/*

 * Copyright (c) 2010, Oracle America, Inc.

 *

 * 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 the "Oracle America, 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.

 */

/*

 * The original source is from the RPCSRC 4.0 package from Sun Microsystems.

 * The Interface to keyserver protocoll 2, RPC over AF_UNIX and Linux/doors

 * was added by Thorsten Kukuk <kukuk@suse.de>

 * Since the Linux/doors project was stopped, I doubt that this code will

 * ever be useful <kukuk@suse.de>.

 */

#include <stdio.h>

#include <errno.h>

#include <fcntl.h>

#include <signal.h>

#include <unistd.h>

#include <string.h>

#include <rpc/rpc.h>

#include <rpc/auth.h>

#include <sys/wait.h>

#include <sys/param.h>

#include <sys/socket.h>

#include <rpc/key_prot.h>

#include <libc-lock.h>

#include <shlib-compat.h>

#define KEY_TIMEOUT	5	/* per-try timeout in seconds */

#define KEY_NRETRY	12	/* number of retries */

#define debug(msg)		/* turn off debugging */

#ifndef SO_PASSCRED

extern int _openchild (const char *command, FILE **fto, FILE **ffrom);

#endif

static int key_call (u_long, xdrproc_t xdr_arg, char *,

		     xdrproc_t xdr_rslt, char *);

static const struct timeval trytimeout = {KEY_TIMEOUT, 0};

static const struct timeval tottimeout = {KEY_TIMEOUT *KEY_NRETRY, 0};

int

key_setsecret (char *secretkey)

{

  keystatus status;

  if (!key_call ((u_long) KEY_SET, (xdrproc_t) xdr_keybuf, secretkey,

		 (xdrproc_t) xdr_keystatus, (char *) &status))

    return -1;

  if (status != KEY_SUCCESS)

    {

      debug ("set status is nonzero");

      return -1;

    }

  return 0;

}

libc_hidden_nolink_sunrpc (key_setsecret, GLIBC_2_1)

/* 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 (&kres, 0, sizeof (kres));

  if (key_call ((u_long) KEY_NET_GET, (xdrproc_t) xdr_void,

		(char *) NULL, (xdrproc_t) xdr_key_netstres,

		(char *) &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;

}

#ifdef EXPORT_RPC_SYMBOLS

libc_hidden_def (key_secretkey_is_set)

#else

libc_hidden_nolink_sunrpc (key_secretkey_is_set, GLIBC_2_1)

#endif

int

key_encryptsession (char *remotename, des_block *deskey)

{

  cryptkeyarg arg;

  cryptkeyres res;

  arg.remotename = remotename;

  arg.deskey = *deskey;

  if (!key_call ((u_long) KEY_ENCRYPT, (xdrproc_t) xdr_cryptkeyarg,

		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres,

		 (char *) &res))

    return -1;

  if (res.status != KEY_SUCCESS)

    {

      debug ("encrypt status is nonzero");

      return -1;

    }

  *deskey = res.cryptkeyres_u.deskey;

  return 0;

}

libc_hidden_nolink_sunrpc (key_encryptsession, GLIBC_2_1)

int

key_decryptsession (char *remotename, des_block *deskey)

{

  cryptkeyarg arg;

  cryptkeyres res;

  arg.remotename = remotename;

  arg.deskey = *deskey;

  if (!key_call ((u_long) KEY_DECRYPT, (xdrproc_t) xdr_cryptkeyarg,

		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres,

		 (char *) &res))

    return -1;

  if (res.status != KEY_SUCCESS)

    {

      debug ("decrypt status is nonzero");

      return -1;

    }

  *deskey = res.cryptkeyres_u.deskey;

  return 0;

}

libc_hidden_nolink_sunrpc (key_decryptsession, GLIBC_2_1)

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,

		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres,

		 (char *) &res))

    return -1;

  if (res.status != KEY_SUCCESS)

    {

      debug ("encrypt status is nonzero");

      return -1;

    }

  *deskey = res.cryptkeyres_u.deskey;

  return 0;

}

libc_hidden_nolink_sunrpc (key_encryptsession_pk, GLIBC_2_1)

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,

		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres,

		 (char *) &res))

    return -1;

  if (res.status != KEY_SUCCESS)

    {

      debug ("decrypt status is nonzero");

      return -1;

    }

  *deskey = res.cryptkeyres_u.deskey;

  return 0;

}

libc_hidden_nolink_sunrpc (key_decryptsession_pk, GLIBC_2_1)

int

key_gendes (des_block *key)

{

  struct sockaddr_in sin;

  CLIENT *client;

  int socket;

  enum clnt_stat stat;

  sin.sin_family = AF_INET;

  sin.sin_port = 0;

  sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK);

  memset (sin.sin_zero, 0, sizeof (sin.sin_zero));

  socket = RPC_ANYSOCK;

  client = clntudp_bufcreate (&sin, (u_long) KEY_PROG, (u_long) KEY_VERS,

			      trytimeout, &socket, RPCSMALLMSGSIZE,

			      RPCSMALLMSGSIZE);

  if (client == NULL)

    return -1;

  stat = clnt_call (client, KEY_GEN, (xdrproc_t) xdr_void, NULL,

		    (xdrproc_t) xdr_des_block, (caddr_t) key,

		    tottimeout);

  clnt_destroy (client);

  __close (socket);

  if (stat != RPC_SUCCESS)

    return -1;

  return 0;

}

#ifdef EXPORT_RPC_SYMBOLS

libc_hidden_def (key_gendes)

#else

libc_hidden_nolink_sunrpc (key_gendes, GLIBC_2_1)

#endif

int

key_setnet (struct key_netstarg *arg)

{

  keystatus status;

  if (!key_call ((u_long) KEY_NET_PUT, (xdrproc_t) xdr_key_netstarg,

		 (char *) arg,(xdrproc_t) xdr_keystatus,

		 (char *) &status))

    return -1;

  if (status != KEY_SUCCESS)

    {

      debug ("key_setnet status is nonzero");

      return -1;

    }

  return 1;

}

libc_hidden_nolink_sunrpc (key_setnet, GLIBC_2_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, (char *) &res))

    return -1;

  if (res.status != KEY_SUCCESS)

    {

      debug ("get_conv status is nonzero");

      return -1;

    }

  *deskey = res.cryptkeyres_u.deskey;

  return 0;

}

libc_hidden_nolink_sunrpc (key_get_conv, GLIBC_2_1)

/*

 * 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, char *);

cryptkeyres *(*__key_decryptsession_pk_LOCAL) (uid_t, char *);

des_block *(*__key_gendes_LOCAL) (uid_t, char *);

#ifndef SO_PASSCRED

static int

key_call_keyenvoy (u_long proc, xdrproc_t xdr_arg, char *arg,

		   xdrproc_t xdr_rslt, char *rslt)

{

  XDR xdrargs;

  XDR xdrrslt;

  FILE *fargs;

  FILE *frslt;

  sigset_t oldmask, mask;

  int status;

  int pid;

  int success;

  uid_t ruid;

  uid_t euid;

  static const char MESSENGER[] = "/usr/etc/keyenvoy";

  success = 1;

  sigemptyset (&mask);

  sigaddset (&mask, SIGCHLD);

  __sigprocmask (SIG_BLOCK, &mask, &oldmask);

  /*

   * We are going to exec a set-uid program which makes our effective uid

   * zero, and authenticates us with our real uid. We need to make the

   * effective uid be the real uid for the setuid program, and

   * the real uid be the effective uid so that we can change things back.

   */

  euid = __geteuid ();

  ruid = __getuid ();

  __setreuid (euid, ruid);

  pid = _openchild (MESSENGER, &fargs, &frslt);

  __setreuid (ruid, euid);

  if (pid < 0)

    {

      debug ("open_streams");

      __sigprocmask (SIG_SETMASK, &oldmask, NULL);

      return (0);

    }

  xdrstdio_create (&xdrargs, fargs, XDR_ENCODE);

  xdrstdio_create (&xdrrslt, frslt, XDR_DECODE);

  if (!xdr_u_long (&xdrargs, &proc) || !(*xdr_arg) (&xdrargs, arg))

    {

      debug ("xdr args");

      success = 0;

    }

  fclose (fargs);

  if (success && !(*xdr_rslt) (&xdrrslt, rslt))

    {

      debug ("xdr rslt");

      success = 0;

    }

  fclose(frslt);

 wait_again:

  if (__wait4 (pid, &status, 0, NULL) < 0)

    {

      if (errno == EINTR)

	goto wait_again;

      debug ("wait4");

      if (errno == ECHILD || errno == ESRCH)

	perror ("wait");

      else

	success = 0;

    }

  else

    if (status != 0)

      {

	debug ("wait4 1");

	success = 0;

      }

  __sigprocmask (SIG_SETMASK, &oldmask, NULL);

  return success;

}

#endif

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 */

};

#define key_call_private_main RPC_THREAD_VARIABLE(key_call_private_s)

__libc_lock_define_initialized (static, keycall_lock)

/*

 * Keep the handle cached.  This call may be made quite often.

 */

static CLIENT *

getkeyserv_handle (int vers)

{

  struct key_call_private *kcp = key_call_private_main;

  struct timeval wait_time;

  int fd;

  struct sockaddr_un name;

  socklen_t namelen = sizeof(struct sockaddr_un);

#define TOTAL_TIMEOUT   30      /* total timeout talking to keyserver */

#define TOTAL_TRIES     5       /* Number of tries */

  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;

      key_call_private_main = kcp;

      kcp->client = NULL;

    }

  /* if pid has changed, destroy client and rebuild */

  if (kcp->client != NULL && kcp->pid != __getpid ())

    {

      auth_destroy (kcp->client->cl_auth);

      clnt_destroy (kcp->client);

      kcp->client = NULL;

    }

  if (kcp->client != NULL)

    {

      /* if other side closed socket, build handle again */

      clnt_control (kcp->client, CLGET_FD, (char *)&fd;;

      if (__getpeername (fd,(struct sockaddr *)&name,&namelen) == -1)

	{

	  auth_destroy (kcp->client->cl_auth);

	  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 =

	  authunix_create ((char *)"", 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 ((kcp->client == (CLIENT *) NULL))

    /* Use the AF_UNIX transport */

    kcp->client = clnt_create ("/var/run/keyservsock", KEY_PROG, vers, "unix");

  if (kcp->client == (CLIENT *) NULL)

    return (CLIENT *) NULL;

  kcp->uid = __geteuid ();

  kcp->pid = __getpid ();

  kcp->client->cl_auth = authunix_create ((char *)"", 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;

  clnt_control (kcp->client, CLSET_RETRY_TIMEOUT,

		(char *)&wait_time);

  if (clnt_control (kcp->client, CLGET_FD, (char *)&fd))

    __fcntl (fd, F_SETFD, FD_CLOEXEC);  /* make it "close on exec" */

  return kcp->client;

}

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

static int

key_call_socket (u_long proc, xdrproc_t xdr_arg, char *arg,

	       xdrproc_t xdr_rslt, char *rslt)

{

  CLIENT *clnt;

  struct timeval wait_time;

  int result = 0;

  __libc_lock_lock (keycall_lock);

  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)

    {

      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)

	result = 1;

    }

  __libc_lock_unlock (keycall_lock);

  return result;

}

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

static int

key_call (u_long proc, xdrproc_t xdr_arg, char *arg,

	  xdrproc_t xdr_rslt, char *rslt)

{

#ifndef SO_PASSCRED

  static int use_keyenvoy;

#endif

  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;

    }

#ifdef SO_PASSCRED

  return key_call_socket (proc, xdr_arg, arg, xdr_rslt, rslt);

#else

  if (!use_keyenvoy)

    {

      if (key_call_socket (proc, xdr_arg, arg, xdr_rslt, rslt))

	return 1;

      use_keyenvoy = 1;

    }

  return key_call_keyenvoy (proc, xdr_arg, arg, xdr_rslt, rslt);

#endif

}

void

__rpc_thread_key_cleanup (void)

{

	struct key_call_private *kcp = RPC_THREAD_VARIABLE(key_call_private_s);

	if (kcp) {

		if (kcp->client) {

			if (kcp->client->cl_auth)

				auth_destroy (kcp->client->cl_auth);

			clnt_destroy(kcp->client);

		}

		free (kcp);

	}

}