/*
 * 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 2003 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 <sys/types.h>
#include <sys/t_lock.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/tiuser.h>
#include <sys/errno.h>
#include <rpc/des_crypt.h>
#include <rpc/types.h>
#include <rpc/auth.h>
#include <rpc/auth_des.h>
#include <rpc/xdr.h>
#include <rpc/clnt.h>
#include <rpc/rpc_msg.h>
#include <netinet/in.h> /* XXX: just to get htonl() and ntohl() */
#include <sys/cmn_err.h>
#include <sys/debug.h>

#define MILLION         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)

#define gettimeofday(tvp, tzp)  uniqtime(tvp)

static void     authdes_nextverf(AUTH *);
static bool_t   authdes_marshal(AUTH *, XDR *, struct cred *);
static bool_t   authdes_validate(AUTH *, struct opaque_auth *);
static bool_t   authdes_refresh(AUTH *, struct rpc_msg *, cred_t *);
static void     authdes_destroy(AUTH *);
static bool_t   synchronize(struct knetconfig *, struct netbuf *,
                        int, struct timeval *);

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 */
        uint_t ad_fullnamelen;          /* length of name, rounded up */
        char *ad_servername;            /* server's full name */
        uint_t ad_servernamelen;        /* length of name, rounded up */
        uint_t ad_window;               /* client specified window */
        bool_t ad_dosync;               /* synchronize? */
        struct netbuf ad_syncaddr;      /* remote host to synch with */
        struct knetconfig ad_synconfig; /* netconfig for the synch host */
        int   ad_calltype;              /* use rpc or straight call for sync */
        struct timeval ad_timediff;     /* server's time - client's time */
        uint32_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 */
};


/*
 * Create the client des authentication object
 */
/* ARGSUSED */
int
authdes_create(char *servername, uint_t window, struct netbuf *syncaddr,
        struct knetconfig *synconfig, des_block *ckey, int calltype,
        AUTH **retauth)
{
        AUTH *auth;
        struct ad_private *ad;
        char namebuf[MAXNETNAMELEN+1];
        int error = 0;
        enum clnt_stat stat;

        if (retauth == NULL)
                return (EINVAL);

        *retauth = NULL;

        /*
         * Allocate everything now
         */
        auth = ALLOC(AUTH);
        ad = ALLOC(struct ad_private);
        bzero(ad, sizeof (struct ad_private));
        if ((stat = kgetnetname(namebuf)) != 0) {
                cmn_err(CE_NOTE,
        "authdes_create: unable to get client's netname: %s (error %d)",
                    clnt_sperrno(stat), stat);
                goto failed;
        }

        ad->ad_fullnamelen = (uint_t)RNDUP(strlen(namebuf));
        ad->ad_fullname = mem_alloc(ad->ad_fullnamelen + 1);

        ad->ad_servernamelen = (uint_t)strlen(servername);
        ad->ad_servername = mem_alloc(ad->ad_servernamelen + 1);

        if (auth == NULL || ad == NULL || ad->ad_fullname == NULL ||
            ad->ad_servername == NULL) {
                cmn_err(CE_NOTE, "authdes_create: out of memory");
                error = ENOMEM;
                goto failed;
        }

        /*
         * Set up private data
         */
        bcopy(namebuf, ad->ad_fullname, ad->ad_fullnamelen + 1);
        bcopy(servername, ad->ad_servername, ad->ad_servernamelen + 1);
        if (syncaddr != NULL) {
                ad->ad_syncaddr = *syncaddr;
                ad->ad_synconfig = *synconfig;
                ad->ad_dosync = TRUE;
                ad->ad_calltype = calltype;
        } else {
                ad->ad_timediff.tv_sec = 0;
                ad->ad_timediff.tv_usec = 0;
                ad->ad_dosync = FALSE;
        }
        ad->ad_window = window;
        if (ckey == NULL) {
                if ((stat = key_gendes(&auth->ah_key)) != RPC_SUCCESS) {
                        cmn_err(CE_NOTE,
        "authdes_create: unable to gen conversation key: %s (error %d)",
                            clnt_sperrno(stat), stat);
                        if (stat == RPC_INTR)
                                error = EINTR;
                        else if (stat == RPC_TIMEDOUT)
                                error = ETIMEDOUT;
                        else
                                error = EINVAL;         /* XXX */
                        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, CRED()))
                goto failed;

        *retauth = auth;
        return (0);

failed:
        if (ad != NULL && ad->ad_fullname != NULL)
                FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
        if (ad != NULL && ad->ad_servername != NULL)
                FREE(ad->ad_servername, ad->ad_servernamelen + 1);
        if (ad != NULL)
                FREE(ad, sizeof (struct ad_private));
        if (auth != NULL)
                FREE(auth, sizeof (AUTH));
        return ((error == 0) ? EINVAL : error);         /* XXX */
}

/*
 * 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
 */
/* ARGSUSED */
static bool_t
authdes_marshal(AUTH *auth, XDR *xdrs, struct cred *cr)
{
        /* 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;
        int32_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;
        if (ad->ad_timestamp.tv_usec >= MILLION) {
                ad->ad_timestamp.tv_usec -= MILLION;
                ad->ad_timestamp.tv_sec += 1;
        }

        /*
         * XDR the timestamp and possibly some other things, then
         * encrypt them.
         */
        ixdr = (int32_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, (char *)&ivec);
        } else {
                status = ecb_crypt((char *)&auth->ah_key, (char *)cryptbuf,
                    sizeof (des_block), DES_ENCRYPT);
        }
        if (DES_FAILED(status)) {
                cmn_err(CE_NOTE, "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,
                    (int32_t *)&auth->ah_cred.oa_flavor));
                ATTEMPT(xdr_putint32(xdrs, (int32_t *)&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,
                    (int32_t *)&auth->ah_verf.oa_flavor));
                ATTEMPT(xdr_putint32(xdrs, (int32_t *)&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 = IXDR_GET_U_INT32(ixdr);

        /*
         * Decrypt the timestamp
         */
        status = ecb_crypt((char *)&auth->ah_key, (char *)&buf,
            sizeof (des_block), DES_DECRYPT);

        if (DES_FAILED(status)) {
                cmn_err(CE_NOTE, "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) {
                cmn_err(CE_NOTE, "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
 *
 *  msg is a dummy argument here.
 */
/* ARGSUSED */
static bool_t
authdes_refresh(AUTH *auth, struct rpc_msg *msg, cred_t *cr)
{
        /* LINTED pointer alignment */
        struct ad_private *ad = AUTH_PRIVATE(auth);
        struct authdes_cred *cred = &ad->ad_cred;
        enum clnt_stat stat;

        if (ad->ad_dosync &&
            !synchronize(&ad->ad_synconfig, &ad->ad_syncaddr,
            ad->ad_calltype, &ad->ad_timediff)) {
                /*
                 * Hope the clocks are synced!
                 */
                timerclear(&ad->ad_timediff);
                cmn_err(CE_NOTE,
"authdes_refresh: unable to synchronize with server %s", ad->ad_servername);
        }
        ad->ad_xkey = auth->ah_key;
        if ((stat = key_encryptsession(ad->ad_servername, &ad->ad_xkey, cr)) !=
            RPC_SUCCESS) {
                cmn_err(CE_NOTE,
"authdes_refresh: unable to encrypt conversation key for user (uid %d): "
                    "%s (error %d)",
                    (int)crgetuid(cr), clnt_sperrno(stat), stat);
                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);
        FREE(ad, sizeof (struct ad_private));
        FREE(auth, sizeof (AUTH));
}


/*
 * Synchronize with the server at the given address, that is,
 * adjust timep to reflect the delta between our clocks
 */
static bool_t
synchronize(struct knetconfig *synconfig, struct netbuf *syncaddr, int calltype,
        struct timeval *timep)
{
        struct timeval mytime;
        struct timeval timout;

        timout.tv_sec = RTIME_TIMEOUT;
        timout.tv_usec = 0;
        if (rtime(synconfig, syncaddr, calltype, timep, &timout) < 0)
                return (FALSE);
        (void) gettimeofday(&mytime, (struct timezone *)NULL);
        timep->tv_sec -= mytime.tv_sec;
        if (mytime.tv_usec > timep->tv_usec) {
                timep->tv_sec -= 1;
                timep->tv_usec += MILLION;
        }
        timep->tv_usec -= mytime.tv_usec;
        return (TRUE);
}

static struct auth_ops *
authdes_ops(void)
{
        static struct auth_ops ops;

        mutex_enter(&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;
                ops.ah_wrap = authany_wrap;
                ops.ah_unwrap = authany_unwrap;
        }
        mutex_exit(&authdes_ops_lock);
        return (&ops);
}