/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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) 1986-1991 by Sun Microsystems Inc. 
 */

/*
 * key_call.c, Interface to keyserver
 *
 * setsecretkey(key) - set your secret key
 * encryptsessionkey(agent, deskey) - encrypt a session key to talk to agent
 * decryptsessionkey(agent, deskey) - decrypt ditto
 * gendeskey(deskey) - generate a secure des key
 */

#include "namespace.h"
#include "reentrant.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <rpc/rpc.h>
#include <rpc/auth.h>
#include <rpc/auth_unix.h>
#include <rpc/key_prot.h>
#include <string.h>
#include <netconfig.h>
#include <sys/utsname.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/fcntl.h>
#include "un-namespace.h"
#include "mt_misc.h"


#define KEY_TIMEOUT     5       /* per-try timeout in seconds */
#define KEY_NRETRY      12      /* number of retries */

#ifdef DEBUG
#define debug(msg)      (void) fprintf(stderr, "%s\n", msg);
#else
#define debug(msg)
#endif /* DEBUG */

/*
 * Hack to allow the keyserver to use AUTH_DES (for authenticated
 * NIS+ calls, for example).  The only functions that get called
 * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
 *
 * The approach is to have the keyserver fill in pointers to local
 * implementations of these functions, and to call those in key_call().
 */

cryptkeyres *(*__key_encryptsession_pk_LOCAL)(uid_t, void *arg) = 0;
cryptkeyres *(*__key_decryptsession_pk_LOCAL)(uid_t, void *arg) = 0;
des_block *(*__key_gendes_LOCAL)(uid_t, void *) = 0;

static int key_call( u_long, xdrproc_t, void *, xdrproc_t, void *);

int
key_setsecret(const char *secretkey)
{
        keystatus status;

        if (!key_call((u_long) KEY_SET, (xdrproc_t)xdr_keybuf,
                        (void *)secretkey,
                        (xdrproc_t)xdr_keystatus, &status)) {
                return (-1);
        }
        if (status != KEY_SUCCESS) {
                debug("set status is nonzero");
                return (-1);
        }
        return (0);
}


/* key_secretkey_is_set() returns 1 if the keyserver has a secret key
 * stored for the caller's effective uid; it returns 0 otherwise
 *
 * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
 * be using it, because it allows them to get the user's secret key.
 */

int
key_secretkey_is_set(void)
{
        struct key_netstres     kres;

        memset((void*)&kres, 0, sizeof (kres));
        if (key_call((u_long) KEY_NET_GET, (xdrproc_t)xdr_void, NULL,
                        (xdrproc_t)xdr_key_netstres, &kres) &&
            (kres.status == KEY_SUCCESS) &&
            (kres.key_netstres_u.knet.st_priv_key[0] != 0)) {
                /* avoid leaving secret key in memory */
                memset(kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
                return (1);
        }
        return (0);
}

int
key_encryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
{
        cryptkeyarg2 arg;
        cryptkeyres res;

        arg.remotename = remotename;
        arg.remotekey = *remotekey;
        arg.deskey = *deskey;
        if (!key_call((u_long)KEY_ENCRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
                        (xdrproc_t)xdr_cryptkeyres, &res)) {
                return (-1);
        }
        if (res.status != KEY_SUCCESS) {
                debug("encrypt status is nonzero");
                return (-1);
        }
        *deskey = res.cryptkeyres_u.deskey;
        return (0);
}

int
key_decryptsession_pk(char *remotename, netobj *remotekey, des_block *deskey)
{
        cryptkeyarg2 arg;
        cryptkeyres res;

        arg.remotename = remotename;
        arg.remotekey = *remotekey;
        arg.deskey = *deskey;
        if (!key_call((u_long)KEY_DECRYPT_PK, (xdrproc_t)xdr_cryptkeyarg2, &arg,
                        (xdrproc_t)xdr_cryptkeyres, &res)) {
                return (-1);
        }
        if (res.status != KEY_SUCCESS) {
                debug("decrypt status is nonzero");
                return (-1);
        }
        *deskey = res.cryptkeyres_u.deskey;
        return (0);
}

int
key_encryptsession(const char *remotename, des_block *deskey)
{
        cryptkeyarg arg;
        cryptkeyres res;

        arg.remotename = (char *) remotename;
        arg.deskey = *deskey;
        if (!key_call((u_long)KEY_ENCRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
                        (xdrproc_t)xdr_cryptkeyres, &res)) {
                return (-1);
        }
        if (res.status != KEY_SUCCESS) {
                debug("encrypt status is nonzero");
                return (-1);
        }
        *deskey = res.cryptkeyres_u.deskey;
        return (0);
}

int
key_decryptsession(const char *remotename, des_block *deskey)
{
        cryptkeyarg arg;
        cryptkeyres res;

        arg.remotename = (char *) remotename;
        arg.deskey = *deskey;
        if (!key_call((u_long)KEY_DECRYPT, (xdrproc_t)xdr_cryptkeyarg, &arg,
                        (xdrproc_t)xdr_cryptkeyres, &res)) {
                return (-1);
        }
        if (res.status != KEY_SUCCESS) {
                debug("decrypt status is nonzero");
                return (-1);
        }
        *deskey = res.cryptkeyres_u.deskey;
        return (0);
}

int
key_gendes(des_block *key)
{
        if (!key_call((u_long)KEY_GEN, (xdrproc_t)xdr_void, NULL,
                        (xdrproc_t)xdr_des_block, key)) {
                return (-1);
        }
        return (0);
}

int
key_setnet(struct key_netstarg *arg)
{
        keystatus status;


        if (!key_call((u_long) KEY_NET_PUT, (xdrproc_t)xdr_key_netstarg, arg,
                        (xdrproc_t)xdr_keystatus, &status)){
                return (-1);
        }

        if (status != KEY_SUCCESS) {
                debug("key_setnet status is nonzero");
                return (-1);
        }
        return (1);
}


int
key_get_conv(char *pkey, des_block *deskey)
{
        cryptkeyres res;

        if (!key_call((u_long) KEY_GET_CONV, (xdrproc_t)xdr_keybuf, pkey,
                        (xdrproc_t)xdr_cryptkeyres, &res)) {
                return (-1);
        }
        if (res.status != KEY_SUCCESS) {
                debug("get_conv status is nonzero");
                return (-1);
        }
        *deskey = res.cryptkeyres_u.deskey;
        return (0);
}

struct  key_call_private {
        CLIENT  *client;        /* Client handle */
        pid_t   pid;            /* process-id at moment of creation */
        uid_t   uid;            /* user-id at last authorization */
};
static struct key_call_private *key_call_private_main = NULL;
static thread_key_t key_call_key;
static once_t key_call_once = ONCE_INITIALIZER;
static int key_call_key_error;

static void
key_call_destroy(void *vp)
{
        struct key_call_private *kcp = (struct key_call_private *)vp;

        if (kcp) {
                if (kcp->client)
                        clnt_destroy(kcp->client);
                free(kcp);
        }
}

static void
key_call_init(void)
{

        key_call_key_error = thr_keycreate(&key_call_key, key_call_destroy);
}

/*
 * Keep the handle cached.  This call may be made quite often.
 */
static CLIENT *
getkeyserv_handle(int vers)
{
        void *localhandle;
        struct netconfig *nconf;
        struct netconfig *tpconf;
        struct key_call_private *kcp;
        struct timeval wait_time;
        struct utsname u;
        int main_thread;
        int fd;

#define TOTAL_TIMEOUT   30      /* total timeout talking to keyserver */
#define TOTAL_TRIES     5       /* Number of tries */

        if ((main_thread = thr_main())) {
                kcp = key_call_private_main;
        } else {
                if (thr_once(&key_call_once, key_call_init) != 0 ||
                    key_call_key_error != 0)
                        return ((CLIENT *) NULL);
                kcp = (struct key_call_private *)thr_getspecific(key_call_key);
        }       
        if (kcp == (struct key_call_private *)NULL) {
                kcp = (struct key_call_private *)malloc(sizeof (*kcp));
                if (kcp == (struct key_call_private *)NULL) {
                        return ((CLIENT *) NULL);
                }
                if (main_thread)
                        key_call_private_main = kcp;
                else
                        thr_setspecific(key_call_key, (void *) kcp);
                kcp->client = NULL;
        }

        /* if pid has changed, destroy client and rebuild */
        if (kcp->client != NULL && kcp->pid != getpid()) {
                clnt_destroy(kcp->client);
                kcp->client = NULL;
        }

        if (kcp->client != NULL) {
                /* if uid has changed, build client handle again */
                if (kcp->uid != geteuid()) {
                        kcp->uid = geteuid();
                        auth_destroy(kcp->client->cl_auth);
                        kcp->client->cl_auth =
                                authsys_create("", kcp->uid, 0, 0, NULL);
                        if (kcp->client->cl_auth == NULL) {
                                clnt_destroy(kcp->client);
                                kcp->client = NULL;
                                return ((CLIENT *) NULL);
                        }
                }
                /* Change the version number to the new one */
                clnt_control(kcp->client, CLSET_VERS, (void *)&vers);
                return (kcp->client);
        }
        if (!(localhandle = setnetconfig())) {
                return ((CLIENT *) NULL);
        }
        tpconf = NULL;
#if defined(__FreeBSD__)
        if (uname(&u) == -1)
#else
#if defined(i386)
        if (_nuname(&u) == -1)
#elif defined(sparc)
        if (_uname(&u) == -1)
#else
#error Unknown architecture!
#endif
#endif
        {
                endnetconfig(localhandle);
                return ((CLIENT *) NULL);
        }
        while ((nconf = getnetconfig(localhandle)) != NULL) {
                if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
                        /*
                         * We use COTS_ORD here so that the caller can
                         * find out immediately if the server is dead.
                         */
                        if (nconf->nc_semantics == NC_TPI_COTS_ORD) {
                                kcp->client = clnt_tp_create(u.nodename,
                                        KEY_PROG, vers, nconf);
                                if (kcp->client)
                                        break;
                        } else {
                                tpconf = nconf;
                        }
                }
        }
        if ((kcp->client == (CLIENT *) NULL) && (tpconf))
                /* Now, try the CLTS or COTS loopback transport */
                kcp->client = clnt_tp_create(u.nodename,
                        KEY_PROG, vers, tpconf);
        endnetconfig(localhandle);

        if (kcp->client == (CLIENT *) NULL) {
                return ((CLIENT *) NULL);
        }
        kcp->uid = geteuid();
        kcp->pid = getpid();
        kcp->client->cl_auth = authsys_create("", kcp->uid, 0, 0, NULL);
        if (kcp->client->cl_auth == NULL) {
                clnt_destroy(kcp->client);
                kcp->client = NULL;
                return ((CLIENT *) NULL);
        }

        wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
        wait_time.tv_usec = 0;
        (void) clnt_control(kcp->client, CLSET_RETRY_TIMEOUT,
                (char *)&wait_time);
        if (clnt_control(kcp->client, CLGET_FD, (char *)&fd))
                _fcntl(fd, F_SETFD, 1); /* make it "close on exec" */

        return (kcp->client);
}

/* returns  0 on failure, 1 on success */

static int
key_call(u_long proc, xdrproc_t xdr_arg, void *arg, xdrproc_t xdr_rslt,
    void *rslt)
{
        CLIENT *clnt;
        struct timeval wait_time;

        if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL) {
                cryptkeyres *res;
                res = (*__key_encryptsession_pk_LOCAL)(geteuid(), arg);
                *(cryptkeyres*)rslt = *res;
                return (1);
        } else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL) {
                cryptkeyres *res;
                res = (*__key_decryptsession_pk_LOCAL)(geteuid(), arg);
                *(cryptkeyres*)rslt = *res;
                return (1);
        } else if (proc == KEY_GEN && __key_gendes_LOCAL) {
                des_block *res;
                res = (*__key_gendes_LOCAL)(geteuid(), 0);
                *(des_block*)rslt = *res;
                return (1);
        }

        if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
            (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
            (proc == KEY_GET_CONV))
                clnt = getkeyserv_handle(2); /* talk to version 2 */
        else
                clnt = getkeyserv_handle(1); /* talk to version 1 */

        if (clnt == NULL) {
                return (0);
        }

        wait_time.tv_sec = TOTAL_TIMEOUT;
        wait_time.tv_usec = 0;

        if (clnt_call(clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
                wait_time) == RPC_SUCCESS) {
                return (1);
        } else {
                return (0);
        }
}