r13107: Follow the lead of Heimdal's kpasswdd and use the HDB (hdb-ldb in our

case) as the keytab.

This avoids issues in replicated setups, as we will replicate the
kpasswd key correctly (including from windows, which is why I care at
the moment).

Andrew Bartlett
(This used to be commit 849500d1aa)

source4/auth/credentials/credentials_files.c

@@ -267,17 +267,12 @@ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 		
 			cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 		} else {
-		
+			cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
-			DEBUG(1, ("Could not find 'secret' in join record to domain: %s\n",
-				  cli_credentials_get_domain(cred)));
-
-			/* set anonymous as the fallback, if the machine account won't work */
-			cli_credentials_set_anonymous(cred);
-
-			talloc_free(mem_ctx);
-			return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 		}
+	} else {
+		cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 	}
+
 	
 	domain = ldb_msg_find_string(msgs[0], "flatname", NULL);
 	if (domain) {
@@ -290,9 +285,6 @@ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 	}
 
 	cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
-	if (password) {
-		cli_credentials_set_password(cred, password, CRED_SPECIFIED);
-	}
 
 	cli_credentials_set_kvno(cred, ldb_msg_find_int(msgs[0], "msDS-KeyVersionNumber", 0));
 
@@ -417,13 +409,14 @@ NTSTATUS cli_credentials_update_all_keytabs(TALLOC_CTX *parent_ctx)
 		return NT_STATUS_ACCESS_DENIED;
 	}
 
-	/* search for the secret record */
+	/* search for the secret record, but only of things we can
+	 * actually update */
 	ldb_ret = gendb_search(ldb,
 			       mem_ctx, NULL,
 			       &msgs, attrs,
-			       "objectClass=kerberosSecret");
+			       "(&(objectClass=kerberosSecret)(|(secret=*)(ntPwdHash=*)))");
 	if (ldb_ret == -1) {
-		DEBUG(1, ("Error looking for kerberos type secrets to push into a keytab"));
+		DEBUG(1, ("Error looking for kerberos type secrets to push into a keytab:: %s", ldb_errstring(ldb)));
 		talloc_free(mem_ctx);
 		return NT_STATUS_INTERNAL_DB_CORRUPTION;
 	}
@@ -442,15 +435,13 @@ NTSTATUS cli_credentials_update_all_keytabs(TALLOC_CTX *parent_ctx)
 		if (!NT_STATUS_IS_OK(status)) {
 			DEBUG(1, ("Failed to read secrets for keytab update for %s\n", 
 				  filter));
-			talloc_free(mem_ctx);
+			continue;
-			return status;
 		} 
 		ret = cli_credentials_update_keytab(creds);
 		if (ret != 0) {
 			DEBUG(1, ("Failed to update keytab for %s\n", 
 				  filter));
-			talloc_free(mem_ctx);
+			continue;
-			return NT_STATUS_UNSUCCESSFUL;
 		}
 	}
 	return NT_STATUS_OK;

source4/auth/credentials/credentials_krb5.c

@@ -43,6 +43,20 @@ int cli_credentials_get_krb5_context(struct cli_credentials *cred,
 	return 0;
 }
 
+/* This needs to be called directly after the cli_credentials_init(),
+ * otherwise we might have problems with the krb5 context already
+ * being here.
+ */
+NTSTATUS cli_credentials_set_krb5_context(struct cli_credentials *cred, 
+					  struct smb_krb5_context *smb_krb5_context)
+{
+	if (!talloc_reference(cred, smb_krb5_context)) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	cred->smb_krb5_context = smb_krb5_context;
+	return NT_STATUS_OK;
+}
+
 int cli_credentials_set_from_ccache(struct cli_credentials *cred, 
 				    enum credentials_obtained obtained)
 {

source4/auth/kerberos/kerberos_util.c

@@ -397,9 +397,9 @@ static int create_keytab(TALLOC_CTX *parent_ctx,
 		const struct samr_Password *mach_pwd;
 		mach_pwd = cli_credentials_get_nt_hash(machine_account, mem_ctx);
 		if (!mach_pwd) {
-			talloc_free(mem_ctx);
 			DEBUG(1, ("create_keytab: Domain trust informaton for account %s not available\n",
 				  cli_credentials_get_principal(machine_account, mem_ctx)));
+			talloc_free(mem_ctx);
 			return EINVAL;
 		}
 		ret = krb5_keyblock_init(smb_krb5_context->krb5_context,
@@ -410,6 +410,7 @@ static int create_keytab(TALLOC_CTX *parent_ctx,
 			DEBUG(1, ("create_keytab: krb5_keyblock_init failed: %s\n",
 				  smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
 							     ret, mem_ctx)));
+			talloc_free(mem_ctx);
 			return ret;
 		}
 
@@ -516,6 +517,7 @@ static krb5_error_code remove_old_entries(TALLOC_CTX *parent_ctx,
 	switch (ret) {
 	case 0:
 		break;
+	case HEIM_ERR_OPNOTSUPP:
 	case ENOENT:
 	case KRB5_KT_END:
 		/* no point enumerating if there isn't anything here */

source4/auth/kerberos/krb5_init_context.c

@@ -448,6 +448,8 @@ static void smb_krb5_send_and_recv_close_func(krb5_context context, void *data)
 		return ret;
 	}
 
+	(*smb_krb5_context)->krb5_context->mem_ctx = *smb_krb5_context;
+
 	talloc_steal(parent_ctx, *smb_krb5_context);
 	talloc_free(tmp_ctx);
 

source4/heimdal/lib/hdb/hdb-protos.h

@@ -490,6 +490,12 @@ hdb_ldapi_create (
 	HDB ** /*db*/,
 	const char */*arg*/);
 
+krb5_error_code
+hdb_ldb_create (
+	krb5_context /*context*/,
+	HDB ** /*db*/,
+	const char */*arg*/);
+
 krb5_error_code
 hdb_list_builtin (
 	krb5_context /*context*/,

source4/heimdal/lib/hdb/hdb.c

@@ -54,6 +54,9 @@ static struct hdb_method methods[] = {
 #if defined(OPENLDAP) && !defined(OPENLDAP_MODULE)
     {"ldap:",	hdb_ldap_create},
     {"ldapi:",	hdb_ldapi_create},
+#endif
+#ifdef _SAMBA_BUILD_
+    {"ldb:",	hdb_ldb_create},
 #endif
     {NULL,	NULL}
 };
@@ -395,6 +398,6 @@ hdb_create(krb5_context context, HDB **db, const char *filename)
 	h = find_dynamic_method (context, filename, &residual);
 #endif
     if (h == NULL)
-	krb5_errx(context, 1, "No database support! (hdb_create)");
+	krb5_errx(context, 1, "No database support! (hdb_create(%s))", filename);
     return (*h->create)(context, db, residual);
 }

source4/heimdal/lib/hdb/keytab.c

@@ -0,0 +1,276 @@
+/*
+ * Copyright (c) 1999 - 2002 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden). 
+ * All rights reserved. 
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions 
+ * are met: 
+ *
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright 
+ *    notice, this list of conditions and the following disclaimer in the 
+ *    documentation and/or other materials provided with the distribution. 
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors 
+ *    may be used to endorse or promote products derived from this software 
+ *    without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
+ * SUCH DAMAGE. 
+ */
+
+#include "hdb_locl.h"
+
+/* keytab backend for HDB databases */
+
+RCSID("$Id: keytab.c,v 1.8 2005/12/12 12:35:36 lha Exp $");
+
+struct hdb_data {
+    char *dbname;
+    char *mkey;
+};
+
+/*
+ * the format for HDB keytabs is:
+ * HDB:[database:file:mkey]
+ */
+
+static krb5_error_code
+hdb_resolve(krb5_context context, const char *name, krb5_keytab id)
+{
+    struct hdb_data *d;
+    const char *db, *mkey;
+
+    d = malloc(sizeof(*d));
+    if(d == NULL) {
+	krb5_set_error_string(context, "malloc: out of memory");
+	return ENOMEM;
+    }
+    db = name;
+    mkey = strrchr(name, ':');
+    if(mkey == NULL || mkey[1] == '\0') {
+	if(*name == '\0')
+	    d->dbname = NULL;
+	else {
+	    d->dbname = strdup(name);
+	    if(d->dbname == NULL) {
+		free(d);
+		krb5_set_error_string(context, "malloc: out of memory");
+		return ENOMEM;
+	    }
+	}
+	d->mkey = NULL;
+    } else {
+	if((mkey - db) == 0) {
+	    d->dbname = NULL;
+	} else {
+	    d->dbname = malloc(mkey - db);
+	    if(d->dbname == NULL) {
+		free(d);
+		krb5_set_error_string(context, "malloc: out of memory");
+		return ENOMEM;
+	    }
+	    memmove(d->dbname, db, mkey - db);
+	    d->dbname[mkey - db] = '\0';
+	}
+	d->mkey = strdup(mkey + 1);
+	if(d->mkey == NULL) {
+	    free(d->dbname);
+	    free(d);
+	    krb5_set_error_string(context, "malloc: out of memory");
+	    return ENOMEM;
+	}
+    }
+    id->data = d;
+    return 0;
+}
+
+static krb5_error_code
+hdb_close(krb5_context context, krb5_keytab id)
+{
+    struct hdb_data *d = id->data;
+
+    free(d->dbname);
+    free(d->mkey);
+    free(d);
+    return 0;
+}
+
+static krb5_error_code 
+hdb_get_name(krb5_context context, 
+	     krb5_keytab id, 
+	     char *name, 
+	     size_t namesize)
+{
+    struct hdb_data *d = id->data;
+
+    snprintf(name, namesize, "%s%s%s", 
+	     d->dbname ? d->dbname : "",
+	     (d->dbname || d->mkey) ? ":" : "",
+	     d->mkey ? d->mkey : "");
+    return 0;
+}
+
+static void
+set_config (krb5_context context,
+	    const krb5_config_binding *binding,
+	    const char **dbname,
+	    const char **mkey)
+{
+    *dbname = krb5_config_get_string(context, binding, "dbname", NULL);
+    *mkey   = krb5_config_get_string(context, binding, "mkey_file", NULL);
+}
+
+/*
+ * try to figure out the database (`dbname') and master-key (`mkey')
+ * that should be used for `principal'.
+ */
+
+static void
+find_db (krb5_context context,
+	 const char **dbname,
+	 const char **mkey,
+	 krb5_const_principal principal)
+{
+    const krb5_config_binding *top_bind = NULL;
+    const krb5_config_binding *default_binding = NULL;
+    const krb5_config_binding *db;
+    krb5_realm *prealm = krb5_princ_realm(context, rk_UNCONST(principal));
+
+    *dbname = *mkey = NULL;
+
+    while ((db =
+	    krb5_config_get_next(context,
+				 NULL,
+				 &top_bind,
+				 krb5_config_list,
+				 "kdc",
+				 "database",
+				 NULL)) != NULL) {
+	const char *p;
+	
+	p = krb5_config_get_string (context, db, "realm", NULL);
+	if (p == NULL) {
+	    if(default_binding) {
+		krb5_warnx(context, "WARNING: more than one realm-less "
+			   "database specification");
+		krb5_warnx(context, "WARNING: using the first encountered");
+	    } else
+		default_binding = db;
+	} else if (strcmp (*prealm, p) == 0) {
+	    set_config (context, db, dbname, mkey);
+	    break;
+	}
+    }
+    if (*dbname == NULL && default_binding != NULL)
+	set_config (context, default_binding, dbname, mkey);
+    if (*dbname == NULL)
+	*dbname = HDB_DEFAULT_DB;
+}
+
+/*
+ * find the keytab entry in `id' for `principal, kvno, enctype' and return
+ * it in `entry'.  return 0 or an error code
+ */
+
+static krb5_error_code
+hdb_get_entry(krb5_context context,
+	      krb5_keytab id,
+	      krb5_const_principal principal,
+	      krb5_kvno kvno,
+	      krb5_enctype enctype,
+	      krb5_keytab_entry *entry)
+{
+    hdb_entry_ex ent;
+    krb5_error_code ret;
+    struct hdb_data *d = id->data;
+    int i;
+    HDB *db;
+    const char *dbname = d->dbname;
+    const char *mkey   = d->mkey;
+
+    if (dbname == NULL)
+	find_db (context, &dbname, &mkey, principal);
+
+    ret = hdb_create (context, &db, dbname);
+    if (ret)
+	return ret;
+    ret = hdb_set_master_keyfile (context, db, mkey);
+    if (ret) {
+	(*db->hdb_destroy)(context, db);
+	return ret;
+    }
+	
+    ret = (*db->hdb_open)(context, db, O_RDONLY, 0);
+    if (ret) {
+	(*db->hdb_destroy)(context, db);
+	return ret;
+    }
+
+    ret = (*db->hdb_fetch)(context, db, HDB_F_DECRYPT, principal, HDB_ENT_TYPE_SERVER, &ent);
+
+    /* Shutdown the hdb on error */
+    if(ret == HDB_ERR_NOENTRY) {
+	(*db->hdb_close)(context, db);
+	(*db->hdb_destroy)(context, db);
+	return KRB5_KT_NOTFOUND;
+    } else if (ret) {
+	(*db->hdb_close)(context, db);
+	(*db->hdb_destroy)(context, db);
+	return ret;
+    }
+    if(kvno && ent.entry.kvno != kvno) {
+	/* The order here matters, we must free these in this order
+	 * due to hdb-ldb and Samba4's talloc */
+	hdb_free_entry(context, &ent);
+	(*db->hdb_close)(context, db);
+	(*db->hdb_destroy)(context, db);
+ 	return KRB5_KT_NOTFOUND;
+    }
+    if(enctype == 0)
+	if(ent.entry.keys.len > 0)
+	    enctype = ent.entry.keys.val[0].key.keytype;
+    ret = KRB5_KT_NOTFOUND;
+    for(i = 0; i < ent.entry.keys.len; i++) {
+	if(ent.entry.keys.val[i].key.keytype == enctype) {
+	    krb5_copy_principal(context, principal, &entry->principal);
+	    entry->vno = ent.entry.kvno;
+	    krb5_copy_keyblock_contents(context, 
+					&ent.entry.keys.val[i].key, 
+					&entry->keyblock);
+	    ret = 0;
+	    break;
+	}
+    }
+    /* The order here matters, we must free these in this order
+     * due to hdb-ldb and Samba4's talloc */
+    hdb_free_entry(context, &ent);
+    (*db->hdb_close)(context, db);
+    (*db->hdb_destroy)(context, db);
+    return ret;
+}
+
+krb5_kt_ops hdb_kt_ops = {
+    "HDB",
+    hdb_resolve,
+    hdb_get_name,
+    hdb_close,
+    hdb_get_entry,
+    NULL,		/* start_seq_get */
+    NULL,		/* next_entry */
+    NULL,		/* end_seq_get */
+    NULL,		/* add */
+    NULL		/* remove */
+};

source4/heimdal/lib/krb5/krb5.h

@@ -451,6 +451,9 @@ typedef struct krb5_context_data {
     int large_msg_size;
     krb5_boolean fdns;                  /* Lookup hostnames to find full name, or send as-is */
     struct send_and_recv *send_and_recv; /* Alternate functions for KDC communication */
+    void *mem_ctx;                      /* Some parts of Samba4 need a valid 
+                                           memory context (under the event 
+					   context) to use */
 } krb5_context_data;
 
 enum {

source4/heimdal_build/config.mk

@@ -23,6 +23,7 @@ OBJ_FILES = \
 	../heimdal/lib/hdb/hdb.o \
 	../heimdal/lib/hdb/ext.o \
 	../heimdal/lib/hdb/keys.o \
+	../heimdal/lib/hdb/keytab.o \
 	../heimdal/lib/hdb/mkey.o \
 	../heimdal/lib/hdb/ndbm.o \
 	../heimdal/lib/hdb/asn1_Event.o \
@@ -40,6 +41,7 @@ OBJ_FILES = \
 	../heimdal/lib/hdb/asn1_Salt.o \
 	../heimdal/lib/hdb/asn1_hdb_entry.o \
 	../heimdal/lib/hdb/hdb_err.o
+REQUIRED_SUBSYSTEMS = HDB_LDB
 NOPROTO = YES
 # End SUBSYSTEM HEIMDAL_HDB
 #######################

source4/kdc/config.mk

@@ -6,10 +6,21 @@
 NOPROTO = YES
 OBJ_FILES = \
 		kdc.o \
-		pac-glue.o \
-		hdb-ldb.o \
 		kpasswdd.o
 REQUIRED_SUBSYSTEMS = \
 		LIBLDB KERBEROS_LIB HEIMDAL_KDC HEIMDAL_HDB 
 # End SUBSYSTEM KDC
 #######################
+
+#######################
+# Start SUBSYSTEM KDC
+[SUBSYSTEM::HDB_LDB]
+NOPROTO = YES
+OBJ_FILES = \
+		hdb-ldb.o \
+		pac-glue.o 
+REQUIRED_SUBSYSTEMS = \
+		LIBLDB KERBEROS_LIB HEIMDAL_HDB 
+# End SUBSYSTEM KDC
+#######################
+

source4/kdc/hdb-ldb.c

@@ -948,8 +948,13 @@ static krb5_error_code LDB_destroy(krb5_context context, HDB *db)
 	return 0;
 }
 
-NTSTATUS hdb_ldb_create(TALLOC_CTX *mem_ctx, 
+/* This interface is to be called by the KDC, which is expecting Samba
-			krb5_context context, struct HDB **db, const char *arg)
+ * calling conventions.  It is also called by a wrapper
+ * (hdb_ldb_create) from the kpasswdd -> krb5 -> keytab_hdb -> hdb
+ * code */
+
+NTSTATUS kdc_hdb_ldb_create(TALLOC_CTX *mem_ctx, 
+			    krb5_context context, struct HDB **db, const char *arg)
 {
 	NTSTATUS nt_status;
 	struct auth_session_info *session_info;
@@ -1008,3 +1013,15 @@ NTSTATUS hdb_ldb_create(TALLOC_CTX *mem_ctx,
 
 	return NT_STATUS_OK;
 }
+
+krb5_error_code hdb_ldb_create(krb5_context context, struct HDB **db, const char *arg)
+{
+	NTSTATUS nt_status;
+	/* Disgusting, ugly hack, but it means one less private hook */
+	nt_status = kdc_hdb_ldb_create(context->mem_ctx, context, db, arg);
+
+	if (NT_STATUS_IS_OK(nt_status)) {
+		return 0;
+	}
+	return EINVAL;
+}

source4/kdc/kdc.c

@@ -570,13 +570,18 @@ static void kdc_task_init(struct task_server *task)
 	}
 	kdc->config->num_db = 1;
 		
-	status = hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context, 
+	status = kdc_hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context, 
-				   &kdc->config->db[0], NULL);
+				    &kdc->config->db[0], NULL);
 	if (!NT_STATUS_IS_OK(status)) {
 		task_server_terminate(task, "kdc: hdb_ldb_create (setup KDC database) failed");
 		return; 
 	}
 
+	ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops);
+	if(ret) {
+		task_server_terminate(task, "kdc: failed to register hdb keytab");
+		return;
+	}
 	/* start listening on the configured network interfaces */
 	status = kdc_startup_interfaces(kdc);
 	if (!NT_STATUS_IS_OK(status)) {

source4/kdc/kdc.h

@@ -29,8 +29,8 @@
 
 struct kdc_server;
 
-NTSTATUS hdb_ldb_create(TALLOC_CTX *mem_ctx, 
+NTSTATUS kdc_hdb_ldb_create(TALLOC_CTX *mem_ctx, 
-			krb5_context context, struct HDB **db, const char *arg);
+			    krb5_context context, struct HDB **db, const char *arg);
 BOOL kpasswdd_process(struct kdc_server *kdc,
 		      TALLOC_CTX *mem_ctx, 
 		      DATA_BLOB *input, 

source4/kdc/kpasswdd.c

@@ -457,7 +457,10 @@ BOOL kpasswdd_process(struct kdc_server *kdc,
 		DEBUG(1, ("Failed to init server credentials\n"));
 		return False;
 	}
-	
+
+	/* We want the credentials subsystem to use the krb5 context
+	 * we already have, rather than a new context */	
+	cli_credentials_set_krb5_context(server_credentials, kdc->smb_krb5_context);
 	cli_credentials_set_conf(server_credentials);
 	nt_status = cli_credentials_set_stored_principal(server_credentials, "kadmin/changepw");
 	if (!NT_STATUS_IS_OK(nt_status)) {

source4/setup/secrets.ldif

@@ -38,18 +38,18 @@ msDS-KeyVersionNumber: 1
 objectSid: ${DOMAINSID}
 privateKeytab: secrets.keytab
 
+# A hook from our credentials system into HDB, as we must be on a KDC,
+# we can look directly into the database.
 dn: samAccountName=krbtgt,flatname=${DOMAIN},CN=Principals
 objectClass: top
 objectClass: secret
 objectClass: kerberosSecret
 flatname: ${DOMAIN}
 realm: ${REALM}
-secret: ${KRBTGTPASS}
 sAMAccountName: krbtgt
 whenCreated: ${LDAPTIME}
 whenChanged: ${LDAPTIME}
-msDS-KeyVersionNumber: 1
 objectSid: ${DOMAINSID}
 servicePrincipalName: kadmin/changepw
-saltPrincipal: krbtgt@${REALM}
+krb5Keytab: HDB:ldb:sam.ldb:/dev/null
-privateKeytab: secrets.keytab
+#The /dev/null here is a HACK, but it matches the Heimdal format.