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 #include "auth.h"
  26
  27 NTSTATUS gssapi_server_auth_start(TALLOC_CTX *mem_ctx,
  28                                   bool do_sign,
  29                                   bool do_seal,
  30                                   bool is_dcerpc,
  31                                   DATA_BLOB *token_in,
  32                                   DATA_BLOB *token_out,
  33                                   struct gse_context **ctx)
  34 {
  35         struct gse_context *gse_ctx = NULL;
  36         uint32_t add_flags = 0;
  37         NTSTATUS status;
  38
  39         if (is_dcerpc) {
  40                 add_flags = GSS_C_DCE_STYLE;
  41         }
  42
  43         /* Let's init the gssapi machinery for this connection */
  44         /* passing a NULL server name means the server will try
  45          * to accept any connection regardless of the name used as
  46          * long as it can find a decryption key */
  47         /* by passing NULL, the code will attempt to set a default
  48          * keytab based on configuration options */
  49         status = gse_init_server(mem_ctx, do_sign, do_seal,
  50                                  add_flags, NULL, &gse_ctx);
  51         if (!NT_STATUS_IS_OK(status)) {
  52                 DEBUG(0, ("Failed to init dcerpc gssapi server (%s)\n",
  53                           nt_errstr(status)));
  54                 return status;
  55         }
  56
  57         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  58                                            token_in, token_out);
  59         if (!NT_STATUS_IS_OK(status)) {
  60                 DEBUG(0, ("Failed to parse initial client token (%s)\n",
  61                           nt_errstr(status)));
  62                 goto done;
  63         }
  64
  65         *ctx = gse_ctx;
  66         status = NT_STATUS_OK;
  67
  68 done:
  69         if (!NT_STATUS_IS_OK(status)) {
  70                 TALLOC_FREE(gse_ctx);
  71         }
  72
  73         return status;
  74 }
  75
  76 NTSTATUS gssapi_server_step(struct gse_context *gse_ctx,
  77                             TALLOC_CTX *mem_ctx,
  78                             DATA_BLOB *token_in,
  79                             DATA_BLOB *token_out)
  80 {
  81         NTSTATUS status;
  82
  83         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  84                                            token_in, token_out);
  85         if (!NT_STATUS_IS_OK(status)) {
  86                 return status;
  87         }
  88
  89         if (gse_require_more_processing(gse_ctx)) {
  90                 /* ask for next leg */
  91                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
  92         }
  93
  94         return NT_STATUS_OK;
  95 }
  96
  97 NTSTATUS gssapi_server_check_flags(struct gse_context *gse_ctx)
  98 {
  99         return gse_verify_server_auth_flags(gse_ctx);
 100 }
 101
 102 NTSTATUS gssapi_server_get_user_info(struct gse_context *gse_ctx,
 103                                      TALLOC_CTX *mem_ctx,
 104                                      struct client_address *client_id,
 105                                      struct auth_serversupplied_info **server_info)
 106 {
 107         TALLOC_CTX *tmp_ctx;
 108         DATA_BLOB auth_data;
 109         time_t tgs_authtime;
 110         NTTIME tgs_authtime_nttime;
 111         DATA_BLOB pac;
 112         struct PAC_DATA *pac_data;
 113         struct PAC_LOGON_NAME *logon_name = NULL;
 114         struct PAC_LOGON_INFO *logon_info = NULL;
 115         enum ndr_err_code ndr_err;
 116         unsigned int i;
 117         bool is_mapped;
 118         bool is_guest;
 119         char *princ_name;
 120         char *ntuser;
 121         char *ntdomain;
 122         char *username;
 123         struct passwd *pw;
 124         NTSTATUS status;
 125         bool bret;
 126
 127         tmp_ctx = talloc_new(mem_ctx);
 128         if (!tmp_ctx) {
 129                 return NT_STATUS_NO_MEMORY;
 130         }
 131
 132         status = gse_get_authz_data(gse_ctx, tmp_ctx, &auth_data);
 133         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 134                 /* TODO: Fetch user by principal name ? */
 135                 status = NT_STATUS_ACCESS_DENIED;
 136                 goto done;
 137         }
 138         if (!NT_STATUS_IS_OK(status)) {
 139                 goto done;
 140         }
 141
 142         bret = unwrap_pac(tmp_ctx, &auth_data, &pac);
 143         if (!bret) {
 144                 DEBUG(1, ("Failed to unwrap PAC\n"));
 145                 status = NT_STATUS_ACCESS_DENIED;
 146                 goto done;
 147         }
 148
 149         status = gse_get_client_name(gse_ctx, tmp_ctx, &princ_name);
 150         if (!NT_STATUS_IS_OK(status)) {
 151                 goto done;
 152         }
 153
 154         status = gse_get_authtime(gse_ctx, &tgs_authtime);
 155         if (!NT_STATUS_IS_OK(status)) {
 156                 goto done;
 157         }
 158         unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
 159
 160         pac_data = talloc_zero(tmp_ctx, struct PAC_DATA);
 161         if (!pac_data) {
 162                 status = NT_STATUS_NO_MEMORY;
 163                 goto done;
 164         }
 165
 166         ndr_err = ndr_pull_struct_blob(&pac, pac_data, pac_data,
 167                                 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 168         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 169                 DEBUG(1, ("Failed to parse the PAC for %s\n", princ_name));
 170                 status = ndr_map_error2ntstatus(ndr_err);
 171                 goto done;
 172         }
 173
 174         /* get logon name and logon info */
 175         for (i = 0; i < pac_data->num_buffers; i++) {
 176                 struct PAC_BUFFER *data_buf = &pac_data->buffers[i];
 177
 178                 switch (data_buf->type) {
 179                 case PAC_TYPE_LOGON_INFO:
 180                         if (!data_buf->info) {
 181                                 break;
 182                         }
 183                         logon_info = data_buf->info->logon_info.info;
 184                         break;
 185                 case PAC_TYPE_LOGON_NAME:
 186                         logon_name = &data_buf->info->logon_name;
 187                         break;
 188                 default:
 189                         break;
 190                 }
 191         }
 192         if (!logon_info) {
 193                 DEBUG(1, ("Invalid PAC data, missing logon info!\n"));
 194                 status = NT_STATUS_NOT_FOUND;
 195                 goto done;
 196         }
 197         if (!logon_name) {
 198                 DEBUG(1, ("Invalid PAC data, missing logon info!\n"));
 199                 status = NT_STATUS_NOT_FOUND;
 200                 goto done;
 201         }
 202
 203         /* check time */
 204         if (tgs_authtime_nttime != logon_name->logon_time) {
 205                 DEBUG(1, ("Logon time mismatch between ticket and PAC!\n"
 206                           "PAC Time = %s | Ticket Time = %s\n",
 207                           nt_time_string(tmp_ctx, logon_name->logon_time),
 208                           nt_time_string(tmp_ctx, tgs_authtime_nttime)));
 209                 status = NT_STATUS_ACCESS_DENIED;
 210                 goto done;
 211         }
 212
 213         /* TODO: Should we check princ_name against account_name in
 214          * logon_name ? Are they supposed to be identical, or can an
 215          * account_name be different from the UPN ? */
 216
 217         status = get_user_from_kerberos_info(tmp_ctx, client_id->name,
 218                                              princ_name, logon_info,
 219                                              &is_mapped, &is_guest,
 220                                              &ntuser, &ntdomain,
 221                                              &username, &pw);
 222         if (!NT_STATUS_IS_OK(status)) {
 223                 DEBUG(1, ("Failed to map kerberos principal to system user "
 224                           "(%s)\n", nt_errstr(status)));
 225                 status = NT_STATUS_ACCESS_DENIED;
 226                 goto done;
 227         }
 228
 229         /* TODO: save PAC data in netsamlogon cache ? */
 230
 231         status = make_server_info_krb5(mem_ctx,
 232                                         ntuser, ntdomain, username, pw,
 233                                         logon_info, is_guest, server_info);
 234         if (!NT_STATUS_IS_OK(status)) {
 235                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 236                           nt_errstr(status)));
 237                 status = NT_STATUS_ACCESS_DENIED;
 238                 goto done;
 239         }
 240
 241         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 242                   ntuser, ntdomain, client_id->name));
 243
 244         status = NT_STATUS_OK;
 245
 246 done:
 247         TALLOC_FREE(tmp_ctx);
 248         return status;
 249 }