auth/gensec/external.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    SASL/EXTERNAL authentication.
   5
   6    Copyright (C) Howard Chu <hyc@symas.com> 2013
   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 <tevent.h>
  24 #include "lib/util/tevent_ntstatus.h"
  25 #include "auth/credentials/credentials.h"
  26 #include "auth/gensec/gensec.h"
  27 #include "auth/gensec/gensec_internal.h"
  28 #include "auth/gensec/gensec_proto.h"
  29 #include "auth/gensec/gensec_toplevel_proto.h"
  30
  31 /* SASL/EXTERNAL is essentially a no-op; it is only usable when the transport
  32  * layer is already mutually authenticated.
  33  */
  34
  35 NTSTATUS gensec_external_init(TALLOC_CTX *ctx);
  36
  37 static NTSTATUS gensec_external_start(struct gensec_security *gensec_security)
  38 {
  39         if (gensec_security->want_features & GENSEC_FEATURE_SIGN)
  40                 return NT_STATUS_INVALID_PARAMETER;
  41         if (gensec_security->want_features & GENSEC_FEATURE_SEAL)
  42                 return NT_STATUS_INVALID_PARAMETER;
  43
  44         return NT_STATUS_OK;
  45 }
  46
  47 struct gensec_external_update_state {
  48         DATA_BLOB out;
  49 };
  50
  51 static struct tevent_req *gensec_external_update_send(TALLOC_CTX *mem_ctx,
  52                                         struct tevent_context *ev,
  53                                         struct gensec_security *gensec_security,
  54                                         const DATA_BLOB in)
  55 {
  56         struct tevent_req *req;
  57         struct gensec_external_update_state *state = NULL;
  58
  59         req = tevent_req_create(mem_ctx, &state,
  60                                 struct gensec_external_update_state);
  61         if (req == NULL) {
  62                 return NULL;
  63         }
  64
  65         state->out = data_blob_talloc(state, "", 0);
  66         if (tevent_req_nomem(state->out.data, req)) {
  67                 return tevent_req_post(req, ev);
  68         }
  69
  70         tevent_req_done(req);
  71         return tevent_req_post(req, ev);
  72 }
  73
  74 static NTSTATUS gensec_external_update_recv(struct tevent_req *req,
  75                                             TALLOC_CTX *out_mem_ctx,
  76                                             DATA_BLOB *out)
  77 {
  78         struct gensec_external_update_state *state =
  79                 tevent_req_data(req,
  80                 struct gensec_external_update_state);
  81         NTSTATUS status;
  82
  83         *out = data_blob_null;
  84
  85         if (tevent_req_is_nterror(req, &status)) {
  86                 tevent_req_received(req);
  87                 return status;
  88         }
  89
  90         *out = state->out;
  91         tevent_req_received(req);
  92         return NT_STATUS_OK;
  93 }
  94
  95 /* We have no features */
  96 static bool gensec_external_have_feature(struct gensec_security *gensec_security,
  97                                      uint32_t feature)
  98 {
  99         return false;
 100 }
 101
 102 static const struct gensec_security_ops gensec_external_ops = {
 103         .name             = "sasl-EXTERNAL",
 104         .sasl_name        = "EXTERNAL",
 105         .client_start     = gensec_external_start,
 106         .update_send      = gensec_external_update_send,
 107         .update_recv      = gensec_external_update_recv,
 108         .have_feature     = gensec_external_have_feature,
 109         .enabled          = true,
 110         .priority         = GENSEC_EXTERNAL
 111 };
 112
 113
 114 NTSTATUS gensec_external_init(TALLOC_CTX *ctx)
 115 {
 116         NTSTATUS ret;
 117
 118         ret = gensec_register(&gensec_external_ops);
 119         if (!NT_STATUS_IS_OK(ret)) {
 120                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 121                          gensec_external_ops.name));
 122         }
 123         return ret;
 124 }