usr/src/lib/krb5/kadm5/clnt/changepw.c

   1 /*
   2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6
   7 /*
   8  * lib/krb5/os/changepw.c
   9  *
  10  * Copyright 1990,1999 by the Massachusetts Institute of Technology.
  11  * All Rights Reserved.
  12  *
  13  * Export of this software from the United States of America may
  14  *   require a specific license from the United States Government.
  15  *   It is the responsibility of any person or organization contemplating
  16  *   export to obtain such a license before exporting.
  17  *
  18  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
  19  * distribute this software and its documentation for any purpose and
  20  * without fee is hereby granted, provided that the above copyright
  21  * notice appear in all copies and that both that copyright notice and
  22  * this permission notice appear in supporting documentation, and that
  23  * the name of M.I.T. not be used in advertising or publicity pertaining
  24  * to distribution of the software without specific, written prior
  25  * permission.  Furthermore if you modify this software you must label
  26  * your software as modified software and not distribute it in such a
  27  * fashion that it might be confused with the original M.I.T. software.
  28  * M.I.T. makes no representations about the suitability of
  29  * this software for any purpose.  It is provided "as is" without express
  30  * or implied warranty.
  31  *
  32  */
  33
  34 #define NEED_SOCKETS
  35 #include <k5-int.h>
  36 #include <kadm5/admin.h>
  37 #include <client_internal.h>
  38 #include <gssapi/gssapi.h>
  39 #include <gssapi_krb5.h>
  40 #include <gssapiP_krb5.h>
  41 #include <krb5.h>
  42
  43 /* #include "adm_err.h" */
  44 #include <stdio.h>
  45 #include <errno.h>
  46
  47 extern krb5_error_code krb5int_mk_chpw_req(krb5_context  context,
  48                                         krb5_auth_context auth_context,
  49                                         krb5_data *ap_req, char *passwd,
  50                                         krb5_data *packet);
  51
  52 extern krb5_error_code krb5int_rd_chpw_rep(krb5_context context,
  53                                         krb5_auth_context auth_context,
  54                                         krb5_data *packet, int *result_code,
  55                                         krb5_data *result_data);
  56
  57 /*
  58  * _kadm5_get_kpasswd_protocol
  59  *
  60  * returns the password change protocol value to the caller.
  61  * Since the 'handle' is an opaque value to higher up callers,
  62  * this method is needed to provide a way for them to get a peek
  63  * at the protocol being used without having to expose the entire
  64  * handle structure.
  65  */
  66 krb5_chgpwd_prot
  67 _kadm5_get_kpasswd_protocol(void *handle)
  68 {
  69         kadm5_server_handle_t srvrhdl = (kadm5_server_handle_t)handle;
  70
  71         return (srvrhdl->params.kpasswd_protocol);
  72 }
  73
  74 /*
  75  * krb5_change_password
  76  *
  77  * Prepare and send a CHANGEPW request to a password server
  78  * using UDP datagrams.  This is only used for sending to
  79  * non-SEAM servers which support the Marc Horowitz defined
  80  * protocol (1998) for password changing.
  81  *
  82  * SUNW14resync - added _local as it conflicts with one in krb5.h
  83  */
  84 static krb5_error_code
  85 krb5_change_password_local(context, params, creds, newpw, srvr_rsp_code,
  86                     srvr_msg)
  87 krb5_context context;
  88 kadm5_config_params *params;
  89 krb5_creds *creds;
  90 char *newpw;
  91 kadm5_ret_t *srvr_rsp_code;
  92 krb5_data *srvr_msg;
  93 {
  94         krb5_auth_context auth_context;
  95         krb5_data ap_req, chpw_req, chpw_rep;
  96         krb5_address local_kaddr, remote_kaddr;
  97         krb5_error_code code = 0;
  98         int i, addrlen;
  99         struct sockaddr *addr_p, local_addr, remote_addr, tmp_addr;
 100         struct sockaddr_in *sin_p;
 101         struct hostent *hp;
 102         int naddr_p;
 103         int cc, local_result_code, tmp_len;
 104         SOCKET s1 = INVALID_SOCKET;
 105         SOCKET s2 = INVALID_SOCKET;
 106
 107
 108         /* Initialize values so that cleanup call can safely check for NULL */
 109         auth_context = NULL;
 110         addr_p = NULL;
 111         memset(&chpw_req, 0, sizeof (krb5_data));
 112         memset(&chpw_rep, 0, sizeof (krb5_data));
 113         memset(&ap_req, 0, sizeof (krb5_data));
 114
 115         /* initialize auth_context so that we know we have to free it */
 116         if ((code = krb5_auth_con_init(context, &auth_context)))
 117                 goto cleanup;
 118
 119         if (code = krb5_mk_req_extended(context, &auth_context,
 120                                         AP_OPTS_USE_SUBKEY,
 121                                         NULL, creds, &ap_req))
 122                 goto cleanup;
 123
 124         /*
 125          * find the address of the kpasswd_server.
 126          */
 127         addr_p = (struct sockaddr *)malloc(sizeof (struct sockaddr));
 128         if (!addr_p)
 129                 goto cleanup;
 130         memset(addr_p, 0, sizeof (struct sockaddr));
 131         if ((hp = gethostbyname(params->kpasswd_server)) == NULL) {
 132                 code = KRB5_REALM_CANT_RESOLVE;
 133                 goto cleanup;
 134         }
 135         sin_p = (struct sockaddr_in *)addr_p;
 136         memset((char *)sin_p, 0, sizeof (struct sockaddr));
 137         sin_p->sin_family = hp->h_addrtype;
 138         sin_p->sin_port = htons(params->kpasswd_port);
 139         memcpy((char *)&sin_p->sin_addr, (char *)hp->h_addr, hp->h_length);
 140         naddr_p = 1;
 141
 142
 143         /*
 144          * this is really obscure.  s1 is used for all communications.  it
 145          * is left unconnected in case the server is multihomed and routes
 146          * are asymmetric.  s2 is connected to resolve routes and get
 147          * addresses.  this is the *only* way to get proper addresses for
 148          * multihomed hosts if routing is asymmetric.
 149          *
 150          * A related problem in the server, but not the client, is that
 151          * many os's have no way to disconnect a connected udp socket, so
 152          * the s2 socket needs to be closed and recreated for each
 153          * request.  The s1 socket must not be closed, or else queued
 154          * requests will be lost.
 155          *
 156          * A "naive" client implementation (one socket, no connect,
 157          * hostname resolution to get the local ip addr) will work and
 158          * interoperate if the client is single-homed.
 159          */
 160
 161         if ((s1 = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET)
 162         {
 163                 code = errno;
 164                 goto cleanup;
 165         }
 166
 167         if ((s2 = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET)
 168         {
 169                 code = errno;
 170                 goto cleanup;
 171         }
 172
 173         for (i = 0; i < naddr_p; i++)
 174         {
 175                 fd_set fdset;
 176                 struct timeval timeout;
 177
 178                 if (connect(s2, &addr_p[i], sizeof (addr_p[i])) ==
 179                     SOCKET_ERROR)
 180                 {
 181                         if ((errno == ECONNREFUSED) ||
 182                             (errno == EHOSTUNREACH))
 183                                 continue; /* try the next addr */
 184
 185                         code = errno;
 186                         goto cleanup;
 187                 }
 188
 189                 addrlen = sizeof (local_addr);
 190
 191                 if (getsockname(s2, &local_addr, &addrlen) < 0)
 192                 {
 193                         if ((errno == ECONNREFUSED) ||
 194                             (errno == EHOSTUNREACH))
 195                                 continue; /* try the next addr */
 196
 197                         code = errno;
 198                         goto cleanup;
 199                 }
 200
 201                 /*
 202                  * some brain-dead OS's don't return useful information from
 203                  * the getsockname call.  Namely, windows and solaris.
 204                  */
 205                 if (((struct sockaddr_in *)&local_addr)->sin_addr.s_addr != 0)
 206                 {
 207                         local_kaddr.addrtype = ADDRTYPE_INET;
 208                         local_kaddr.length = sizeof (((struct sockaddr_in *)
 209                                                     &local_addr)->sin_addr);
 210                         local_kaddr.contents = (krb5_octet *)
 211                                 &(((struct sockaddr_in *)
 212                                 &local_addr)->sin_addr);
 213                 }
 214                 else
 215                 {
 216                         krb5_address **addrs;
 217
 218                         krb5_os_localaddr(context, &addrs);
 219
 220                         local_kaddr.magic = addrs[0]->magic;
 221                         local_kaddr.addrtype = addrs[0]->addrtype;
 222                         local_kaddr.length = addrs[0]->length;
 223                         local_kaddr.contents = malloc(addrs[0]->length);
 224                         memcpy(local_kaddr.contents, addrs[0]->contents,
 225                             addrs[0]->length);
 226
 227                         krb5_free_addresses(context, addrs);
 228                 }
 229
 230                 addrlen = sizeof (remote_addr);
 231                 if (getpeername(s2, &remote_addr, &addrlen) < 0)
 232                 {
 233                         if ((errno == ECONNREFUSED) ||
 234                             (errno == EHOSTUNREACH))
 235                                 continue; /* try the next addr */
 236
 237                         code = errno;
 238                         goto cleanup;
 239                 }
 240
 241                 remote_kaddr.addrtype = ADDRTYPE_INET;
 242                 remote_kaddr.length = sizeof (((struct sockaddr_in *)
 243                                             &remote_addr)->sin_addr);
 244                 remote_kaddr.contents = (krb5_octet *)
 245                         &(((struct sockaddr_in *)&remote_addr)->sin_addr);
 246
 247                 /*
 248                  * mk_priv requires that the local address be set.
 249                  * getsockname is used for this.  rd_priv requires that the
 250                  * remote address be set.  recvfrom is used for this.  If
 251                  * rd_priv is given a local address, and the message has the
 252                  * recipient addr in it, this will be checked.  However, there
 253                  * is simply no way to know ahead of time what address the
 254                  * message will be delivered *to*.  Therefore, it is important
 255                  * that either no recipient address is in the messages when
 256                  * mk_priv is called, or that no local address is passed to
 257                  * rd_priv.  Both is a better idea, and I have done that.  In
 258                  * summary, when mk_priv is called, *only* a local address is
 259                  * specified.  when rd_priv is called, *only* a remote address
 260                  * is specified.  Are we having fun yet?
 261                  */
 262
 263                 if (code = krb5_auth_con_setaddrs(context, auth_context,
 264                                                 &local_kaddr, NULL))
 265                 {
 266                         code = errno;
 267                         goto cleanup;
 268                 }
 269
 270                 if (code = krb5int_mk_chpw_req(context, auth_context,
 271                                             &ap_req, newpw, &chpw_req))
 272                 {
 273                         code = errno;
 274                         goto cleanup;
 275                 }
 276
 277                 if ((cc = sendto(s1, chpw_req.data, chpw_req.length, 0,
 278                     (struct sockaddr *)&addr_p[i],
 279                     sizeof (addr_p[i]))) != chpw_req.length)
 280                 {
 281                         if ((cc < 0) && ((errno == ECONNREFUSED) ||
 282                                         (errno == EHOSTUNREACH)))
 283                                 continue; /* try the next addr */
 284
 285                         code = (cc < 0) ? errno : ECONNABORTED;
 286                         goto cleanup;
 287                 }
 288
 289                 chpw_rep.length = 1500;
 290                 chpw_rep.data = (char *)malloc(chpw_rep.length);
 291
 292                 /* XXX need a timeout/retry loop here */
 293                 FD_ZERO(&fdset);
 294                 FD_SET(s1, &fdset);
 295                 timeout.tv_sec = 120;
 296                 timeout.tv_usec = 0;
 297                 switch (select(s1 + 1, &fdset, 0, 0, &timeout)) {
 298                 case -1:
 299                         code = errno;
 300                         goto cleanup;
 301                 case 0:
 302                         code = ETIMEDOUT;
 303                         goto cleanup;
 304                 default:
 305                         /* fall through */
 306                         ;
 307                 }
 308
 309                 tmp_len = sizeof (tmp_addr);
 310                 if ((cc = recvfrom(s1, chpw_rep.data, chpw_rep.length,
 311                                 0, &tmp_addr, &tmp_len)) < 0)
 312                 {
 313                         code = errno;
 314                         goto cleanup;
 315                 }
 316
 317                 closesocket(s1);
 318                 s1 = INVALID_SOCKET;
 319                 closesocket(s2);
 320                 s2 = INVALID_SOCKET;
 321
 322                 chpw_rep.length = cc;
 323
 324                 if (code = krb5_auth_con_setaddrs(context, auth_context,
 325                                                 NULL, &remote_kaddr))
 326                         goto cleanup;
 327
 328                 if (code = krb5int_rd_chpw_rep(context, auth_context, &chpw_rep,
 329                                         &local_result_code, srvr_msg))
 330                         goto cleanup;
 331
 332                 if (srvr_rsp_code)
 333                         *srvr_rsp_code = local_result_code;
 334
 335                 code = 0;
 336                 goto cleanup;
 337         }
 338
 339         code = errno;
 340
 341 cleanup:
 342         if (auth_context != NULL)
 343                 krb5_auth_con_free(context, auth_context);
 344
 345         if (addr_p != NULL)
 346                 krb5_xfree(addr_p);
 347
 348         if (s1 != INVALID_SOCKET)
 349                 closesocket(s1);
 350
 351         if (s2 != INVALID_SOCKET)
 352                 closesocket(s2);
 353
 354         krb5_xfree(chpw_req.data);
 355         krb5_xfree(chpw_rep.data);
 356         krb5_xfree(ap_req.data);
 357
 358         return (code);
 359 }
 360
 361
 362 /*
 363  * kadm5_chpass_principal_v2
 364  *
 365  * New function used to prepare to make the change password request to a
 366  * non-SEAM admin server.  The protocol used in this case is not based on
 367  * RPCSEC_GSS, it simply makes the request to port 464 (udp and tcp).
 368  * This is the same way that MIT KRB5 1.2.1 changes passwords.
 369  */
 370 kadm5_ret_t
 371 kadm5_chpass_principal_v2(void *server_handle,
 372                         krb5_principal princ,
 373                         char *newpw,
 374                         kadm5_ret_t *srvr_rsp_code,
 375                         krb5_data *srvr_msg)
 376 {
 377         kadm5_ret_t code;
 378         kadm5_server_handle_t handle  = (kadm5_server_handle_t)server_handle;
 379         krb5_error_code result;
 380         krb5_creds mcreds;
 381         krb5_creds ncreds;
 382         krb5_ccache ccache;
 383         int cpwlen;
 384         char *cpw_service = NULL;
 385
 386         /*
 387          * The credentials have already been stored in the cache in the
 388          * initialization step earlier, but we dont have direct access to it
 389          * at this level. Derive the cache and fetch the credentials to use for
 390          * sending the request.
 391          */
 392         memset(&mcreds, 0, sizeof (krb5_creds));
 393         if ((code = krb5_cc_resolve(handle->context, handle->cache_name,
 394                                     &ccache)))
 395                 return (code);
 396
 397         /* set the client principal in the credential match structure */
 398         mcreds.client = princ;
 399
 400         /*
 401          * set the server principal (kadmin/changepw@REALM) in the credential
 402          * match struct
 403          */
 404         cpwlen = strlen(KADM5_CHANGEPW_SERVICE) +
 405                 strlen(handle->params.realm) + 2;
 406         cpw_service = malloc(cpwlen);
 407         if (cpw_service == NULL) {
 408                 return (ENOMEM);
 409         }
 410
 411         snprintf(cpw_service, cpwlen, "%s@%s",
 412                 KADM5_CHANGEPW_SERVICE, handle->params.realm);
 413
 414         /* generate the server principal from the name string we generated */
 415         if ((code = krb5_parse_name(handle->context, cpw_service,
 416                 &mcreds.server))) {
 417                 free(cpw_service);
 418                 return (code);
 419         }
 420
 421         /* Find the credentials in the cache */
 422         if ((code = krb5_cc_retrieve_cred(handle->context, ccache, 0, &mcreds,
 423                                         &ncreds))) {
 424                 free(cpw_service);
 425                 return (code);
 426         }
 427
 428         /* Now we have all we need to make the change request. */
 429         result = krb5_change_password_local(handle->context, &handle->params,
 430                                     &ncreds, newpw,
 431                                     srvr_rsp_code,
 432                                     srvr_msg);
 433
 434         free(cpw_service);
 435         return (result);
 436 }