auth_des.c

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/*
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice, 
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, 
 *   this list of conditions and the following disclaimer in the documentation 
 *   and/or other materials provided with the distribution.
 * - Neither the name of Sun Microsystems, Inc. nor the names of its 
 *   contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * Copyright (c) 1988 by Sun Microsystems, Inc.
 */
/*
 * auth_des.c, client-side implementation of DES authentication
 */
 
#include <wintirpc.h>
//#include <pthread.h>
#include <reentrant.h>
//#include <err.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
//#include <unistd.h>
//#include <sys/cdefs.h>
#include <rpc/des_crypt.h>
//#include <syslog.h>
#include <rpc/types.h>
#include <rpc/auth.h>
#include <rpc/auth_des.h>
#include <rpc/clnt.h>
#include <rpc/xdr.h>
//#include <sys/socket.h>
#undef NIS
#include <rpcsvc/nis.h>
 
#if defined(LIBC_SCCS) && !defined(lint)
#endif
//#include <sys/cdefs.h>
 
#define USEC_PER_SEC        1000000
#define RTIME_TIMEOUT       5   /* seconds to wait for sync */
 
#define AUTH_PRIVATE(auth)  (struct ad_private *) auth->ah_private
#define ALLOC(object_type)  (object_type *) mem_alloc(sizeof(object_type))
#define FREE(ptr, size)     mem_free((char *)(ptr), (int) size)
#define ATTEMPT(xdr_op)     if (!(xdr_op)) return (FALSE)
 
extern bool_t xdr_authdes_cred( XDR *, struct authdes_cred *);
extern bool_t xdr_authdes_verf( XDR *, struct authdes_verf *);
extern int key_encryptsession_pk();
 
extern bool_t __rpc_get_time_offset(struct timeval *, nis_server *, char *,
    char **, char **);
 
/* 
 * DES authenticator operations vector
 */
static void authdes_nextverf(AUTH *);
static bool_t   authdes_marshal(AUTH *, XDR *);
static bool_t   authdes_validate(AUTH *, struct opaque_auth *);
static bool_t   authdes_refresh(AUTH *, void *);
static void authdes_destroy(AUTH *);
 
static struct auth_ops *authdes_ops(void);
 
/*
 * This struct is pointed to by the ah_private field of an "AUTH *"
 */
struct ad_private {
    char *ad_fullname;      /* client's full name */
    u_int ad_fullnamelen;       /* length of name, rounded up */
    char *ad_servername;        /* server's full name */
    u_int ad_servernamelen;     /* length of name, rounded up */
    u_int ad_window;        /* client specified window */
    bool_t ad_dosync;       /* synchronize? */      
    struct netbuf ad_syncaddr;  /* remote host to synch with */
    char *ad_timehost;      /* remote host to synch with */
    struct timeval ad_timediff; /* server's time - client's time */
    u_int ad_nickname;      /* server's nickname for client */
    struct authdes_cred ad_cred;    /* storage for credential */
    struct authdes_verf ad_verf;    /* storage for verifier */
    struct timeval ad_timestamp;    /* timestamp sent */
    des_block ad_xkey;      /* encrypted conversation key */
    u_char ad_pkey[1024];       /* Server's actual public key */
    char *ad_netid;         /* Timehost netid */
    char *ad_uaddr;         /* Timehost uaddr */
    nis_server *ad_nis_srvr;    /* NIS+ server struct */
};
 
AUTH *authdes_pk_seccreate(const char *, netobj *, u_int, const char *,
    const des_block *, nis_server *);
 
/*
 * documented version of authdes_seccreate
 */
/*
    servername: network name of server
    win:        time to live
    timehost:   optional hostname to sync with
    ckey:       optional conversation key to use
*/
 
AUTH *
authdes_seccreate(const char *servername, const u_int win,
    const char *timehost, const des_block *ckey)
{
    u_char  pkey_data[1024];
    netobj  pkey;
    AUTH    *dummy;
 
    if (! getpublickey(servername, (char *) pkey_data)) {
        //syslog(LOG_ERR,
        //    "authdes_seccreate: no public key found for %s",
        //    servername);
        return (NULL);
    }
 
    pkey.n_bytes = (char *) pkey_data;
    pkey.n_len = (u_int)strlen((char *)pkey_data) + 1;
    dummy = authdes_pk_seccreate(servername, &pkey, win, timehost,
        ckey, NULL);
    return (dummy);
}
 
/*
 * Slightly modified version of authdessec_create which takes the public key
 * of the server principal as an argument. This spares us a call to
 * getpublickey() which in the nameserver context can cause a deadlock.
 */
AUTH *
authdes_pk_seccreate(const char *servername, netobj *pkey, u_int window,
    const char *timehost, const des_block *ckey, nis_server *srvr)
{
    AUTH *auth;
    struct ad_private *ad;
    char namebuf[MAXNETNAMELEN+1];
 
    /*
     * Allocate everything now
     */
    auth = ALLOC(AUTH);
    if (auth == NULL) {
        //syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
        return (NULL);
    }
    ad = ALLOC(struct ad_private);
    if (ad == NULL) {
        //syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
        goto failed;
    }
    ad->ad_fullname = ad->ad_servername = NULL; /* Sanity reasons */
    ad->ad_timehost = NULL;
    ad->ad_netid = NULL;
    ad->ad_uaddr = NULL;
    ad->ad_nis_srvr = NULL;
    ad->ad_timediff.tv_sec = 0;
    ad->ad_timediff.tv_usec = 0;
    memcpy(ad->ad_pkey, pkey->n_bytes, pkey->n_len);
    if (!getnetname(namebuf))
        goto failed;
    ad->ad_fullnamelen = RNDUP((u_int) strlen(namebuf));
    ad->ad_fullname = (char *)mem_alloc(ad->ad_fullnamelen + 1);
    ad->ad_servernamelen = strlen(servername);
    ad->ad_servername = (char *)mem_alloc(ad->ad_servernamelen + 1);
 
    if (ad->ad_fullname == NULL || ad->ad_servername == NULL) {
        //syslog(LOG_ERR, "authdes_seccreate: out of memory");
        goto failed;
    }
    if (timehost != NULL) {
        ad->ad_timehost = (char *)mem_alloc(strlen(timehost) + 1);
        if (ad->ad_timehost == NULL) {
            //syslog(LOG_ERR, "authdes_seccreate: out of memory");
            goto failed;
        }
        memcpy(ad->ad_timehost, timehost, strlen(timehost) + 1);
        ad->ad_dosync = TRUE;
    } else if (srvr != NULL) {
        ad->ad_nis_srvr = srvr; /* transient */
        ad->ad_dosync = TRUE;
    } else {
        ad->ad_dosync = FALSE;
    }
    memcpy(ad->ad_fullname, namebuf, ad->ad_fullnamelen + 1);
    memcpy(ad->ad_servername, servername, ad->ad_servernamelen + 1);
    ad->ad_window = window;
    if (ckey == NULL) {
        if (key_gendes(&auth->ah_key) < 0) {
            //syslog(LOG_ERR,
            //      "authdes_seccreate: keyserv(1m) is unable to generate session key");
            goto failed;
        }
    } else {
        auth->ah_key = *ckey;
    }
 
    /*
     * Set up auth handle
     */
    auth->ah_cred.oa_flavor = AUTH_DES;
    auth->ah_verf.oa_flavor = AUTH_DES;
    auth->ah_ops = authdes_ops();
    auth->ah_private = (caddr_t)ad;
 
    if (!authdes_refresh(auth, NULL)) {
        goto failed;
    }
    ad->ad_nis_srvr = NULL; /* not needed any longer */
    return (auth);
 
failed:
    if (auth)
        FREE(auth, sizeof (AUTH));
    if (ad) {
        if (ad->ad_fullname)
            FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
        if (ad->ad_servername)
            FREE(ad->ad_servername, ad->ad_servernamelen + 1);
        if (ad->ad_timehost)
            FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
        if (ad->ad_netid)
            FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
        if (ad->ad_uaddr)
            FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
        FREE(ad, sizeof (struct ad_private));
    }
    return (NULL);
}
 
/*
 * Implement the five authentication operations
 */
 
 
/*
 * 1. Next Verifier
 */ 
/*ARGSUSED*/
static void
authdes_nextverf(AUTH *auth)
{
    /* what the heck am I supposed to do??? */
}
 
 
/*
 * 2. Marshal
 */
static bool_t
authdes_marshal(AUTH *auth, XDR *xdrs)
{
/* LINTED pointer alignment */
    struct ad_private *ad = AUTH_PRIVATE(auth);
    struct authdes_cred *cred = &ad->ad_cred;
    struct authdes_verf *verf = &ad->ad_verf;
    des_block cryptbuf[2];  
    des_block ivec;
    int status;
    int len;
    rpc_inline_t *ixdr;
 
    /*
     * Figure out the "time", accounting for any time difference
     * with the server if necessary.
     */
    (void) gettimeofday(&ad->ad_timestamp, (struct timezone *)NULL);
    ad->ad_timestamp.tv_sec += ad->ad_timediff.tv_sec;
    ad->ad_timestamp.tv_usec += ad->ad_timediff.tv_usec;
    while (ad->ad_timestamp.tv_usec >= USEC_PER_SEC) {
        ad->ad_timestamp.tv_usec -= USEC_PER_SEC;
        ad->ad_timestamp.tv_sec++;
    }
 
    /*
     * XDR the timestamp and possibly some other things, then
     * encrypt them.
     */
    ixdr = (rpc_inline_t *)cryptbuf;
    IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_sec);
    IXDR_PUT_INT32(ixdr, ad->ad_timestamp.tv_usec);
    if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
        IXDR_PUT_U_INT32(ixdr, ad->ad_window);
        IXDR_PUT_U_INT32(ixdr, ad->ad_window - 1);
        ivec.key.high = ivec.key.low = 0;   
        status = cbc_crypt((char *)&auth->ah_key, (char *)cryptbuf, 
            (u_int) 2 * sizeof (des_block),
            DES_ENCRYPT | DES_HW, (char *)&ivec);
    } else {
        status = ecb_crypt((char *)&auth->ah_key, (char *)cryptbuf, 
            (u_int) sizeof (des_block),
            DES_ENCRYPT | DES_HW);
    }
    if (DES_FAILED(status)) {
        //syslog(LOG_ERR, "authdes_marshal: DES encryption failure");
        return (FALSE);
    }
    ad->ad_verf.adv_xtimestamp = cryptbuf[0];
    if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
        ad->ad_cred.adc_fullname.window = cryptbuf[1].key.high;
        ad->ad_verf.adv_winverf = cryptbuf[1].key.low;
    } else {
        ad->ad_cred.adc_nickname = ad->ad_nickname;
        ad->ad_verf.adv_winverf = 0;
    }
 
    /*
     * Serialize the credential and verifier into opaque
     * authentication data.
     */
    if (ad->ad_cred.adc_namekind == ADN_FULLNAME) {
        len = ((1 + 1 + 2 + 1)*BYTES_PER_XDR_UNIT + ad->ad_fullnamelen);
    } else {
        len = (1 + 1)*BYTES_PER_XDR_UNIT;
    }
 
    if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
        IXDR_PUT_INT32(ixdr, AUTH_DES);
        IXDR_PUT_INT32(ixdr, len);
    } else {
        ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_cred.oa_flavor));
        ATTEMPT(xdr_putint32(xdrs, &len));
    }
    ATTEMPT(xdr_authdes_cred(xdrs, cred));
 
    len = (2 + 1)*BYTES_PER_XDR_UNIT; 
    if ((ixdr = xdr_inline(xdrs, 2*BYTES_PER_XDR_UNIT))) {
        IXDR_PUT_INT32(ixdr, AUTH_DES);
        IXDR_PUT_INT32(ixdr, len);
    } else {
        ATTEMPT(xdr_putint32(xdrs, (int *)&auth->ah_verf.oa_flavor));
        ATTEMPT(xdr_putint32(xdrs, &len));
    }
    ATTEMPT(xdr_authdes_verf(xdrs, verf));
    return (TRUE);
}
 
 
/*
 * 3. Validate
 */
static bool_t
authdes_validate(AUTH *auth, struct opaque_auth *rverf)
{
/* LINTED pointer alignment */
    struct ad_private *ad = AUTH_PRIVATE(auth);
    struct authdes_verf verf;
    int status;
    uint32_t *ixdr;
    des_block buf;
 
    if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT) {
        return (FALSE);
    }
/* LINTED pointer alignment */
    ixdr = (uint32_t *)rverf->oa_base;
    buf.key.high = (uint32_t)*ixdr++;
    buf.key.low = (uint32_t)*ixdr++;
    verf.adv_int_u = (uint32_t)*ixdr++;
 
    /*
     * Decrypt the timestamp
     */
    status = ecb_crypt((char *)&auth->ah_key, (char *)&buf,
        (u_int)sizeof (des_block), DES_DECRYPT | DES_HW);
 
    if (DES_FAILED(status)) {
        //syslog(LOG_ERR, "authdes_validate: DES decryption failure");
        return (FALSE);
    }
 
    /*
     * xdr the decrypted timestamp
     */
/* LINTED pointer alignment */
    ixdr = (uint32_t *)buf.c;
    verf.adv_timestamp.tv_sec = IXDR_GET_INT32(ixdr) + 1;
    verf.adv_timestamp.tv_usec = IXDR_GET_INT32(ixdr);
 
    /*
     * validate
     */
    if (bcmp((char *)&ad->ad_timestamp, (char *)&verf.adv_timestamp,
         sizeof(struct timeval)) != 0) {
        //syslog(LOG_DEBUG, "authdes_validate: verifier mismatch");
        return (FALSE);
    }
 
    /*
     * We have a nickname now, let's use it
     */
    ad->ad_nickname = verf.adv_nickname;
    ad->ad_cred.adc_namekind = ADN_NICKNAME;
    return (TRUE);
}
 
/*
 * 4. Refresh
 */
/*ARGSUSED*/
static bool_t
authdes_refresh(AUTH *auth, void *dummy)
{
/* LINTED pointer alignment */
    struct ad_private *ad = AUTH_PRIVATE(auth);
    struct authdes_cred *cred = &ad->ad_cred;
    int     ok;
    netobj      pkey;
 
    if (ad->ad_dosync) {
#if 1 // WINDOWS
        ok = 1;
#else
                ok = __rpc_get_time_offset(&ad->ad_timediff, ad->ad_nis_srvr,
            ad->ad_timehost, &(ad->ad_uaddr),
            &(ad->ad_netid));
#endif
        if (! ok) {
            /*
             * Hope the clocks are synced!
             */
            ad->ad_dosync = 0;
            //syslog(LOG_DEBUG,
            //    "authdes_refresh: unable to synchronize clock");
         }
    }
    ad->ad_xkey = auth->ah_key;
    pkey.n_bytes = (char *)(ad->ad_pkey);
    pkey.n_len = (u_int)strlen((char *)ad->ad_pkey) + 1;
    if (key_encryptsession_pk(ad->ad_servername, &pkey, &ad->ad_xkey) < 0) {
        //syslog(LOG_INFO,
        //    "authdes_refresh: keyserv(1m) is unable to encrypt session key");
        return (FALSE);
    }
    cred->adc_fullname.key = ad->ad_xkey;
    cred->adc_namekind = ADN_FULLNAME;
    cred->adc_fullname.name = ad->ad_fullname;
    return (TRUE);
}
 
 
/*
 * 5. Destroy
 */
static void
authdes_destroy(AUTH *auth)
{
/* LINTED pointer alignment */
    struct ad_private *ad = AUTH_PRIVATE(auth);
 
    FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
    FREE(ad->ad_servername, ad->ad_servernamelen + 1);
    if (ad->ad_timehost)
        FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
    if (ad->ad_netid)
        FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
    if (ad->ad_uaddr)
        FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
    FREE(ad, sizeof (struct ad_private));
    FREE(auth, sizeof(AUTH));
}
 
static struct auth_ops *
authdes_ops(void)
{
    static struct auth_ops ops;
    extern mutex_t authdes_ops_lock;
 
    /* VARIABLES PROTECTED BY ops_lock: ops */
 
    mutex_lock(&authdes_ops_lock);
    if (ops.ah_nextverf == NULL) {
        ops.ah_nextverf = authdes_nextverf;
        ops.ah_marshal = authdes_marshal;
        ops.ah_validate = authdes_validate;
        ops.ah_refresh = authdes_refresh;
        ops.ah_destroy = authdes_destroy;
        }
    mutex_unlock(&authdes_ops_lock);
    return (&ops);
}