s3:kerberos_verify: ads_dedicated_keytab_verify_ticket() only needs read access
[metze/samba/wip.git] / source3 / libads / kerberos_verify.c
index f9a6c5c97b72b5a45878c874f2283375c52a5d9f..0c44db988e62e364816906388470339a5c9c673a 100644 (file)
-/* 
+/*
    Unix SMB/CIFS implementation.
    kerberos utility library
    Copyright (C) Andrew Tridgell 2001
    Copyright (C) Remus Koos 2001
-   Copyright (C) Luke Howard 2003   
-   
+   Copyright (C) Luke Howard 2003
+   Copyright (C) Guenther Deschner 2003, 2005
+   Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
+   Copyright (C) Jeremy Allison 2007
+
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
-   
+
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
-   
+
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "includes.h"
+#include "smb_krb5.h"
+#include "libads/kerberos_proto.h"
+#include "secrets.h"
+#include "../librpc/gen_ndr/krb5pac.h"
 
 #ifdef HAVE_KRB5
 
-/*
-  verify an incoming ticket and parse out the principal name and 
-  authorization_data if available 
-*/
-NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket, 
-                          char **principal, DATA_BLOB *auth_data,
-                          DATA_BLOB *ap_rep,
-                          uint8 session_key[16])
+#if !defined(HAVE_KRB5_PRINC_COMPONENT)
+const krb5_data *krb5_princ_component(krb5_context, krb5_principal, int );
+#endif
+
+static bool ads_dedicated_keytab_verify_ticket(krb5_context context,
+                                         krb5_auth_context auth_context,
+                                         const DATA_BLOB *ticket,
+                                         krb5_ticket **pp_tkt,
+                                         krb5_keyblock **keyblock,
+                                         krb5_error_code *perr)
 {
-       NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
-       krb5_context context = NULL;
-       krb5_auth_context auth_context = NULL;
+       krb5_error_code ret = 0;
+       bool auth_ok = false;
        krb5_keytab keytab = NULL;
+       krb5_keytab_entry kt_entry;
+       krb5_ticket *dec_ticket = NULL;
+
        krb5_data packet;
-       krb5_ticket *tkt = NULL;
-       krb5_rcache rcache = NULL;
-       int ret, i;
-       krb5_keyblock *key = NULL;
-       krb5_principal host_princ;
-       char *host_princ_s = NULL;
-       fstring myname;
-       char *password_s = NULL;
-       krb5_data password;
-       krb5_enctype *enctypes = NULL;
-#if 0
-       krb5_address local_addr;
-       krb5_address remote_addr;
+       krb5_kvno kvno = 0;
+       krb5_enctype enctype;
+
+       *pp_tkt = NULL;
+       *keyblock = NULL;
+       *perr = 0;
+
+       ZERO_STRUCT(kt_entry);
+
+       ret = smb_krb5_open_keytab(context, lp_dedicated_keytab_file(), false,
+           &keytab);
+       if (ret) {
+               DEBUG(1, ("smb_krb5_open_keytab failed (%s)\n",
+                       error_message(ret)));
+               goto out;
+       }
+
+       packet.length = ticket->length;
+       packet.data = (char *)ticket->data;
+
+       ret = krb5_rd_req(context, &auth_context, &packet, NULL, keytab,
+           NULL, &dec_ticket);
+       if (ret) {
+               DEBUG(0, ("krb5_rd_req failed (%s)\n", error_message(ret)));
+               goto out;
+       }
+
+#ifdef HAVE_ETYPE_IN_ENCRYPTEDDATA /* Heimdal */
+       enctype = dec_ticket->ticket.key.keytype;
+#else /* MIT */
+       enctype = dec_ticket->enc_part.enctype;
+       kvno    = dec_ticket->enc_part.kvno;
 #endif
-       BOOL auth_ok = False;
 
-       ZERO_STRUCT(packet);
-       ZERO_STRUCT(password);
-       ZERO_STRUCTP(auth_data);
-       ZERO_STRUCTP(ap_rep);
+       /* Get the key for checking the pac signature */
+       ret = krb5_kt_get_entry(context, keytab, dec_ticket->server,
+                               kvno, enctype, &kt_entry);
+       if (ret) {
+               DEBUG(0, ("krb5_kt_get_entry failed (%s)\n",
+                         error_message(ret)));
+               goto out;
+       }
+
+       ret = krb5_copy_keyblock(context, KRB5_KT_KEY(&kt_entry), keyblock);
+       smb_krb5_kt_free_entry(context, &kt_entry);
+
+       if (ret) {
+               DEBUG(0, ("failed to copy key: %s\n",
+                         error_message(ret)));
+               goto out;
+       }
+
+       auth_ok = true;
+       *pp_tkt = dec_ticket;
+       dec_ticket = NULL;
+
+  out:
+       if (dec_ticket)
+               krb5_free_ticket(context, dec_ticket);
+
+       if (keytab)
+               krb5_kt_close(context, keytab);
+
+       *perr = ret;
+       return auth_ok;
+}
+
+/******************************************************************************
+ Try to verify a ticket using the system keytab... the system keytab has
+ kvno -1 entries, so it's more like what microsoft does... see comment in
+ utils/net_ads.c in the ads_keytab_add_entry function for details.
+******************************************************************************/
+
+static bool ads_keytab_verify_ticket(krb5_context context,
+                                       krb5_auth_context auth_context,
+                                       const DATA_BLOB *ticket,
+                                       krb5_ticket **pp_tkt,
+                                       krb5_keyblock **keyblock,
+                                       krb5_error_code *perr)
+{
+       krb5_error_code ret = 0;
+       bool auth_ok = False;
+       krb5_keytab keytab = NULL;
+       krb5_kt_cursor kt_cursor;
+       krb5_keytab_entry kt_entry;
+       char *valid_princ_formats[7] = { NULL, NULL, NULL,
+                                        NULL, NULL, NULL, NULL };
+       char *entry_princ_s = NULL;
+       fstring my_name, my_fqdn;
+       int i;
+       int number_matched_principals = 0;
+       krb5_data packet;
+       int err;
+
+       *pp_tkt = NULL;
+       *keyblock = NULL;
+       *perr = 0;
+
+       /* Generate the list of principal names which we expect
+        * clients might want to use for authenticating to the file
+        * service.  We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
+
+       fstrcpy(my_name, lp_netbios_name());
+
+       my_fqdn[0] = '\0';
+       name_to_fqdn(my_fqdn, lp_netbios_name());
+
+       err = asprintf(&valid_princ_formats[0],
+                       "%s$@%s", my_name, lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+       err = asprintf(&valid_princ_formats[1],
+                       "host/%s@%s", my_name, lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+       err = asprintf(&valid_princ_formats[2],
+                       "host/%s@%s", my_fqdn, lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+       err = asprintf(&valid_princ_formats[3],
+                       "host/%s.%s@%s", my_name, lp_realm(), lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+       err = asprintf(&valid_princ_formats[4],
+                       "cifs/%s@%s", my_name, lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+       err = asprintf(&valid_princ_formats[5],
+                       "cifs/%s@%s", my_fqdn, lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+       err = asprintf(&valid_princ_formats[6],
+                       "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm());
+       if (err == -1) {
+               goto out;
+       }
+
+       ZERO_STRUCT(kt_entry);
+       ZERO_STRUCT(kt_cursor);
+
+       ret = smb_krb5_open_keytab(context, NULL, False, &keytab);
+       if (ret) {
+               DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
+                         error_message(ret)));
+               goto out;
+       }
+
+       /* Iterate through the keytab.  For each key, if the principal
+        * name case-insensitively matches one of the allowed formats,
+        * try verifying the ticket using that principal. */
+
+       ret = krb5_kt_start_seq_get(context, keytab, &kt_cursor);
+       if (ret) {
+               DEBUG(1, (__location__ ": krb5_kt_start_seq_get failed (%s)\n",
+                         error_message(ret)));
+               goto out;
+       }
+  
+       while (!auth_ok &&
+              (krb5_kt_next_entry(context, keytab,
+                                  &kt_entry, &kt_cursor) == 0)) {
+               ret = smb_krb5_unparse_name(talloc_tos(), context,
+                                           kt_entry.principal,
+                                           &entry_princ_s);
+               if (ret) {
+                       DEBUG(1, (__location__ ": smb_krb5_unparse_name "
+                                 "failed (%s)\n", error_message(ret)));
+                       goto out;
+               }
+
+               for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
+
+                       if (!strequal(entry_princ_s, valid_princ_formats[i])) {
+                               continue;
+                       }
+
+                       number_matched_principals++;
+                       packet.length = ticket->length;
+                       packet.data = (char *)ticket->data;
+                       *pp_tkt = NULL;
+
+                       ret = krb5_rd_req_return_keyblock_from_keytab(context,
+                                               &auth_context, &packet,
+                                               kt_entry.principal, keytab,
+                                               NULL, pp_tkt, keyblock);
+
+                       if (ret) {
+                               DEBUG(10, (__location__ ": krb5_rd_req_return"
+                                          "_keyblock_from_keytab(%s) "
+                                          "failed: %s\n", entry_princ_s,
+                                          error_message(ret)));
+
+                               /* workaround for MIT:
+                               * as krb5_ktfile_get_entry will explicitly
+                               * close the krb5_keytab as soon as krb5_rd_req
+                               * has successfully decrypted the ticket but the
+                               * ticket is not valid yet (due to clockskew)
+                               * there is no point in querying more keytab
+                               * entries - Guenther */
+
+                               if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
+                                   ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
+                                   ret == KRB5KRB_AP_ERR_SKEW) {
+                                       break;
+                               }
+                       } else {
+                               DEBUG(3, (__location__ ": krb5_rd_req_return"
+                                         "_keyblock_from_keytab succeeded "
+                                         "for principal %s\n",
+                                         entry_princ_s));
+                               auth_ok = True;
+                               break;
+                       }
+               }
+
+               /* Free the name we parsed. */
+               TALLOC_FREE(entry_princ_s);
+
+               /* Free the entry we just read. */
+               smb_krb5_kt_free_entry(context, &kt_entry);
+               ZERO_STRUCT(kt_entry);
+       }
+       krb5_kt_end_seq_get(context, keytab, &kt_cursor);
+
+       ZERO_STRUCT(kt_cursor);
+
+out:
+
+       for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
+               SAFE_FREE(valid_princ_formats[i]);
+       }
+
+       if (!auth_ok) {
+               if (!number_matched_principals) {
+                       DEBUG(3, (__location__ ": no keytab principals "
+                                 "matched expected file service name.\n"));
+               } else {
+                       DEBUG(3, (__location__ ": krb5_rd_req failed for "
+                                 "all %d matched keytab principals\n",
+                                 number_matched_principals));
+               }
+       }
+
+       TALLOC_FREE(entry_princ_s);
+
+       {
+               krb5_keytab_entry zero_kt_entry;
+               ZERO_STRUCT(zero_kt_entry);
+               if (memcmp(&zero_kt_entry, &kt_entry,
+                          sizeof(krb5_keytab_entry))) {
+                       smb_krb5_kt_free_entry(context, &kt_entry);
+               }
+       }
+
+       {
+               krb5_kt_cursor zero_csr;
+               ZERO_STRUCT(zero_csr);
+               if ((memcmp(&kt_cursor, &zero_csr,
+                           sizeof(krb5_kt_cursor)) != 0) && keytab) {
+                       krb5_kt_end_seq_get(context, keytab, &kt_cursor);
+               }
+       }
+
+       if (keytab) {
+               krb5_kt_close(context, keytab);
+       }
+       *perr = ret;
+       return auth_ok;
+}
+
+/*****************************************************************************
+ Try to verify a ticket using the secrets.tdb.
+******************************************************************************/
+
+static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
+                                               krb5_auth_context auth_context,
+                                               krb5_principal host_princ,
+                                               const DATA_BLOB *ticket,
+                                               krb5_ticket **pp_tkt,
+                                               krb5_keyblock **keyblock,
+                                               krb5_error_code *perr)
+{
+       krb5_error_code ret = 0;
+       bool auth_ok = False;
+       bool cont = true;
+       char *password_s = NULL;
+       /* Let's make some room for 2 password (old and new)*/
+       krb5_data passwords[2];
+       krb5_enctype enctypes[] = {
+               ENCTYPE_ARCFOUR_HMAC,
+               ENCTYPE_DES_CBC_CRC,
+               ENCTYPE_DES_CBC_MD5,
+               ENCTYPE_NULL
+       };
+       krb5_data packet;
+       int i, j;
+
+       *pp_tkt = NULL;
+       *keyblock = NULL;
+       *perr = 0;
+
+       ZERO_STRUCT(passwords);
 
        if (!secrets_init()) {
-               DEBUG(1,("ads_verify_ticket: secrets_init failed\n"));
-               return NT_STATUS_LOGON_FAILURE;
+               DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
+               *perr = KRB5_CONFIG_CANTOPEN;
+               return False;
        }
 
-       password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
+       password_s = secrets_fetch_machine_password(lp_workgroup(),
+                                                   NULL, NULL);
        if (!password_s) {
-               DEBUG(1,("ads_verify_ticket: failed to fetch machine password\n"));
-               return NT_STATUS_LOGON_FAILURE;
+               DEBUG(1,(__location__ ": failed to fetch machine password\n"));
+               *perr = KRB5_LIBOS_CANTREADPWD;
+               return False;
+       }
+
+       passwords[0].data = password_s;
+       passwords[0].length = strlen(password_s);
+
+       password_s = secrets_fetch_prev_machine_password(lp_workgroup());
+       if (password_s) {
+               DEBUG(10, (__location__ ": found previous password\n"));
+               passwords[1].data = password_s;
+               passwords[1].length = strlen(password_s);
        }
 
-       password.data = password_s;
-       password.length = strlen(password_s);
+       /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
+
+       packet.length = ticket->length;
+       packet.data = (char *)ticket->data;
+
+       /* We need to setup a auth context with each possible encoding type
+        * in turn. */
+       for (j=0; j<2 && passwords[j].length; j++) {
+
+               for (i=0;enctypes[i];i++) {
+                       krb5_keyblock *key = NULL;
+
+                       if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
+                               ret = ENOMEM;
+                               goto out;
+                       }
+
+                       if (create_kerberos_key_from_string(context,
+                                               host_princ, &passwords[j],
+                                               key, enctypes[i], false)) {
+                               SAFE_FREE(key);
+                               continue;
+                       }
+
+                       krb5_auth_con_setuseruserkey(context,
+                                                       auth_context, key);
+
+                       if (!(ret = krb5_rd_req(context, &auth_context,
+                                               &packet, NULL, NULL,
+                                               NULL, pp_tkt))) {
+                               DEBUG(10, (__location__ ": enc type [%u] "
+                                          "decrypted message !\n",
+                                          (unsigned int)enctypes[i]));
+                               auth_ok = True;
+                               cont = false;
+                               krb5_copy_keyblock(context, key, keyblock);
+                               krb5_free_keyblock(context, key);
+                               break;
+                       }
+
+                       DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
+                               (__location__ ": enc type [%u] failed to "
+                                "decrypt with error %s\n",
+                                (unsigned int)enctypes[i],
+                                error_message(ret)));
+
+                       /* successfully decrypted but ticket is just not
+                        * valid at the moment */
+                       if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
+                           ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
+                           ret == KRB5KRB_AP_ERR_SKEW) {
+                               krb5_free_keyblock(context, key);
+                               cont = false;
+                               break;
+                       }
+
+                       krb5_free_keyblock(context, key);
+               }
+               if (!cont) {
+                       /* If we found a valid pass then no need to try
+                        * the next one or we have invalid ticket so no need
+                        * to try next password*/
+                       break;
+               }
+       }
 
+ out:
+       SAFE_FREE(passwords[0].data);
+       SAFE_FREE(passwords[1].data);
+       *perr = ret;
+       return auth_ok;
+}
+
+/*****************************************************************************
+ Verify an incoming ticket and parse out the principal name and
+ authorization_data if available.
+******************************************************************************/
+
+NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
+                          const char *realm,
+                          time_t time_offset,
+                          const DATA_BLOB *ticket,
+                          char **principal,
+                          struct PAC_LOGON_INFO **logon_info,
+                          DATA_BLOB *ap_rep,
+                          DATA_BLOB *session_key,
+                          bool use_replay_cache)
+{
+       NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
+       NTSTATUS pac_ret;
+       DATA_BLOB auth_data;
+       krb5_context context = NULL;
+       krb5_auth_context auth_context = NULL;
+       krb5_data packet;
+       krb5_ticket *tkt = NULL;
+       krb5_rcache rcache = NULL;
+       krb5_keyblock *keyblock = NULL;
+       time_t authtime;
+       krb5_error_code ret = 0;
+       int flags = 0;
+       krb5_principal host_princ = NULL;
+       krb5_const_principal client_principal = NULL;
+       char *host_princ_s = NULL;
+       bool auth_ok = False;
+       bool got_auth_data = False;
+       struct named_mutex *mutex = NULL;
+
+       ZERO_STRUCT(packet);
+       ZERO_STRUCT(auth_data);
+
+       *principal = NULL;
+       *logon_info = NULL;
+       *ap_rep = data_blob_null;
+       *session_key = data_blob_null;
+
+       initialize_krb5_error_table();
        ret = krb5_init_context(&context);
        if (ret) {
-               DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
+               DEBUG(1, (__location__ ": krb5_init_context failed (%s)\n",
+                         error_message(ret)));
                return NT_STATUS_LOGON_FAILURE;
        }
 
-       ret = krb5_set_default_realm(context, ads->auth.realm);
+       if (time_offset != 0) {
+               krb5_set_real_time(context, time(NULL) + time_offset, 0);
+       }
+
+       ret = krb5_set_default_realm(context, realm);
        if (ret) {
-               DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
+               DEBUG(1, (__location__ ": krb5_set_default_realm "
+                         "failed (%s)\n", error_message(ret)));
                goto out;
        }
 
@@ -92,150 +522,253 @@ NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket,
 
        ret = krb5_auth_con_init(context, &auth_context);
        if (ret) {
-               DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
+               DEBUG(1, (__location__ ": krb5_auth_con_init failed (%s)\n",
+                         error_message(ret)));
                goto out;
        }
 
-       fstrcpy(myname, global_myname());
-       strlower_m(myname);
-       asprintf(&host_princ_s, "HOST/%s@%s", myname, lp_realm());
-       ret = krb5_parse_name(context, host_princ_s, &host_princ);
-       if (ret) {
-               DEBUG(1,("ads_verify_ticket: krb5_parse_name(%s) failed (%s)\n",
-                                       host_princ_s, error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
-               goto out;
+       krb5_auth_con_getflags( context, auth_context, &flags );
+       if ( !use_replay_cache ) {
+               /* Disable default use of a replay cache */
+               flags &= ~KRB5_AUTH_CONTEXT_DO_TIME;
+               krb5_auth_con_setflags( context, auth_context, flags );
        }
 
-       /*
-        * JRA. We must set the rcache and the allowed addresses in the auth_context
-        * here. This will prevent replay attacks and ensure the client has got a key from
-        * the correct IP address.
-        */
-
-       ret = krb5_get_server_rcache(context, krb5_princ_component(context, host_princ, 0), &rcache);
-       if (ret) {
-               DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache failed (%s)\n", error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
+       if (asprintf(&host_princ_s, "%s$", lp_netbios_name()) == -1) {
                goto out;
        }
 
-       ret = krb5_auth_con_setrcache(context, auth_context, rcache);
+       strlower_m(host_princ_s);
+       ret = smb_krb5_parse_name(context, host_princ_s, &host_princ);
        if (ret) {
-               DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache failed (%s)\n", error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
+               DEBUG(1, (__location__ ": smb_krb5_parse_name(%s) "
+                         "failed (%s)\n", host_princ_s, error_message(ret)));
                goto out;
        }
 
-       /* CIFS doesn't use addresses in tickets. This would breat NAT. JRA */
 
-       if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
-               sret = NT_STATUS_NO_MEMORY;
-               goto out;
-       }
-       
-       if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
-               DEBUG(1,("ads_verify_ticket: krb5_get_permitted_enctypes failed (%s)\n", 
-                        error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
-               goto out;
-       }
+       if (use_replay_cache) {
+
+               /* Lock a mutex surrounding the replay as there is no
+                  locking in the MIT krb5 code surrounding the replay
+                  cache... */
+
+               mutex = grab_named_mutex(talloc_tos(),
+                                        "replay cache mutex", 10);
+               if (mutex == NULL) {
+                       DEBUG(1, (__location__ ": unable to protect replay "
+                                 "cache with mutex.\n"));
+                       ret = KRB5_CC_IO;
+                       goto out;
+               }
 
-       /* we need to setup a auth context with each possible encoding type in turn */
-       for (i=0;enctypes[i];i++) {
-               if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
-                       continue;
+               /* JRA. We must set the rcache here. This will prevent
+                  replay attacks. */
+
+               ret = krb5_get_server_rcache(
+                               context,
+                               krb5_princ_component(context, host_princ, 0),
+                               &rcache);
+               if (ret) {
+                       DEBUG(1, (__location__ ": krb5_get_server_rcache "
+                                 "failed (%s)\n", error_message(ret)));
+                       goto out;
                }
 
-               krb5_auth_con_setuseruserkey(context, auth_context, key);
+               ret = krb5_auth_con_setrcache(context, auth_context, rcache);
+               if (ret) {
+                       DEBUG(1, (__location__ ": krb5_auth_con_setrcache "
+                                 "failed (%s)\n", error_message(ret)));
+                       goto out;
+               }
+       }
 
-               packet.length = ticket->length;
-               packet.data = (krb5_pointer)ticket->data;
+       switch (lp_kerberos_method()) {
+       default:
+       case KERBEROS_VERIFY_SECRETS:
+               auth_ok = ads_secrets_verify_ticket(context, auth_context,
+                   host_princ, ticket, &tkt, &keyblock, &ret);
+               break;
+       case KERBEROS_VERIFY_SYSTEM_KEYTAB:
+               auth_ok = ads_keytab_verify_ticket(context, auth_context,
+                   ticket, &tkt, &keyblock, &ret);
+               break;
+       case KERBEROS_VERIFY_DEDICATED_KEYTAB:
+               auth_ok = ads_dedicated_keytab_verify_ticket(context,
+                   auth_context, ticket, &tkt, &keyblock, &ret);
+               break;
+       case KERBEROS_VERIFY_SECRETS_AND_KEYTAB:
+               /* First try secrets.tdb and fallback to the krb5.keytab if
+                  necessary.  This is the pre 3.4 behavior when
+                  "use kerberos keytab" was true.*/
+               auth_ok = ads_secrets_verify_ticket(context, auth_context,
+                   host_princ, ticket, &tkt, &keyblock, &ret);
+
+               if (!auth_ok) {
+                       /* Only fallback if we failed to decrypt the ticket */
+                       if (ret != KRB5KRB_AP_ERR_TKT_NYV &&
+                           ret != KRB5KRB_AP_ERR_TKT_EXPIRED &&
+                           ret != KRB5KRB_AP_ERR_SKEW) {
+                               auth_ok = ads_keytab_verify_ticket(context,
+                                   auth_context, ticket, &tkt, &keyblock,
+                                   &ret);
+                       }
+               }
+               break;
+       }
 
-               if (!(ret = krb5_rd_req(context, &auth_context, &packet, 
-                                      NULL, keytab, NULL, &tkt))) {
-                       DEBUG(10,("ads_verify_ticket: enc type [%u] decrypted message !\n",
-                               (unsigned int)enctypes[i] ));
-                       free_kerberos_etypes(context, enctypes);
-                       auth_ok = True;
-                       break;
+       if (use_replay_cache) {
+               TALLOC_FREE(mutex);
+#if 0
+               /* Heimdal leaks here, if we fix the leak, MIT crashes */
+               if (rcache) {
+                       krb5_rc_close(context, rcache);
                }
-       
-               DEBUG( 3,
-                               ("ads_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
-                               (unsigned int)enctypes[i], error_message(ret)));
+#endif
        }
 
        if (!auth_ok) {
-               DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n", 
-                        error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
+               DEBUG(3, (__location__ ": krb5_rd_req with auth "
+                         "failed (%s)\n", error_message(ret)));
+               /* Try map the error return in case it's something like
+                * a clock skew error.
+                */
+               sret = krb5_to_nt_status(ret);
+               if (NT_STATUS_IS_OK(sret) ||
+                   NT_STATUS_EQUAL(sret,NT_STATUS_UNSUCCESSFUL)) {
+                       sret = NT_STATUS_LOGON_FAILURE;
+               }
+               DEBUG(10, (__location__ ": returning error %s\n",
+                          nt_errstr(sret) ));
                goto out;
        }
 
+       authtime = get_authtime_from_tkt(tkt);
+       client_principal = get_principal_from_tkt(tkt);
+
        ret = krb5_mk_rep(context, auth_context, &packet);
        if (ret) {
-               DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
-                       error_message(ret)));
-               sret = NT_STATUS_LOGON_FAILURE;
+               DEBUG(3, (__location__ ": Failed to generate mutual "
+                         "authentication reply (%s)\n", error_message(ret)));
                goto out;
        }
 
        *ap_rep = data_blob(packet.data, packet.length);
-       free(packet.data);
+       if (packet.data) {
+               kerberos_free_data_contents(context, &packet);
+               ZERO_STRUCT(packet);
+       }
 
-       get_krb5_smb_session_key(context, auth_context, session_key, True);
-#ifdef DEBUG_PASSWORD
-       DEBUG(10,("SMB session key (from ticket) follows:\n"));
-       dump_data(10, session_key, 16);
-#endif
+       get_krb5_smb_session_key(mem_ctx, context,
+                                auth_context, session_key, true);
+       dump_data_pw("SMB session key (from ticket)\n",
+                    session_key->data, session_key->length);
 
 #if 0
        file_save("/tmp/ticket.dat", ticket->data, ticket->length);
 #endif
 
-       get_auth_data_from_tkt(auth_data, tkt);
+       /* continue when no PAC is retrieved or we couldn't decode the PAC
+          (like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
+          Kerberos tickets encrypted using a DES key) - Guenther */
 
-       {
-               TALLOC_CTX *ctx = talloc_init("pac data");
-               decode_pac_data(auth_data, ctx);
-               talloc_destroy(ctx);
+       got_auth_data = get_auth_data_from_tkt(mem_ctx, &auth_data, tkt);
+       if (!got_auth_data) {
+               DEBUG(3, (__location__ ": did not retrieve auth data. "
+                         "continuing without PAC\n"));
+       }
+
+       if (got_auth_data) {
+               struct PAC_DATA *pac_data;
+               pac_ret = kerberos_decode_pac(mem_ctx, auth_data, context,
+                                             NULL, keyblock, client_principal,
+                                             authtime, &pac_data);
+               data_blob_free(&auth_data);
+               if (!NT_STATUS_IS_OK(pac_ret)) {
+                       DEBUG(3, (__location__ ": failed to decode "
+                                 "PAC_DATA: %s\n", nt_errstr(pac_ret)));
+               } else {
+                       uint32_t i;
+                       for (i = 0; i < pac_data->num_buffers; i++) {
+
+                               if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
+                                       continue;
+                               }
+
+                               *logon_info = pac_data->buffers[i].info->logon_info.info;
+                       }
+
+                       if (!*logon_info) {
+                               DEBUG(1, ("correctly decoded PAC but found "
+                                         "no logon_info! "
+                                         "This should not happen\n"));
+                               return NT_STATUS_INVALID_USER_BUFFER;
+                       }
+               }
        }
 
 #if 0
+#if defined(HAVE_KRB5_TKT_ENC_PART2)
+       /* MIT */
        if (tkt->enc_part2) {
                file_save("/tmp/authdata.dat",
                          tkt->enc_part2->authorization_data[0]->contents,
                          tkt->enc_part2->authorization_data[0]->length);
+       }
+#else
+       /* Heimdal */
+       if (tkt->ticket.authorization_data) {
+               file_save("/tmp/authdata.dat",
+                         tkt->ticket.authorization_data->val->ad_data.data,
+                         tkt->ticket.authorization_data->val->ad_data.length);
+       }
+#endif
 #endif
 
-       if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
-                                    principal))) {
-               DEBUG(3,("ads_verify_ticket: krb5_unparse_name failed (%s)\n", 
-                        error_message(ret)));
+       ret = smb_krb5_unparse_name(mem_ctx, context,
+                                   client_principal, principal);
+       if (ret) {
+               DEBUG(3, (__location__ ": smb_krb5_unparse_name "
+                         "failed (%s)\n", error_message(ret)));
                sret = NT_STATUS_LOGON_FAILURE;
                goto out;
        }
 
        sret = NT_STATUS_OK;
 
- out:
+out:
 
-       if (!NT_STATUS_IS_OK(sret))
-               data_blob_free(auth_data);
+       TALLOC_FREE(mutex);
 
-       if (!NT_STATUS_IS_OK(sret))
+       if (!NT_STATUS_IS_OK(sret)) {
+               data_blob_free(&auth_data);
+       }
+
+       if (!NT_STATUS_IS_OK(sret)) {
                data_blob_free(ap_rep);
+       }
+
+       if (host_princ) {
+               krb5_free_principal(context, host_princ);
+       }
+
+       if (keyblock) {
+               krb5_free_keyblock(context, keyblock);
+       }
+
+       if (tkt != NULL) {
+               krb5_free_ticket(context, tkt);
+       }
 
        SAFE_FREE(host_princ_s);
-       SAFE_FREE(password_s);
 
-       if (auth_context)
+       if (auth_context) {
                krb5_auth_con_free(context, auth_context);
+       }
 
-       if (context)
+       if (context) {
                krb5_free_context(context);
+       }
 
        return sret;
 }