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 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_AUTH
  33
  34 /* SASL/EXTERNAL is essentially a no-op; it is only usable when the transport
  35  * layer is already mutually authenticated.
  36  */
  37
  38 NTSTATUS gensec_external_init(TALLOC_CTX *ctx);
  39
  40 static NTSTATUS gensec_external_start(struct gensec_security *gensec_security)
  41 {
  42         if (gensec_security->want_features & GENSEC_FEATURE_SIGN)
  43                 return NT_STATUS_INVALID_PARAMETER;
  44         if (gensec_security->want_features & GENSEC_FEATURE_SEAL)
  45                 return NT_STATUS_INVALID_PARAMETER;
  46
  47         return NT_STATUS_OK;
  48 }
  49
  50 struct gensec_external_update_state {
  51         DATA_BLOB out;
  52 };
  53
  54 static struct tevent_req *gensec_external_update_send(TALLOC_CTX *mem_ctx,
  55                                         struct tevent_context *ev,
  56                                         struct gensec_security *gensec_security,
  57                                         const DATA_BLOB in)
  58 {
  59         struct tevent_req *req;
  60         struct gensec_external_update_state *state = NULL;
  61
  62         req = tevent_req_create(mem_ctx, &state,
  63                                 struct gensec_external_update_state);
  64         if (req == NULL) {
  65                 return NULL;
  66         }
  67
  68         state->out = data_blob_talloc(state, "", 0);
  69         if (tevent_req_nomem(state->out.data, req)) {
  70                 return tevent_req_post(req, ev);
  71         }
  72
  73         tevent_req_done(req);
  74         return tevent_req_post(req, ev);
  75 }
  76
  77 static NTSTATUS gensec_external_update_recv(struct tevent_req *req,
  78                                             TALLOC_CTX *out_mem_ctx,
  79                                             DATA_BLOB *out)
  80 {
  81         struct gensec_external_update_state *state =
  82                 tevent_req_data(req,
  83                 struct gensec_external_update_state);
  84         NTSTATUS status;
  85
  86         *out = data_blob_null;
  87
  88         if (tevent_req_is_nterror(req, &status)) {
  89                 tevent_req_received(req);
  90                 return status;
  91         }
  92
  93         *out = state->out;
  94         tevent_req_received(req);
  95         return NT_STATUS_OK;
  96 }
  97
  98 /* We have no features */
  99 static bool gensec_external_have_feature(struct gensec_security *gensec_security,
 100                                      uint32_t feature)
 101 {
 102         return false;
 103 }
 104
 105 static const struct gensec_security_ops gensec_external_ops = {
 106         .name             = "sasl-EXTERNAL",
 107         .sasl_name        = "EXTERNAL",
 108         .client_start     = gensec_external_start,
 109         .update_send      = gensec_external_update_send,
 110         .update_recv      = gensec_external_update_recv,
 111         .have_feature     = gensec_external_have_feature,
 112         .enabled          = true,
 113         .priority         = GENSEC_EXTERNAL
 114 };
 115
 116
 117 NTSTATUS gensec_external_init(TALLOC_CTX *ctx)
 118 {
 119         NTSTATUS ret;
 120
 121         ret = gensec_register(ctx, &gensec_external_ops);
 122         if (!NT_STATUS_IS_OK(ret)) {
 123                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 124                          gensec_external_ops.name));
 125         }
 126         return ret;
 127 }