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 849500d1aa658817052423051b1f5d0b7a1db8e0)

3 files changed, 286 insertions, 1 deletions

diff --git a/source4/heimdal/lib/hdb/hdb-protos.h b/source4/heimdal/lib/hdb/hdb-protos.h
index c221175e41..67e19f7e4a 100644
--- a/source4/heimdal/lib/hdb/hdb-protos.h
+++ b/source4/heimdal/lib/hdb/hdb-protos.h
@@ -491,6 +491,12 @@ hdb_ldapi_create (
 	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*/,
 	char **/*list*/);
diff --git a/source4/heimdal/lib/hdb/hdb.c b/source4/heimdal/lib/hdb/hdb.c
index 5631d05332..406a50ecbd 100644
--- a/source4/heimdal/lib/hdb/hdb.c
+++ b/source4/heimdal/lib/hdb/hdb.c
@@ -55,6 +55,9 @@ static struct hdb_method methods[] = {
     {"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);
 }
diff --git a/source4/heimdal/lib/hdb/keytab.c b/source4/heimdal/lib/hdb/keytab.c
new file mode 100644
index 0000000000..21ee2f4274
--- /dev/null
+++ b/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 */
+};