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 "../libcli/auth/spnego.h"
  34 #include "lib/util/asn1.h"
  35
  36 #ifdef HAVE_KRB5
  37
  38 #include "auth/kerberos/pac_utils.h"
  39
  40 struct smb_krb5_context;
  41
  42 /*
  43   generate a krb5 GSS-API wrapper packet given a ticket
  44 */
  45 static DATA_BLOB spnego_gen_krb5_wrap(
  46         TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
  47 {
  48         ASN1_DATA *data;
  49         DATA_BLOB ret = data_blob_null;
  50
  51         data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
  52         if (data == NULL) {
  53                 return data_blob_null;
  54         }
  55
  56         if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
  57         if (!asn1_write_OID(data, OID_KERBEROS5)) goto err;
  58
  59         if (!asn1_write(data, tok_id, 2)) goto err;
  60         if (!asn1_write(data, ticket.data, ticket.length)) goto err;
  61         if (!asn1_pop_tag(data)) goto err;
  62
  63         if (!asn1_extract_blob(data, ctx, &ret)) {
  64                 goto err;
  65         }
  66
  67         asn1_free(data);
  68         data = NULL;
  69
  70   err:
  71
  72         if (data != NULL) {
  73                 if (asn1_has_error(data)) {
  74                         DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
  75                                   (int)asn1_current_ofs(data)));
  76                 }
  77
  78                 asn1_free(data);
  79         }
  80
  81         return ret;
  82 }
  83
  84 /*
  85  * Given the username/password, do a kinit, store the ticket in
  86  * cache_name if specified, and return the PAC_LOGON_INFO (the
  87  * structure containing the important user information such as
  88  * groups).
  89  */
  90 NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
  91                              const char *name,
  92                              const char *pass,
  93                              time_t time_offset,
  94                              time_t *expire_time,
  95                              time_t *renew_till_time,
  96                              const char *cache_name,
  97                              bool request_pac,
  98                              bool add_netbios_addr,
  99                              time_t renewable_time,
 100                              const char *impersonate_princ_s,
 101                              const char *local_service,
 102                              char **_canon_principal,
 103                              char **_canon_realm,
 104                              struct PAC_DATA_CTR **_pac_data_ctr)
 105 {
 106         krb5_error_code ret;
 107         NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
 108         DATA_BLOB tkt = data_blob_null;
 109         DATA_BLOB tkt_wrapped = data_blob_null;
 110         DATA_BLOB ap_rep = data_blob_null;
 111         DATA_BLOB sesskey1 = data_blob_null;
 112         const char *auth_princ = NULL;
 113         const char *cc = "MEMORY:kerberos_return_pac";
 114         struct auth_session_info *session_info;
 115         struct gensec_security *gensec_server_context;
 116         const struct gensec_security_ops **backends;
 117         struct gensec_settings *gensec_settings;
 118         size_t idx = 0;
 119         struct auth4_context *auth_context;
 120         struct loadparm_context *lp_ctx;
 121         struct PAC_DATA_CTR *pac_data_ctr = NULL;
 122         char *canon_principal = NULL;
 123         char *canon_realm = NULL;
 124
 125         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 126         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 127
 128         ZERO_STRUCT(tkt);
 129         ZERO_STRUCT(ap_rep);
 130         ZERO_STRUCT(sesskey1);
 131
 132         if (!name || !pass) {
 133                 status = NT_STATUS_INVALID_PARAMETER;
 134                 goto out;
 135         }
 136
 137         if (_canon_principal != NULL) {
 138                 *_canon_principal = NULL;
 139         }
 140
 141         if (_canon_realm != NULL) {
 142                 *_canon_realm = NULL;
 143         }
 144
 145         if (cache_name) {
 146                 cc = cache_name;
 147         }
 148
 149         if (!strchr_m(name, '@')) {
 150                 auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
 151                         lp_realm());
 152         } else {
 153                 auth_princ = name;
 154         }
 155         NT_STATUS_HAVE_NO_MEMORY(auth_princ);
 156
 157         ret = kerberos_kinit_password_ext(auth_princ,
 158                                           pass,
 159                                           time_offset,
 160                                           expire_time,
 161                                           renew_till_time,
 162                                           cc,
 163                                           request_pac,
 164                                           add_netbios_addr,
 165                                           renewable_time,
 166                                           tmp_ctx,
 167                                           &canon_principal,
 168                                           &canon_realm,
 169                                           &status);
 170         if (ret) {
 171                 DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
 172                         auth_princ, error_message(ret), ret));
 173                 /* status already set */
 174                 goto out;
 175         }
 176
 177         DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
 178         if (expire_time) {
 179                 DEBUGADD(10,("\tvalid until: %s (%d)\n",
 180                         http_timestring(talloc_tos(), *expire_time),
 181                         (int)*expire_time));
 182         }
 183         if (renew_till_time) {
 184                 DEBUGADD(10,("\trenewable till: %s (%d)\n",
 185                         http_timestring(talloc_tos(), *renew_till_time),
 186                         (int)*renew_till_time));
 187         }
 188
 189         /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
 190          * in that case fallback to NTLM - gd */
 191
 192         if (expire_time && renew_till_time &&
 193             (*expire_time == 0) && (*renew_till_time == 0)) {
 194                 status = NT_STATUS_INVALID_LOGON_TYPE;
 195                 goto out;
 196         }
 197
 198         ret = ads_krb5_cli_get_ticket(mem_ctx,
 199                                       local_service,
 200                                       time_offset,
 201                                       &tkt,
 202                                       &sesskey1,
 203                                       0,
 204                                       cc,
 205                                       NULL,
 206                                       impersonate_princ_s);
 207         if (ret) {
 208                 DEBUG(1,("failed to get ticket for %s: %s\n",
 209                         local_service, error_message(ret)));
 210                 if (impersonate_princ_s) {
 211                         DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
 212                                 impersonate_princ_s));
 213                 }
 214                 status = krb5_to_nt_status(ret);
 215                 goto out;
 216         }
 217
 218         /* wrap that up in a nice GSS-API wrapping */
 219         tkt_wrapped = spnego_gen_krb5_wrap(tmp_ctx, tkt, TOK_ID_KRB_AP_REQ);
 220         if (tkt_wrapped.data == NULL) {
 221                 status = NT_STATUS_NO_MEMORY;
 222                 goto out;
 223         }
 224
 225         auth_context = auth4_context_for_PAC_DATA_CTR(tmp_ctx);
 226         if (auth_context == NULL) {
 227                 status = NT_STATUS_NO_MEMORY;
 228                 goto out;
 229         }
 230
 231         lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
 232         if (lp_ctx == NULL) {
 233                 status = NT_STATUS_INVALID_SERVER_STATE;
 234                 DEBUG(10, ("loadparm_init_s3 failed\n"));
 235                 goto out;
 236         }
 237
 238         gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
 239         if (gensec_settings == NULL) {
 240                 status = NT_STATUS_NO_MEMORY;
 241                 DEBUG(10, ("lpcfg_gensec_settings failed\n"));
 242                 goto out;
 243         }
 244
 245         backends = talloc_zero_array(gensec_settings,
 246                                      const struct gensec_security_ops *, 2);
 247         if (backends == NULL) {
 248                 status = NT_STATUS_NO_MEMORY;
 249                 goto out;
 250         }
 251         gensec_settings->backends = backends;
 252
 253         gensec_init();
 254
 255         backends[idx++] = &gensec_gse_krb5_security_ops;
 256
 257         status = gensec_server_start(tmp_ctx, gensec_settings,
 258                                         auth_context, &gensec_server_context);
 259
 260         if (!NT_STATUS_IS_OK(status)) {
 261                 DEBUG(1, (__location__ "Failed to start server-side GENSEC to validate a Kerberos ticket: %s\n", nt_errstr(status)));
 262                 goto out;
 263         }
 264
 265         talloc_unlink(tmp_ctx, lp_ctx);
 266         talloc_unlink(tmp_ctx, gensec_settings);
 267         talloc_unlink(tmp_ctx, auth_context);
 268
 269         /* Session info is not complete, do not pass to auth log */
 270         gensec_want_feature(gensec_server_context, GENSEC_FEATURE_NO_AUTHZ_LOG);
 271
 272         status = gensec_start_mech_by_oid(gensec_server_context, GENSEC_OID_KERBEROS5);
 273         if (!NT_STATUS_IS_OK(status)) {
 274                 DEBUG(1, (__location__ "Failed to start server-side GENSEC krb5 to validate a Kerberos ticket: %s\n", nt_errstr(status)));
 275                 goto out;
 276         }
 277
 278         /* Do a client-server update dance */
 279         status = gensec_update(gensec_server_context, tmp_ctx, tkt_wrapped, &ap_rep);
 280         if (!NT_STATUS_IS_OK(status)) {
 281                 DEBUG(1, ("gensec_update() failed: %s\n", nt_errstr(status)));
 282                 goto out;
 283         }
 284
 285         /* Now return the PAC information to the callers.  We ignore
 286          * the session_info and instead pick out the PAC via the
 287          * private_data on the auth_context */
 288         status = gensec_session_info(gensec_server_context, tmp_ctx, &session_info);
 289         if (!NT_STATUS_IS_OK(status)) {
 290                 DEBUG(1, ("Unable to obtain PAC via gensec_session_info\n"));
 291                 goto out;
 292         }
 293
 294         pac_data_ctr = auth4_context_get_PAC_DATA_CTR(auth_context, mem_ctx);
 295         if (pac_data_ctr == NULL) {
 296                 DEBUG(1,("no PAC\n"));
 297                 status = NT_STATUS_INVALID_PARAMETER;
 298                 goto out;
 299         }
 300
 301         *_pac_data_ctr = talloc_move(mem_ctx, &pac_data_ctr);
 302         if (_canon_principal != NULL) {
 303                 *_canon_principal = talloc_move(mem_ctx, &canon_principal);
 304         }
 305         if (_canon_realm != NULL) {
 306                 *_canon_realm = talloc_move(mem_ctx, &canon_realm);
 307         }
 308
 309 out:
 310         talloc_free(tmp_ctx);
 311         if (cc != cache_name) {
 312                 ads_kdestroy(cc);
 313         }
 314
 315         data_blob_free(&tkt);
 316         data_blob_free(&ap_rep);
 317         data_blob_free(&sesskey1);
 318
 319         return status;
 320 }
 321
 322 #endif