s4:kdc move db functions in their own file

Keep all heimdal related plugin code within hdb_samba4.c
Move interfaces needed by multiple plugins in db-glue.c

Move sequence context in main db context so that we do
not depend on db->hdb_dbc in the common code.

Remove unnecessary paremeters from function prototypes

1 files changed, 1509 insertions, 0 deletions

diff --git a/source4/kdc/db-glue.c b/source4/kdc/db-glue.c
new file mode 100644
index 0000000000..2f75fd9996
--- /dev/null
+++ b/source4/kdc/db-glue.c
@@ -0,0 +1,1509 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Database Glue between Samba and the KDC
+
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2009
+   Copyright (C) Simo Sorce <idra@samba.org> 2010
+
+   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 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "system/time.h"
+#include "../libds/common/flags.h"
+#include "lib/ldb/include/ldb.h"
+#include "librpc/gen_ndr/netlogon.h"
+#include "libcli/security/security.h"
+#include "auth/auth.h"
+#include "auth/credentials/credentials.h"
+#include "auth/auth_sam.h"
+#include "../lib/util/util_ldb.h"
+#include "dsdb/samdb/samdb.h"
+#include "librpc/ndr/libndr.h"
+#include "librpc/gen_ndr/ndr_drsblobs.h"
+#include "librpc/gen_ndr/lsa.h"
+#include "libcli/auth/libcli_auth.h"
+#include "param/param.h"
+#include "../lib/crypto/md4.h"
+#include "system/kerberos.h"
+#include <hdb.h>
+#include "kdc/samba_kdc.h"
+#include "kdc/db-glue.h"
+
+enum samba_kdc_ent_type
+{ SAMBA_KDC_ENT_TYPE_CLIENT, SAMBA_KDC_ENT_TYPE_SERVER,
+  SAMBA_KDC_ENT_TYPE_KRBTGT, SAMBA_KDC_ENT_TYPE_TRUST, SAMBA_KDC_ENT_TYPE_ANY };
+
+enum trust_direction {
+	UNKNOWN = 0,
+	INBOUND = LSA_TRUST_DIRECTION_INBOUND,
+	OUTBOUND = LSA_TRUST_DIRECTION_OUTBOUND
+};
+
+static const char *trust_attrs[] = {
+	"trustPartner",
+	"trustAuthIncoming",
+	"trustAuthOutgoing",
+	"whenCreated",
+	"msDS-SupportedEncryptionTypes",
+	"trustAttributes",
+	"trustDirection",
+	"trustType",
+	NULL
+};
+
+static KerberosTime ldb_msg_find_krb5time_ldap_time(struct ldb_message *msg, const char *attr, KerberosTime default_val)
+{
+    const char *tmp;
+    const char *gentime;
+    struct tm tm;
+
+    gentime = ldb_msg_find_attr_as_string(msg, attr, NULL);
+    if (!gentime)
+	return default_val;
+
+    tmp = strptime(gentime, "%Y%m%d%H%M%SZ", &tm);
+    if (tmp == NULL) {
+	    return default_val;
+    }
+
+    return timegm(&tm);
+}
+
+static HDBFlags uf2HDBFlags(krb5_context context, int userAccountControl, enum samba_kdc_ent_type ent_type)
+{
+	HDBFlags flags = int2HDBFlags(0);
+
+	/* we don't allow kadmin deletes */
+	flags.immutable = 1;
+
+	/* mark the principal as invalid to start with */
+	flags.invalid = 1;
+
+	flags.renewable = 1;
+
+	/* All accounts are servers, but this may be disabled again in the caller */
+	flags.server = 1;
+
+	/* Account types - clear the invalid bit if it turns out to be valid */
+	if (userAccountControl & UF_NORMAL_ACCOUNT) {
+		if (ent_type == SAMBA_KDC_ENT_TYPE_CLIENT || ent_type == SAMBA_KDC_ENT_TYPE_ANY) {
+			flags.client = 1;
+		}
+		flags.invalid = 0;
+	}
+
+	if (userAccountControl & UF_INTERDOMAIN_TRUST_ACCOUNT) {
+		if (ent_type == SAMBA_KDC_ENT_TYPE_CLIENT || ent_type == SAMBA_KDC_ENT_TYPE_ANY) {
+			flags.client = 1;
+		}
+		flags.invalid = 0;
+	}
+	if (userAccountControl & UF_WORKSTATION_TRUST_ACCOUNT) {
+		if (ent_type == SAMBA_KDC_ENT_TYPE_CLIENT || ent_type == SAMBA_KDC_ENT_TYPE_ANY) {
+			flags.client = 1;
+		}
+		flags.invalid = 0;
+	}
+	if (userAccountControl & UF_SERVER_TRUST_ACCOUNT) {
+		if (ent_type == SAMBA_KDC_ENT_TYPE_CLIENT || ent_type == SAMBA_KDC_ENT_TYPE_ANY) {
+			flags.client = 1;
+		}
+		flags.invalid = 0;
+	}
+
+	/* Not permitted to act as a client if disabled */
+	if (userAccountControl & UF_ACCOUNTDISABLE) {
+		flags.client = 0;
+	}
+	if (userAccountControl & UF_LOCKOUT) {
+		flags.invalid = 1;
+	}
+/*
+	if (userAccountControl & UF_PASSWORD_NOTREQD) {
+		flags.invalid = 1;
+	}
+*/
+/*
+	UF_PASSWORD_CANT_CHANGE and UF_ENCRYPTED_TEXT_PASSWORD_ALLOWED are irrelevent
+*/
+	if (userAccountControl & UF_TEMP_DUPLICATE_ACCOUNT) {
+		flags.invalid = 1;
+	}
+
+/* UF_DONT_EXPIRE_PASSWD and UF_USE_DES_KEY_ONLY handled in samba_kdc_message2entry() */
+
+/*
+	if (userAccountControl & UF_MNS_LOGON_ACCOUNT) {
+		flags.invalid = 1;
+	}
+*/
+	if (userAccountControl & UF_SMARTCARD_REQUIRED) {
+		flags.require_hwauth = 1;
+	}
+	if (userAccountControl & UF_TRUSTED_FOR_DELEGATION) {
+		flags.ok_as_delegate = 1;
+	}
+	if (!(userAccountControl & UF_NOT_DELEGATED)) {
+		flags.forwardable = 1;
+		flags.proxiable = 1;
+	}
+
+	if (userAccountControl & UF_DONT_REQUIRE_PREAUTH) {
+		flags.require_preauth = 0;
+	} else {
+		flags.require_preauth = 1;
+
+	}
+	return flags;
+}
+
+static int samba_kdc_entry_destructor(struct samba_kdc_entry *p)
+{
+    hdb_entry_ex *entry_ex = p->entry_ex;
+    free_hdb_entry(&entry_ex->entry);
+    return 0;
+}
+
+static void samba_kdc_free_entry(krb5_context context, hdb_entry_ex *entry_ex)
+{
+	talloc_free(entry_ex->ctx);
+}
+
+static krb5_error_code samba_kdc_message2entry_keys(krb5_context context,
+					      struct smb_iconv_convenience *iconv_convenience,
+					      TALLOC_CTX *mem_ctx,
+					      struct ldb_message *msg,
+					      unsigned int userAccountControl,
+					      hdb_entry_ex *entry_ex)
+{
+	krb5_error_code ret = 0;
+	enum ndr_err_code ndr_err;
+	struct samr_Password *hash;
+	const struct ldb_val *sc_val;
+	struct supplementalCredentialsBlob scb;
+	struct supplementalCredentialsPackage *scpk = NULL;
+	bool newer_keys = false;
+	struct package_PrimaryKerberosBlob _pkb;
+	struct package_PrimaryKerberosCtr3 *pkb3 = NULL;
+	struct package_PrimaryKerberosCtr4 *pkb4 = NULL;
+	uint32_t i;
+	uint32_t allocated_keys = 0;
+
+	entry_ex->entry.keys.val = NULL;
+	entry_ex->entry.keys.len = 0;
+
+	entry_ex->entry.kvno = ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0);
+
+	/* Get keys from the db */
+
+	hash = samdb_result_hash(mem_ctx, msg, "unicodePwd");
+	sc_val = ldb_msg_find_ldb_val(msg, "supplementalCredentials");
+
+	/* unicodePwd for enctype 0x17 (23) if present */
+	if (hash) {
+		allocated_keys++;
+	}
+
+	/* supplementalCredentials if present */
+	if (sc_val) {
+		ndr_err = ndr_pull_struct_blob_all(sc_val, mem_ctx, iconv_convenience, &scb,
+						   (ndr_pull_flags_fn_t)ndr_pull_supplementalCredentialsBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			dump_data(0, sc_val->data, sc_val->length);
+			ret = EINVAL;
+			goto out;
+		}
+
+		if (scb.sub.signature != SUPPLEMENTAL_CREDENTIALS_SIGNATURE) {
+			NDR_PRINT_DEBUG(supplementalCredentialsBlob, &scb);
+			ret = EINVAL;
+			goto out;
+		}
+
+		for (i=0; i < scb.sub.num_packages; i++) {
+			if (strcmp("Primary:Kerberos-Newer-Keys", scb.sub.packages[i].name) == 0) {
+				scpk = &scb.sub.packages[i];
+				if (!scpk->data || !scpk->data[0]) {
+					scpk = NULL;
+					continue;
+				}
+				newer_keys = true;
+				break;
+			} else if (strcmp("Primary:Kerberos", scb.sub.packages[i].name) == 0) {
+				scpk = &scb.sub.packages[i];
+				if (!scpk->data || !scpk->data[0]) {
+					scpk = NULL;
+				}
+				/*
+				 * we don't break here in hope to find
+				 * a Kerberos-Newer-Keys package
+				 */
+			}
+		}
+	}
+	/*
+	 * Primary:Kerberos-Newer-Keys or Primary:Kerberos element
+	 * of supplementalCredentials
+	 */
+	if (scpk) {
+		DATA_BLOB blob;
+
+		blob = strhex_to_data_blob(mem_ctx, scpk->data);
+		if (!blob.data) {
+			ret = ENOMEM;
+			goto out;
+		}
+
+		/* we cannot use ndr_pull_struct_blob_all() here, as w2k and w2k3 add padding bytes */
+		ndr_err = ndr_pull_struct_blob(&blob, mem_ctx, iconv_convenience, &_pkb,
+					       (ndr_pull_flags_fn_t)ndr_pull_package_PrimaryKerberosBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			ret = EINVAL;
+			krb5_set_error_message(context, ret, "samba_kdc_message2entry_keys: could not parse package_PrimaryKerberosBlob");
+			krb5_warnx(context, "samba_kdc_message2entry_keys: could not parse package_PrimaryKerberosBlob");
+			goto out;
+		}
+
+		if (newer_keys && _pkb.version != 4) {
+			ret = EINVAL;
+			krb5_set_error_message(context, ret, "samba_kdc_message2entry_keys: Primary:Kerberos-Newer-Keys not version 4");
+			krb5_warnx(context, "samba_kdc_message2entry_keys: Primary:Kerberos-Newer-Keys not version 4");
+			goto out;
+		}
+
+		if (!newer_keys && _pkb.version != 3) {
+			ret = EINVAL;
+			krb5_set_error_message(context, ret, "samba_kdc_message2entry_keys: could not parse Primary:Kerberos not version 3");
+			krb5_warnx(context, "samba_kdc_message2entry_keys: could not parse Primary:Kerberos not version 3");
+			goto out;
+		}
+
+		if (_pkb.version == 4) {
+			pkb4 = &_pkb.ctr.ctr4;
+			allocated_keys += pkb4->num_keys;
+		} else if (_pkb.version == 3) {
+			pkb3 = &_pkb.ctr.ctr3;
+			allocated_keys += pkb3->num_keys;
+		}
+	}
+
+	if (allocated_keys == 0) {
+		/* oh, no password.  Apparently (comment in
+		 * hdb-ldap.c) this violates the ASN.1, but this
+		 * allows an entry with no keys (yet). */
+		return 0;
+	}
+
+	/* allocate space to decode into */
+	entry_ex->entry.keys.len = 0;
+	entry_ex->entry.keys.val = calloc(allocated_keys, sizeof(Key));
+	if (entry_ex->entry.keys.val == NULL) {
+		ret = ENOMEM;
+		goto out;
+	}
+
+	if (hash && !(userAccountControl & UF_USE_DES_KEY_ONLY)) {
+		Key key;
+
+		key.mkvno = 0;
+		key.salt = NULL; /* No salt for this enc type */
+
+		ret = krb5_keyblock_init(context,
+					 ENCTYPE_ARCFOUR_HMAC,
+					 hash->hash, sizeof(hash->hash),
+					 &key.key);
+		if (ret) {
+			goto out;
+		}
+
+		entry_ex->entry.keys.val[entry_ex->entry.keys.len] = key;
+		entry_ex->entry.keys.len++;
+	}
+
+	if (pkb4) {
+		for (i=0; i < pkb4->num_keys; i++) {
+			bool use = true;
+			Key key;
+
+			if (!pkb4->keys[i].value) continue;
+
+			if (userAccountControl & UF_USE_DES_KEY_ONLY) {
+				switch (pkb4->keys[i].keytype) {
+				case ENCTYPE_DES_CBC_CRC:
+				case ENCTYPE_DES_CBC_MD5:
+					break;
+				default:
+					use = false;
+					break;
+				}
+			}
+
+			if (!use) continue;
+
+			key.mkvno = 0;
+			key.salt = NULL;
+
+			if (pkb4->salt.string) {
+				DATA_BLOB salt;
+
+				salt = data_blob_string_const(pkb4->salt.string);
+
+				key.salt = calloc(1, sizeof(*key.salt));
+				if (key.salt == NULL) {
+					ret = ENOMEM;
+					goto out;
+				}
+
+				key.salt->type = hdb_pw_salt;
+
+				ret = krb5_data_copy(&key.salt->salt, salt.data, salt.length);
+				if (ret) {
+					free(key.salt);
+					key.salt = NULL;
+					goto out;
+				}
+			}
+
+			/* TODO: maybe pass the iteration_count somehow... */
+
+			ret = krb5_keyblock_init(context,
+						 pkb4->keys[i].keytype,
+						 pkb4->keys[i].value->data,
+						 pkb4->keys[i].value->length,
+						 &key.key);
+			if (ret == KRB5_PROG_ETYPE_NOSUPP) {
+				DEBUG(2,("Unsupported keytype ignored - type %u\n",
+					 pkb4->keys[i].keytype));
+				ret = 0;
+				continue;
+			}
+			if (ret) {
+				if (key.salt) {
+					free_Salt(key.salt);
+					free(key.salt);
+					key.salt = NULL;
+				}
+				goto out;
+			}
+
+			entry_ex->entry.keys.val[entry_ex->entry.keys.len] = key;
+			entry_ex->entry.keys.len++;
+		}
+	} else if (pkb3) {
+		for (i=0; i < pkb3->num_keys; i++) {
+			bool use = true;
+			Key key;
+
+			if (!pkb3->keys[i].value) continue;
+
+			if (userAccountControl & UF_USE_DES_KEY_ONLY) {
+				switch (pkb3->keys[i].keytype) {
+				case ENCTYPE_DES_CBC_CRC:
+				case ENCTYPE_DES_CBC_MD5:
+					break;
+				default:
+					use = false;
+					break;
+				}
+			}
+
+			if (!use) continue;
+
+			key.mkvno = 0;
+			key.salt = NULL;
+
+			if (pkb3->salt.string) {
+				DATA_BLOB salt;
+
+				salt = data_blob_string_const(pkb3->salt.string);
+
+				key.salt = calloc(1, sizeof(*key.salt));
+				if (key.salt == NULL) {
+					ret = ENOMEM;
+					goto out;
+				}
+
+				key.salt->type = hdb_pw_salt;
+
+				ret = krb5_data_copy(&key.salt->salt, salt.data, salt.length);
+				if (ret) {
+					free(key.salt);
+					key.salt = NULL;
+					goto out;
+				}
+			}
+
+			ret = krb5_keyblock_init(context,
+						 pkb3->keys[i].keytype,
+						 pkb3->keys[i].value->data,
+						 pkb3->keys[i].value->length,
+						 &key.key);
+			if (ret) {
+				if (key.salt) {
+					free_Salt(key.salt);
+					free(key.salt);
+					key.salt = NULL;
+				}
+				goto out;
+			}
+
+			entry_ex->entry.keys.val[entry_ex->entry.keys.len] = key;
+			entry_ex->entry.keys.len++;
+		}
+	}
+
+out:
+	if (ret != 0) {
+		entry_ex->entry.keys.len = 0;
+	}
+	if (entry_ex->entry.keys.len == 0 && entry_ex->entry.keys.val) {
+		free(entry_ex->entry.keys.val);
+		entry_ex->entry.keys.val = NULL;
+	}
+	return ret;
+}
+
+/*
+ * Construct an hdb_entry from a directory entry.
+ */
+static krb5_error_code samba_kdc_message2entry(krb5_context context,
+					 struct samba_kdc_db_context *kdc_db_ctx,
+					 TALLOC_CTX *mem_ctx, krb5_const_principal principal,
+					 enum samba_kdc_ent_type ent_type,
+					 struct ldb_dn *realm_dn,
+					 struct ldb_message *msg,
+					 hdb_entry_ex *entry_ex)
+{
+	struct loadparm_context *lp_ctx = kdc_db_ctx->lp_ctx;
+	unsigned int userAccountControl;
+	int i;
+	krb5_error_code ret = 0;
+	krb5_boolean is_computer = FALSE;
+	char *realm = strupper_talloc(mem_ctx, lp_realm(lp_ctx));
+
+	struct samba_kdc_entry *p;
+	NTTIME acct_expiry;
+	NTSTATUS status;
+
+	uint32_t rid;
+	struct ldb_message_element *objectclasses;
+	struct ldb_val computer_val;
+	const char *samAccountName = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
+	computer_val.data = discard_const_p(uint8_t,"computer");
+	computer_val.length = strlen((const char *)computer_val.data);
+
+	if (!samAccountName) {
+		ret = ENOENT;
+		krb5_set_error_message(context, ret, "samba_kdc_message2entry: no samAccountName present");
+		goto out;
+	}
+
+	objectclasses = ldb_msg_find_element(msg, "objectClass");
+
+	if (objectclasses && ldb_msg_find_val(objectclasses, &computer_val)) {
+		is_computer = TRUE;
+	}
+
+	memset(entry_ex, 0, sizeof(*entry_ex));
+
+	if (!realm) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "talloc_strdup: out of memory");
+		goto out;
+	}
+
+	p = talloc(mem_ctx, struct samba_kdc_entry);
+	if (!p) {
+		ret = ENOMEM;
+		goto out;
+	}
+
+	p->kdc_db_ctx = kdc_db_ctx;
+	p->entry_ex = entry_ex;
+	p->realm_dn = talloc_reference(p, realm_dn);
+	if (!p->realm_dn) {
+		ret = ENOMEM;
+		goto out;
+	}
+
+	talloc_set_destructor(p, samba_kdc_entry_destructor);
+
+	entry_ex->ctx = p;
+	entry_ex->free_entry = samba_kdc_free_entry;
+
+	userAccountControl = ldb_msg_find_attr_as_uint(msg, "userAccountControl", 0);
+
+
+	entry_ex->entry.principal = malloc(sizeof(*(entry_ex->entry.principal)));
+	if (ent_type == SAMBA_KDC_ENT_TYPE_ANY && principal == NULL) {
+		krb5_make_principal(context, &entry_ex->entry.principal, realm, samAccountName, NULL);
+	} else {
+		ret = copy_Principal(principal, entry_ex->entry.principal);
+		if (ret) {
+			krb5_clear_error_message(context);
+			goto out;
+		}
+
+		/* While we have copied the client principal, tests
+		 * show that Win2k3 returns the 'corrected' realm, not
+		 * the client-specified realm.  This code attempts to
+		 * replace the client principal's realm with the one
+		 * we determine from our records */
+
+		/* this has to be with malloc() */
+		krb5_principal_set_realm(context, entry_ex->entry.principal, realm);
+	}
+
+	/* First try and figure out the flags based on the userAccountControl */
+	entry_ex->entry.flags = uf2HDBFlags(context, userAccountControl, ent_type);
+
+	/* Windows 2008 seems to enforce this (very sensible) rule by
+	 * default - don't allow offline attacks on a user's password
+	 * by asking for a ticket to them as a service (encrypted with
+	 * their probably patheticly insecure password) */
+
+	if (entry_ex->entry.flags.server
+	    && lp_parm_bool(lp_ctx, NULL, "kdc", "require spn for service", true)) {
+		if (!is_computer && !ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL)) {
+			entry_ex->entry.flags.server = 0;
+		}
+	}
+
+	{
+		/* These (created_by, modified_by) parts of the entry are not relevant for Samba4's use
+		 * of the Heimdal KDC.  They are stored in a the traditional
+		 * DB for audit purposes, and still form part of the structure
+		 * we must return */
+
+		/* use 'whenCreated' */
+		entry_ex->entry.created_by.time = ldb_msg_find_krb5time_ldap_time(msg, "whenCreated", 0);
+		/* use '???' */
+		entry_ex->entry.created_by.principal = NULL;
+
+		entry_ex->entry.modified_by = (Event *) malloc(sizeof(Event));
+		if (entry_ex->entry.modified_by == NULL) {
+			ret = ENOMEM;
+			krb5_set_error_message(context, ret, "malloc: out of memory");
+			goto out;
+		}
+
+		/* use 'whenChanged' */
+		entry_ex->entry.modified_by->time = ldb_msg_find_krb5time_ldap_time(msg, "whenChanged", 0);
+		/* use '???' */
+		entry_ex->entry.modified_by->principal = NULL;
+	}
+
+
+	/* The lack of password controls etc applies to krbtgt by
+	 * virtue of being that particular RID */
+	status = dom_sid_split_rid(NULL, samdb_result_dom_sid(mem_ctx, msg, "objectSid"), NULL, &rid);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		ret = EINVAL;
+		goto out;
+	}
+
+	if (rid == DOMAIN_RID_KRBTGT) {
+		entry_ex->entry.valid_end = NULL;
+		entry_ex->entry.pw_end = NULL;
+
+		entry_ex->entry.flags.invalid = 0;
+		entry_ex->entry.flags.server = 1;
+
+		/* Don't mark all requests for the krbtgt/realm as
+		 * 'change password', as otherwise we could get into
+		 * trouble, and not enforce the password expirty.
+		 * Instead, only do it when request is for the kpasswd service */
+		if (ent_type == SAMBA_KDC_ENT_TYPE_SERVER
+		    && principal->name.name_string.len == 2
+		    && (strcmp(principal->name.name_string.val[0], "kadmin") == 0)
+		    && (strcmp(principal->name.name_string.val[1], "changepw") == 0)
+		    && lp_is_my_domain_or_realm(lp_ctx, principal->realm)) {
+			entry_ex->entry.flags.change_pw = 1;
+		}
+		entry_ex->entry.flags.client = 0;
+		entry_ex->entry.flags.forwardable = 1;
+		entry_ex->entry.flags.ok_as_delegate = 1;
+	} else if (entry_ex->entry.flags.server && ent_type == SAMBA_KDC_ENT_TYPE_SERVER) {
+		/* The account/password expiry only applies when the account is used as a
+		 * client (ie password login), not when used as a server */
+
+		/* Make very well sure we don't use this for a client,
+		 * it could bypass the password restrictions */
+		entry_ex->entry.flags.client = 0;
+
+		entry_ex->entry.valid_end = NULL;
+		entry_ex->entry.pw_end = NULL;
+
+	} else {
+		NTTIME must_change_time
+			= samdb_result_force_password_change(kdc_db_ctx->samdb, mem_ctx,
+							     realm_dn, msg);
+		if (must_change_time == 0x7FFFFFFFFFFFFFFFULL) {
+			entry_ex->entry.pw_end = NULL;
+		} else {
+			entry_ex->entry.pw_end = malloc(sizeof(*entry_ex->entry.pw_end));
+			if (entry_ex->entry.pw_end == NULL) {
+				ret = ENOMEM;
+				goto out;
+			}
+			*entry_ex->entry.pw_end = nt_time_to_unix(must_change_time);
+		}
+
+		acct_expiry = samdb_result_account_expires(msg);
+		if (acct_expiry == 0x7FFFFFFFFFFFFFFFULL) {
+			entry_ex->entry.valid_end = NULL;
+		} else {
+			entry_ex->entry.valid_end = malloc(sizeof(*entry_ex->entry.valid_end));
+			if (entry_ex->entry.valid_end == NULL) {
+				ret = ENOMEM;
+				goto out;
+			}
+			*entry_ex->entry.valid_end = nt_time_to_unix(acct_expiry);
+		}
+	}
+
+	entry_ex->entry.valid_start = NULL;
+
+	entry_ex->entry.max_life = NULL;
+
+	entry_ex->entry.max_renew = NULL;
+
+	entry_ex->entry.generation = NULL;
+
+	/* Get keys from the db */
+	ret = samba_kdc_message2entry_keys(context, p->kdc_db_ctx->ic_ctx, p,
+					    msg, userAccountControl, entry_ex);
+	if (ret) {
+		/* Could be bougus data in the entry, or out of memory */
+		goto out;
+	}
+
+	entry_ex->entry.etypes = malloc(sizeof(*(entry_ex->entry.etypes)));
+	if (entry_ex->entry.etypes == NULL) {
+		krb5_clear_error_message(context);
+		ret = ENOMEM;
+		goto out;
+	}
+	entry_ex->entry.etypes->len = entry_ex->entry.keys.len;
+	entry_ex->entry.etypes->val = calloc(entry_ex->entry.etypes->len, sizeof(int));
+	if (entry_ex->entry.etypes->val == NULL) {
+		krb5_clear_error_message(context);
+		ret = ENOMEM;
+		goto out;
+	}
+	for (i=0; i < entry_ex->entry.etypes->len; i++) {
+		entry_ex->entry.etypes->val[i] = entry_ex->entry.keys.val[i].key.keytype;
+	}
+
+
+	p->msg = talloc_steal(p, msg);
+
+out:
+	if (ret != 0) {
+		/* This doesn't free ent itself, that is for the eventual caller to do */
+		hdb_free_entry(context, entry_ex);
+	} else {
+		talloc_steal(kdc_db_ctx, entry_ex->ctx);
+	}
+
+	return ret;
+}
+
+/*
+ * Construct an hdb_entry from a directory entry.
+ */
+static krb5_error_code samba_kdc_trust_message2entry(krb5_context context,
+					       struct samba_kdc_db_context *kdc_db_ctx,
+					       TALLOC_CTX *mem_ctx, krb5_const_principal principal,
+					       enum trust_direction direction,
+					       struct ldb_dn *realm_dn,
+					       struct ldb_message *msg,
+					       hdb_entry_ex *entry_ex)
+{
+	struct loadparm_context *lp_ctx = kdc_db_ctx->lp_ctx;
+	const char *dnsdomain;
+	char *realm;
+	DATA_BLOB password_utf16;
+	struct samr_Password password_hash;
+	const struct ldb_val *password_val;
+	struct trustAuthInOutBlob password_blob;
+	struct samba_kdc_entry *p;
+
+	enum ndr_err_code ndr_err;
+	int i, ret, trust_direction_flags;
+
+	p = talloc(mem_ctx, struct samba_kdc_entry);
+	if (!p) {
+		ret = ENOMEM;
+		goto out;
+	}
+
+	p->kdc_db_ctx = kdc_db_ctx;
+	p->entry_ex = entry_ex;
+	p->realm_dn = realm_dn;
+
+	talloc_set_destructor(p, samba_kdc_entry_destructor);
+
+	entry_ex->ctx = p;
+	entry_ex->free_entry = samba_kdc_free_entry;
+
+	/* use 'whenCreated' */
+	entry_ex->entry.created_by.time = ldb_msg_find_krb5time_ldap_time(msg, "whenCreated", 0);
+	/* use '???' */
+	entry_ex->entry.created_by.principal = NULL;
+
+	entry_ex->entry.valid_start = NULL;
+
+	trust_direction_flags = ldb_msg_find_attr_as_int(msg, "trustDirection", 0);
+
+	if (direction == INBOUND) {
+		realm = strupper_talloc(mem_ctx, lp_realm(lp_ctx));
+		password_val = ldb_msg_find_ldb_val(msg, "trustAuthIncoming");
+
+	} else { /* OUTBOUND */
+		dnsdomain = ldb_msg_find_attr_as_string(msg, "trustPartner", NULL);
+		realm = strupper_talloc(mem_ctx, dnsdomain);
+		password_val = ldb_msg_find_ldb_val(msg, "trustAuthOutgoing");
+	}
+
+	if (!password_val || !(trust_direction_flags & direction)) {
+		ret = ENOENT;
+		goto out;
+	}
+
+	ndr_err = ndr_pull_struct_blob(password_val, mem_ctx, p->kdc_db_ctx->ic_ctx, &password_blob,
+					   (ndr_pull_flags_fn_t)ndr_pull_trustAuthInOutBlob);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		ret = EINVAL;
+		goto out;
+	}
+
+	entry_ex->entry.kvno = -1;
+	for (i=0; i < password_blob.count; i++) {
+		if (password_blob.current->array[i].AuthType == TRUST_AUTH_TYPE_VERSION) {
+			entry_ex->entry.kvno = password_blob.current->array[i].AuthInfo.version.version;
+		}
+	}
+
+	for (i=0; i < password_blob.count; i++) {
+		if (password_blob.current->array[i].AuthType == TRUST_AUTH_TYPE_CLEAR) {
+			password_utf16 = data_blob_const(password_blob.current->array[i].AuthInfo.clear.password,
+							 password_blob.current->array[i].AuthInfo.clear.size);
+			/* In the future, generate all sorts of
+			 * hashes, but for now we can't safely convert
+			 * the random strings windows uses into
+			 * utf8 */
+
+			/* but as it is utf16 already, we can get the NT password/arcfour-hmac-md5 key */
+			mdfour(password_hash.hash, password_utf16.data, password_utf16.length);
+			break;
+		} else if (password_blob.current->array[i].AuthType == TRUST_AUTH_TYPE_NT4OWF) {
+			password_hash = password_blob.current->array[i].AuthInfo.nt4owf.password;
+			break;
+		}
+	}
+	entry_ex->entry.keys.len = 0;
+	entry_ex->entry.keys.val = NULL;
+
+	if (i < password_blob.count) {
+		Key key;
+		/* Must have found a cleartext or MD4 password */
+		entry_ex->entry.keys.val = calloc(1, sizeof(Key));
+
+		key.mkvno = 0;
+		key.salt = NULL; /* No salt for this enc type */
+
+		if (entry_ex->entry.keys.val == NULL) {
+			ret = ENOMEM;
+			goto out;
+		}
+
+		ret = krb5_keyblock_init(context,
+					 ENCTYPE_ARCFOUR_HMAC,
+					 password_hash.hash, sizeof(password_hash.hash),
+					 &key.key);
+
+		entry_ex->entry.keys.val[entry_ex->entry.keys.len] = key;
+		entry_ex->entry.keys.len++;
+	}
+
+	entry_ex->entry.principal = malloc(sizeof(*(entry_ex->entry.principal)));
+
+	ret = copy_Principal(principal, entry_ex->entry.principal);
+	if (ret) {
+		krb5_clear_error_message(context);
+		goto out;
+	}
+
+	/* While we have copied the client principal, tests
+	 * show that Win2k3 returns the 'corrected' realm, not
+	 * the client-specified realm.  This code attempts to
+	 * replace the client principal's realm with the one
+	 * we determine from our records */
+
+	krb5_principal_set_realm(context, entry_ex->entry.principal, realm);
+	entry_ex->entry.flags = int2HDBFlags(0);
+	entry_ex->entry.flags.immutable = 1;
+	entry_ex->entry.flags.invalid = 0;
+	entry_ex->entry.flags.server = 1;
+	entry_ex->entry.flags.require_preauth = 1;
+
+	entry_ex->entry.pw_end = NULL;
+
+	entry_ex->entry.max_life = NULL;
+
+	entry_ex->entry.max_renew = NULL;
+
+	entry_ex->entry.generation = NULL;
+
+	entry_ex->entry.etypes = malloc(sizeof(*(entry_ex->entry.etypes)));
+	if (entry_ex->entry.etypes == NULL) {
+		krb5_clear_error_message(context);
+		ret = ENOMEM;
+		goto out;
+	}
+	entry_ex->entry.etypes->len = entry_ex->entry.keys.len;
+	entry_ex->entry.etypes->val = calloc(entry_ex->entry.etypes->len, sizeof(int));
+	if (entry_ex->entry.etypes->val == NULL) {
+		krb5_clear_error_message(context);
+		ret = ENOMEM;
+		goto out;
+	}
+	for (i=0; i < entry_ex->entry.etypes->len; i++) {
+		entry_ex->entry.etypes->val[i] = entry_ex->entry.keys.val[i].key.keytype;
+	}
+
+
+	p->msg = talloc_steal(p, msg);
+
+out:
+	if (ret != 0) {
+		/* This doesn't free ent itself, that is for the eventual caller to do */
+		hdb_free_entry(context, entry_ex);
+	} else {
+		talloc_steal(kdc_db_ctx, entry_ex->ctx);
+	}
+
+	return ret;
+
+}
+
+static krb5_error_code samba_kdc_lookup_trust(krb5_context context, struct ldb_context *ldb_ctx,
+					TALLOC_CTX *mem_ctx,
+					const char *realm,
+					struct ldb_dn *realm_dn,
+					struct ldb_message **pmsg)
+{
+	int lret;
+	krb5_error_code ret;
+	char *filter = NULL;
+	const char * const *attrs = trust_attrs;
+
+	struct ldb_result *res = NULL;
+	filter = talloc_asprintf(mem_ctx, "(&(objectClass=trustedDomain)(|(flatname=%s)(trustPartner=%s)))", realm, realm);
+
+	if (!filter) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "talloc_asprintf: out of memory");
+		return ret;
+	}
+
+	lret = ldb_search(ldb_ctx, mem_ctx, &res,
+			  ldb_get_default_basedn(ldb_ctx),
+			  LDB_SCOPE_SUBTREE, attrs, "%s", filter);
+	if (lret != LDB_SUCCESS) {
+		DEBUG(3, ("Failed to search for %s: %s\n", filter, ldb_errstring(ldb_ctx)));
+		return HDB_ERR_NOENTRY;
+	} else if (res->count == 0 || res->count > 1) {
+		DEBUG(3, ("Failed find a single entry for %s: got %d\n", filter, res->count));
+		talloc_free(res);
+		return HDB_ERR_NOENTRY;
+	}
+	talloc_steal(mem_ctx, res->msgs);
+	*pmsg = res->msgs[0];
+	talloc_free(res);
+	return 0;
+}
+
+static krb5_error_code samba_kdc_lookup_client(krb5_context context,
+						struct samba_kdc_db_context *kdc_db_ctx,
+						TALLOC_CTX *mem_ctx,
+						krb5_const_principal principal,
+						const char **attrs,
+						struct ldb_dn **realm_dn,
+						struct ldb_message **msg) {
+	NTSTATUS nt_status;
+	char *principal_string;
+	krb5_error_code ret;
+
+	ret = krb5_unparse_name(context, principal, &principal_string);
+
+	if (ret != 0) {
+		return ret;
+	}
+
+	nt_status = sam_get_results_principal(kdc_db_ctx->samdb,
+					      mem_ctx, principal_string, attrs,
+					      realm_dn, msg);
+	free(principal_string);
+	if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_SUCH_USER)) {
+		return HDB_ERR_NOENTRY;
+	} else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
+		return ENOMEM;
+	} else if (!NT_STATUS_IS_OK(nt_status)) {
+		return EINVAL;
+	}
+
+	return ret;
+}
+
+static krb5_error_code samba_kdc_fetch_client(krb5_context context,
+					       struct samba_kdc_db_context *kdc_db_ctx,
+					       TALLOC_CTX *mem_ctx,
+					       krb5_const_principal principal,
+					       hdb_entry_ex *entry_ex) {
+	struct ldb_dn *realm_dn;
+	krb5_error_code ret;
+	struct ldb_message *msg = NULL;
+
+	ret = samba_kdc_lookup_client(context, kdc_db_ctx,
+				       mem_ctx, principal, user_attrs,
+				       &realm_dn, &msg);
+	if (ret != 0) {
+		return ret;
+	}
+
+	ret = samba_kdc_message2entry(context, kdc_db_ctx, mem_ctx,
+				       principal, SAMBA_KDC_ENT_TYPE_CLIENT,
+				       realm_dn, msg, entry_ex);
+	return ret;
+}
+
+static krb5_error_code samba_kdc_fetch_krbtgt(krb5_context context,
+					struct samba_kdc_db_context *kdc_db_ctx,
+					TALLOC_CTX *mem_ctx,
+					krb5_const_principal principal,
+					hdb_entry_ex *entry_ex)
+{
+	struct loadparm_context *lp_ctx = kdc_db_ctx->lp_ctx;
+	krb5_error_code ret;
+	struct ldb_message *msg = NULL;
+	struct ldb_dn *realm_dn = ldb_get_default_basedn(kdc_db_ctx->samdb);
+	const char *realm;
+
+	krb5_principal alloc_principal = NULL;
+	if (principal->name.name_string.len != 2
+	    || (strcmp(principal->name.name_string.val[0], KRB5_TGS_NAME) != 0)) {
+		/* Not a krbtgt */
+		return HDB_ERR_NOENTRY;
+	}
+
+	/* krbtgt case.  Either us or a trusted realm */
+
+	if (lp_is_my_domain_or_realm(lp_ctx, principal->realm)
+	    && lp_is_my_domain_or_realm(lp_ctx, principal->name.name_string.val[1])) {
+		/* us */
+ 		/* Cludge, cludge cludge.  If the realm part of krbtgt/realm,
+ 		 * is in our db, then direct the caller at our primary
+ 		 * krbtgt */
+
+		int lret;
+		char *realm_fixed;
+
+		lret = gendb_search_single_extended_dn(kdc_db_ctx->samdb, mem_ctx,
+						       realm_dn, LDB_SCOPE_SUBTREE,
+						       &msg, krbtgt_attrs,
+						       "(&(objectClass=user)(samAccountName=krbtgt))");
+		if (lret == LDB_ERR_NO_SUCH_OBJECT) {
+			krb5_warnx(context, "samba_kdc_fetch: could not find own KRBTGT in DB!");
+			krb5_set_error_message(context, HDB_ERR_NOENTRY, "samba_kdc_fetch: could not find own KRBTGT in DB!");
+			return HDB_ERR_NOENTRY;
+		} else if (lret != LDB_SUCCESS) {
+			krb5_warnx(context, "samba_kdc_fetch: could not find own KRBTGT in DB: %s", ldb_errstring(kdc_db_ctx->samdb));
+			krb5_set_error_message(context, HDB_ERR_NOENTRY, "samba_kdc_fetch: could not find own KRBTGT in DB: %s", ldb_errstring(kdc_db_ctx->samdb));
+			return HDB_ERR_NOENTRY;
+		}
+
+ 		realm_fixed = strupper_talloc(mem_ctx, lp_realm(lp_ctx));
+ 		if (!realm_fixed) {
+			ret = ENOMEM;
+ 			krb5_set_error_message(context, ret, "strupper_talloc: out of memory");
+ 			return ret;
+ 		}
+
+ 		ret = krb5_copy_principal(context, principal, &alloc_principal);
+ 		if (ret) {
+ 			return ret;
+ 		}
+
+ 		free(alloc_principal->name.name_string.val[1]);
+		alloc_principal->name.name_string.val[1] = strdup(realm_fixed);
+ 		talloc_free(realm_fixed);
+ 		if (!alloc_principal->name.name_string.val[1]) {
+			ret = ENOMEM;
+ 			krb5_set_error_message(context, ret, "samba_kdc_fetch: strdup() failed!");
+ 			return ret;
+ 		}
+ 		principal = alloc_principal;
+
+		ret = samba_kdc_message2entry(context, kdc_db_ctx, mem_ctx,
+					principal, SAMBA_KDC_ENT_TYPE_KRBTGT,
+					realm_dn, msg, entry_ex);
+		if (ret != 0) {
+			krb5_warnx(context, "samba_kdc_fetch: self krbtgt message2entry failed");
+		}
+		return ret;
+
+	} else {
+		enum trust_direction direction = UNKNOWN;
+
+		/* Either an inbound or outbound trust */
+
+		if (strcasecmp(lp_realm(lp_ctx), principal->realm) == 0) {
+			/* look for inbound trust */
+			direction = INBOUND;
+			realm = principal->name.name_string.val[1];
+		}
+
+		if (strcasecmp(lp_realm(lp_ctx), principal->name.name_string.val[1]) == 0) {
+			/* look for outbound trust */
+			direction = OUTBOUND;
+			realm = principal->realm;
+		}
+
+		/* Trusted domains are under CN=system */
+
+		ret = samba_kdc_lookup_trust(context, kdc_db_ctx->samdb,
+				       mem_ctx,
+				       realm, realm_dn, &msg);
+
+		if (ret != 0) {
+			krb5_warnx(context, "samba_kdc_fetch: could not find principal in DB");
+			krb5_set_error_message(context, ret, "samba_kdc_fetch: could not find principal in DB");
+			return ret;
+		}
+
+		ret = samba_kdc_trust_message2entry(context, kdc_db_ctx, mem_ctx,
+					      principal, direction,
+					      realm_dn, msg, entry_ex);
+		if (ret != 0) {
+			krb5_warnx(context, "samba_kdc_fetch: trust_message2entry failed");
+		}
+		return ret;
+
+
+		/* we should lookup trusted domains */
+		return HDB_ERR_NOENTRY;
+	}
+
+}
+
+static krb5_error_code samba_kdc_lookup_server(krb5_context context,
+						struct samba_kdc_db_context *kdc_db_ctx,
+						TALLOC_CTX *mem_ctx,
+						krb5_const_principal principal,
+						const char **attrs,
+						struct ldb_dn **realm_dn,
+						struct ldb_message **msg)
+{
+	krb5_error_code ret;
+	const char *realm;
+	if (principal->name.name_string.len >= 2) {
+		/* 'normal server' case */
+		int ldb_ret;
+		NTSTATUS nt_status;
+		struct ldb_dn *user_dn;
+		char *principal_string;
+
+		ret = krb5_unparse_name_flags(context, principal,
+					      KRB5_PRINCIPAL_UNPARSE_NO_REALM,
+					      &principal_string);
+		if (ret != 0) {
+			return ret;
+		}
+
+		/* At this point we may find the host is known to be
+		 * in a different realm, so we should generate a
+		 * referral instead */
+		nt_status = crack_service_principal_name(kdc_db_ctx->samdb,
+							 mem_ctx, principal_string,
+							 &user_dn, realm_dn);
+		free(principal_string);
+
+		if (!NT_STATUS_IS_OK(nt_status)) {
+			return HDB_ERR_NOENTRY;
+		}
+
+		ldb_ret = gendb_search_single_extended_dn(kdc_db_ctx->samdb,
+							  mem_ctx,
+							  user_dn, LDB_SCOPE_BASE,
+							  msg, attrs,
+							  "(objectClass=*)");
+		if (ldb_ret != LDB_SUCCESS) {
+			return HDB_ERR_NOENTRY;
+		}
+
+	} else {
+		int lret;
+		char *filter = NULL;
+		char *short_princ;
+		/* server as client principal case, but we must not lookup userPrincipalNames */
+		*realm_dn = ldb_get_default_basedn(kdc_db_ctx->samdb);
+		realm = krb5_principal_get_realm(context, principal);
+
+		/* TODO: Check if it is our realm, otherwise give referall */
+
+		ret = krb5_unparse_name_flags(context, principal,  KRB5_PRINCIPAL_UNPARSE_NO_REALM, &short_princ);
+
+		if (ret != 0) {
+			krb5_set_error_message(context, ret, "samba_kdc_lookup_principal: could not parse principal");
+			krb5_warnx(context, "samba_kdc_lookup_principal: could not parse principal");
+			return ret;
+		}
+
+		lret = gendb_search_single_extended_dn(kdc_db_ctx->samdb, mem_ctx,
+						       *realm_dn, LDB_SCOPE_SUBTREE,
+						       msg, attrs, "(&(objectClass=user)(samAccountName=%s))",
+						       ldb_binary_encode_string(mem_ctx, short_princ));
+		free(short_princ);
+		if (lret == LDB_ERR_NO_SUCH_OBJECT) {
+			DEBUG(3, ("Failed find a entry for %s\n", filter));
+			return HDB_ERR_NOENTRY;
+		}
+		if (lret != LDB_SUCCESS) {
+			DEBUG(3, ("Failed single search for for %s - %s\n",
+				  filter, ldb_errstring(kdc_db_ctx->samdb)));
+			return HDB_ERR_NOENTRY;
+		}
+	}
+
+	return 0;
+}
+
+static krb5_error_code samba_kdc_fetch_server(krb5_context context,
+					       struct samba_kdc_db_context *kdc_db_ctx,
+					       TALLOC_CTX *mem_ctx,
+					       krb5_const_principal principal,
+					       hdb_entry_ex *entry_ex)
+{
+	krb5_error_code ret;
+	struct ldb_dn *realm_dn;
+	struct ldb_message *msg;
+
+	ret = samba_kdc_lookup_server(context, kdc_db_ctx, mem_ctx, principal,
+				       server_attrs, &realm_dn, &msg);
+	if (ret != 0) {
+		return ret;
+	}
+
+	ret = samba_kdc_message2entry(context, kdc_db_ctx, mem_ctx,
+				principal, SAMBA_KDC_ENT_TYPE_SERVER,
+				realm_dn, msg, entry_ex);
+	if (ret != 0) {
+		krb5_warnx(context, "samba_kdc_fetch: message2entry failed");
+	}
+
+	return ret;
+}
+
+krb5_error_code samba_kdc_fetch(krb5_context context,
+				struct samba_kdc_db_context *kdc_db_ctx,
+				krb5_const_principal principal,
+				unsigned flags,
+				hdb_entry_ex *entry_ex)
+{
+	krb5_error_code ret = HDB_ERR_NOENTRY;
+	TALLOC_CTX *mem_ctx = talloc_named(kdc_db_ctx, 0, "samba_kdc_fetch context");
+
+	if (!mem_ctx) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "samba_kdc_fetch: talloc_named() failed!");
+		return ret;
+	}
+
+	if (flags & HDB_F_GET_CLIENT) {
+		ret = samba_kdc_fetch_client(context, kdc_db_ctx, mem_ctx, principal, entry_ex);
+		if (ret != HDB_ERR_NOENTRY) goto done;
+	}
+	if (flags & HDB_F_GET_SERVER) {
+		/* krbtgt fits into this situation for trusted realms, and for resolving different versions of our own realm name */
+		ret = samba_kdc_fetch_krbtgt(context, kdc_db_ctx, mem_ctx, principal, entry_ex);
+		if (ret != HDB_ERR_NOENTRY) goto done;
+
+		/* We return 'no entry' if it does not start with krbtgt/, so move to the common case quickly */
+		ret = samba_kdc_fetch_server(context, kdc_db_ctx, mem_ctx, principal, entry_ex);
+		if (ret != HDB_ERR_NOENTRY) goto done;
+	}
+	if (flags & HDB_F_GET_KRBTGT) {
+		ret = samba_kdc_fetch_krbtgt(context, kdc_db_ctx, mem_ctx, principal, entry_ex);
+		if (ret != HDB_ERR_NOENTRY) goto done;
+	}
+
+done:
+	talloc_free(mem_ctx);
+	return ret;
+}
+
+struct samba_kdc_seq {
+	int index;
+	int count;
+	struct ldb_message **msgs;
+	struct ldb_dn *realm_dn;
+};
+
+static krb5_error_code samba_kdc_seq(krb5_context context,
+				     struct samba_kdc_db_context *kdc_db_ctx,
+				     hdb_entry_ex *entry)
+{
+	krb5_error_code ret;
+	struct samba_kdc_seq *priv = kdc_db_ctx->seq_ctx;
+	TALLOC_CTX *mem_ctx;
+	hdb_entry_ex entry_ex;
+	memset(&entry_ex, '\0', sizeof(entry_ex));
+
+	if (!priv) {
+		return HDB_ERR_NOENTRY;
+	}
+
+	mem_ctx = talloc_named(priv, 0, "samba_kdc_seq context");
+
+	if (!mem_ctx) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "samba_kdc_seq: talloc_named() failed!");
+		return ret;
+	}
+
+	if (priv->index < priv->count) {
+		ret = samba_kdc_message2entry(context, kdc_db_ctx, mem_ctx,
+					NULL, SAMBA_KDC_ENT_TYPE_ANY,
+					priv->realm_dn, priv->msgs[priv->index++], entry);
+	} else {
+		ret = HDB_ERR_NOENTRY;
+	}
+
+	if (ret != 0) {
+		talloc_free(priv);
+		kdc_db_ctx->seq_ctx = NULL;
+	} else {
+		talloc_free(mem_ctx);
+	}
+
+	return ret;
+}
+
+krb5_error_code samba_kdc_firstkey(krb5_context context,
+				   struct samba_kdc_db_context *kdc_db_ctx,
+				   hdb_entry_ex *entry)
+{
+	struct ldb_context *ldb_ctx = kdc_db_ctx->samdb;
+	struct samba_kdc_seq *priv = kdc_db_ctx->seq_ctx;
+	char *realm;
+	struct ldb_result *res = NULL;
+	krb5_error_code ret;
+	TALLOC_CTX *mem_ctx;
+	int lret;
+
+	if (priv) {
+		talloc_free(priv);
+		kdc_db_ctx->seq_ctx = NULL;
+	}
+
+	priv = (struct samba_kdc_seq *) talloc(kdc_db_ctx, struct samba_kdc_seq);
+	if (!priv) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "talloc: out of memory");
+		return ret;
+	}
+
+	priv->index = 0;
+	priv->msgs = NULL;
+	priv->realm_dn = ldb_get_default_basedn(ldb_ctx);
+	priv->count = 0;
+
+	mem_ctx = talloc_named(priv, 0, "samba_kdc_firstkey context");
+
+	if (!mem_ctx) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "samba_kdc_firstkey: talloc_named() failed!");
+		return ret;
+	}
+
+	ret = krb5_get_default_realm(context, &realm);
+	if (ret != 0) {
+		talloc_free(priv);
+		return ret;
+	}
+
+	lret = ldb_search(ldb_ctx, priv, &res,
+			  priv->realm_dn, LDB_SCOPE_SUBTREE, user_attrs,
+			  "(objectClass=user)");
+
+	if (lret != LDB_SUCCESS) {
+		talloc_free(priv);
+		return HDB_ERR_NOENTRY;
+	}
+
+	priv->count = res->count;
+	priv->msgs = talloc_steal(priv, res->msgs);
+	talloc_free(res);
+
+	kdc_db_ctx->seq_ctx = priv;
+
+	ret = samba_kdc_seq(context, kdc_db_ctx, entry);
+
+	if (ret != 0) {
+    		talloc_free(priv);
+		kdc_db_ctx->seq_ctx = NULL;
+	} else {
+		talloc_free(mem_ctx);
+	}
+	return ret;
+}
+
+krb5_error_code samba_kdc_nextkey(krb5_context context,
+				  struct samba_kdc_db_context *kdc_db_ctx,
+				  hdb_entry_ex *entry)
+{
+	return samba_kdc_seq(context, kdc_db_ctx, entry);
+}
+
+/* Check if a given entry may delegate to this target principal
+ *
+ * This is currently a very nasty hack - allowing only delegation to itself.
+ */
+krb5_error_code
+samba_kdc_check_constrained_delegation(krb5_context context,
+				       struct samba_kdc_db_context *kdc_db_ctx,
+					hdb_entry_ex *entry,
+					krb5_const_principal target_principal)
+{
+	krb5_error_code ret;
+	krb5_principal enterprise_prinicpal = NULL;
+	struct ldb_dn *realm_dn;
+	struct ldb_message *msg;
+	struct dom_sid *orig_sid;
+	struct dom_sid *target_sid;
+	struct samba_kdc_entry *p = talloc_get_type(entry->ctx, struct samba_kdc_entry);
+	const char *delegation_check_attrs[] = {
+		"objectSid", NULL
+	};
+
+	TALLOC_CTX *mem_ctx = talloc_named(kdc_db_ctx, 0, "samba_kdc_check_constrained_delegation");
+
+	if (!mem_ctx) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "samba_kdc_fetch: talloc_named() failed!");
+		return ret;
+	}
+
+	if (target_principal->name.name_type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
+		/* Need to reparse the enterprise principal to find the real target */
+		if (target_principal->name.name_string.len != 1) {
+			ret = KRB5_PARSE_MALFORMED;
+			krb5_set_error_message(context, ret, "samba_kdc_check_constrained_delegation: request for delegation to enterprise principal with wrong (%d) number of components",
+					       target_principal->name.name_string.len);
+			talloc_free(mem_ctx);
+			return ret;
+		}
+		ret = krb5_parse_name(context, target_principal->name.name_string.val[0],
+				      &enterprise_prinicpal);
+		if (ret) {
+			talloc_free(mem_ctx);
+			return ret;
+		}
+		target_principal = enterprise_prinicpal;
+	}
+
+	ret = samba_kdc_lookup_server(context, kdc_db_ctx, mem_ctx, target_principal,
+				       delegation_check_attrs, &realm_dn, &msg);
+
+	krb5_free_principal(context, enterprise_prinicpal);
+
+	if (ret != 0) {
+		talloc_free(mem_ctx);
+		return ret;
+	}
+
+	orig_sid = samdb_result_dom_sid(mem_ctx, p->msg, "objectSid");
+	target_sid = samdb_result_dom_sid(mem_ctx, msg, "objectSid");
+
+	/* Allow delegation to the same principal, even if by a different
+	 * name.  The easy and safe way to prove this is by SID
+	 * comparison */
+	if (!(orig_sid && target_sid && dom_sid_equal(orig_sid, target_sid))) {
+		talloc_free(mem_ctx);
+		return KRB5KDC_ERR_BADOPTION;
+	}
+
+	talloc_free(mem_ctx);
+	return ret;
+}
+
+/* Certificates printed by a the Certificate Authority might have a
+ * slightly different form of the user principal name to that in the
+ * database.  Allow a mismatch where they both refer to the same
+ * SID */
+
+krb5_error_code
+samba_kdc_check_pkinit_ms_upn_match(krb5_context context,
+				    struct samba_kdc_db_context *kdc_db_ctx,
+				     hdb_entry_ex *entry,
+				     krb5_const_principal certificate_principal)
+{
+	krb5_error_code ret;
+	struct ldb_dn *realm_dn;
+	struct ldb_message *msg;
+	struct dom_sid *orig_sid;
+	struct dom_sid *target_sid;
+	struct samba_kdc_entry *p = talloc_get_type(entry->ctx, struct samba_kdc_entry);
+	const char *ms_upn_check_attrs[] = {
+		"objectSid", NULL
+	};
+
+	TALLOC_CTX *mem_ctx = talloc_named(kdc_db_ctx, 0, "samba_kdc_check_pkinit_ms_upn_match");
+
+	if (!mem_ctx) {
+		ret = ENOMEM;
+		krb5_set_error_message(context, ret, "samba_kdc_fetch: talloc_named() failed!");
+		return ret;
+	}
+
+	ret = samba_kdc_lookup_client(context, kdc_db_ctx,
+				       mem_ctx, certificate_principal,
+				       ms_upn_check_attrs, &realm_dn, &msg);
+
+	if (ret != 0) {
+		talloc_free(mem_ctx);
+		return ret;
+	}
+
+	orig_sid = samdb_result_dom_sid(mem_ctx, p->msg, "objectSid");
+	target_sid = samdb_result_dom_sid(mem_ctx, msg, "objectSid");
+
+	/* Consider these to be the same principal, even if by a different
+	 * name.  The easy and safe way to prove this is by SID
+	 * comparison */
+	if (!(orig_sid && target_sid && dom_sid_equal(orig_sid, target_sid))) {
+		talloc_free(mem_ctx);
+		return KRB5_KDC_ERR_CLIENT_NAME_MISMATCH;
+	}
+
+	talloc_free(mem_ctx);
+	return ret;
+}
+