =
    "authsys_create_default:  get%s failed:  %m";

AUTH *
authsys_create_default(void)
{
    int len;
    char machname[MAX_MACHINE_NAME + 1];
    uid_t uid;
    gid_t gid;
    gid_t gids[NGRPS];

    if (gethostname(machname, MAX_MACHINE_NAME) == -1) {
        (void) syslog(LOG_ERR, authsys_def_str, "hostname");
        return (NULL);
    }
    machname[MAX_MACHINE_NAME] = 0;
    uid = geteuid();
    gid = getegid();
    if ((len = getgroups(NGRPS, gids)) < 0) {
        (void) syslog(LOG_ERR, authsys_def_str, "groups");
        return (NULL);
    }
    return (authsys_create(machname, uid, gid, len, gids));
}

/*
 * authsys_create_ruid() is a private routine and is a
 * variant of authsys_create_default().
 *
 * authsys_create_default() is using the effective uid.
 * authsys_create_ruid() is using the real uid.
 *
 * This routine is used by key_call_ext() in key_call.c
 */
AUTH *
authsys_create_ruid(void)
{
    int len;
    char machname[MAX_MACHINE_NAME + 1];
    uid_t uid;
    gid_t gid;
    gid_t gids[NGRPS];
    AUTH *res;

    if (gethostname(machname, MAX_MACHINE_NAME) == -1) {
        (void) syslog(LOG_ERR,
            "authsys_create_ruid:gethostname failed");
        return (NULL);
    }
    machname[MAX_MACHINE_NAME] = 0;
    uid = getuid();
    gid = getgid();
    if ((len = getgroups(NGRPS, gids)) < 0) {
        (void) syslog(LOG_ERR,
            "authsys_create_ruid:getgroups failed");
        return (NULL);
    }
    res = authsys_create(machname, uid, gid, len, gids);
    return (res);
}

/*
 * authsys operations
 */

/*ARGSUSED*/
static void
authsys_nextverf(AUTH *auth)
{
    /* no action necessary */
}

static bool_t
authsys_marshal(AUTH *auth, XDR *xdrs)
{
/* LINTED pointer alignment */
    struct audata *au = AUTH_PRIVATE(auth);

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

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

    if (verf->oa_flavor == AUTH_SHORT) {
/* LINTED pointer alignment */
        au = AUTH_PRIVATE(auth);
        xdrmem_create(&xdrs, verf->oa_base,
            verf->oa_length, XDR_DECODE);

        if (au->au_shcred.oa_base != NULL) {
            free(au->au_shcred.oa_base);
            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;
        }
        (void) marshal_new_auth(auth);
    }
    return (TRUE);
}

/*ARGSUSED*/
static bool_t
authsys_refresh(AUTH *auth, void *dummy)
{
/* LINTED pointer alignment */
    struct audata *au = AUTH_PRIVATE(auth);
    struct authsys_parms aup;
    struct timeval now;
    XDR xdrs;
    int stat;

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

    /* first deserialize the creds back into a struct authsys_parms */
    aup.aup_machname = NULL;
    aup.aup_gids = NULL;
    xdrmem_create(&xdrs, au->au_origcred.oa_base,
        au->au_origcred.oa_length, XDR_DECODE);
    stat = xdr_authsys_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_authsys_parms(&xdrs, &aup);
    if (!stat)
        goto done;
    auth->ah_cred = au->au_origcred;
    (void) marshal_new_auth(auth);
done:
    /* free the struct authsys_parms created by deserializing */
    xdrs.x_op = XDR_FREE;
    (void) xdr_authsys_parms(&xdrs, &aup);
    XDR_DESTROY(&xdrs);
    return (stat);
}

static void
authsys_destroy(AUTH *auth)
{
/* LINTED pointer alignment */
    struct audata *au = AUTH_PRIVATE(auth);

    free(au->au_origcred.oa_base);
    if (au->au_shcred.oa_base != NULL)
        free(au->au_shcred.oa_base);
    free(auth->ah_private);
    if (auth->ah_verf.oa_base != NULL)
        free(auth->ah_verf.oa_base);
    free(auth);
}

/*
 * Marshals (pre-serializes) an auth struct.
 * sets private data, au_marshed and au_mpos
 */

static const char marshal_new_auth_str[] =
        "marshal_new_auth - Fatal marshalling problem";
static void
marshal_new_auth(AUTH *auth)
{
    XDR xdr_stream;
    XDR *xdrs = &xdr_stream;
/* LINTED pointer alignment */
    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)))) {
        (void) syslog(LOG_ERR, marshal_new_auth_str);
    } else {
        au->au_mpos = XDR_GETPOS(xdrs);
    }
    XDR_DESTROY(xdrs);
}

static struct auth_ops *
authsys_ops(void)
{
    static struct auth_ops ops;
    extern mutex_t ops_lock;

    /* VARIABLES PROTECTED BY ops_lock: ops */

    (void) mutex_lock(&ops_lock);
    if (ops.ah_nextverf == NULL) {
        ops.ah_nextverf = authsys_nextverf;
        ops.ah_marshal = authsys_marshal;
        ops.ah_validate = authsys_validate;
        ops.ah_refresh = authsys_refresh;
        ops.ah_destroy = authsys_destroy;
    }
    (void) mutex_unlock(&ops_lock);
    return (&ops);
}