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 #ifdef HAVE_KRB5
  27 #include "libcli/auth/krb5_wrap.h"
  28 #endif
  29 NTSTATUS gssapi_server_auth_start(TALLOC_CTX *mem_ctx,
  30                                   bool do_sign,
  31                                   bool do_seal,
  32                                   bool is_dcerpc,
  33                                   DATA_BLOB *token_in,
  34                                   DATA_BLOB *token_out,
  35                                   struct gse_context **ctx)
  36 {
  37         struct gse_context *gse_ctx = NULL;
  38         uint32_t add_flags = 0;
  39         NTSTATUS status;
  40
  41         if (is_dcerpc) {
  42                 add_flags = GSS_C_DCE_STYLE;
  43         }
  44
  45         /* Let's init the gssapi machinery for this connection */
  46         /* passing a NULL server name means the server will try
  47          * to accept any connection regardless of the name used as
  48          * long as it can find a decryption key */
  49         /* by passing NULL, the code will attempt to set a default
  50          * keytab based on configuration options */
  51         status = gse_init_server(mem_ctx, do_sign, do_seal,
  52                                  add_flags, &gse_ctx);
  53         if (!NT_STATUS_IS_OK(status)) {
  54                 DEBUG(0, ("Failed to init dcerpc gssapi server (%s)\n",
  55                           nt_errstr(status)));
  56                 return status;
  57         }
  58
  59         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  60                                            token_in, token_out);
  61         if (!NT_STATUS_IS_OK(status)) {
  62                 DEBUG(0, ("Failed to parse initial client token (%s)\n",
  63                           nt_errstr(status)));
  64                 goto done;
  65         }
  66
  67         *ctx = gse_ctx;
  68         status = NT_STATUS_OK;
  69
  70 done:
  71         if (!NT_STATUS_IS_OK(status)) {
  72                 TALLOC_FREE(gse_ctx);
  73         }
  74
  75         return status;
  76 }
  77
  78 NTSTATUS gssapi_server_step(struct gse_context *gse_ctx,
  79                             TALLOC_CTX *mem_ctx,
  80                             DATA_BLOB *token_in,
  81                             DATA_BLOB *token_out)
  82 {
  83         NTSTATUS status;
  84
  85         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  86                                            token_in, token_out);
  87         if (!NT_STATUS_IS_OK(status)) {
  88                 return status;
  89         }
  90
  91         if (gse_require_more_processing(gse_ctx)) {
  92                 /* ask for next leg */
  93                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
  94         }
  95
  96         return NT_STATUS_OK;
  97 }
  98
  99 NTSTATUS gssapi_server_check_flags(struct gse_context *gse_ctx)
 100 {
 101         return gse_verify_server_auth_flags(gse_ctx);
 102 }
 103
 104 NTSTATUS gssapi_server_get_user_info(struct gse_context *gse_ctx,
 105                                      TALLOC_CTX *mem_ctx,
 106                                      struct client_address *client_id,
 107                                      struct auth_serversupplied_info **server_info)
 108 {
 109         TALLOC_CTX *tmp_ctx;
 110         DATA_BLOB pac_blob;
 111         struct PAC_DATA *pac_data = NULL;
 112         struct PAC_LOGON_INFO *logon_info = NULL;
 113         unsigned int i;
 114         bool is_mapped;
 115         bool is_guest;
 116         char *princ_name;
 117         char *ntuser;
 118         char *ntdomain;
 119         char *username;
 120         struct passwd *pw;
 121         NTSTATUS status;
 122
 123         tmp_ctx = talloc_new(mem_ctx);
 124         if (!tmp_ctx) {
 125                 return NT_STATUS_NO_MEMORY;
 126         }
 127
 128         status = gse_get_pac_blob(gse_ctx, tmp_ctx, &pac_blob);
 129         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 130                 /* TODO: Fetch user by principal name ? */
 131                 status = NT_STATUS_ACCESS_DENIED;
 132                 goto done;
 133         }
 134         if (!NT_STATUS_IS_OK(status)) {
 135                 goto done;
 136         }
 137
 138 #ifdef HAVE_KRB5
 139         status = kerberos_decode_pac(tmp_ctx,
 140                                      pac_blob,
 141                                      NULL, NULL, NULL, NULL, 0, &pac_data);
 142 #else
 143         status = NT_STATUS_ACCESS_DENIED;
 144 #endif
 145         data_blob_free(&pac_blob);
 146         if (!NT_STATUS_IS_OK(status)) {
 147                 goto done;
 148         }
 149
 150         status = gse_get_client_name(gse_ctx, tmp_ctx, &princ_name);
 151         if (!NT_STATUS_IS_OK(status)) {
 152                 goto done;
 153         }
 154
 155         /* get logon name and logon info */
 156         for (i = 0; i < pac_data->num_buffers; i++) {
 157                 struct PAC_BUFFER *data_buf = &pac_data->buffers[i];
 158
 159                 switch (data_buf->type) {
 160                 case PAC_TYPE_LOGON_INFO:
 161                         if (!data_buf->info) {
 162                                 break;
 163                         }
 164                         logon_info = data_buf->info->logon_info.info;
 165                         break;
 166                 default:
 167                         break;
 168                 }
 169         }
 170         if (!logon_info) {
 171                 DEBUG(1, ("Invalid PAC data, missing logon info!\n"));
 172                 status = NT_STATUS_NOT_FOUND;
 173                 goto done;
 174         }
 175
 176         status = get_user_from_kerberos_info(tmp_ctx, client_id->name,
 177                                              princ_name, logon_info,
 178                                              &is_mapped, &is_guest,
 179                                              &ntuser, &ntdomain,
 180                                              &username, &pw);
 181         if (!NT_STATUS_IS_OK(status)) {
 182                 DEBUG(1, ("Failed to map kerberos principal to system user "
 183                           "(%s)\n", nt_errstr(status)));
 184                 status = NT_STATUS_ACCESS_DENIED;
 185                 goto done;
 186         }
 187
 188         /* TODO: save PAC data in netsamlogon cache ? */
 189
 190         status = make_session_info_krb5(mem_ctx,
 191                                         ntuser, ntdomain, username, pw,
 192                                         logon_info, is_guest, is_mapped, NULL /* No session key for now */,
 193                                         server_info);
 194         if (!NT_STATUS_IS_OK(status)) {
 195                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 196                           nt_errstr(status)));
 197                 status = NT_STATUS_ACCESS_DENIED;
 198                 goto done;
 199         }
 200
 201         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 202                   ntuser, ntdomain, client_id->name));
 203
 204         status = NT_STATUS_OK;
 205
 206 done:
 207         TALLOC_FREE(tmp_ctx);
 208         return status;
 209 }