source4/kdc/kpasswd-service-mit.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Samba kpasswd implementation
   5
   6    Copyright (c) 2016      Andreas Schneider <asn@samba.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/service_task.h"
  24 #include "param/param.h"
  25 #include "auth/auth.h"
  26 #include "auth/gensec/gensec.h"
  27 #include "kdc/kdc-server.h"
  28 #include "kdc/kpasswd_glue.h"
  29 #include "kdc/kpasswd-service.h"
  30 #include "kdc/kpasswd-helper.h"
  31
  32 #define RFC3244_VERSION 0xff80
  33
  34 krb5_error_code decode_krb5_setpw_req(const krb5_data *code,
  35                                       krb5_data **password_out,
  36                                       krb5_principal *target_out);
  37
  38 static krb5_error_code kpasswd_change_password(struct kdc_server *kdc,
  39                                                TALLOC_CTX *mem_ctx,
  40                                                struct auth_session_info *session_info,
  41                                                DATA_BLOB *password,
  42                                                DATA_BLOB *kpasswd_reply,
  43                                                const char **error_string)
  44 {
  45         NTSTATUS status;
  46         NTSTATUS result = NT_STATUS_UNSUCCESSFUL;
  47         enum samPwdChangeReason reject_reason;
  48         const char *reject_string = NULL;
  49         struct samr_DomInfo1 *dominfo;
  50         bool ok;
  51
  52         status = samdb_kpasswd_change_password(mem_ctx,
  53                                                kdc->task->lp_ctx,
  54                                                kdc->task->event_ctx,
  55                                                kdc->samdb,
  56                                                session_info,
  57                                                password,
  58                                                &reject_reason,
  59                                                &dominfo,
  60                                                &reject_string,
  61                                                &result);
  62         if (!NT_STATUS_IS_OK(status)) {
  63                 ok = kpasswd_make_error_reply(mem_ctx,
  64                                               KRB5_KPASSWD_ACCESSDENIED,
  65                                               reject_string,
  66                                               kpasswd_reply);
  67                 if (!ok) {
  68                         *error_string = "Failed to create reply";
  69                         return KRB5_KPASSWD_HARDERROR;
  70                 }
  71                 /* We want to send an an authenticated packet. */
  72                 return 0;
  73         }
  74
  75         ok = kpasswd_make_pwchange_reply(mem_ctx,
  76                                          result,
  77                                          reject_reason,
  78                                          dominfo,
  79                                          kpasswd_reply);
  80         if (!ok) {
  81                 *error_string = "Failed to create reply";
  82                 return KRB5_KPASSWD_HARDERROR;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static krb5_error_code kpasswd_set_password(struct kdc_server *kdc,
  89                                             TALLOC_CTX *mem_ctx,
  90                                             struct auth_session_info *session_info,
  91                                             DATA_BLOB *decoded_data,
  92                                             DATA_BLOB *kpasswd_reply,
  93                                             const char **error_string)
  94 {
  95         krb5_context context = kdc->smb_krb5_context->krb5_context;
  96         krb5_data k_dec_data;
  97         krb5_data *k_clear_data;
  98         krb5_principal target_principal;
  99         krb5_error_code code;
 100         DATA_BLOB password;
 101         char *target_realm = NULL;
 102         char *target_name = NULL;
 103         char *target_principal_string = NULL;
 104         bool is_service_principal = false;
 105         bool ok;
 106         size_t num_components;
 107         enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
 108         struct samr_DomInfo1 *dominfo = NULL;
 109         NTSTATUS status;
 110
 111         k_dec_data.length = decoded_data->length;
 112         k_dec_data.data   = (char *)decoded_data->data;
 113
 114         code = decode_krb5_setpw_req(&k_dec_data,
 115                                      &k_clear_data,
 116                                      &target_principal);
 117         if (code != 0) {
 118                 DBG_WARNING("decode_krb5_setpw_req failed: %s\n",
 119                             error_message(code));
 120                 ok = kpasswd_make_error_reply(mem_ctx,
 121                                               KRB5_KPASSWD_MALFORMED,
 122                                               "Failed to decode packet",
 123                                               kpasswd_reply);
 124                 if (!ok) {
 125                         *error_string = "Failed to create reply";
 126                         return KRB5_KPASSWD_HARDERROR;
 127                 }
 128                 return 0;
 129         }
 130
 131         ok = convert_string_talloc_handle(mem_ctx,
 132                                           lpcfg_iconv_handle(kdc->task->lp_ctx),
 133                                           CH_UTF8,
 134                                           CH_UTF16,
 135                                           (const char *)k_clear_data->data,
 136                                           k_clear_data->length,
 137                                           (void **)&password.data,
 138                                           &password.length);
 139         krb5_free_data(context, k_clear_data);
 140         if (!ok) {
 141                 DBG_WARNING("String conversion failed\n");
 142                 *error_string = "String conversion failed";
 143                 return KRB5_KPASSWD_HARDERROR;
 144         }
 145
 146         target_realm = smb_krb5_principal_get_realm(
 147                 mem_ctx, context, target_principal);
 148         code = krb5_unparse_name_flags(context,
 149                                        target_principal,
 150                                        KRB5_PRINCIPAL_UNPARSE_NO_REALM,
 151                                        &target_name);
 152         if (code != 0) {
 153                 DBG_WARNING("Failed to parse principal\n");
 154                 *error_string = "String conversion failed";
 155                 return KRB5_KPASSWD_HARDERROR;
 156         }
 157
 158         if ((target_name != NULL && target_realm == NULL) ||
 159             (target_name == NULL && target_realm != NULL)) {
 160                 krb5_free_principal(context, target_principal);
 161                 TALLOC_FREE(target_realm);
 162                 SAFE_FREE(target_name);
 163
 164                 ok = kpasswd_make_error_reply(mem_ctx,
 165                                               KRB5_KPASSWD_MALFORMED,
 166                                               "Realm and principal must be "
 167                                               "both present, or neither "
 168                                               "present",
 169                                               kpasswd_reply);
 170                 if (!ok) {
 171                         *error_string = "Failed to create reply";
 172                         return KRB5_KPASSWD_HARDERROR;
 173                 }
 174                 return 0;
 175         }
 176
 177         if (target_name != NULL && target_realm != NULL) {
 178                 TALLOC_FREE(target_realm);
 179                 SAFE_FREE(target_name);
 180         } else {
 181                 krb5_free_principal(context, target_principal);
 182                 TALLOC_FREE(target_realm);
 183                 SAFE_FREE(target_name);
 184
 185                 return kpasswd_change_password(kdc,
 186                                                mem_ctx,
 187                                                session_info,
 188                                                &password,
 189                                                kpasswd_reply,
 190                                                error_string);
 191         }
 192
 193         num_components = krb5_princ_size(context, target_principal);
 194         if (num_components >= 2) {
 195                 is_service_principal = true;
 196                 code = krb5_unparse_name_flags(context,
 197                                                target_principal,
 198                                                KRB5_PRINCIPAL_UNPARSE_SHORT,
 199                                                &target_principal_string);
 200         } else {
 201                 code = krb5_unparse_name(context,
 202                                          target_principal,
 203                                          &target_principal_string);
 204         }
 205         krb5_free_principal(context, target_principal);
 206         if (code != 0) {
 207                 ok = kpasswd_make_error_reply(mem_ctx,
 208                                               KRB5_KPASSWD_MALFORMED,
 209                                               "Failed to parse principal",
 210                                               kpasswd_reply);
 211                 if (!ok) {
 212                         *error_string = "Failed to create reply";
 213                         return KRB5_KPASSWD_HARDERROR;
 214                 }
 215         }
 216
 217         status = kpasswd_samdb_set_password(mem_ctx,
 218                                             kdc->task->event_ctx,
 219                                             kdc->task->lp_ctx,
 220                                             session_info,
 221                                             is_service_principal,
 222                                             target_principal_string,
 223                                             &password,
 224                                             &reject_reason,
 225                                             &dominfo);
 226         if (!NT_STATUS_IS_OK(status)) {
 227                 DBG_ERR("kpasswd_samdb_set_password failed - %s\n",
 228                         nt_errstr(status));
 229         }
 230
 231         ok = kpasswd_make_pwchange_reply(mem_ctx,
 232                                          status,
 233                                          reject_reason,
 234                                          dominfo,
 235                                          kpasswd_reply);
 236         if (!ok) {
 237                 *error_string = "Failed to create reply";
 238                 return KRB5_KPASSWD_HARDERROR;
 239         }
 240
 241         return 0;
 242 }
 243
 244 krb5_error_code kpasswd_handle_request(struct kdc_server *kdc,
 245                                        TALLOC_CTX *mem_ctx,
 246                                        struct gensec_security *gensec_security,
 247                                        uint16_t verno,
 248                                        DATA_BLOB *decoded_data,
 249                                        DATA_BLOB *kpasswd_reply,
 250                                        const char **error_string)
 251 {
 252         struct auth_session_info *session_info;
 253         NTSTATUS status;
 254
 255         status = gensec_session_info(gensec_security,
 256                                      mem_ctx,
 257                                      &session_info);
 258         if (!NT_STATUS_IS_OK(status)) {
 259                 *error_string = talloc_asprintf(mem_ctx,
 260                                                 "gensec_session_info failed - "
 261                                                 "%s",
 262                                                 nt_errstr(status));
 263                 return KRB5_KPASSWD_HARDERROR;
 264         }
 265
 266         switch(verno) {
 267         case 1: {
 268                 DATA_BLOB password;
 269                 bool ok;
 270
 271                 ok = convert_string_talloc_handle(mem_ctx,
 272                                                   lpcfg_iconv_handle(kdc->task->lp_ctx),
 273                                                   CH_UTF8,
 274                                                   CH_UTF16,
 275                                                   (const char *)decoded_data->data,
 276                                                   decoded_data->length,
 277                                                   (void **)&password.data,
 278                                                   &password.length);
 279                 if (!ok) {
 280                         *error_string = "String conversion failed!";
 281                         DBG_WARNING("%s\n", *error_string);
 282                         return KRB5_KPASSWD_HARDERROR;
 283                 }
 284
 285                 return kpasswd_change_password(kdc,
 286                                                mem_ctx,
 287                                                session_info,
 288                                                &password,
 289                                                kpasswd_reply,
 290                                                error_string);
 291         }
 292         case RFC3244_VERSION: {
 293                 return kpasswd_set_password(kdc,
 294                                             mem_ctx,
 295                                             session_info,
 296                                             decoded_data,
 297                                             kpasswd_reply,
 298                                             error_string);
 299         }
 300         default:
 301                 return KRB5_KPASSWD_BAD_VERSION;
 302         }
 303
 304         return 0;
 305 }