source3/libads/authdata.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    kerberos authorization data (PAC) utility library
   4    Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   6    Copyright (C) Andrew Tridgell 2001
   7    Copyright (C) Luke Howard 2002-2003
   8    Copyright (C) Stefan Metzmacher 2004-2005
   9    Copyright (C) Guenther Deschner 2005,2007,2008
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "librpc/gen_ndr/ndr_krb5pac.h"
  27 #include "smb_krb5.h"
  28 #include "libads/kerberos_proto.h"
  29 #include "auth/common_auth.h"
  30 #include "lib/param/param.h"
  31 #include "librpc/crypto/gse.h"
  32 #include "auth/gensec/gensec.h"
  33 #include "auth/gensec/gensec_internal.h" /* TODO: remove this */
  34 #include "../libcli/auth/spnego.h"
  35 #include "lib/util/asn1.h"
  36
  37 #ifdef HAVE_KRB5
  38
  39 #include "auth/kerberos/pac_utils.h"
  40
  41 struct smb_krb5_context;
  42
  43 /*
  44   generate a krb5 GSS-API wrapper packet given a ticket
  45 */
  46 static DATA_BLOB spnego_gen_krb5_wrap(
  47         TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
  48 {
  49         ASN1_DATA *data;
  50         DATA_BLOB ret = data_blob_null;
  51
  52         data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
  53         if (data == NULL) {
  54                 return data_blob_null;
  55         }
  56
  57         if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
  58         if (!asn1_write_OID(data, OID_KERBEROS5)) goto err;
  59
  60         if (!asn1_write(data, tok_id, 2)) goto err;
  61         if (!asn1_write(data, ticket.data, ticket.length)) goto err;
  62         if (!asn1_pop_tag(data)) goto err;
  63
  64         if (!asn1_extract_blob(data, ctx, &ret)) {
  65                 goto err;
  66         }
  67
  68         asn1_free(data);
  69         data = NULL;
  70
  71   err:
  72
  73         if (data != NULL) {
  74                 if (asn1_has_error(data)) {
  75                         DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
  76                                   (int)asn1_current_ofs(data)));
  77                 }
  78
  79                 asn1_free(data);
  80         }
  81
  82         return ret;
  83 }
  84
  85 /*
  86  * Given the username/password, do a kinit, store the ticket in
  87  * cache_name if specified, and return the PAC_LOGON_INFO (the
  88  * structure containing the important user information such as
  89  * groups).
  90  */
  91 NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
  92                              const char *name,
  93                              const char *pass,
  94                              time_t time_offset,
  95                              time_t *expire_time,
  96                              time_t *renew_till_time,
  97                              const char *cache_name,
  98                              bool request_pac,
  99                              bool add_netbios_addr,
 100                              time_t renewable_time,
 101                              const char *impersonate_princ_s,
 102                              const char *local_service,
 103                              char **_canon_principal,
 104                              char **_canon_realm,
 105                              struct PAC_DATA_CTR **_pac_data_ctr)
 106 {
 107         krb5_error_code ret;
 108         NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
 109         DATA_BLOB tkt = data_blob_null;
 110         DATA_BLOB tkt_wrapped = data_blob_null;
 111         DATA_BLOB ap_rep = data_blob_null;
 112         DATA_BLOB sesskey1 = data_blob_null;
 113         const char *auth_princ = NULL;
 114         const char *cc = "MEMORY:kerberos_return_pac";
 115         struct auth_session_info *session_info;
 116         struct gensec_security *gensec_server_context;
 117         const struct gensec_security_ops **backends;
 118         struct gensec_settings *gensec_settings;
 119         size_t idx = 0;
 120         struct auth4_context *auth_context;
 121         struct loadparm_context *lp_ctx;
 122         struct PAC_DATA_CTR *pac_data_ctr = NULL;
 123         char *canon_principal = NULL;
 124         char *canon_realm = NULL;
 125
 126         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 127         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 128
 129         ZERO_STRUCT(tkt);
 130         ZERO_STRUCT(ap_rep);
 131         ZERO_STRUCT(sesskey1);
 132
 133         if (!name || !pass) {
 134                 status = NT_STATUS_INVALID_PARAMETER;
 135                 goto out;
 136         }
 137
 138         if (_canon_principal != NULL) {
 139                 *_canon_principal = NULL;
 140         }
 141
 142         if (_canon_realm != NULL) {
 143                 *_canon_realm = NULL;
 144         }
 145
 146         if (cache_name) {
 147                 cc = cache_name;
 148         }
 149
 150         if (!strchr_m(name, '@')) {
 151                 auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
 152                         lp_realm());
 153         } else {
 154                 auth_princ = name;
 155         }
 156         NT_STATUS_HAVE_NO_MEMORY(auth_princ);
 157
 158         ret = kerberos_kinit_password_ext(auth_princ,
 159                                           pass,
 160                                           time_offset,
 161                                           expire_time,
 162                                           renew_till_time,
 163                                           cc,
 164                                           request_pac,
 165                                           add_netbios_addr,
 166                                           renewable_time,
 167                                           tmp_ctx,
 168                                           &canon_principal,
 169                                           &canon_realm,
 170                                           &status);
 171         if (ret) {
 172                 DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
 173                         auth_princ, error_message(ret), ret));
 174                 /* status already set */
 175                 goto out;
 176         }
 177
 178         DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
 179         if (expire_time) {
 180                 DEBUGADD(10,("\tvalid until: %s (%d)\n",
 181                         http_timestring(talloc_tos(), *expire_time),
 182                         (int)*expire_time));
 183         }
 184         if (renew_till_time) {
 185                 DEBUGADD(10,("\trenewable till: %s (%d)\n",
 186                         http_timestring(talloc_tos(), *renew_till_time),
 187                         (int)*renew_till_time));
 188         }
 189
 190         /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
 191          * in that case fallback to NTLM - gd */
 192
 193         if (expire_time && renew_till_time &&
 194             (*expire_time == 0) && (*renew_till_time == 0)) {
 195                 status = NT_STATUS_INVALID_LOGON_TYPE;
 196                 goto out;
 197         }
 198
 199         ret = ads_krb5_cli_get_ticket(mem_ctx,
 200                                       local_service,
 201                                       time_offset,
 202                                       &tkt,
 203                                       &sesskey1,
 204                                       0,
 205                                       cc,
 206                                       NULL,
 207                                       impersonate_princ_s);
 208         if (ret) {
 209                 DEBUG(1,("failed to get ticket for %s: %s\n",
 210                         local_service, error_message(ret)));
 211                 if (impersonate_princ_s) {
 212                         DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
 213                                 impersonate_princ_s));
 214                 }
 215                 status = krb5_to_nt_status(ret);
 216                 goto out;
 217         }
 218
 219         /* wrap that up in a nice GSS-API wrapping */
 220         tkt_wrapped = spnego_gen_krb5_wrap(tmp_ctx, tkt, TOK_ID_KRB_AP_REQ);
 221         if (tkt_wrapped.data == NULL) {
 222                 status = NT_STATUS_NO_MEMORY;
 223                 goto out;
 224         }
 225
 226         auth_context = auth4_context_for_PAC_DATA_CTR(tmp_ctx);
 227         if (auth_context == NULL) {
 228                 status = NT_STATUS_NO_MEMORY;
 229                 goto out;
 230         }
 231
 232         lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
 233         if (lp_ctx == NULL) {
 234                 status = NT_STATUS_INVALID_SERVER_STATE;
 235                 DEBUG(10, ("loadparm_init_s3 failed\n"));
 236                 goto out;
 237         }
 238
 239         gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
 240         if (gensec_settings == NULL) {
 241                 status = NT_STATUS_NO_MEMORY;
 242                 DEBUG(10, ("lpcfg_gensec_settings failed\n"));
 243                 goto out;
 244         }
 245
 246         backends = talloc_zero_array(gensec_settings,
 247                                      const struct gensec_security_ops *, 2);
 248         if (backends == NULL) {
 249                 status = NT_STATUS_NO_MEMORY;
 250                 goto out;
 251         }
 252         gensec_settings->backends = backends;
 253
 254         gensec_init();
 255
 256         backends[idx++] = &gensec_gse_krb5_security_ops;
 257
 258         status = gensec_server_start(tmp_ctx, gensec_settings,
 259                                         auth_context, &gensec_server_context);
 260
 261         if (!NT_STATUS_IS_OK(status)) {
 262                 DEBUG(1, (__location__ "Failed to start server-side GENSEC to validate a Kerberos ticket: %s\n", nt_errstr(status)));
 263                 goto out;
 264         }
 265
 266         talloc_unlink(tmp_ctx, lp_ctx);
 267         talloc_unlink(tmp_ctx, gensec_settings);
 268         talloc_unlink(tmp_ctx, auth_context);
 269
 270         /* Session info is not complete, do not pass to auth log */
 271         gensec_want_feature(gensec_server_context, GENSEC_FEATURE_NO_AUTHZ_LOG);
 272
 273         status = gensec_start_mech_by_oid(gensec_server_context, GENSEC_OID_KERBEROS5);
 274         if (!NT_STATUS_IS_OK(status)) {
 275                 DEBUG(1, (__location__ "Failed to start server-side GENSEC krb5 to validate a Kerberos ticket: %s\n", nt_errstr(status)));
 276                 goto out;
 277         }
 278
 279         /* Do a client-server update dance */
 280         status = gensec_update(gensec_server_context, tmp_ctx, tkt_wrapped, &ap_rep);
 281         if (!NT_STATUS_IS_OK(status)) {
 282                 DEBUG(1, ("gensec_update() failed: %s\n", nt_errstr(status)));
 283                 goto out;
 284         }
 285
 286         /* Now return the PAC information to the callers.  We ignore
 287          * the session_info and instead pick out the PAC via the
 288          * private_data on the auth_context */
 289         status = gensec_session_info(gensec_server_context, tmp_ctx, &session_info);
 290         if (!NT_STATUS_IS_OK(status)) {
 291                 DEBUG(1, ("Unable to obtain PAC via gensec_session_info\n"));
 292                 goto out;
 293         }
 294
 295         pac_data_ctr = auth4_context_get_PAC_DATA_CTR(auth_context, mem_ctx);
 296         if (pac_data_ctr == NULL) {
 297                 DEBUG(1,("no PAC\n"));
 298                 status = NT_STATUS_INVALID_PARAMETER;
 299                 goto out;
 300         }
 301
 302         *_pac_data_ctr = talloc_move(mem_ctx, &pac_data_ctr);
 303         if (_canon_principal != NULL) {
 304                 *_canon_principal = talloc_move(mem_ctx, &canon_principal);
 305         }
 306         if (_canon_realm != NULL) {
 307                 *_canon_realm = talloc_move(mem_ctx, &canon_realm);
 308         }
 309
 310 out:
 311         talloc_free(tmp_ctx);
 312         if (cc != cache_name) {
 313                 ads_kdestroy(cc);
 314         }
 315
 316         data_blob_free(&tkt);
 317         data_blob_free(&ap_rep);
 318         data_blob_free(&sesskey1);
 319
 320         return status;
 321 }
 322
 323 #endif