key_call.c

Go to the documentation of this file.

/*
 * 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. 
 */


//#include <sys/cdefs.h>

/*
 * 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
 */
 
#ifndef _WIN32

#include <pthread.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>


#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)() = 0;
cryptkeyres *(*__key_decryptsession_pk_LOCAL)() = 0;
des_block *(*__key_gendes_LOCAL)() = 0;

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

int
key_setsecret(secretkey)
    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(remotename, remotekey, deskey)
    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(remotename, remotekey, deskey)
    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(remotename, deskey)
    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(remotename, deskey)
    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(key)
    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(arg)
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(pkey, deskey)
    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 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);
    }
}

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

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

    if (key_call_key == -1) {
        mutex_lock(&tsd_lock);
        if (key_call_key == -1)
            thr_keycreate(&key_call_key, key_call_destroy);
        mutex_unlock(&tsd_lock);
    }
    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);
        }
                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 (uname(&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(proc, xdr_arg, arg, xdr_rslt, rslt)
    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);
    }
}
#endif