sunrpc/auth_des.c

   1 /*
   2  * Copyright (c) 1988 by Sun Microsystems, Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  *       notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  *       copyright notice, this list of conditions and the following
  12  *       disclaimer in the documentation and/or other materials
  13  *       provided with the distribution.
  14  *     * Neither the name of Sun Microsystems, Inc. nor the names of its
  15  *       contributors may be used to endorse or promote products derived
  16  *       from this software without specific prior written permission.
  17  *
  18  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  21  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  22  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  23  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  25  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  27  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 /*
  32  * auth_des.c, client-side implementation of DES authentication
  33  */
  34
  35 #include <string.h>
  36 #include <rpc/des_crypt.h>
  37 #include <rpc/types.h>
  38 #include <rpc/auth.h>
  39 #include <rpc/auth_des.h>
  40 #include <rpc/xdr.h>
  41 #include <netinet/in.h>         /* XXX: just to get htonl() and ntohl() */
  42 #include <sys/socket.h>
  43
  44 #define MILLION         1000000L
  45 #define RTIME_TIMEOUT 5         /* seconds to wait for sync */
  46
  47 #define AUTH_PRIVATE(auth)      (struct ad_private *) auth->ah_private
  48 #define ALLOC(object_type)      (object_type *) mem_alloc(sizeof(object_type))
  49 #define FREE(ptr, size)         mem_free((char *)(ptr), (int) size)
  50 #define ATTEMPT(xdr_op)         if (!(xdr_op)) return (FALSE)
  51
  52 #define debug(msg)              /* printf("%s\n", msg) */
  53
  54 extern bool_t INTUSE(xdr_authdes_cred) (XDR *, struct authdes_cred *);
  55 extern bool_t INTUSE(xdr_authdes_verf) (XDR *, struct authdes_verf *);
  56
  57 /*
  58  * DES authenticator operations vector
  59  */
  60 static void authdes_nextverf (AUTH *);
  61 static bool_t authdes_marshal (AUTH *, XDR *);
  62 static bool_t authdes_validate (AUTH *, struct opaque_auth *);
  63 static bool_t authdes_refresh (AUTH *);
  64 static void authdes_destroy (AUTH *);
  65 static bool_t synchronize (struct sockaddr *, struct rpc_timeval *)
  66      internal_function;
  67
  68 static const struct auth_ops authdes_ops = {
  69   authdes_nextverf,
  70   authdes_marshal,
  71   authdes_validate,
  72   authdes_refresh,
  73   authdes_destroy
  74 };
  75
  76
  77 /*
  78  * This struct is pointed to by the ah_private field of an "AUTH *"
  79  */
  80 struct ad_private {
  81   char *ad_fullname;            /* client's full name */
  82   u_int ad_fullnamelen;         /* length of name, rounded up */
  83   char *ad_servername;          /* server's full name */
  84   u_int ad_servernamelen;       /* length of name, rounded up */
  85   uint32_t ad_window;           /* client specified window */
  86   bool_t ad_dosync;             /* synchronize? */
  87   struct sockaddr ad_syncaddr;  /* remote host to synch with */
  88   struct rpc_timeval ad_timediff;       /* server's time - client's time */
  89   uint32_t ad_nickname;         /* server's nickname for client */
  90   struct authdes_cred ad_cred;  /* storage for credential */
  91   struct authdes_verf ad_verf;  /* storage for verifier */
  92   struct rpc_timeval ad_timestamp;      /* timestamp sent */
  93   des_block ad_xkey;            /* encrypted conversation key */
  94   u_char ad_pkey[1024];         /* Servers actual public key */
  95 };
  96
  97
  98 /*
  99  * Create the client des authentication object
 100  */
 101 AUTH *
 102 authdes_create (const char *servername, u_int window,
 103                 struct sockaddr *syncaddr, des_block *ckey)
 104   /* servername - network name of server */
 105   /* window     - time to live */
 106   /* syncaddr   - optional addr of host to sync with */
 107   /* ckey       - optional conversation key to use */
 108 {
 109   char pkey_data[1024];
 110   netobj pkey;
 111
 112   if (!getpublickey (servername, pkey_data))
 113     return NULL;
 114
 115   pkey.n_bytes = pkey_data;
 116   pkey.n_len = strlen (pkey_data) + 1;
 117   return INTUSE(authdes_pk_create) (servername, &pkey, window, syncaddr, ckey);
 118 }
 119
 120 AUTH *
 121 authdes_pk_create (const char *servername, netobj *pkey, u_int window,
 122                    struct sockaddr *syncaddr, des_block *ckey)
 123 {
 124   AUTH *auth;
 125   struct ad_private *ad;
 126   char namebuf[MAXNETNAMELEN + 1];
 127
 128   /*
 129    * Allocate everything now
 130    */
 131   auth = ALLOC (AUTH);
 132   ad = ALLOC (struct ad_private);
 133
 134   if (auth == NULL || ad == NULL)
 135     {
 136       debug ("authdes_create: out of memory");
 137       goto failed;
 138     }
 139
 140   memset (ad, 0, sizeof (struct ad_private));
 141   memcpy (ad->ad_pkey, pkey->n_bytes, pkey->n_len);
 142   if (!getnetname (namebuf))
 143     goto failed;
 144   ad->ad_fullnamelen = RNDUP (strlen (namebuf));
 145   ad->ad_fullname = mem_alloc (ad->ad_fullnamelen + 1);
 146
 147   ad->ad_servernamelen = strlen (servername);
 148   ad->ad_servername = mem_alloc (ad->ad_servernamelen + 1);
 149
 150   if (ad->ad_fullname == NULL || ad->ad_servername == NULL)
 151     {
 152       debug ("authdes_create: out of memory");
 153       goto failed;
 154     }
 155
 156   /*
 157    * Set up private data
 158    */
 159   memcpy (ad->ad_fullname, namebuf, ad->ad_fullnamelen + 1);
 160   memcpy (ad->ad_servername, servername, ad->ad_servernamelen + 1);
 161   ad->ad_timediff.tv_sec = ad->ad_timediff.tv_usec = 0;
 162   if (syncaddr != NULL)
 163     {
 164       ad->ad_syncaddr = *syncaddr;
 165       ad->ad_dosync = TRUE;
 166     }
 167   else
 168     ad->ad_dosync = FALSE;
 169
 170   ad->ad_window = window;
 171   if (ckey == NULL)
 172     {
 173       if (key_gendes (&auth->ah_key) < 0)
 174         {
 175           debug ("authdes_create: unable to gen conversation key");
 176           goto failed;
 177         }
 178     }
 179   else
 180     auth->ah_key = *ckey;
 181
 182   /*
 183    * Set up auth handle
 184    */
 185   auth->ah_cred.oa_flavor = AUTH_DES;
 186   auth->ah_verf.oa_flavor = AUTH_DES;
 187   auth->ah_ops = (struct auth_ops *) &authdes_ops;
 188   auth->ah_private = (caddr_t) ad;
 189
 190   if (!authdes_refresh (auth))
 191     goto failed;
 192
 193   return auth;
 194
 195 failed:
 196   if (auth != NULL)
 197     FREE (auth, sizeof (AUTH));
 198   if (ad != NULL)
 199     {
 200       if (ad->ad_fullname != NULL)
 201         FREE (ad->ad_fullname, ad->ad_fullnamelen + 1);
 202       if (ad->ad_servername != NULL)
 203         FREE (ad->ad_servername, ad->ad_servernamelen + 1);
 204       FREE (ad, sizeof (struct ad_private));
 205     }
 206   return NULL;
 207 }
 208 INTDEF(authdes_pk_create)
 209
 210 /*
 211  * Implement the five authentication operations
 212  */
 213
 214
 215 /*
 216  * 1. Next Verifier
 217  */
 218 /*ARGSUSED */
 219 static void
 220 authdes_nextverf (AUTH *auth)
 221 {
 222   /* what the heck am I supposed to do??? */
 223 }
 224
 225
 226
 227 /*
 228  * 2. Marshal
 229  */
 230 static bool_t
 231 authdes_marshal (AUTH *auth, XDR *xdrs)
 232 {
 233   struct ad_private *ad = AUTH_PRIVATE (auth);
 234   struct authdes_cred *cred = &ad->ad_cred;
 235   struct authdes_verf *verf = &ad->ad_verf;
 236   des_block cryptbuf[2];
 237   des_block ivec;
 238   int status;
 239   int len;
 240   register int32_t *ixdr;
 241   struct timeval tval;
 242
 243   /*
 244    * Figure out the "time", accounting for any time difference
 245    * with the server if necessary.
 246    */
 247   __gettimeofday (&tval, (struct timezone *) NULL);
 248   ad->ad_timestamp.tv_sec = tval.tv_sec + ad->ad_timediff.tv_sec;
 249   ad->ad_timestamp.tv_usec = tval.tv_usec + ad->ad_timediff.tv_usec;
 250   if (ad->ad_timestamp.tv_usec >= MILLION)
 251     {
 252       ad->ad_timestamp.tv_usec -= MILLION;
 253       ad->ad_timestamp.tv_sec += 1;
 254     }
 255
 256   /*
 257    * XDR the timestamp and possibly some other things, then
 258    * encrypt them.
 259    * XXX We have a real Year 2038 problem here.
 260    */
 261   ixdr = (int32_t *) cryptbuf;
 262   IXDR_PUT_INT32 (ixdr, ad->ad_timestamp.tv_sec);
 263   IXDR_PUT_INT32 (ixdr, ad->ad_timestamp.tv_usec);
 264   if (ad->ad_cred.adc_namekind == ADN_FULLNAME)
 265     {
 266       IXDR_PUT_U_INT32 (ixdr, ad->ad_window);
 267       IXDR_PUT_U_INT32 (ixdr, ad->ad_window - 1);
 268       ivec.key.high = ivec.key.low = 0;
 269       status = cbc_crypt ((char *) &auth->ah_key, (char *) cryptbuf,
 270               2 * sizeof (des_block), DES_ENCRYPT | DES_HW, (char *) &ivec);
 271     }
 272   else
 273     status = ecb_crypt ((char *) &auth->ah_key, (char *) cryptbuf,
 274                         sizeof (des_block), DES_ENCRYPT | DES_HW);
 275
 276   if (DES_FAILED (status))
 277     {
 278       debug ("authdes_marshal: DES encryption failure");
 279       return FALSE;
 280     }
 281   ad->ad_verf.adv_xtimestamp = cryptbuf[0];
 282   if (ad->ad_cred.adc_namekind == ADN_FULLNAME)
 283     {
 284       ad->ad_cred.adc_fullname.window = cryptbuf[1].key.high;
 285       ad->ad_verf.adv_winverf = cryptbuf[1].key.low;
 286     }
 287   else
 288     {
 289       ad->ad_cred.adc_nickname = ad->ad_nickname;
 290       ad->ad_verf.adv_winverf = 0;
 291     }
 292
 293   /*
 294    * Serialize the credential and verifier into opaque
 295    * authentication data.
 296    */
 297   if (ad->ad_cred.adc_namekind == ADN_FULLNAME)
 298     len = ((1 + 1 + 2 + 1) * BYTES_PER_XDR_UNIT + ad->ad_fullnamelen);
 299   else
 300     len = (1 + 1) * BYTES_PER_XDR_UNIT;
 301
 302   if ((ixdr = xdr_inline (xdrs, 2 * BYTES_PER_XDR_UNIT)) != NULL)
 303     {
 304       IXDR_PUT_INT32 (ixdr, AUTH_DES);
 305       IXDR_PUT_U_INT32 (ixdr, len);
 306     }
 307   else
 308     {
 309       ATTEMPT (xdr_putint32 (xdrs, &auth->ah_cred.oa_flavor));
 310       ATTEMPT (xdr_putint32 (xdrs, &len));
 311     }
 312   ATTEMPT (INTUSE(xdr_authdes_cred) (xdrs, cred));
 313
 314   len = (2 + 1) * BYTES_PER_XDR_UNIT;
 315   if ((ixdr = xdr_inline (xdrs, 2 * BYTES_PER_XDR_UNIT)) != NULL)
 316     {
 317       IXDR_PUT_INT32 (ixdr, AUTH_DES);
 318       IXDR_PUT_U_INT32 (ixdr, len);
 319     }
 320   else
 321     {
 322       ATTEMPT (xdr_putint32 (xdrs, &auth->ah_verf.oa_flavor));
 323       ATTEMPT (xdr_putint32 (xdrs, &len));
 324     }
 325   ATTEMPT (INTUSE(xdr_authdes_verf) (xdrs, verf));
 326
 327   return TRUE;
 328 }
 329
 330
 331 /*
 332  * 3. Validate
 333  */
 334 static bool_t
 335 authdes_validate (AUTH *auth, struct opaque_auth *rverf)
 336 {
 337   struct ad_private *ad = AUTH_PRIVATE (auth);
 338   struct authdes_verf verf;
 339   int status;
 340   register uint32_t *ixdr;
 341
 342   if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT)
 343     return FALSE;
 344
 345   ixdr = (uint32_t *) rverf->oa_base;
 346   verf.adv_xtimestamp.key.high = *ixdr++;
 347   verf.adv_xtimestamp.key.low = *ixdr++;
 348   verf.adv_int_u = *ixdr++;     /* nickname not XDR'd ! */
 349
 350   /*
 351    * Decrypt the timestamp
 352    */
 353   status = ecb_crypt ((char *) &auth->ah_key, (char *) &verf.adv_xtimestamp,
 354                       sizeof (des_block), DES_DECRYPT | DES_HW);
 355
 356   if (DES_FAILED (status))
 357     {
 358       debug ("authdes_validate: DES decryption failure");
 359       return FALSE;
 360     }
 361
 362   /*
 363    * xdr the decrypted timestamp
 364    */
 365   ixdr = (uint32_t *) verf.adv_xtimestamp.c;
 366   verf.adv_timestamp.tv_sec = IXDR_GET_U_INT32 (ixdr) + 1;
 367   verf.adv_timestamp.tv_usec = IXDR_GET_U_INT32 (ixdr);
 368
 369   /*
 370    * validate
 371    */
 372   if (memcmp ((char *) &ad->ad_timestamp, (char *) &verf.adv_timestamp,
 373               sizeof (struct rpc_timeval)) != 0)
 374     {
 375       debug ("authdes_validate: verifier mismatch\n");
 376       return FALSE;
 377     }
 378
 379   /*
 380    * We have a nickname now, let's use it
 381    */
 382   ad->ad_nickname = verf.adv_nickname;
 383   ad->ad_cred.adc_namekind = ADN_NICKNAME;
 384   return TRUE;
 385 }
 386
 387 /*
 388  * 4. Refresh
 389  */
 390 static bool_t
 391 authdes_refresh (AUTH *auth)
 392 {
 393   netobj pkey;
 394   struct ad_private *ad = AUTH_PRIVATE (auth);
 395   struct authdes_cred *cred = &ad->ad_cred;
 396
 397   if (ad->ad_dosync && !synchronize (&ad->ad_syncaddr, &ad->ad_timediff))
 398     {
 399       /*
 400        * Hope the clocks are synced!
 401        */
 402       ad->ad_timediff.tv_sec = ad->ad_timediff.tv_usec = 0;
 403       debug ("authdes_refresh: unable to synchronize with server");
 404     }
 405   ad->ad_xkey = auth->ah_key;
 406   pkey.n_bytes = (char *) (ad->ad_pkey);
 407   pkey.n_len = strlen ((char *) ad->ad_pkey) + 1;
 408   if (key_encryptsession_pk (ad->ad_servername, &pkey, &ad->ad_xkey) < 0)
 409     {
 410       debug ("authdes_create: unable to encrypt conversation key");
 411       return FALSE;
 412     }
 413   cred->adc_fullname.key = ad->ad_xkey;
 414   cred->adc_namekind = ADN_FULLNAME;
 415   cred->adc_fullname.name = ad->ad_fullname;
 416   return TRUE;
 417 }
 418
 419 /*
 420  * 5. Destroy
 421  */
 422 static void
 423 authdes_destroy (AUTH *auth)
 424 {
 425   struct ad_private *ad = AUTH_PRIVATE (auth);
 426
 427   FREE (ad->ad_fullname, ad->ad_fullnamelen + 1);
 428   FREE (ad->ad_servername, ad->ad_servernamelen + 1);
 429   FREE (ad, sizeof (struct ad_private));
 430   FREE (auth, sizeof (AUTH));
 431 }
 432
 433 /*
 434  * Synchronize with the server at the given address, that is,
 435  * adjust timep to reflect the delta between our clocks
 436  */
 437 static bool_t
 438 internal_function
 439 synchronize (struct sockaddr *syncaddr, struct rpc_timeval *timep)
 440 {
 441   struct timeval mytime;
 442   struct rpc_timeval timeout;
 443
 444   timeout.tv_sec = RTIME_TIMEOUT;
 445   timeout.tv_usec = 0;
 446   if (rtime ((struct sockaddr_in *) syncaddr, timep, &timeout) < 0)
 447     return FALSE;
 448
 449   __gettimeofday (&mytime, (struct timezone *) NULL);
 450   timep->tv_sec -= mytime.tv_sec;
 451   if (mytime.tv_usec > timep->tv_usec)
 452     {
 453       timep->tv_sec -= 1;
 454       timep->tv_usec += MILLION;
 455     }
 456   timep->tv_usec -= mytime.tv_usec;
 457   return TRUE;
 458 }