source3/rpc_server/dcesrv_gssapi.c

   1 /*
   2  *  GSSAPI Acceptor
   3  *  DCERPC Server functions
   4  *  Copyright (C) Simo Sorce 2010.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20
  21 #include "includes.h"
  22 #include "rpc_server/dcesrv_gssapi.h"
  23 #include "../librpc/gen_ndr/ndr_krb5pac.h"
  24 #include "librpc/crypto/gse.h"
  25
  26 NTSTATUS gssapi_server_auth_start(TALLOC_CTX *mem_ctx,
  27                                   bool do_sign,
  28                                   bool do_seal,
  29                                   bool is_dcerpc,
  30                                   DATA_BLOB *token_in,
  31                                   DATA_BLOB *token_out,
  32                                   struct gse_context **ctx)
  33 {
  34         struct gse_context *gse_ctx = NULL;
  35         uint32_t add_flags = 0;
  36         NTSTATUS status;
  37
  38         if (is_dcerpc) {
  39                 add_flags = GSS_C_DCE_STYLE;
  40         }
  41
  42         /* Let's init the gssapi machinery for this connection */
  43         /* passing a NULL server name means the server will try
  44          * to accept any connection regardless of the name used as
  45          * long as it can find a decryption key */
  46         /* by passing NULL, the code will attempt to set a default
  47          * keytab based on configuration options */
  48         status = gse_init_server(mem_ctx, do_sign, do_seal,
  49                                  add_flags, NULL, &gse_ctx);
  50         if (!NT_STATUS_IS_OK(status)) {
  51                 DEBUG(0, ("Failed to init dcerpc gssapi server (%s)\n",
  52                           nt_errstr(status)));
  53                 return status;
  54         }
  55
  56         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  57                                            token_in, token_out);
  58         if (!NT_STATUS_IS_OK(status)) {
  59                 DEBUG(0, ("Failed to parse initial client token (%s)\n",
  60                           nt_errstr(status)));
  61                 goto done;
  62         }
  63
  64         *ctx = gse_ctx;
  65         status = NT_STATUS_OK;
  66
  67 done:
  68         if (!NT_STATUS_IS_OK(status)) {
  69                 TALLOC_FREE(gse_ctx);
  70         }
  71
  72         return status;
  73 }
  74
  75 NTSTATUS gssapi_server_step(struct gse_context *gse_ctx,
  76                             TALLOC_CTX *mem_ctx,
  77                             DATA_BLOB *token_in,
  78                             DATA_BLOB *token_out)
  79 {
  80         NTSTATUS status;
  81
  82         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  83                                            token_in, token_out);
  84         if (!NT_STATUS_IS_OK(status)) {
  85                 return status;
  86         }
  87
  88         if (gse_require_more_processing(gse_ctx)) {
  89                 /* ask for next leg */
  90                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
  91         }
  92
  93         return NT_STATUS_OK;
  94 }
  95
  96 NTSTATUS gssapi_server_check_flags(struct gse_context *gse_ctx)
  97 {
  98         return gse_verify_server_auth_flags(gse_ctx);
  99 }
 100
 101 NTSTATUS gssapi_server_get_user_info(struct gse_context *gse_ctx,
 102                                      TALLOC_CTX *mem_ctx,
 103                                      struct client_address *client_id,
 104                                      struct auth_serversupplied_info **server_info)
 105 {
 106         TALLOC_CTX *tmp_ctx;
 107         DATA_BLOB auth_data;
 108         time_t tgs_authtime;
 109         NTTIME tgs_authtime_nttime;
 110         DATA_BLOB pac;
 111         struct PAC_DATA *pac_data;
 112         struct PAC_LOGON_NAME *logon_name = NULL;
 113         struct PAC_LOGON_INFO *logon_info = NULL;
 114         enum ndr_err_code ndr_err;
 115         unsigned int i;
 116         bool is_mapped;
 117         bool is_guest;
 118         char *princ_name;
 119         char *ntuser;
 120         char *ntdomain;
 121         char *username;
 122         struct passwd *pw;
 123         NTSTATUS status;
 124         bool bret;
 125
 126         tmp_ctx = talloc_new(mem_ctx);
 127         if (!tmp_ctx) {
 128                 return NT_STATUS_NO_MEMORY;
 129         }
 130
 131         status = gse_get_authz_data(gse_ctx, tmp_ctx, &auth_data);
 132         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 133                 /* TODO: Fetch user by principal name ? */
 134                 status = NT_STATUS_ACCESS_DENIED;
 135                 goto done;
 136         }
 137         if (!NT_STATUS_IS_OK(status)) {
 138                 goto done;
 139         }
 140
 141         bret = unwrap_pac(tmp_ctx, &auth_data, &pac);
 142         if (!bret) {
 143                 DEBUG(1, ("Failed to unwrap PAC\n"));
 144                 status = NT_STATUS_ACCESS_DENIED;
 145                 goto done;
 146         }
 147
 148         status = gse_get_client_name(gse_ctx, tmp_ctx, &princ_name);
 149         if (!NT_STATUS_IS_OK(status)) {
 150                 goto done;
 151         }
 152
 153         status = gse_get_authtime(gse_ctx, &tgs_authtime);
 154         if (!NT_STATUS_IS_OK(status)) {
 155                 goto done;
 156         }
 157         unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
 158
 159         pac_data = talloc_zero(tmp_ctx, struct PAC_DATA);
 160         if (!pac_data) {
 161                 status = NT_STATUS_NO_MEMORY;
 162                 goto done;
 163         }
 164
 165         ndr_err = ndr_pull_struct_blob(&pac, pac_data, pac_data,
 166                                 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 167         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 168                 DEBUG(1, ("Failed to parse the PAC for %s\n", princ_name));
 169                 status = ndr_map_error2ntstatus(ndr_err);
 170                 goto done;
 171         }
 172
 173         /* get logon name and logon info */
 174         for (i = 0; i < pac_data->num_buffers; i++) {
 175                 struct PAC_BUFFER *data_buf = &pac_data->buffers[i];
 176
 177                 switch (data_buf->type) {
 178                 case PAC_TYPE_LOGON_INFO:
 179                         if (!data_buf->info) {
 180                                 break;
 181                         }
 182                         logon_info = data_buf->info->logon_info.info;
 183                         break;
 184                 case PAC_TYPE_LOGON_NAME:
 185                         logon_name = &data_buf->info->logon_name;
 186                         break;
 187                 default:
 188                         break;
 189                 }
 190         }
 191         if (!logon_info) {
 192                 DEBUG(1, ("Invalid PAC data, missing logon info!\n"));
 193                 status = NT_STATUS_NOT_FOUND;
 194                 goto done;
 195         }
 196         if (!logon_name) {
 197                 DEBUG(1, ("Invalid PAC data, missing logon info!\n"));
 198                 status = NT_STATUS_NOT_FOUND;
 199                 goto done;
 200         }
 201
 202         /* check time */
 203         if (tgs_authtime_nttime != logon_name->logon_time) {
 204                 DEBUG(1, ("Logon time mismatch between ticket and PAC!\n"
 205                           "PAC Time = %s | Ticket Time = %s\n",
 206                           nt_time_string(tmp_ctx, logon_name->logon_time),
 207                           nt_time_string(tmp_ctx, tgs_authtime_nttime)));
 208                 status = NT_STATUS_ACCESS_DENIED;
 209                 goto done;
 210         }
 211
 212         /* TODO: Should we check princ_name against account_name in
 213          * logon_name ? Are they supposed to be identical, or can an
 214          * account_name be different from the UPN ? */
 215
 216         status = get_user_from_kerberos_info(tmp_ctx, client_id->name,
 217                                              princ_name, logon_info,
 218                                              &is_mapped, &is_guest,
 219                                              &ntuser, &ntdomain,
 220                                              &username, &pw);
 221         if (!NT_STATUS_IS_OK(status)) {
 222                 DEBUG(1, ("Failed to map kerberos principal to system user "
 223                           "(%s)\n", nt_errstr(status)));
 224                 status = NT_STATUS_ACCESS_DENIED;
 225                 goto done;
 226         }
 227
 228         /* TODO: save PAC data in netsamlogon cache ? */
 229
 230         status = make_server_info_krb5(mem_ctx,
 231                                         ntuser, ntdomain, username, pw,
 232                                         logon_info, is_guest, server_info);
 233         if (!NT_STATUS_IS_OK(status)) {
 234                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 235                           nt_errstr(status)));
 236                 status = NT_STATUS_ACCESS_DENIED;
 237                 goto done;
 238         }
 239
 240         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 241                   ntuser, ntdomain, client_id->name));
 242
 243         status = NT_STATUS_OK;
 244
 245 done:
 246         TALLOC_FREE(tmp_ctx);
 247         return status;
 248 }