/*
 * 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.
 */

/*
 * auth_des.c, client-side implementation of DES authentication
 *
 */

#include "mt.h"
#include "rpc_mt.h"
#include <rpc/rpc.h>
#include <rpc/des_crypt.h>
#include <syslog.h>
#include <stdlib.h>
#include <string.h>
#include <synch.h>
#undef NIS
#include <rpcsvc/nis.h>

#define USEC_PER_SEC            1000000
#define RTIME_TIMEOUT           5       /* seconds to wait for sync */

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(const char *, netobj *, des_block *);

extern bool_t __rpc_get_time_offset(struct timeval *, nis_server *, char *,
                                                char **, char **);
static struct auth_ops *authdes_ops(void);
static bool_t authdes_refresh(AUTH *, void *);

/*
 * This struct is pointed to by the ah_private field of an "AUTH *"
 */
struct ad_private {
        char *ad_fullname;              /* client's full name */
        uint_t ad_fullnamelen;          /* length of name, rounded up */
        char *ad_servername;            /* server's full name */
        size_t ad_servernamelen;        /* length of name, rounded up */
        uint_t ad_window;               /* client specified window */
        bool_t ad_dosync;               /* synchronize? */
        char *ad_timehost;              /* remote host to sync with */
        struct timeval ad_timediff;     /* server's time - client's time */
        uint_t 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 */
        uchar_t ad_pkey[1024];          /* Servers actual public key */
        char *ad_netid;                 /* Timehost netid */
        char *ad_uaddr;                 /* Timehost uaddr */
        nis_server *ad_nis_srvr;        /* NIS+ server struct */
};

extern AUTH *authdes_pk_seccreate(const char *, netobj *, uint_t, 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 uint_t win,
        const char *timehost, const des_block *ckey)
{
        uchar_t pkey_data[1024];
        netobj  pkey;

        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 = (uint_t)strlen((char *)pkey_data) + 1;
        return (authdes_pk_seccreate(servername, &pkey, win, timehost,
                                        ckey, NULL));
}

/*
 * Slightly modified version of authdes_seccreate 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, uint_t 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 = malloc(sizeof (AUTH));
        if (auth == NULL) {
                syslog(LOG_ERR, "authdes_pk_seccreate: out of memory");
                return (NULL);
        }
        ad = malloc(sizeof (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;
        (void) memcpy(ad->ad_pkey, pkey->n_bytes, pkey->n_len);
        if (!getnetname(namebuf))
                goto failed;
        ad->ad_fullnamelen = RNDUP((uint_t)strlen(namebuf));
        ad->ad_fullname = malloc(ad->ad_fullnamelen + 1);
        ad->ad_servernamelen = strlen(servername);
        ad->ad_servername = malloc(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 = malloc(strlen(timehost) + 1);
                if (ad->ad_timehost == NULL) {
                        syslog(LOG_ERR, "authdes_seccreate: out of memory");
                        goto failed;
                }
                (void) 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;
        }
        (void) memcpy(ad->ad_fullname, namebuf, ad->ad_fullnamelen + 1);
        (void) 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(8) 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);
        if (ad) {
                if (ad->ad_fullname)
                        free(ad->ad_fullname);
                if (ad->ad_servername)
                        free(ad->ad_servername);
                if (ad->ad_timehost)
                        free(ad->ad_timehost);
                if (ad->ad_netid)
                        free(ad->ad_netid);
                if (ad->ad_uaddr)
                        free(ad->ad_uaddr);
                free(ad);
        }
        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 = (struct ad_private *)auth->ah_private;
        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, 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,
                                2 * sizeof (des_block),
                                DES_ENCRYPT | DES_HW, (char *)&ivec);
        } else {
                status = ecb_crypt((char *)&auth->ah_key, (char *)cryptbuf,
                                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 {
                if (!xdr_putint32(xdrs, (int *)&auth->ah_cred.oa_flavor))
                        return (FALSE);
                if (!xdr_putint32(xdrs, &len))
                        return (FALSE);
        }
        if (!xdr_authdes_cred(xdrs, cred))
                return (FALSE);

        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 {
                if (!xdr_putint32(xdrs, (int *)&auth->ah_verf.oa_flavor))
                        return (FALSE);
                if (!xdr_putint32(xdrs, &len))
                        return (FALSE);
        }
        return (xdr_authdes_verf(xdrs, verf));
}


/*
 * 3. Validate
 */
static bool_t
authdes_validate(AUTH *auth, struct opaque_auth *rverf)
{
/* LINTED pointer alignment */
        struct ad_private *ad = (struct ad_private *)auth->ah_private;
        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,
                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 (memcmp(&ad->ad_timestamp, &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 = (struct ad_private *)auth->ah_private;
        struct authdes_cred *cred = &ad->ad_cred;
        int             ok;
        netobj          pkey;

        if (ad->ad_dosync) {
                ok = __rpc_get_time_offset(&ad->ad_timediff, ad->ad_nis_srvr,
                                            ad->ad_timehost, &(ad->ad_uaddr),
                                            &(ad->ad_netid));
                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 = (uint_t)strlen((char *)ad->ad_pkey) + 1;
        if (key_encryptsession_pk(ad->ad_servername, &pkey, &ad->ad_xkey) < 0) {
                syslog(LOG_INFO,
        "authdes_refresh: keyserv(8) 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 = (struct ad_private *)auth->ah_private;

        free(ad->ad_fullname);
        free(ad->ad_servername);
        if (ad->ad_timehost)
                free(ad->ad_timehost);
        if (ad->ad_netid)
                free(ad->ad_netid);
        if (ad->ad_uaddr)
                free(ad->ad_uaddr);
        free(ad);
        free(auth);
}

static struct auth_ops *
authdes_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 = authdes_nextverf;
                ops.ah_marshal = authdes_marshal;
                ops.ah_validate = authdes_validate;
                ops.ah_refresh = authdes_refresh;
                ops.ah_destroy = authdes_destroy;
        }
        (void) mutex_unlock(&ops_lock);
        return (&ops);
}