source/libcli/auth/gensec_gssapi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
   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 2 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
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "system/kerberos.h"
  26 #include "system/time.h"
  27 #include "libcli/auth/kerberos.h"
  28 #include "auth/auth.h"
  29
  30 #undef DBGC_CLASS
  31 #define DBGC_CLASS DBGC_AUTH
  32
  33 struct gensec_gssapi_state {
  34         gss_ctx_id_t gssapi_context;
  35         struct gss_channel_bindings_struct *input_chan_bindings;
  36         gss_name_t server_name;
  37         gss_name_t client_name;
  38         int want_flags, got_flags;
  39 };
  40 static int gensec_gssapi_destory(void *ptr)
  41 {
  42         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  43         OM_uint32 maj_stat, min_stat;
  44
  45         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  46                 maj_stat = gss_delete_sec_context (&min_stat,
  47                                                    &gensec_gssapi_state->gssapi_context,
  48                                                    GSS_C_NO_BUFFER);
  49         }
  50
  51         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
  52                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
  53         }
  54         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
  55                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
  56         }
  57         return 0;
  58 }
  59
  60 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
  61 {
  62         struct gensec_gssapi_state *gensec_gssapi_state;
  63
  64         gensec_gssapi_state = talloc_p(gensec_security, struct gensec_gssapi_state);
  65         if (!gensec_gssapi_state) {
  66                 return NT_STATUS_NO_MEMORY;
  67         }
  68
  69         gensec_security->private_data = gensec_gssapi_state;
  70
  71         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
  72         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
  73         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
  74
  75         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
  76
  77         /* TODO: Fill in channel bindings */
  78         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
  79
  80         gensec_gssapi_state->want_flags = 0;
  81         gensec_gssapi_state->got_flags = 0;
  82
  83         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
  84                 /* GSSAPI won't give us the session keys */
  85                 return NT_STATUS_INVALID_PARAMETER;
  86         }
  87         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
  88                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
  89         }
  90         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
  91                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
  92         }
  93
  94         return NT_STATUS_OK;
  95 }
  96
  97 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
  98 {
  99         NTSTATUS nt_status;
 100         struct gensec_gssapi_state *gensec_gssapi_state;
 101
 102         nt_status = gensec_gssapi_start(gensec_security);
 103         if (!NT_STATUS_IS_OK(nt_status)) {
 104                 return nt_status;
 105         }
 106
 107         gensec_gssapi_state = gensec_security->private_data;
 108
 109         return NT_STATUS_OK;
 110 }
 111
 112 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 113 {
 114         struct gensec_gssapi_state *gensec_gssapi_state;
 115         NTSTATUS nt_status;
 116         gss_buffer_desc name_token;
 117         OM_uint32 maj_stat, min_stat;
 118
 119         nt_status = gensec_gssapi_start(gensec_security);
 120         if (!NT_STATUS_IS_OK(nt_status)) {
 121                 return nt_status;
 122         }
 123
 124         gensec_gssapi_state = gensec_security->private_data;
 125
 126         name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s", gensec_get_target_service(gensec_security),
 127                                            gensec_get_target_hostname(gensec_security));
 128         DEBUG(0, ("name: %s\n", (char *)name_token.value));
 129         name_token.length = strlen(name_token.value);
 130
 131         maj_stat = gss_import_name (&min_stat,
 132                                     &name_token,
 133                                     GSS_C_NT_HOSTBASED_SERVICE,
 134                                     &gensec_gssapi_state->server_name);
 135
 136
 137         if (maj_stat) {
 138                 return NT_STATUS_UNSUCCESSFUL;
 139         }
 140         return NT_STATUS_OK;
 141 }
 142
 143
 144
 145 /**
 146  * Next state function for the GSSAPI GENSEC mechanism
 147  *
 148  * @param gensec_gssapi_state GSSAPI State
 149  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 150  * @param in The request, as a DATA_BLOB
 151  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 152  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 153  *                or NT_STATUS_OK if the user is authenticated.
 154  */
 155
 156 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 157                                    TALLOC_CTX *out_mem_ctx,
 158                                    const DATA_BLOB in, DATA_BLOB *out)
 159 {
 160         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 161         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 162         OM_uint32 maj_stat, min_stat;
 163         OM_uint32 min_stat2;
 164         gss_buffer_desc input_token, output_token;
 165
 166         input_token.length = in.length;
 167         input_token.value = in.data;
 168
 169         switch (gensec_security->gensec_role) {
 170         case GENSEC_CLIENT:
 171         {
 172                 maj_stat = gss_init_sec_context(&min_stat,
 173                                                 GSS_C_NO_CREDENTIAL,
 174                                                 &gensec_gssapi_state->gssapi_context,
 175                                                 gensec_gssapi_state->server_name,
 176                                                 GSS_C_NO_OID,
 177                                                 gensec_gssapi_state->want_flags,
 178                                                 0,
 179                                                 gensec_gssapi_state->input_chan_bindings,
 180                                                 &input_token,
 181                                                 NULL,
 182                                                 &output_token,
 183                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 184                                                 NULL);
 185                 break;
 186         }
 187         case GENSEC_SERVER:
 188         {
 189                 maj_stat = gss_accept_sec_context(&min_stat,
 190                                                   gensec_gssapi_state->gssapi_context,
 191                                                   GSS_C_NO_CREDENTIAL,
 192                                                   &input_token,
 193                                                   gensec_gssapi_state->input_chan_bindings,
 194                                                   &gensec_gssapi_state->client_name,
 195                                                   NULL /* mech oid */,
 196                                                   &output_token,
 197                                                   &gensec_gssapi_state->got_flags,
 198                                                   NULL,
 199                                                   NULL);
 200                 break;
 201         }
 202         default:
 203                 return NT_STATUS_INVALID_PARAMETER;
 204
 205         }
 206
 207         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 208         gss_release_buffer(&min_stat2, &output_token);
 209
 210         if (maj_stat == GSS_S_COMPLETE) {
 211                 return NT_STATUS_OK;
 212         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 213                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 214         } else {
 215                 gss_buffer_desc msg1, msg2;
 216                 OM_uint32 msg_ctx = 0;
 217
 218                 msg1.value = NULL;
 219                 msg2.value = NULL;
 220                 gss_display_status(&min_stat2, maj_stat, GSS_C_GSS_CODE,
 221                                    GSS_C_NULL_OID, &msg_ctx, &msg1);
 222                 gss_display_status(&min_stat2, min_stat, GSS_C_MECH_CODE,
 223                                    GSS_C_NULL_OID, &msg_ctx, &msg2);
 224                 DEBUG(1, ("gensec_gssapi_update: %s : %s\n", (char *)msg1.value, (char *)msg2.value));
 225                 gss_release_buffer(&min_stat2, &msg1);
 226                 gss_release_buffer(&min_stat2, &msg2);
 227
 228                 return nt_status;
 229         }
 230
 231 }
 232
 233 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 234                                    TALLOC_CTX *mem_ctx,
 235                                    const DATA_BLOB *in,
 236                                    DATA_BLOB *out)
 237 {
 238         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 239         OM_uint32 maj_stat, min_stat;
 240         gss_buffer_desc input_token, output_token;
 241         int conf_state;
 242         input_token.length = in->length;
 243         input_token.value = in->data;
 244
 245         maj_stat = gss_wrap(&min_stat,
 246                             gensec_gssapi_state->gssapi_context,
 247                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 248                             GSS_C_QOP_DEFAULT,
 249                             &input_token,
 250                             &conf_state,
 251                             &output_token);
 252         if (GSS_ERROR(maj_stat)) {
 253                 return NT_STATUS_ACCESS_DENIED;
 254         }
 255         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 256
 257         gss_release_buffer(&min_stat, &output_token);
 258
 259         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 260             && !conf_state) {
 261                 return NT_STATUS_ACCESS_DENIED;
 262         }
 263         return NT_STATUS_OK;
 264 }
 265
 266 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 267                                      TALLOC_CTX *mem_ctx,
 268                                      const DATA_BLOB *in,
 269                                      DATA_BLOB *out)
 270 {
 271         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 272         OM_uint32 maj_stat, min_stat;
 273         gss_buffer_desc input_token, output_token;
 274         int conf_state;
 275         gss_qop_t qop_state;
 276         input_token.length = in->length;
 277         input_token.value = in->data;
 278
 279         maj_stat = gss_unwrap(&min_stat,
 280                               gensec_gssapi_state->gssapi_context,
 281                               &input_token,
 282                               &output_token,
 283                               &conf_state,
 284                               &qop_state);
 285         if (GSS_ERROR(maj_stat)) {
 286                 return NT_STATUS_ACCESS_DENIED;
 287         }
 288         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 289
 290         gss_release_buffer(&min_stat, &output_token);
 291
 292         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 293             && !conf_state) {
 294                 return NT_STATUS_ACCESS_DENIED;
 295         }
 296         return NT_STATUS_OK;
 297 }
 298
 299 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 300                                        uint32 feature)
 301 {
 302         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 303         if (feature & GENSEC_FEATURE_SIGN) {
 304                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 305         }
 306         if (feature & GENSEC_FEATURE_SEAL) {
 307                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 308         }
 309         return False;
 310 }
 311
 312 static const struct gensec_security_ops gensec_gssapi_security_ops = {
 313         .name           = "gssapi",
 314         .oid            = GENSEC_OID_KERBEROS5,
 315         .client_start   = gensec_gssapi_client_start,
 316         .server_start   = gensec_gssapi_server_start,
 317         .update         = gensec_gssapi_update,
 318         .wrap           = gensec_gssapi_wrap,
 319         .unwrap         = gensec_gssapi_unwrap,
 320         .have_feature   = gensec_gssapi_have_feature
 321
 322 };
 323
 324 NTSTATUS gensec_gssapi_init(void)
 325 {
 326         NTSTATUS ret;
 327
 328         ret = gensec_register(&gensec_gssapi_security_ops);
 329         if (!NT_STATUS_IS_OK(ret)) {
 330                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 331                         gensec_gssapi_security_ops.name));
 332                 return ret;
 333         }
 334
 335         return ret;
 336 }