source4/kdc/kpasswdd.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    kpasswd Server implementation
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   7    Copyright (C) Andrew Tridgell        2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "smbd/service_task.h"
  25 #include "lib/events/events.h"
  26 #include "lib/socket/socket.h"
  27 #include "system/network.h"
  28 #include "../lib/util/dlinklist.h"
  29 #include "lib/ldb/include/ldb.h"
  30 #include "auth/gensec/gensec.h"
  31 #include "auth/credentials/credentials.h"
  32 #include "auth/credentials/credentials_krb5.h"
  33 #include "auth/auth.h"
  34 #include "dsdb/samdb/samdb.h"
  35 #include "rpc_server/dcerpc_server.h"
  36 #include "rpc_server/samr/proto.h"
  37 #include "libcli/security/security.h"
  38 #include "param/param.h"
  39 #include "kdc/kdc.h"
  40
  41 /* TODO: remove all SAMBA4_INTERNAL_HEIMDAL stuff from this file */
  42 #ifdef SAMBA4_INTERNAL_HEIMDAL
  43 #include "heimdal_build/kpasswdd-glue.h"
  44 #endif
  45
  46 /* Return true if there is a valid error packet formed in the error_blob */
  47 static bool kpasswdd_make_error_reply(struct kdc_server *kdc,
  48                                      TALLOC_CTX *mem_ctx,
  49                                      uint16_t result_code,
  50                                      const char *error_string,
  51                                      DATA_BLOB *error_blob)
  52 {
  53         char *error_string_utf8;
  54         size_t len;
  55
  56         DEBUG(result_code ? 3 : 10, ("kpasswdd: %s\n", error_string));
  57
  58         if (!push_utf8_talloc(mem_ctx, &error_string_utf8, error_string, &len)) {
  59                 return false;
  60         }
  61
  62         *error_blob = data_blob_talloc(mem_ctx, NULL, 2 + len + 1);
  63         if (!error_blob->data) {
  64                 return false;
  65         }
  66         RSSVAL(error_blob->data, 0, result_code);
  67         memcpy(error_blob->data + 2, error_string_utf8, len + 1);
  68         return true;
  69 }
  70
  71 /* Return true if there is a valid error packet formed in the error_blob */
  72 static bool kpasswdd_make_unauth_error_reply(struct kdc_server *kdc,
  73                                             TALLOC_CTX *mem_ctx,
  74                                             uint16_t result_code,
  75                                             const char *error_string,
  76                                             DATA_BLOB *error_blob)
  77 {
  78         bool ret;
  79         int kret;
  80         DATA_BLOB error_bytes;
  81         krb5_data k5_error_bytes, k5_error_blob;
  82         ret = kpasswdd_make_error_reply(kdc, mem_ctx, result_code, error_string,
  83                                        &error_bytes);
  84         if (!ret) {
  85                 return false;
  86         }
  87         k5_error_bytes.data = error_bytes.data;
  88         k5_error_bytes.length = error_bytes.length;
  89         kret = krb5_mk_error(kdc->smb_krb5_context->krb5_context,
  90                              result_code, NULL, &k5_error_bytes,
  91                              NULL, NULL, NULL, NULL, &k5_error_blob);
  92         if (kret) {
  93                 return false;
  94         }
  95         *error_blob = data_blob_talloc(mem_ctx, k5_error_blob.data, k5_error_blob.length);
  96         krb5_data_free(&k5_error_blob);
  97         if (!error_blob->data) {
  98                 return false;
  99         }
 100         return true;
 101 }
 102
 103 static bool kpasswd_make_pwchange_reply(struct kdc_server *kdc,
 104                                         TALLOC_CTX *mem_ctx,
 105                                         NTSTATUS status,
 106                                         enum samPwdChangeReason reject_reason,
 107                                         struct samr_DomInfo1 *dominfo,
 108                                         DATA_BLOB *error_blob)
 109 {
 110         if (NT_STATUS_EQUAL(status, NT_STATUS_NO_SUCH_USER)) {
 111                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 112                                                 KRB5_KPASSWD_ACCESSDENIED,
 113                                                 "No such user when changing password",
 114                                                 error_blob);
 115         }
 116         if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 117                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 118                                                 KRB5_KPASSWD_ACCESSDENIED,
 119                                                 "Not permitted to change password",
 120                                                 error_blob);
 121         }
 122         if (dominfo && NT_STATUS_EQUAL(status, NT_STATUS_PASSWORD_RESTRICTION)) {
 123                 const char *reject_string;
 124                 switch (reject_reason) {
 125                 case SAM_PWD_CHANGE_PASSWORD_TOO_SHORT:
 126                         reject_string = talloc_asprintf(mem_ctx, "Password too short, password must be at least %d characters long",
 127                                                         dominfo->min_password_length);
 128                         break;
 129                 case SAM_PWD_CHANGE_NOT_COMPLEX:
 130                         reject_string = "Password does not meet complexity requirements";
 131                         break;
 132                 case SAM_PWD_CHANGE_PWD_IN_HISTORY:
 133                         reject_string = "Password is already in password history";
 134                         break;
 135                 default:
 136                         reject_string = talloc_asprintf(mem_ctx, "Password must be at least %d characters long, and cannot match any of your %d previous passwords",
 137                                                         dominfo->min_password_length, dominfo->password_history_length);
 138                         break;
 139                 }
 140                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 141                                                 KRB5_KPASSWD_SOFTERROR,
 142                                                 reject_string,
 143                                                 error_blob);
 144         }
 145         if (!NT_STATUS_IS_OK(status)) {
 146                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 147                                                  KRB5_KPASSWD_HARDERROR,
 148                                                  talloc_asprintf(mem_ctx, "failed to set password: %s", nt_errstr(status)),
 149                                                  error_blob);
 150
 151         }
 152         return kpasswdd_make_error_reply(kdc, mem_ctx, KRB5_KPASSWD_SUCCESS,
 153                                         "Password changed",
 154                                         error_blob);
 155 }
 156
 157 /*
 158    A user password change
 159
 160    Return true if there is a valid error packet (or sucess) formed in
 161    the error_blob
 162 */
 163 static bool kpasswdd_change_password(struct kdc_server *kdc,
 164                                      TALLOC_CTX *mem_ctx,
 165                                      struct auth_session_info *session_info,
 166                                      const DATA_BLOB *password,
 167                                      DATA_BLOB *reply)
 168 {
 169         NTSTATUS status;
 170         enum samPwdChangeReason reject_reason;
 171         struct samr_DomInfo1 *dominfo;
 172         struct ldb_context *samdb;
 173
 174         samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, system_session(kdc->task->lp_ctx));
 175         if (!samdb) {
 176                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 177                                                 KRB5_KPASSWD_HARDERROR,
 178                                                 "Failed to open samdb",
 179                                                 reply);
 180         }
 181
 182         DEBUG(3, ("Changing password of %s\\%s (%s)\n",
 183                   session_info->server_info->domain_name,
 184                   session_info->server_info->account_name,
 185                   dom_sid_string(mem_ctx, session_info->security_token->user_sid)));
 186
 187         /* User password change */
 188         status = samdb_set_password_sid(samdb, mem_ctx,
 189                                         session_info->security_token->user_sid,
 190                                         password, NULL, NULL,
 191                                         true, /* this is a user password change */
 192                                         &reject_reason,
 193                                         &dominfo);
 194         return kpasswd_make_pwchange_reply(kdc, mem_ctx,
 195                                            status,
 196                                            reject_reason,
 197                                            dominfo,
 198                                            reply);
 199
 200 }
 201
 202 static bool kpasswd_process_request(struct kdc_server *kdc,
 203                                     TALLOC_CTX *mem_ctx,
 204                                     struct gensec_security *gensec_security,
 205                                     uint16_t version,
 206                                     DATA_BLOB *input,
 207                                     DATA_BLOB *reply)
 208 {
 209         struct auth_session_info *session_info;
 210         size_t pw_len;
 211
 212         if (!NT_STATUS_IS_OK(gensec_session_info(gensec_security,
 213                                                  &session_info))) {
 214                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 215                                                 KRB5_KPASSWD_HARDERROR,
 216                                                 "gensec_session_info failed!",
 217                                                 reply);
 218         }
 219
 220         switch (version) {
 221         case KRB5_KPASSWD_VERS_CHANGEPW:
 222         {
 223                 DATA_BLOB password;
 224                 if (!convert_string_talloc_convenience(mem_ctx, lp_iconv_convenience(kdc->task->lp_ctx),
 225                                                CH_UTF8, CH_UTF16,
 226                                                (const char *)input->data,
 227                                                input->length,
 228                                                (void **)&password.data, &pw_len, false)) {
 229                         return false;
 230                 }
 231                 password.length = pw_len;
 232
 233                 return kpasswdd_change_password(kdc, mem_ctx, session_info,
 234                                                 &password, reply);
 235                 break;
 236         }
 237         case KRB5_KPASSWD_VERS_SETPW:
 238         {
 239                 NTSTATUS status;
 240                 enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
 241                 struct samr_DomInfo1 *dominfo = NULL;
 242                 struct ldb_context *samdb;
 243                 struct ldb_message *msg;
 244                 krb5_context context = kdc->smb_krb5_context->krb5_context;
 245
 246                 ChangePasswdDataMS chpw;
 247                 DATA_BLOB password;
 248
 249                 krb5_principal principal;
 250                 char *set_password_on_princ;
 251                 struct ldb_dn *set_password_on_dn;
 252
 253                 size_t len;
 254                 int ret;
 255
 256                 msg = ldb_msg_new(mem_ctx);
 257                 if (!msg) {
 258                         return false;
 259                 }
 260
 261                 ret = decode_ChangePasswdDataMS(input->data, input->length,
 262                                                 &chpw, &len);
 263                 if (ret) {
 264                         return kpasswdd_make_error_reply(kdc, mem_ctx,
 265                                                         KRB5_KPASSWD_MALFORMED,
 266                                                         "failed to decode password change structure",
 267                                                         reply);
 268                 }
 269
 270                 if (!convert_string_talloc_convenience(mem_ctx, lp_iconv_convenience(kdc->task->lp_ctx),
 271                                                CH_UTF8, CH_UTF16,
 272                                                (const char *)chpw.newpasswd.data,
 273                                                chpw.newpasswd.length,
 274                                                (void **)&password.data, &pw_len, false)) {
 275                         free_ChangePasswdDataMS(&chpw);
 276                         return false;
 277                 }
 278
 279                 password.length = pw_len;
 280
 281                 if ((chpw.targname && !chpw.targrealm)
 282                     || (!chpw.targname && chpw.targrealm)) {
 283                         return kpasswdd_make_error_reply(kdc, mem_ctx,
 284                                                         KRB5_KPASSWD_MALFORMED,
 285                                                         "Realm and principal must be both present, or neither present",
 286                                                         reply);
 287                 }
 288                 if (chpw.targname && chpw.targrealm) {
 289 #ifdef SAMBA4_INTERNAL_HEIMDAL
 290                         if (_krb5_principalname2krb5_principal(kdc->smb_krb5_context->krb5_context,
 291                                                                &principal, *chpw.targname,
 292                                                                *chpw.targrealm) != 0) {
 293                                 free_ChangePasswdDataMS(&chpw);
 294                                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 295                                                                 KRB5_KPASSWD_MALFORMED,
 296                                                                 "failed to extract principal to set",
 297                                                                 reply);
 298
 299                         }
 300 #else /* SAMBA4_INTERNAL_HEIMDAL */
 301                                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 302                                                                 KRB5_KPASSWD_BAD_VERSION,
 303                                                                 "Operation Not Implemented",
 304                                                                 reply);
 305 #endif /* SAMBA4_INTERNAL_HEIMDAL */
 306                 } else {
 307                         free_ChangePasswdDataMS(&chpw);
 308                         return kpasswdd_change_password(kdc, mem_ctx, session_info,
 309                                                         &password, reply);
 310                 }
 311                 free_ChangePasswdDataMS(&chpw);
 312
 313                 if (krb5_unparse_name(context, principal, &set_password_on_princ) != 0) {
 314                         krb5_free_principal(context, principal);
 315                         return kpasswdd_make_error_reply(kdc, mem_ctx,
 316                                                         KRB5_KPASSWD_MALFORMED,
 317                                                         "krb5_unparse_name failed!",
 318                                                         reply);
 319                 }
 320
 321                 krb5_free_principal(context, principal);
 322
 323                 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, session_info);
 324                 if (!samdb) {
 325                         return kpasswdd_make_error_reply(kdc, mem_ctx,
 326                                                          KRB5_KPASSWD_HARDERROR,
 327                                                          "Unable to open database!",
 328                                                          reply);
 329                 }
 330
 331                 DEBUG(3, ("%s\\%s (%s) is changing password of %s\n",
 332                           session_info->server_info->domain_name,
 333                           session_info->server_info->account_name,
 334                           dom_sid_string(mem_ctx, session_info->security_token->user_sid),
 335                           set_password_on_princ));
 336                 ret = ldb_transaction_start(samdb);
 337                 if (ret) {
 338                         status = NT_STATUS_TRANSACTION_ABORTED;
 339                         return kpasswd_make_pwchange_reply(kdc, mem_ctx,
 340                                                            status,
 341                                                            SAM_PWD_CHANGE_NO_ERROR,
 342                                                            NULL,
 343                                                            reply);
 344                 }
 345
 346                 status = crack_user_principal_name(samdb, mem_ctx,
 347                                                    set_password_on_princ,
 348                                                    &set_password_on_dn, NULL);
 349                 free(set_password_on_princ);
 350                 if (!NT_STATUS_IS_OK(status)) {
 351                         ldb_transaction_cancel(samdb);
 352                         return kpasswd_make_pwchange_reply(kdc, mem_ctx,
 353                                                            status,
 354                                                            SAM_PWD_CHANGE_NO_ERROR,
 355                                                            NULL,
 356                                                            reply);
 357                 }
 358
 359                 msg = ldb_msg_new(mem_ctx);
 360                 if (msg == NULL) {
 361                         ldb_transaction_cancel(samdb);
 362                         status = NT_STATUS_NO_MEMORY;
 363                 } else {
 364                         msg->dn = ldb_dn_copy(msg, set_password_on_dn);
 365                         if (!msg->dn) {
 366                                 status = NT_STATUS_NO_MEMORY;
 367                         }
 368                 }
 369
 370                 if (NT_STATUS_IS_OK(status)) {
 371                         /* Admin password set */
 372                         status = samdb_set_password(samdb, mem_ctx,
 373                                                     set_password_on_dn, NULL,
 374                                                     msg, &password, NULL, NULL,
 375                                                     false, /* this is not a user password change */
 376                                                     &reject_reason, &dominfo);
 377                 }
 378
 379                 if (NT_STATUS_IS_OK(status)) {
 380                         /* modify the samdb record */
 381                         ret = samdb_replace(samdb, mem_ctx, msg);
 382                         if (ret != 0) {
 383                                 DEBUG(2,("Failed to modify record to set password on %s: %s\n",
 384                                          ldb_dn_get_linearized(msg->dn),
 385                                          ldb_errstring(samdb)));
 386                                 status = NT_STATUS_ACCESS_DENIED;
 387                         }
 388                 }
 389                 if (NT_STATUS_IS_OK(status)) {
 390                         ret = ldb_transaction_commit(samdb);
 391                         if (ret != 0) {
 392                                 DEBUG(1,("Failed to commit transaction to set password on %s: %s\n",
 393                                          ldb_dn_get_linearized(msg->dn),
 394                                          ldb_errstring(samdb)));
 395                                 status = NT_STATUS_TRANSACTION_ABORTED;
 396                         }
 397                 } else {
 398                         ldb_transaction_cancel(samdb);
 399                 }
 400                 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
 401                                                    status,
 402                                                    reject_reason,
 403                                                    dominfo,
 404                                                    reply);
 405         }
 406         default:
 407                 return kpasswdd_make_error_reply(kdc, mem_ctx,
 408                                                  KRB5_KPASSWD_BAD_VERSION,
 409                                                  talloc_asprintf(mem_ctx,
 410                                                                  "Protocol version %u not supported",
 411                                                                  version),
 412                                                  reply);
 413         }
 414         return true;
 415 }
 416
 417 bool kpasswdd_process(struct kdc_server *kdc,
 418                       TALLOC_CTX *mem_ctx,
 419                       DATA_BLOB *input,
 420                       DATA_BLOB *reply,
 421                       struct socket_address *peer_addr,
 422                       struct socket_address *my_addr,
 423                       int datagram_reply)
 424 {
 425         bool ret;
 426         const uint16_t header_len = 6;
 427         uint16_t len;
 428         uint16_t ap_req_len;
 429         uint16_t krb_priv_len;
 430         uint16_t version;
 431         NTSTATUS nt_status;
 432         DATA_BLOB ap_req, krb_priv_req;
 433         DATA_BLOB krb_priv_rep = data_blob(NULL, 0);
 434         DATA_BLOB ap_rep = data_blob(NULL, 0);
 435         DATA_BLOB kpasswd_req, kpasswd_rep;
 436         struct cli_credentials *server_credentials;
 437         struct gensec_security *gensec_security;
 438         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 439
 440         char *keytab_name;
 441
 442         if (!tmp_ctx) {
 443                 return false;
 444         }
 445
 446         /* Be parinoid.  We need to ensure we don't just let the
 447          * caller lead us into a buffer overflow */
 448         if (input->length <= header_len) {
 449                 talloc_free(tmp_ctx);
 450                 return false;
 451         }
 452
 453         len = RSVAL(input->data, 0);
 454         if (input->length != len) {
 455                 talloc_free(tmp_ctx);
 456                 return false;
 457         }
 458
 459         /* There are two different versions of this protocol so far,
 460          * plus others in the standards pipe.  Fortunetly they all
 461          * take a very similar framing */
 462         version = RSVAL(input->data, 2);
 463         ap_req_len = RSVAL(input->data, 4);
 464         if ((ap_req_len >= len) || (ap_req_len + header_len) >= len) {
 465                 talloc_free(tmp_ctx);
 466                 return false;
 467         }
 468
 469         krb_priv_len = len - ap_req_len;
 470         ap_req = data_blob_const(&input->data[header_len], ap_req_len);
 471         krb_priv_req = data_blob_const(&input->data[header_len + ap_req_len], krb_priv_len);
 472
 473         server_credentials = cli_credentials_init(tmp_ctx);
 474         if (!server_credentials) {
 475                 DEBUG(1, ("Failed to init server credentials\n"));
 476                 return false;
 477         }
 478
 479         /* We want the credentials subsystem to use the krb5 context
 480          * we already have, rather than a new context */
 481         cli_credentials_set_krb5_context(server_credentials, kdc->smb_krb5_context);
 482         cli_credentials_set_conf(server_credentials, kdc->task->lp_ctx);
 483
 484         keytab_name = talloc_asprintf(server_credentials, "HDB:samba4&%p", kdc->hdb_samba4_context);
 485
 486         cli_credentials_set_username(server_credentials, "kadmin/changepw", CRED_SPECIFIED);
 487         ret = cli_credentials_set_keytab_name(server_credentials, kdc->task->event_ctx, kdc->task->lp_ctx, keytab_name, CRED_SPECIFIED);
 488         if (ret != 0) {
 489                 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
 490                                                        KRB5_KPASSWD_HARDERROR,
 491                                                        talloc_asprintf(mem_ctx,
 492                                                                        "Failed to obtain server credentials for kadmin/changepw: %s\n",
 493                                                                        nt_errstr(nt_status)),
 494                                                        &krb_priv_rep);
 495                 ap_rep.length = 0;
 496                 if (ret) {
 497                         goto reply;
 498                 }
 499                 talloc_free(tmp_ctx);
 500                 return ret;
 501         }
 502
 503         /* We don't strictly need to call this wrapper, and could call
 504          * gensec_server_start directly, as we have no need for NTLM
 505          * and we have a PAC, but this ensures that the wrapper can be
 506          * safely extended for other helpful things in future */
 507         nt_status = samba_server_gensec_start(tmp_ctx, kdc->task->event_ctx,
 508                                               kdc->task->msg_ctx,
 509                                               kdc->task->lp_ctx,
 510                                               server_credentials,
 511                                               "kpasswd",
 512                                               &gensec_security);
 513         if (!NT_STATUS_IS_OK(nt_status)) {
 514                 talloc_free(tmp_ctx);
 515                 return false;
 516         }
 517
 518         /* The kerberos PRIV packets include these addresses.  MIT
 519          * clients check that they are present */
 520 #if 0
 521         /* Skip this part for now, it breaks with a NetAPP filer and
 522          * in any case where the client address is behind NAT.  If
 523          * older MIT clients need this, we might have to insert more
 524          * complex code */
 525
 526         nt_status = gensec_set_peer_addr(gensec_security, peer_addr);
 527         if (!NT_STATUS_IS_OK(nt_status)) {
 528                 talloc_free(tmp_ctx);
 529                 return false;
 530         }
 531 #endif
 532
 533         nt_status = gensec_set_my_addr(gensec_security, my_addr);
 534         if (!NT_STATUS_IS_OK(nt_status)) {
 535                 talloc_free(tmp_ctx);
 536                 return false;
 537         }
 538
 539         /* We want the GENSEC wrap calls to generate PRIV tokens */
 540         gensec_want_feature(gensec_security, GENSEC_FEATURE_SEAL);
 541
 542         nt_status = gensec_start_mech_by_name(gensec_security, "krb5");
 543         if (!NT_STATUS_IS_OK(nt_status)) {
 544                 talloc_free(tmp_ctx);
 545                 return false;
 546         }
 547
 548         /* Accept the AP-REQ and generate teh AP-REP we need for the reply */
 549         nt_status = gensec_update(gensec_security, tmp_ctx, ap_req, &ap_rep);
 550         if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 551
 552                 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
 553                                                        KRB5_KPASSWD_HARDERROR,
 554                                                        talloc_asprintf(mem_ctx,
 555                                                                        "gensec_update failed: %s",
 556                                                                        nt_errstr(nt_status)),
 557                                                        &krb_priv_rep);
 558                 ap_rep.length = 0;
 559                 if (ret) {
 560                         goto reply;
 561                 }
 562                 talloc_free(tmp_ctx);
 563                 return ret;
 564         }
 565
 566         /* Extract the data from the KRB-PRIV half of the message */
 567         nt_status = gensec_unwrap(gensec_security, tmp_ctx, &krb_priv_req, &kpasswd_req);
 568         if (!NT_STATUS_IS_OK(nt_status)) {
 569                 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
 570                                                        KRB5_KPASSWD_HARDERROR,
 571                                                        talloc_asprintf(mem_ctx,
 572                                                                        "gensec_unwrap failed: %s",
 573                                                                        nt_errstr(nt_status)),
 574                                                        &krb_priv_rep);
 575                 ap_rep.length = 0;
 576                 if (ret) {
 577                         goto reply;
 578                 }
 579                 talloc_free(tmp_ctx);
 580                 return ret;
 581         }
 582
 583         /* Figure out something to do with it (probably changing a password...) */
 584         ret = kpasswd_process_request(kdc, tmp_ctx,
 585                                       gensec_security,
 586                                       version,
 587                                       &kpasswd_req, &kpasswd_rep);
 588         if (!ret) {
 589                 /* Argh! */
 590                 return false;
 591         }
 592
 593         /* And wrap up the reply: This ensures that the error message
 594          * or success can be verified by the client */
 595         nt_status = gensec_wrap(gensec_security, tmp_ctx,
 596                                 &kpasswd_rep, &krb_priv_rep);
 597         if (!NT_STATUS_IS_OK(nt_status)) {
 598                 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
 599                                                        KRB5_KPASSWD_HARDERROR,
 600                                                        talloc_asprintf(mem_ctx,
 601                                                                        "gensec_wrap failed: %s",
 602                                                                        nt_errstr(nt_status)),
 603                                                        &krb_priv_rep);
 604                 ap_rep.length = 0;
 605                 if (ret) {
 606                         goto reply;
 607                 }
 608                 talloc_free(tmp_ctx);
 609                 return ret;
 610         }
 611
 612 reply:
 613         *reply = data_blob_talloc(mem_ctx, NULL, krb_priv_rep.length + ap_rep.length + header_len);
 614         if (!reply->data) {
 615                 return false;
 616         }
 617
 618         RSSVAL(reply->data, 0, reply->length);
 619         RSSVAL(reply->data, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
 620         RSSVAL(reply->data, 4, ap_rep.length);
 621         memcpy(reply->data + header_len,
 622                ap_rep.data,
 623                ap_rep.length);
 624         memcpy(reply->data + header_len + ap_rep.length,
 625                krb_priv_rep.data,
 626                krb_priv_rep.length);
 627
 628         talloc_free(tmp_ctx);
 629         return ret;
 630 }
 631