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 "../lib/tsocket/tsocket.h"
  25 #include "librpc/crypto/gse.h"
  26 #include "auth.h"
  27 #ifdef HAVE_KRB5
  28 #include "libcli/auth/krb5_wrap.h"
  29 #endif
  30 NTSTATUS gssapi_server_auth_start(TALLOC_CTX *mem_ctx,
  31                                   bool do_sign,
  32                                   bool do_seal,
  33                                   bool is_dcerpc,
  34                                   DATA_BLOB *token_in,
  35                                   DATA_BLOB *token_out,
  36                                   struct gse_context **ctx)
  37 {
  38         struct gse_context *gse_ctx = NULL;
  39         uint32_t add_flags = 0;
  40         NTSTATUS status;
  41
  42         if (is_dcerpc) {
  43                 add_flags = GSS_C_DCE_STYLE;
  44         }
  45
  46         /* Let's init the gssapi machinery for this connection */
  47         /* passing a NULL server name means the server will try
  48          * to accept any connection regardless of the name used as
  49          * long as it can find a decryption key */
  50         /* by passing NULL, the code will attempt to set a default
  51          * keytab based on configuration options */
  52         status = gse_init_server(mem_ctx, do_sign, do_seal,
  53                                  add_flags, &gse_ctx);
  54         if (!NT_STATUS_IS_OK(status)) {
  55                 DEBUG(0, ("Failed to init dcerpc gssapi server (%s)\n",
  56                           nt_errstr(status)));
  57                 return status;
  58         }
  59
  60         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  61                                            token_in, token_out);
  62         if (!NT_STATUS_IS_OK(status)) {
  63                 DEBUG(0, ("Failed to parse initial client token (%s)\n",
  64                           nt_errstr(status)));
  65                 goto done;
  66         }
  67
  68         *ctx = gse_ctx;
  69         status = NT_STATUS_OK;
  70
  71 done:
  72         if (!NT_STATUS_IS_OK(status)) {
  73                 TALLOC_FREE(gse_ctx);
  74         }
  75
  76         return status;
  77 }
  78
  79 NTSTATUS gssapi_server_step(struct gse_context *gse_ctx,
  80                             TALLOC_CTX *mem_ctx,
  81                             DATA_BLOB *token_in,
  82                             DATA_BLOB *token_out)
  83 {
  84         NTSTATUS status;
  85
  86         status = gse_get_server_auth_token(mem_ctx, gse_ctx,
  87                                            token_in, token_out);
  88         if (!NT_STATUS_IS_OK(status)) {
  89                 return status;
  90         }
  91
  92         if (gse_require_more_processing(gse_ctx)) {
  93                 /* ask for next leg */
  94                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
  95         }
  96
  97         return NT_STATUS_OK;
  98 }
  99
 100 NTSTATUS gssapi_server_check_flags(struct gse_context *gse_ctx)
 101 {
 102         return gse_verify_server_auth_flags(gse_ctx);
 103 }
 104
 105 NTSTATUS gssapi_server_get_user_info(struct gse_context *gse_ctx,
 106                                      TALLOC_CTX *mem_ctx,
 107                                      const struct tsocket_address *remote_address,
 108                                      struct auth_session_info **session_info)
 109 {
 110         TALLOC_CTX *tmp_ctx;
 111         DATA_BLOB pac_blob;
 112         struct PAC_DATA *pac_data = NULL;
 113         struct PAC_LOGON_INFO *logon_info = NULL;
 114         unsigned int i;
 115         bool is_mapped;
 116         bool is_guest;
 117         char *princ_name;
 118         char *ntuser;
 119         char *ntdomain;
 120         char *username;
 121         char *rhost;
 122         struct passwd *pw;
 123         NTSTATUS status;
 124         int rc;
 125
 126         tmp_ctx = talloc_new(mem_ctx);
 127         if (!tmp_ctx) {
 128                 return NT_STATUS_NO_MEMORY;
 129         }
 130
 131         status = gse_get_pac_blob(gse_ctx, tmp_ctx, &pac_blob);
 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 #ifdef HAVE_KRB5
 142         status = kerberos_decode_pac(tmp_ctx,
 143                                      pac_blob,
 144                                      NULL, NULL, NULL, NULL, 0, &pac_data);
 145 #else
 146         status = NT_STATUS_ACCESS_DENIED;
 147 #endif
 148         data_blob_free(&pac_blob);
 149         if (!NT_STATUS_IS_OK(status)) {
 150                 goto done;
 151         }
 152
 153         status = gse_get_client_name(gse_ctx, tmp_ctx, &princ_name);
 154         if (!NT_STATUS_IS_OK(status)) {
 155                 goto done;
 156         }
 157
 158         /* get logon name and logon info */
 159         for (i = 0; i < pac_data->num_buffers; i++) {
 160                 struct PAC_BUFFER *data_buf = &pac_data->buffers[i];
 161
 162                 switch (data_buf->type) {
 163                 case PAC_TYPE_LOGON_INFO:
 164                         if (!data_buf->info) {
 165                                 break;
 166                         }
 167                         logon_info = data_buf->info->logon_info.info;
 168                         break;
 169                 default:
 170                         break;
 171                 }
 172         }
 173         if (!logon_info) {
 174                 DEBUG(1, ("Invalid PAC data, missing logon info!\n"));
 175                 status = NT_STATUS_NOT_FOUND;
 176                 goto done;
 177         }
 178
 179         rc = get_remote_hostname(remote_address,
 180                                  &rhost,
 181                                  tmp_ctx);
 182         if (rc < 0) {
 183                 status = NT_STATUS_NO_MEMORY;
 184                 goto done;
 185         }
 186         if (strequal(rhost, "UNKNOWN")) {
 187                 rhost = tsocket_address_inet_addr_string(remote_address,
 188                                                          tmp_ctx);
 189                 if (rhost == NULL) {
 190                         status = NT_STATUS_NO_MEMORY;
 191                         goto done;
 192                 }
 193         }
 194
 195         status = get_user_from_kerberos_info(tmp_ctx, rhost,
 196                                              princ_name, logon_info,
 197                                              &is_mapped, &is_guest,
 198                                              &ntuser, &ntdomain,
 199                                              &username, &pw);
 200         if (!NT_STATUS_IS_OK(status)) {
 201                 DEBUG(1, ("Failed to map kerberos principal to system user "
 202                           "(%s)\n", nt_errstr(status)));
 203                 status = NT_STATUS_ACCESS_DENIED;
 204                 goto done;
 205         }
 206
 207         /* TODO: save PAC data in netsamlogon cache ? */
 208
 209         status = make_session_info_krb5(mem_ctx,
 210                                         ntuser, ntdomain, username, pw,
 211                                         logon_info, is_guest, is_mapped, NULL /* No session key for now */,
 212                                         session_info);
 213         if (!NT_STATUS_IS_OK(status)) {
 214                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 215                           nt_errstr(status)));
 216                 status = NT_STATUS_ACCESS_DENIED;
 217                 goto done;
 218         }
 219
 220         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 221                   ntuser, ntdomain, rhost));
 222
 223         status = NT_STATUS_OK;
 224
 225 done:
 226         TALLOC_FREE(tmp_ctx);
 227         return status;
 228 }