Adding upstream version 1:9.16.44.upstream/1%9.16.44

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2280 insertions, 0 deletions

diff --git a/lib/dns/update.c b/lib/dns/update.c
new file mode 100644
index 0000000..9d71238
--- /dev/null
+++ b/lib/dns/update.c
@@ -0,0 +1,2280 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <time.h>
+
+#include <isc/log.h>
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/netaddr.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/random.h>
+#include <isc/serial.h>
+#include <isc/stats.h>
+#include <isc/stdtime.h>
+#include <isc/string.h>
+#include <isc/taskpool.h>
+#include <isc/time.h>
+#include <isc/util.h>
+
+#include <dns/db.h>
+#include <dns/dbiterator.h>
+#include <dns/diff.h>
+#include <dns/dnssec.h>
+#include <dns/events.h>
+#include <dns/fixedname.h>
+#include <dns/journal.h>
+#include <dns/kasp.h>
+#include <dns/keyvalues.h>
+#include <dns/log.h>
+#include <dns/message.h>
+#include <dns/nsec.h>
+#include <dns/nsec3.h>
+#include <dns/private.h>
+#include <dns/rdataclass.h>
+#include <dns/rdataset.h>
+#include <dns/rdatasetiter.h>
+#include <dns/rdatastruct.h>
+#include <dns/rdatatype.h>
+#include <dns/result.h>
+#include <dns/soa.h>
+#include <dns/ssu.h>
+#include <dns/stats.h>
+#include <dns/tsig.h>
+#include <dns/update.h>
+#include <dns/view.h>
+#include <dns/zone.h>
+#include <dns/zt.h>
+
+/**************************************************************************/
+
+#define STATE_MAGIC	       ISC_MAGIC('S', 'T', 'T', 'E')
+#define DNS_STATE_VALID(state) ISC_MAGIC_VALID(state, STATE_MAGIC)
+
+/*%
+ * Log level for tracing dynamic update protocol requests.
+ */
+#define LOGLEVEL_PROTOCOL ISC_LOG_INFO
+
+/*%
+ * Log level for low-level debug tracing.
+ */
+#define LOGLEVEL_DEBUG ISC_LOG_DEBUG(8)
+
+/*%
+ * Check an operation for failure.  These macros all assume that
+ * the function using them has a 'result' variable and a 'failure'
+ * label.
+ */
+#define CHECK(op)                            \
+	do {                                 \
+		result = (op);               \
+		if (result != ISC_R_SUCCESS) \
+			goto failure;        \
+	} while (0)
+
+/*%
+ * Fail unconditionally with result 'code', which must not
+ * be ISC_R_SUCCESS.  The reason for failure presumably has
+ * been logged already.
+ *
+ * The test against ISC_R_SUCCESS is there to keep the Solaris compiler
+ * from complaining about "end-of-loop code not reached".
+ */
+
+#define FAIL(code)                           \
+	do {                                 \
+		result = (code);             \
+		if (result != ISC_R_SUCCESS) \
+			goto failure;        \
+	} while (0)
+
+/*%
+ * Fail unconditionally and log as a client error.
+ * The test against ISC_R_SUCCESS is there to keep the Solaris compiler
+ * from complaining about "end-of-loop code not reached".
+ */
+#define FAILC(code, msg)                                                       \
+	do {                                                                   \
+		const char *_what = "failed";                                  \
+		result = (code);                                               \
+		switch (result) {                                              \
+		case DNS_R_NXDOMAIN:                                           \
+		case DNS_R_YXDOMAIN:                                           \
+		case DNS_R_YXRRSET:                                            \
+		case DNS_R_NXRRSET:                                            \
+			_what = "unsuccessful";                                \
+		}                                                              \
+		update_log(log, zone, LOGLEVEL_PROTOCOL, "update %s: %s (%s)", \
+			   _what, msg, isc_result_totext(result));             \
+		if (result != ISC_R_SUCCESS)                                   \
+			goto failure;                                          \
+	} while (0)
+
+#define FAILN(code, name, msg)                                             \
+	do {                                                               \
+		const char *_what = "failed";                              \
+		result = (code);                                           \
+		switch (result) {                                          \
+		case DNS_R_NXDOMAIN:                                       \
+		case DNS_R_YXDOMAIN:                                       \
+		case DNS_R_YXRRSET:                                        \
+		case DNS_R_NXRRSET:                                        \
+			_what = "unsuccessful";                            \
+		}                                                          \
+		if (isc_log_wouldlog(dns_lctx, LOGLEVEL_PROTOCOL)) {       \
+			char _nbuf[DNS_NAME_FORMATSIZE];                   \
+			dns_name_format(name, _nbuf, sizeof(_nbuf));       \
+			update_log(log, zone, LOGLEVEL_PROTOCOL,           \
+				   "update %s: %s: %s (%s)", _what, _nbuf, \
+				   msg, isc_result_totext(result));        \
+		}                                                          \
+		if (result != ISC_R_SUCCESS)                               \
+			goto failure;                                      \
+	} while (0)
+
+#define FAILNT(code, name, type, msg)                                         \
+	do {                                                                  \
+		const char *_what = "failed";                                 \
+		result = (code);                                              \
+		switch (result) {                                             \
+		case DNS_R_NXDOMAIN:                                          \
+		case DNS_R_YXDOMAIN:                                          \
+		case DNS_R_YXRRSET:                                           \
+		case DNS_R_NXRRSET:                                           \
+			_what = "unsuccessful";                               \
+		}                                                             \
+		if (isc_log_wouldlog(dns_lctx, LOGLEVEL_PROTOCOL)) {          \
+			char _nbuf[DNS_NAME_FORMATSIZE];                      \
+			char _tbuf[DNS_RDATATYPE_FORMATSIZE];                 \
+			dns_name_format(name, _nbuf, sizeof(_nbuf));          \
+			dns_rdatatype_format(type, _tbuf, sizeof(_tbuf));     \
+			update_log(log, zone, LOGLEVEL_PROTOCOL,              \
+				   "update %s: %s/%s: %s (%s)", _what, _nbuf, \
+				   _tbuf, msg, isc_result_totext(result));    \
+		}                                                             \
+		if (result != ISC_R_SUCCESS)                                  \
+			goto failure;                                         \
+	} while (0)
+
+/*%
+ * Fail unconditionally and log as a server error.
+ * The test against ISC_R_SUCCESS is there to keep the Solaris compiler
+ * from complaining about "end-of-loop code not reached".
+ */
+#define FAILS(code, msg)                                                       \
+	do {                                                                   \
+		result = (code);                                               \
+		update_log(log, zone, LOGLEVEL_PROTOCOL, "error: %s: %s", msg, \
+			   isc_result_totext(result));                         \
+		if (result != ISC_R_SUCCESS)                                   \
+			goto failure;                                          \
+	} while (0)
+
+/**************************************************************************/
+
+typedef struct rr rr_t;
+
+struct rr {
+	/* dns_name_t name; */
+	uint32_t ttl;
+	dns_rdata_t rdata;
+};
+
+typedef struct update_event update_event_t;
+
+/**************************************************************************/
+
+static void
+update_log(dns_update_log_t *callback, dns_zone_t *zone, int level,
+	   const char *fmt, ...) ISC_FORMAT_PRINTF(4, 5);
+
+static void
+update_log(dns_update_log_t *callback, dns_zone_t *zone, int level,
+	   const char *fmt, ...) {
+	va_list ap;
+	char message[4096];
+
+	if (callback == NULL) {
+		return;
+	}
+
+	if (!isc_log_wouldlog(dns_lctx, level)) {
+		return;
+	}
+
+	va_start(ap, fmt);
+	vsnprintf(message, sizeof(message), fmt, ap);
+	va_end(ap);
+
+	(callback->func)(callback->arg, zone, level, message);
+}
+
+/*%
+ * Update a single RR in version 'ver' of 'db' and log the
+ * update in 'diff'.
+ *
+ * Ensures:
+ * \li	'*tuple' == NULL.  Either the tuple is freed, or its
+ *	ownership has been transferred to the diff.
+ */
+static isc_result_t
+do_one_tuple(dns_difftuple_t **tuple, dns_db_t *db, dns_dbversion_t *ver,
+	     dns_diff_t *diff) {
+	dns_diff_t temp_diff;
+	isc_result_t result;
+
+	/*
+	 * Create a singleton diff.
+	 */
+	dns_diff_init(diff->mctx, &temp_diff);
+	ISC_LIST_APPEND(temp_diff.tuples, *tuple, link);
+
+	/*
+	 * Apply it to the database.
+	 */
+	result = dns_diff_apply(&temp_diff, db, ver);
+	ISC_LIST_UNLINK(temp_diff.tuples, *tuple, link);
+	if (result != ISC_R_SUCCESS) {
+		dns_difftuple_free(tuple);
+		return (result);
+	}
+
+	/*
+	 * Merge it into the current pending journal entry.
+	 */
+	dns_diff_appendminimal(diff, tuple);
+
+	/*
+	 * Do not clear temp_diff.
+	 */
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+update_one_rr(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
+	      dns_diffop_t op, dns_name_t *name, dns_ttl_t ttl,
+	      dns_rdata_t *rdata) {
+	dns_difftuple_t *tuple = NULL;
+	isc_result_t result;
+	result = dns_difftuple_create(diff->mctx, op, name, ttl, rdata, &tuple);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	return (do_one_tuple(&tuple, db, ver, diff));
+}
+
+/**************************************************************************/
+/*
+ * Callback-style iteration over rdatasets and rdatas.
+ *
+ * foreach_rrset() can be used to iterate over the RRsets
+ * of a name and call a callback function with each
+ * one.  Similarly, foreach_rr() can be used to iterate
+ * over the individual RRs at name, optionally restricted
+ * to RRs of a given type.
+ *
+ * The callback functions are called "actions" and take
+ * two arguments: a void pointer for passing arbitrary
+ * context information, and a pointer to the current RRset
+ * or RR.  By convention, their names end in "_action".
+ */
+
+/*
+ * XXXRTH  We might want to make this public somewhere in libdns.
+ */
+
+/*%
+ * Function type for foreach_rrset() iterator actions.
+ */
+typedef isc_result_t
+rrset_func(void *data, dns_rdataset_t *rrset);
+
+/*%
+ * Function type for foreach_rr() iterator actions.
+ */
+typedef isc_result_t
+rr_func(void *data, rr_t *rr);
+
+/*%
+ * Internal context struct for foreach_node_rr().
+ */
+typedef struct {
+	rr_func *rr_action;
+	void *rr_action_data;
+} foreach_node_rr_ctx_t;
+
+/*%
+ * Internal helper function for foreach_node_rr().
+ */
+static isc_result_t
+foreach_node_rr_action(void *data, dns_rdataset_t *rdataset) {
+	isc_result_t result;
+	foreach_node_rr_ctx_t *ctx = data;
+	for (result = dns_rdataset_first(rdataset); result == ISC_R_SUCCESS;
+	     result = dns_rdataset_next(rdataset))
+	{
+		rr_t rr = { 0, DNS_RDATA_INIT };
+
+		dns_rdataset_current(rdataset, &rr.rdata);
+		rr.ttl = rdataset->ttl;
+		result = (*ctx->rr_action)(ctx->rr_action_data, &rr);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+	}
+	if (result != ISC_R_NOMORE) {
+		return (result);
+	}
+	return (ISC_R_SUCCESS);
+}
+
+/*%
+ * For each rdataset of 'name' in 'ver' of 'db', call 'action'
+ * with the rdataset and 'action_data' as arguments.  If the name
+ * does not exist, do nothing.
+ *
+ * If 'action' returns an error, abort iteration and return the error.
+ */
+static isc_result_t
+foreach_rrset(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+	      rrset_func *action, void *action_data) {
+	isc_result_t result;
+	dns_dbnode_t *node;
+	dns_rdatasetiter_t *iter;
+
+	node = NULL;
+	result = dns_db_findnode(db, name, false, &node);
+	if (result == ISC_R_NOTFOUND) {
+		return (ISC_R_SUCCESS);
+	}
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	iter = NULL;
+	result = dns_db_allrdatasets(db, node, ver, 0, (isc_stdtime_t)0, &iter);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_node;
+	}
+
+	for (result = dns_rdatasetiter_first(iter); result == ISC_R_SUCCESS;
+	     result = dns_rdatasetiter_next(iter))
+	{
+		dns_rdataset_t rdataset;
+
+		dns_rdataset_init(&rdataset);
+		dns_rdatasetiter_current(iter, &rdataset);
+
+		result = (*action)(action_data, &rdataset);
+
+		dns_rdataset_disassociate(&rdataset);
+		if (result != ISC_R_SUCCESS) {
+			goto cleanup_iterator;
+		}
+	}
+	if (result == ISC_R_NOMORE) {
+		result = ISC_R_SUCCESS;
+	}
+
+cleanup_iterator:
+	dns_rdatasetiter_destroy(&iter);
+
+cleanup_node:
+	dns_db_detachnode(db, &node);
+
+	return (result);
+}
+
+/*%
+ * For each RR of 'name' in 'ver' of 'db', call 'action'
+ * with the RR and 'action_data' as arguments.  If the name
+ * does not exist, do nothing.
+ *
+ * If 'action' returns an error, abort iteration
+ * and return the error.
+ */
+static isc_result_t
+foreach_node_rr(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+		rr_func *rr_action, void *rr_action_data) {
+	foreach_node_rr_ctx_t ctx;
+	ctx.rr_action = rr_action;
+	ctx.rr_action_data = rr_action_data;
+	return (foreach_rrset(db, ver, name, foreach_node_rr_action, &ctx));
+}
+
+/*%
+ * For each of the RRs specified by 'db', 'ver', 'name', 'type',
+ * (which can be dns_rdatatype_any to match any type), and 'covers', call
+ * 'action' with the RR and 'action_data' as arguments. If the name
+ * does not exist, or if no RRset of the given type exists at the name,
+ * do nothing.
+ *
+ * If 'action' returns an error, abort iteration and return the error.
+ */
+static isc_result_t
+foreach_rr(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+	   dns_rdatatype_t type, dns_rdatatype_t covers, rr_func *rr_action,
+	   void *rr_action_data) {
+	isc_result_t result;
+	dns_dbnode_t *node;
+	dns_rdataset_t rdataset;
+
+	if (type == dns_rdatatype_any) {
+		return (foreach_node_rr(db, ver, name, rr_action,
+					rr_action_data));
+	}
+
+	node = NULL;
+	if (type == dns_rdatatype_nsec3 ||
+	    (type == dns_rdatatype_rrsig && covers == dns_rdatatype_nsec3))
+	{
+		result = dns_db_findnsec3node(db, name, false, &node);
+	} else {
+		result = dns_db_findnode(db, name, false, &node);
+	}
+	if (result == ISC_R_NOTFOUND) {
+		return (ISC_R_SUCCESS);
+	}
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	dns_rdataset_init(&rdataset);
+	result = dns_db_findrdataset(db, node, ver, type, covers,
+				     (isc_stdtime_t)0, &rdataset, NULL);
+	if (result == ISC_R_NOTFOUND) {
+		result = ISC_R_SUCCESS;
+		goto cleanup_node;
+	}
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_node;
+	}
+
+	for (result = dns_rdataset_first(&rdataset); result == ISC_R_SUCCESS;
+	     result = dns_rdataset_next(&rdataset))
+	{
+		rr_t rr = { 0, DNS_RDATA_INIT };
+		dns_rdataset_current(&rdataset, &rr.rdata);
+		rr.ttl = rdataset.ttl;
+		result = (*rr_action)(rr_action_data, &rr);
+		if (result != ISC_R_SUCCESS) {
+			goto cleanup_rdataset;
+		}
+	}
+	if (result != ISC_R_NOMORE) {
+		goto cleanup_rdataset;
+	}
+	result = ISC_R_SUCCESS;
+
+cleanup_rdataset:
+	dns_rdataset_disassociate(&rdataset);
+cleanup_node:
+	dns_db_detachnode(db, &node);
+
+	return (result);
+}
+
+/**************************************************************************/
+/*
+ * Various tests on the database contents (for prerequisites, etc).
+ */
+
+/*%
+ * Function type for predicate functions that compare a database RR 'db_rr'
+ * against an update RR 'update_rr'.
+ */
+typedef bool
+rr_predicate(dns_rdata_t *update_rr, dns_rdata_t *db_rr);
+
+/*%
+ * Helper function for rrset_exists().
+ */
+static isc_result_t
+rrset_exists_action(void *data, rr_t *rr) {
+	UNUSED(data);
+	UNUSED(rr);
+	return (ISC_R_EXISTS);
+}
+
+/*%
+ * Utility macro for RR existence checking functions.
+ *
+ * If the variable 'result' has the value ISC_R_EXISTS or
+ * ISC_R_SUCCESS, set *exists to true or false,
+ * respectively, and return success.
+ *
+ * If 'result' has any other value, there was a failure.
+ * Return the failure result code and do not set *exists.
+ *
+ * This would be more readable as "do { if ... } while(0)",
+ * but that form generates tons of warnings on Solaris 2.6.
+ */
+#define RETURN_EXISTENCE_FLAG                                         \
+	return ((result == ISC_R_EXISTS)                              \
+			? (*exists = true, ISC_R_SUCCESS)             \
+			: ((result == ISC_R_SUCCESS)                  \
+				   ? (*exists = false, ISC_R_SUCCESS) \
+				   : result))
+
+/*%
+ * Set '*exists' to true iff an rrset of the given type exists,
+ * to false otherwise.
+ */
+static isc_result_t
+rrset_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+	     dns_rdatatype_t type, dns_rdatatype_t covers, bool *exists) {
+	isc_result_t result;
+	result = foreach_rr(db, ver, name, type, covers, rrset_exists_action,
+			    NULL);
+	RETURN_EXISTENCE_FLAG;
+}
+
+/*%
+ * Set '*visible' to true if the RRset exists and is part of the
+ * visible zone.  Otherwise '*visible' is set to false unless a
+ * error occurs.
+ */
+static isc_result_t
+rrset_visible(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+	      dns_rdatatype_t type, bool *visible) {
+	isc_result_t result;
+	dns_fixedname_t fixed;
+
+	dns_fixedname_init(&fixed);
+	result = dns_db_find(db, name, ver, type, DNS_DBFIND_NOWILD,
+			     (isc_stdtime_t)0, NULL, dns_fixedname_name(&fixed),
+			     NULL, NULL);
+	switch (result) {
+	case ISC_R_SUCCESS:
+		*visible = true;
+		break;
+	/*
+	 * Glue, obscured, deleted or replaced records.
+	 */
+	case DNS_R_DELEGATION:
+	case DNS_R_DNAME:
+	case DNS_R_CNAME:
+	case DNS_R_NXDOMAIN:
+	case DNS_R_NXRRSET:
+	case DNS_R_EMPTYNAME:
+	case DNS_R_COVERINGNSEC:
+		*visible = false;
+		result = ISC_R_SUCCESS;
+		break;
+	default:
+		*visible = false; /* silence false compiler warning */
+		break;
+	}
+	return (result);
+}
+
+/*%
+ * Context struct and helper function for name_exists().
+ */
+
+static isc_result_t
+name_exists_action(void *data, dns_rdataset_t *rrset) {
+	UNUSED(data);
+	UNUSED(rrset);
+	return (ISC_R_EXISTS);
+}
+
+/*%
+ * Set '*exists' to true iff the given name exists, to false otherwise.
+ */
+static isc_result_t
+name_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+	    bool *exists) {
+	isc_result_t result;
+	result = foreach_rrset(db, ver, name, name_exists_action, NULL);
+	RETURN_EXISTENCE_FLAG;
+}
+
+/**************************************************************************/
+/*
+ * Checking of "RRset exists (value dependent)" prerequisites.
+ *
+ * In the RFC2136 section 3.2.5, this is the pseudocode involving
+ * a variable called "temp", a mapping of <name, type> tuples to rrsets.
+ *
+ * Here, we represent the "temp" data structure as (non-minimal) "dns_diff_t"
+ * where each tuple has op==DNS_DIFFOP_EXISTS.
+ */
+
+/*%
+ * A comparison function defining the sorting order for the entries
+ * in the "temp" data structure.  The major sort key is the owner name,
+ * followed by the type and rdata.
+ */
+static int
+temp_order(const void *av, const void *bv) {
+	dns_difftuple_t const *const *ap = av;
+	dns_difftuple_t const *const *bp = bv;
+	dns_difftuple_t const *a = *ap;
+	dns_difftuple_t const *b = *bp;
+	int r;
+	r = dns_name_compare(&a->name, &b->name);
+	if (r != 0) {
+		return (r);
+	}
+	r = (b->rdata.type - a->rdata.type);
+	if (r != 0) {
+		return (r);
+	}
+	r = dns_rdata_casecompare(&a->rdata, &b->rdata);
+	return (r);
+}
+
+/**************************************************************************/
+/*
+ * Conditional deletion of RRs.
+ */
+
+/*%
+ * Context structure for delete_if().
+ */
+
+typedef struct {
+	rr_predicate *predicate;
+	dns_db_t *db;
+	dns_dbversion_t *ver;
+	dns_diff_t *diff;
+	dns_name_t *name;
+	dns_rdata_t *update_rr;
+} conditional_delete_ctx_t;
+
+/*%
+ * Predicate functions for delete_if().
+ */
+
+/*%
+ * Return true always.
+ */
+static bool
+true_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
+	UNUSED(update_rr);
+	UNUSED(db_rr);
+	return (true);
+}
+
+/*%
+ * Return true if the record is a RRSIG.
+ */
+static bool
+rrsig_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
+	UNUSED(update_rr);
+	return ((db_rr->type == dns_rdatatype_rrsig) ? true : false);
+}
+
+/*%
+ * Internal helper function for delete_if().
+ */
+static isc_result_t
+delete_if_action(void *data, rr_t *rr) {
+	conditional_delete_ctx_t *ctx = data;
+	if ((*ctx->predicate)(ctx->update_rr, &rr->rdata)) {
+		isc_result_t result;
+		result = update_one_rr(ctx->db, ctx->ver, ctx->diff,
+				       DNS_DIFFOP_DEL, ctx->name, rr->ttl,
+				       &rr->rdata);
+		return (result);
+	} else {
+		return (ISC_R_SUCCESS);
+	}
+}
+
+/*%
+ * Conditionally delete RRs.  Apply 'predicate' to the RRs
+ * specified by 'db', 'ver', 'name', and 'type' (which can
+ * be dns_rdatatype_any to match any type).  Delete those
+ * RRs for which the predicate returns true, and log the
+ * deletions in 'diff'.
+ */
+static isc_result_t
+delete_if(rr_predicate *predicate, dns_db_t *db, dns_dbversion_t *ver,
+	  dns_name_t *name, dns_rdatatype_t type, dns_rdatatype_t covers,
+	  dns_rdata_t *update_rr, dns_diff_t *diff) {
+	conditional_delete_ctx_t ctx;
+	ctx.predicate = predicate;
+	ctx.db = db;
+	ctx.ver = ver;
+	ctx.diff = diff;
+	ctx.name = name;
+	ctx.update_rr = update_rr;
+	return (foreach_rr(db, ver, name, type, covers, delete_if_action,
+			   &ctx));
+}
+
+/**************************************************************************/
+/*
+ * Incremental updating of NSECs and RRSIGs.
+ */
+
+/*%
+ * We abuse the dns_diff_t type to represent a set of domain names
+ * affected by the update.
+ */
+static isc_result_t
+namelist_append_name(dns_diff_t *list, dns_name_t *name) {
+	isc_result_t result;
+	dns_difftuple_t *tuple = NULL;
+	static dns_rdata_t dummy_rdata = DNS_RDATA_INIT;
+
+	CHECK(dns_difftuple_create(list->mctx, DNS_DIFFOP_EXISTS, name, 0,
+				   &dummy_rdata, &tuple));
+	dns_diff_append(list, &tuple);
+failure:
+	return (result);
+}
+
+static isc_result_t
+namelist_append_subdomain(dns_db_t *db, dns_name_t *name,
+			  dns_diff_t *affected) {
+	isc_result_t result;
+	dns_fixedname_t fixedname;
+	dns_name_t *child;
+	dns_dbiterator_t *dbit = NULL;
+
+	child = dns_fixedname_initname(&fixedname);
+
+	CHECK(dns_db_createiterator(db, DNS_DB_NONSEC3, &dbit));
+
+	for (result = dns_dbiterator_seek(dbit, name); result == ISC_R_SUCCESS;
+	     result = dns_dbiterator_next(dbit))
+	{
+		dns_dbnode_t *node = NULL;
+		CHECK(dns_dbiterator_current(dbit, &node, child));
+		dns_db_detachnode(db, &node);
+		if (!dns_name_issubdomain(child, name)) {
+			break;
+		}
+		CHECK(namelist_append_name(affected, child));
+	}
+	if (result == ISC_R_NOMORE) {
+		result = ISC_R_SUCCESS;
+	}
+failure:
+	if (dbit != NULL) {
+		dns_dbiterator_destroy(&dbit);
+	}
+	return (result);
+}
+
+/*%
+ * Helper function for non_nsec_rrset_exists().
+ */
+static isc_result_t
+is_non_nsec_action(void *data, dns_rdataset_t *rrset) {
+	UNUSED(data);
+	if (!(rrset->type == dns_rdatatype_nsec ||
+	      rrset->type == dns_rdatatype_nsec3 ||
+	      (rrset->type == dns_rdatatype_rrsig &&
+	       (rrset->covers == dns_rdatatype_nsec ||
+		rrset->covers == dns_rdatatype_nsec3))))
+	{
+		return (ISC_R_EXISTS);
+	}
+	return (ISC_R_SUCCESS);
+}
+
+/*%
+ * Check whether there is an rrset other than a NSEC or RRSIG NSEC,
+ * i.e., anything that justifies the continued existence of a name
+ * after a secure update.
+ *
+ * If such an rrset exists, set '*exists' to true.
+ * Otherwise, set it to false.
+ */
+static isc_result_t
+non_nsec_rrset_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+		      bool *exists) {
+	isc_result_t result;
+	result = foreach_rrset(db, ver, name, is_non_nsec_action, NULL);
+	RETURN_EXISTENCE_FLAG;
+}
+
+/*%
+ * A comparison function for sorting dns_diff_t:s by name.
+ */
+static int
+name_order(const void *av, const void *bv) {
+	dns_difftuple_t const *const *ap = av;
+	dns_difftuple_t const *const *bp = bv;
+	dns_difftuple_t const *a = *ap;
+	dns_difftuple_t const *b = *bp;
+	return (dns_name_compare(&a->name, &b->name));
+}
+
+static isc_result_t
+uniqify_name_list(dns_diff_t *list) {
+	isc_result_t result;
+	dns_difftuple_t *p, *q;
+
+	CHECK(dns_diff_sort(list, name_order));
+
+	p = ISC_LIST_HEAD(list->tuples);
+	while (p != NULL) {
+		do {
+			q = ISC_LIST_NEXT(p, link);
+			if (q == NULL || !dns_name_equal(&p->name, &q->name)) {
+				break;
+			}
+			ISC_LIST_UNLINK(list->tuples, q, link);
+			dns_difftuple_free(&q);
+		} while (1);
+		p = ISC_LIST_NEXT(p, link);
+	}
+failure:
+	return (result);
+}
+
+static isc_result_t
+is_active(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name, bool *flag,
+	  bool *cut, bool *unsecure) {
+	isc_result_t result;
+	dns_fixedname_t foundname;
+	dns_fixedname_init(&foundname);
+	result = dns_db_find(db, name, ver, dns_rdatatype_any,
+			     DNS_DBFIND_GLUEOK | DNS_DBFIND_NOWILD,
+			     (isc_stdtime_t)0, NULL,
+			     dns_fixedname_name(&foundname), NULL, NULL);
+	if (result == ISC_R_SUCCESS || result == DNS_R_EMPTYNAME) {
+		*flag = true;
+		*cut = false;
+		if (unsecure != NULL) {
+			*unsecure = false;
+		}
+		return (ISC_R_SUCCESS);
+	} else if (result == DNS_R_ZONECUT) {
+		*flag = true;
+		*cut = true;
+		if (unsecure != NULL) {
+			/*
+			 * We are at the zonecut.  Check to see if there
+			 * is a DS RRset.
+			 */
+			if (dns_db_find(db, name, ver, dns_rdatatype_ds, 0,
+					(isc_stdtime_t)0, NULL,
+					dns_fixedname_name(&foundname), NULL,
+					NULL) == DNS_R_NXRRSET)
+			{
+				*unsecure = true;
+			} else {
+				*unsecure = false;
+			}
+		}
+		return (ISC_R_SUCCESS);
+	} else if (result == DNS_R_GLUE || result == DNS_R_DNAME ||
+		   result == DNS_R_DELEGATION || result == DNS_R_NXDOMAIN)
+	{
+		*flag = false;
+		*cut = false;
+		if (unsecure != NULL) {
+			*unsecure = false;
+		}
+		return (ISC_R_SUCCESS);
+	} else {
+		/*
+		 * Silence compiler.
+		 */
+		*flag = false;
+		*cut = false;
+		if (unsecure != NULL) {
+			*unsecure = false;
+		}
+		return (result);
+	}
+}
+
+/*%
+ * Find the next/previous name that has a NSEC record.
+ * In other words, skip empty database nodes and names that
+ * have had their NSECs removed because they are obscured by
+ * a zone cut.
+ */
+static isc_result_t
+next_active(dns_update_log_t *log, dns_zone_t *zone, dns_db_t *db,
+	    dns_dbversion_t *ver, dns_name_t *oldname, dns_name_t *newname,
+	    bool forward) {
+	isc_result_t result;
+	dns_dbiterator_t *dbit = NULL;
+	bool has_nsec = false;
+	unsigned int wraps = 0;
+	bool secure = dns_db_issecure(db);
+
+	CHECK(dns_db_createiterator(db, 0, &dbit));
+
+	CHECK(dns_dbiterator_seek(dbit, oldname));
+	do {
+		dns_dbnode_t *node = NULL;
+
+		if (forward) {
+			result = dns_dbiterator_next(dbit);
+		} else {
+			result = dns_dbiterator_prev(dbit);
+		}
+		if (result == ISC_R_NOMORE) {
+			/*
+			 * Wrap around.
+			 */
+			if (forward) {
+				CHECK(dns_dbiterator_first(dbit));
+			} else {
+				CHECK(dns_dbiterator_last(dbit));
+			}
+			wraps++;
+			if (wraps == 2) {
+				update_log(log, zone, ISC_LOG_ERROR,
+					   "secure zone with no NSECs");
+				result = DNS_R_BADZONE;
+				goto failure;
+			}
+		}
+		CHECK(dns_dbiterator_current(dbit, &node, newname));
+		dns_db_detachnode(db, &node);
+
+		/*
+		 * The iterator may hold the tree lock, and
+		 * rrset_exists() calls dns_db_findnode() which
+		 * may try to reacquire it.  To avoid deadlock
+		 * we must pause the iterator first.
+		 */
+		CHECK(dns_dbiterator_pause(dbit));
+		if (secure) {
+			CHECK(rrset_exists(db, ver, newname, dns_rdatatype_nsec,
+					   0, &has_nsec));
+		} else {
+			dns_fixedname_t ffound;
+			dns_name_t *found;
+			found = dns_fixedname_initname(&ffound);
+			result = dns_db_find(
+				db, newname, ver, dns_rdatatype_soa,
+				DNS_DBFIND_NOWILD, 0, NULL, found, NULL, NULL);
+			if (result == ISC_R_SUCCESS ||
+			    result == DNS_R_EMPTYNAME ||
+			    result == DNS_R_NXRRSET || result == DNS_R_CNAME ||
+			    (result == DNS_R_DELEGATION &&
+			     dns_name_equal(newname, found)))
+			{
+				has_nsec = true;
+				result = ISC_R_SUCCESS;
+			} else if (result != DNS_R_NXDOMAIN) {
+				break;
+			}
+		}
+	} while (!has_nsec);
+failure:
+	if (dbit != NULL) {
+		dns_dbiterator_destroy(&dbit);
+	}
+
+	return (result);
+}
+
+/*%
+ * Add a NSEC record for "name", recording the change in "diff".
+ * The existing NSEC is removed.
+ */
+static isc_result_t
+add_nsec(dns_update_log_t *log, dns_zone_t *zone, dns_db_t *db,
+	 dns_dbversion_t *ver, dns_name_t *name, dns_ttl_t nsecttl,
+	 dns_diff_t *diff) {
+	isc_result_t result;
+	dns_dbnode_t *node = NULL;
+	unsigned char buffer[DNS_NSEC_BUFFERSIZE];
+	dns_rdata_t rdata = DNS_RDATA_INIT;
+	dns_difftuple_t *tuple = NULL;
+	dns_fixedname_t fixedname;
+	dns_name_t *target;
+
+	target = dns_fixedname_initname(&fixedname);
+
+	/*
+	 * Find the successor name, aka NSEC target.
+	 */
+	CHECK(next_active(log, zone, db, ver, name, target, true));
+
+	/*
+	 * Create the NSEC RDATA.
+	 */
+	CHECK(dns_db_findnode(db, name, false, &node));
+	dns_rdata_init(&rdata);
+	CHECK(dns_nsec_buildrdata(db, ver, node, target, buffer, &rdata));
+	dns_db_detachnode(db, &node);
+
+	/*
+	 * Delete the old NSEC and record the change.
+	 */
+	CHECK(delete_if(true_p, db, ver, name, dns_rdatatype_nsec, 0, NULL,
+			diff));
+	/*
+	 * Add the new NSEC and record the change.
+	 */
+	CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD, name, nsecttl,
+				   &rdata, &tuple));
+	CHECK(do_one_tuple(&tuple, db, ver, diff));
+	INSIST(tuple == NULL);
+
+failure:
+	if (node != NULL) {
+		dns_db_detachnode(db, &node);
+	}
+	return (result);
+}
+
+/*%
+ * Add a placeholder NSEC record for "name", recording the change in "diff".
+ */
+static isc_result_t
+add_placeholder_nsec(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+		     dns_diff_t *diff) {
+	isc_result_t result;
+	dns_difftuple_t *tuple = NULL;
+	isc_region_t r;
+	unsigned char data[1] = { 0 }; /* The root domain, no bits. */
+	dns_rdata_t rdata = DNS_RDATA_INIT;
+
+	r.base = data;
+	r.length = sizeof(data);
+	dns_rdata_fromregion(&rdata, dns_db_class(db), dns_rdatatype_nsec, &r);
+	CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD, name, 0, &rdata,
+				   &tuple));
+	CHECK(do_one_tuple(&tuple, db, ver, diff));
+failure:
+	return (result);
+}
+
+static isc_result_t
+find_zone_keys(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
+	       isc_mem_t *mctx, unsigned int maxkeys, dst_key_t **keys,
+	       unsigned int *nkeys) {
+	isc_result_t result;
+	isc_stdtime_t now;
+	dns_dbnode_t *node = NULL;
+	const char *directory = dns_zone_getkeydirectory(zone);
+
+	CHECK(dns_db_findnode(db, dns_db_origin(db), false, &node));
+	isc_stdtime_get(&now);
+
+	dns_zone_lock_keyfiles(zone);
+	result = dns_dnssec_findzonekeys(db, ver, node, dns_db_origin(db),
+					 directory, now, mctx, maxkeys, keys,
+					 nkeys);
+	dns_zone_unlock_keyfiles(zone);
+
+failure:
+	if (node != NULL) {
+		dns_db_detachnode(db, &node);
+	}
+	return (result);
+}
+
+/*%
+ * Add RRSIG records for an RRset, recording the change in "diff".
+ */
+static isc_result_t
+add_sigs(dns_update_log_t *log, dns_zone_t *zone, dns_db_t *db,
+	 dns_dbversion_t *ver, dns_name_t *name, dns_rdatatype_t type,
+	 dns_diff_t *diff, dst_key_t **keys, unsigned int nkeys,
+	 isc_stdtime_t inception, isc_stdtime_t expire, bool check_ksk,
+	 bool keyset_kskonly) {
+	isc_result_t result;
+	dns_dbnode_t *node = NULL;
+	dns_kasp_t *kasp = dns_zone_getkasp(zone);
+	dns_rdataset_t rdataset;
+	dns_rdata_t sig_rdata = DNS_RDATA_INIT;
+	dns_stats_t *dnssecsignstats = dns_zone_getdnssecsignstats(zone);
+	isc_buffer_t buffer;
+	unsigned char data[1024]; /* XXX */
+	unsigned int i, j;
+	bool added_sig = false;
+	bool use_kasp = false;
+	isc_mem_t *mctx = diff->mctx;
+
+	if (kasp != NULL) {
+		check_ksk = false;
+		keyset_kskonly = true;
+		use_kasp = true;
+	}
+
+	dns_rdataset_init(&rdataset);
+	isc_buffer_init(&buffer, data, sizeof(data));
+
+	/* Get the rdataset to sign. */
+	if (type == dns_rdatatype_nsec3) {
+		CHECK(dns_db_findnsec3node(db, name, false, &node));
+	} else {
+		CHECK(dns_db_findnode(db, name, false, &node));
+	}
+	CHECK(dns_db_findrdataset(db, node, ver, type, 0, (isc_stdtime_t)0,
+				  &rdataset, NULL));
+	dns_db_detachnode(db, &node);
+
+#define REVOKE(x) ((dst_key_flags(x) & DNS_KEYFLAG_REVOKE) != 0)
+#define KSK(x)	  ((dst_key_flags(x) & DNS_KEYFLAG_KSK) != 0)
+#define ID(x)	  dst_key_id(x)
+#define ALG(x)	  dst_key_alg(x)
+
+	/*
+	 * If we are honoring KSK flags then we need to check that we
+	 * have both KSK and non-KSK keys that are not revoked per
+	 * algorithm.
+	 */
+	for (i = 0; i < nkeys; i++) {
+		bool both = false;
+
+		/* Don't add signatures for offline or inactive keys */
+		if (!dst_key_isprivate(keys[i])) {
+			continue;
+		}
+		if (dst_key_inactive(keys[i])) {
+			continue;
+		}
+
+		if (check_ksk && !REVOKE(keys[i])) {
+			bool have_ksk, have_nonksk;
+			if (KSK(keys[i])) {
+				have_ksk = true;
+				have_nonksk = false;
+			} else {
+				have_ksk = false;
+				have_nonksk = true;
+			}
+			for (j = 0; j < nkeys; j++) {
+				if (j == i || ALG(keys[i]) != ALG(keys[j])) {
+					continue;
+				}
+
+				/* Don't consider inactive keys, however
+				 * the KSK may be temporary offline, so do
+				 * consider KSKs which private key files are
+				 * unavailable.
+				 */
+				if (dst_key_inactive(keys[j])) {
+					continue;
+				}
+
+				if (REVOKE(keys[j])) {
+					continue;
+				}
+				if (KSK(keys[j])) {
+					have_ksk = true;
+				} else if (dst_key_isprivate(keys[j])) {
+					have_nonksk = true;
+				}
+				both = have_ksk && have_nonksk;
+				if (both) {
+					break;
+				}
+			}
+		}
+
+		if (use_kasp) {
+			/*
+			 * A dnssec-policy is found. Check what RRsets this
+			 * key should sign.
+			 */
+			isc_stdtime_t when;
+			isc_result_t kresult;
+			bool ksk = false;
+			bool zsk = false;
+
+			kresult = dst_key_getbool(keys[i], DST_BOOL_KSK, &ksk);
+			if (kresult != ISC_R_SUCCESS) {
+				if (KSK(keys[i])) {
+					ksk = true;
+				}
+			}
+			kresult = dst_key_getbool(keys[i], DST_BOOL_ZSK, &zsk);
+			if (kresult != ISC_R_SUCCESS) {
+				if (!KSK(keys[i])) {
+					zsk = true;
+				}
+			}
+
+			if (type == dns_rdatatype_dnskey ||
+			    type == dns_rdatatype_cdnskey ||
+			    type == dns_rdatatype_cds)
+			{
+				/*
+				 * DNSKEY RRset is signed with KSK.
+				 * CDS and CDNSKEY RRsets too (RFC 7344, 4.1).
+				 */
+				if (!ksk) {
+					continue;
+				}
+			} else if (!zsk) {
+				/*
+				 * Other RRsets are signed with ZSK.
+				 */
+				continue;
+			} else if (zsk &&
+				   !dst_key_is_signing(keys[i], DST_BOOL_ZSK,
+						       inception, &when))
+			{
+				/*
+				 * This key is not active for zone-signing.
+				 */
+				continue;
+			}
+
+			/*
+			 * If this key is revoked, it may only sign the
+			 * DNSKEY RRset.
+			 */
+			if (REVOKE(keys[i]) && type != dns_rdatatype_dnskey) {
+				continue;
+			}
+		} else if (both) {
+			/*
+			 * CDS and CDNSKEY are signed with KSK (RFC 7344, 4.1).
+			 */
+			if (type == dns_rdatatype_dnskey ||
+			    type == dns_rdatatype_cdnskey ||
+			    type == dns_rdatatype_cds)
+			{
+				if (!KSK(keys[i]) && keyset_kskonly) {
+					continue;
+				}
+			} else if (KSK(keys[i])) {
+				continue;
+			}
+		} else if (REVOKE(keys[i]) && type != dns_rdatatype_dnskey) {
+			continue;
+		}
+
+		/* Calculate the signature, creating a RRSIG RDATA. */
+		CHECK(dns_dnssec_sign(name, &rdataset, keys[i], &inception,
+				      &expire, mctx, &buffer, &sig_rdata));
+
+		/* Update the database and journal with the RRSIG. */
+		/* XXX inefficient - will cause dataset merging */
+		CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADDRESIGN, name,
+				    rdataset.ttl, &sig_rdata));
+		dns_rdata_reset(&sig_rdata);
+		isc_buffer_init(&buffer, data, sizeof(data));
+		added_sig = true;
+		/* Update DNSSEC sign statistics. */
+		if (dnssecsignstats != NULL) {
+			dns_dnssecsignstats_increment(dnssecsignstats,
+						      ID(keys[i]),
+						      (uint8_t)ALG(keys[i]),
+						      dns_dnssecsignstats_sign);
+		}
+	}
+	if (!added_sig) {
+		update_log(log, zone, ISC_LOG_ERROR,
+			   "found no active private keys, "
+			   "unable to generate any signatures");
+		result = ISC_R_NOTFOUND;
+	}
+
+failure:
+	if (dns_rdataset_isassociated(&rdataset)) {
+		dns_rdataset_disassociate(&rdataset);
+	}
+	if (node != NULL) {
+		dns_db_detachnode(db, &node);
+	}
+	return (result);
+}
+
+/*
+ * Delete expired RRsigs and any RRsigs we are about to re-sign.
+ * See also zone.c:del_sigs().
+ */
+static isc_result_t
+del_keysigs(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
+	    dns_diff_t *diff, dst_key_t **keys, unsigned int nkeys) {
+	isc_result_t result;
+	dns_dbnode_t *node = NULL;
+	dns_rdataset_t rdataset;
+	dns_rdata_t rdata = DNS_RDATA_INIT;
+	unsigned int i;
+	dns_rdata_rrsig_t rrsig;
+	bool found;
+
+	dns_rdataset_init(&rdataset);
+
+	result = dns_db_findnode(db, name, false, &node);
+	if (result == ISC_R_NOTFOUND) {
+		return (ISC_R_SUCCESS);
+	}
+	if (result != ISC_R_SUCCESS) {
+		goto failure;
+	}
+	result = dns_db_findrdataset(db, node, ver, dns_rdatatype_rrsig,
+				     dns_rdatatype_dnskey, (isc_stdtime_t)0,
+				     &rdataset, NULL);
+	dns_db_detachnode(db, &node);
+
+	if (result == ISC_R_NOTFOUND) {
+		return (ISC_R_SUCCESS);
+	}
+	if (result != ISC_R_SUCCESS) {
+		goto failure;
+	}
+
+	for (result = dns_rdataset_first(&rdataset); result == ISC_R_SUCCESS;
+	     result = dns_rdataset_next(&rdataset))
+	{
+		dns_rdataset_current(&rdataset, &rdata);
+		result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
+		RUNTIME_CHECK(result == ISC_R_SUCCESS);
+		found = false;
+		for (i = 0; i < nkeys; i++) {
+			if (rrsig.keyid == dst_key_id(keys[i])) {
+				found = true;
+				if (!dst_key_isprivate(keys[i]) &&
+				    !dst_key_inactive(keys[i]))
+				{
+					/*
+					 * The re-signing code in zone.c
+					 * will mark this as offline.
+					 * Just skip the record for now.
+					 */
+					break;
+				}
+				result = update_one_rr(db, ver, diff,
+						       DNS_DIFFOP_DEL, name,
+						       rdataset.ttl, &rdata);
+				break;
+			}
+		}
+		/*
+		 * If there is not a matching DNSKEY then delete the RRSIG.
+		 */
+		if (!found) {
+			result = update_one_rr(db, ver, diff, DNS_DIFFOP_DEL,
+					       name, rdataset.ttl, &rdata);
+		}
+		dns_rdata_reset(&rdata);
+		if (result != ISC_R_SUCCESS) {
+			break;
+		}
+	}
+	dns_rdataset_disassociate(&rdataset);
+	if (result == ISC_R_NOMORE) {
+		result = ISC_R_SUCCESS;
+	}
+failure:
+	if (node != NULL) {
+		dns_db_detachnode(db, &node);
+	}
+	return (result);
+}
+
+static isc_result_t
+add_exposed_sigs(dns_update_log_t *log, dns_zone_t *zone, dns_db_t *db,
+		 dns_dbversion_t *ver, dns_name_t *name, bool cut,
+		 dns_diff_t *diff, dst_key_t **keys, unsigned int nkeys,
+		 isc_stdtime_t inception, isc_stdtime_t expire, bool check_ksk,
+		 bool keyset_kskonly, unsigned int *sigs) {
+	isc_result_t result;
+	dns_dbnode_t *node;
+	dns_rdatasetiter_t *iter;
+
+	node = NULL;
+	result = dns_db_findnode(db, name, false, &node);
+	if (result == ISC_R_NOTFOUND) {
+		return (ISC_R_SUCCESS);
+	}
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	iter = NULL;
+	result = dns_db_allrdatasets(db, node, ver, 0, (isc_stdtime_t)0, &iter);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_node;
+	}
+
+	for (result = dns_rdatasetiter_first(iter); result == ISC_R_SUCCESS;
+	     result = dns_rdatasetiter_next(iter))
+	{
+		dns_rdataset_t rdataset;
+		dns_rdatatype_t type;
+		bool flag;
+
+		dns_rdataset_init(&rdataset);
+		dns_rdatasetiter_current(iter, &rdataset);
+		type = rdataset.type;
+		dns_rdataset_disassociate(&rdataset);
+
+		/*
+		 * We don't need to sign unsigned NSEC records at the cut
+		 * as they are handled elsewhere.
+		 */
+		if ((type == dns_rdatatype_rrsig) ||
+		    (cut && type != dns_rdatatype_ds))
+		{
+			continue;
+		}
+		result = rrset_exists(db, ver, name, dns_rdatatype_rrsig, type,
+				      &flag);
+		if (result != ISC_R_SUCCESS) {
+			goto cleanup_iterator;
+		}
+		if (flag) {
+			continue;
+		}
+		result = add_sigs(log, zone, db, ver, name, type, diff, keys,
+				  nkeys, inception, expire, check_ksk,
+				  keyset_kskonly);
+		if (result != ISC_R_SUCCESS) {
+			goto cleanup_iterator;
+		}
+		(*sigs)++;
+	}
+	if (result == ISC_R_NOMORE) {
+		result = ISC_R_SUCCESS;
+	}
+
+cleanup_iterator:
+	dns_rdatasetiter_destroy(&iter);
+
+cleanup_node:
+	dns_db_detachnode(db, &node);
+
+	return (result);
+}
+
+/*%
+ * Update RRSIG, NSEC and NSEC3 records affected by an update.  The original
+ * update, including the SOA serial update but excluding the RRSIG & NSEC
+ * changes, is in "diff" and has already been applied to "newver" of "db".
+ * The database version prior to the update is "oldver".
+ *
+ * The necessary RRSIG, NSEC and NSEC3 changes will be applied to "newver"
+ * and added (as a minimal diff) to "diff".
+ *
+ * The RRSIGs generated will be valid for 'sigvalidityinterval' seconds.
+ */
+isc_result_t
+dns_update_signatures(dns_update_log_t *log, dns_zone_t *zone, dns_db_t *db,
+		      dns_dbversion_t *oldver, dns_dbversion_t *newver,
+		      dns_diff_t *diff, uint32_t sigvalidityinterval) {
+	return (dns_update_signaturesinc(log, zone, db, oldver, newver, diff,
+					 sigvalidityinterval, NULL));
+}
+
+struct dns_update_state {
+	unsigned int magic;
+	dns_diff_t diffnames;
+	dns_diff_t affected;
+	dns_diff_t sig_diff;
+	dns_diff_t nsec_diff;
+	dns_diff_t nsec_mindiff;
+	dns_diff_t work;
+	dst_key_t *zone_keys[DNS_MAXZONEKEYS];
+	unsigned int nkeys;
+	isc_stdtime_t inception, expire, soaexpire, keyexpire;
+	dns_ttl_t nsecttl;
+	bool check_ksk, keyset_kskonly, build_nsec3;
+	enum {
+		sign_updates,
+		remove_orphaned,
+		build_chain,
+		process_nsec,
+		sign_nsec,
+		update_nsec3,
+		process_nsec3,
+		sign_nsec3
+	} state;
+};
+
+static uint32_t
+dns__jitter_expire(dns_zone_t *zone, uint32_t sigvalidityinterval) {
+	/* Spread out signatures over time */
+	if (sigvalidityinterval >= 3600U) {
+		uint32_t expiryinterval =
+			dns_zone_getsigresigninginterval(zone);
+
+		if (sigvalidityinterval < 7200U) {
+			expiryinterval = 1200;
+		} else if (expiryinterval > sigvalidityinterval) {
+			expiryinterval = sigvalidityinterval;
+		} else {
+			expiryinterval = sigvalidityinterval - expiryinterval;
+		}
+		uint32_t jitter = isc_random_uniform(expiryinterval);
+		sigvalidityinterval -= jitter;
+	}
+	return (sigvalidityinterval);
+}
+
+isc_result_t
+dns_update_signaturesinc(dns_update_log_t *log, dns_zone_t *zone, dns_db_t *db,
+			 dns_dbversion_t *oldver, dns_dbversion_t *newver,
+			 dns_diff_t *diff, uint32_t sigvalidityinterval,
+			 dns_update_state_t **statep) {
+	isc_result_t result = ISC_R_SUCCESS;
+	dns_update_state_t mystate, *state;
+
+	dns_difftuple_t *t, *next;
+	bool flag, build_nsec;
+	unsigned int i;
+	isc_stdtime_t now;
+	dns_rdata_soa_t soa;
+	dns_rdata_t rdata = DNS_RDATA_INIT;
+	dns_rdataset_t rdataset;
+	dns_dbnode_t *node = NULL;
+	bool unsecure;
+	bool cut;
+	dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);
+	unsigned int sigs = 0;
+	unsigned int maxsigs = dns_zone_getsignatures(zone);
+
+	if (statep == NULL || *statep == NULL) {
+		if (statep == NULL) {
+			state = &mystate;
+		} else {
+			state = isc_mem_get(diff->mctx, sizeof(*state));
+		}
+
+		dns_diff_init(diff->mctx, &state->diffnames);
+		dns_diff_init(diff->mctx, &state->affected);
+		dns_diff_init(diff->mctx, &state->sig_diff);
+		dns_diff_init(diff->mctx, &state->nsec_diff);
+		dns_diff_init(diff->mctx, &state->nsec_mindiff);
+		dns_diff_init(diff->mctx, &state->work);
+		state->nkeys = 0;
+		state->build_nsec3 = false;
+
+		result = find_zone_keys(zone, db, newver, diff->mctx,
+					DNS_MAXZONEKEYS, state->zone_keys,
+					&state->nkeys);
+		if (result != ISC_R_SUCCESS) {
+			update_log(log, zone, ISC_LOG_ERROR,
+				   "could not get zone keys for secure "
+				   "dynamic update");
+			goto failure;
+		}
+
+		isc_stdtime_get(&now);
+		state->inception = now - 3600; /* Allow for some clock skew. */
+		state->expire = now +
+				dns__jitter_expire(zone, sigvalidityinterval);
+		state->soaexpire = now + sigvalidityinterval;
+		state->keyexpire = dns_zone_getkeyvalidityinterval(zone);
+		if (state->keyexpire == 0) {
+			state->keyexpire = state->expire;
+		} else {
+			state->keyexpire += now;
+		}
+
+		/*
+		 * Do we look at the KSK flag on the DNSKEY to determining which
+		 * keys sign which RRsets?  First check the zone option then
+		 * check the keys flags to make sure at least one has a ksk set
+		 * and one doesn't.
+		 */
+		state->check_ksk = ((dns_zone_getoptions(zone) &
+				     DNS_ZONEOPT_UPDATECHECKKSK) != 0);
+		state->keyset_kskonly = ((dns_zone_getoptions(zone) &
+					  DNS_ZONEOPT_DNSKEYKSKONLY) != 0);
+
+		/*
+		 * Calculate the NSEC/NSEC3 TTL as a minimum of the SOA TTL and
+		 * MINIMUM field.
+		 */
+		CHECK(dns_db_findnode(db, dns_db_origin(db), false, &node));
+		dns_rdataset_init(&rdataset);
+		CHECK(dns_db_findrdataset(db, node, newver, dns_rdatatype_soa,
+					  0, (isc_stdtime_t)0, &rdataset,
+					  NULL));
+		CHECK(dns_rdataset_first(&rdataset));
+		dns_rdataset_current(&rdataset, &rdata);
+		CHECK(dns_rdata_tostruct(&rdata, &soa, NULL));
+		state->nsecttl = ISC_MIN(rdataset.ttl, soa.minimum);
+		dns_rdataset_disassociate(&rdataset);
+		dns_db_detachnode(db, &node);
+
+		/*
+		 * Find all RRsets directly affected by the update, and
+		 * update their RRSIGs.  Also build a list of names affected
+		 * by the update in "diffnames".
+		 */
+		CHECK(dns_diff_sort(diff, temp_order));
+		state->state = sign_updates;
+		state->magic = STATE_MAGIC;
+		if (statep != NULL) {
+			*statep = state;
+		}
+	} else {
+		REQUIRE(DNS_STATE_VALID(*statep));
+		state = *statep;
+	}
+
+next_state:
+	switch (state->state) {
+	case sign_updates:
+		t = ISC_LIST_HEAD(diff->tuples);
+		while (t != NULL) {
+			dns_name_t *name = &t->name;
+			/*
+			 * Now "name" is a new, unique name affected by the
+			 * update.
+			 */
+
+			CHECK(namelist_append_name(&state->diffnames, name));
+
+			while (t != NULL && dns_name_equal(&t->name, name)) {
+				dns_rdatatype_t type;
+				type = t->rdata.type;
+
+				/*
+				 * Now "name" and "type" denote a new unique
+				 * RRset affected by the update.
+				 */
+
+				/* Don't sign RRSIGs. */
+				if (type == dns_rdatatype_rrsig) {
+					goto skip;
+				}
+
+				/*
+				 * Delete all old RRSIGs covering this type,
+				 * since they are all invalid when the signed
+				 * RRset has changed.  We may not be able to
+				 * recreate all of them - tough.
+				 * Special case changes to the zone's DNSKEY
+				 * records to support offline KSKs.
+				 */
+				if (type == dns_rdatatype_dnskey) {
+					del_keysigs(db, newver, name,
+						    &state->sig_diff,
+						    state->zone_keys,
+						    state->nkeys);
+				} else {
+					CHECK(delete_if(
+						true_p, db, newver, name,
+						dns_rdatatype_rrsig, type, NULL,
+						&state->sig_diff));
+				}
+
+				/*
+				 * If this RRset is still visible after the
+				 * update, add a new signature for it.
+				 */
+				CHECK(rrset_visible(db, newver, name, type,
+						    &flag));
+				if (flag) {
+					isc_stdtime_t exp;
+					if (type == dns_rdatatype_dnskey ||
+					    type == dns_rdatatype_cdnskey ||
+					    type == dns_rdatatype_cds)
+					{
+						exp = state->keyexpire;
+					} else if (type == dns_rdatatype_soa) {
+						exp = state->soaexpire;
+					} else {
+						exp = state->expire;
+					}
+
+					CHECK(add_sigs(
+						log, zone, db, newver, name,
+						type, &state->sig_diff,
+						state->zone_keys, state->nkeys,
+						state->inception, exp,
+						state->check_ksk,
+						state->keyset_kskonly));
+					sigs++;
+				}
+			skip:
+				/* Skip any other updates to the same RRset. */
+				while (t != NULL &&
+				       dns_name_equal(&t->name, name) &&
+				       t->rdata.type == type)
+				{
+					next = ISC_LIST_NEXT(t, link);
+					ISC_LIST_UNLINK(diff->tuples, t, link);
+					ISC_LIST_APPEND(state->work.tuples, t,
+							link);
+					t = next;
+				}
+			}
+			if (state != &mystate && sigs > maxsigs) {
+				return (DNS_R_CONTINUE);
+			}
+		}
+		ISC_LIST_APPENDLIST(diff->tuples, state->work.tuples, link);
+
+		update_log(log, zone, ISC_LOG_DEBUG(3),
+			   "updated data signatures");
+		FALLTHROUGH;
+	case remove_orphaned:
+		state->state = remove_orphaned;
+
+		/* Remove orphaned NSECs and RRSIG NSECs. */
+		for (t = ISC_LIST_HEAD(state->diffnames.tuples); t != NULL;
+		     t = ISC_LIST_NEXT(t, link))
+		{
+			CHECK(non_nsec_rrset_exists(db, newver, &t->name,
+						    &flag));
+			if (!flag) {
+				CHECK(delete_if(true_p, db, newver, &t->name,
+						dns_rdatatype_any, 0, NULL,
+						&state->sig_diff));
+			}
+		}
+		update_log(log, zone, ISC_LOG_DEBUG(3),
+			   "removed any orphaned NSEC records");
+
+		/*
+		 * See if we need to build NSEC or NSEC3 chains.
+		 */
+		CHECK(dns_private_chains(db, newver, privatetype, &build_nsec,
+					 &state->build_nsec3));
+		if (!build_nsec) {
+			state->state = update_nsec3;
+			goto next_state;
+		}
+
+		update_log(log, zone, ISC_LOG_DEBUG(3),
+			   "rebuilding NSEC chain");
+
+		FALLTHROUGH;
+	case build_chain:
+		state->state = build_chain;
+		/*
+		 * When a name is created or deleted, its predecessor needs to
+		 * have its NSEC updated.
+		 */
+		for (t = ISC_LIST_HEAD(state->diffnames.tuples); t != NULL;
+		     t = ISC_LIST_NEXT(t, link))
+		{
+			bool existed, exists;
+			dns_fixedname_t fixedname;
+			dns_name_t *prevname;
+
+			prevname = dns_fixedname_initname(&fixedname);
+
+			if (oldver != NULL) {
+				CHECK(name_exists(db, oldver, &t->name,
+						  &existed));
+			} else {
+				existed = false;
+			}
+			CHECK(name_exists(db, newver, &t->name, &exists));
+			if (exists == existed) {
+				continue;
+			}
+
+			/*
+			 * Find the predecessor.
+			 * When names become obscured or unobscured in this
+			 * update transaction, we may find the wrong
+			 * predecessor because the NSECs have not yet been
+			 * updated to reflect the delegation change.  This
+			 * should not matter because in this case, the correct
+			 * predecessor is either the delegation node or a
+			 * newly unobscured node, and those nodes are on the
+			 * "affected" list in any case.
+			 */
+			CHECK(next_active(log, zone, db, newver, &t->name,
+					  prevname, false));
+			CHECK(namelist_append_name(&state->affected, prevname));
+		}
+
+		/*
+		 * Find names potentially affected by delegation changes
+		 * (obscured by adding an NS or DNAME, or unobscured by
+		 * removing one).
+		 */
+		for (t = ISC_LIST_HEAD(state->diffnames.tuples); t != NULL;
+		     t = ISC_LIST_NEXT(t, link))
+		{
+			bool ns_existed, dname_existed;
+			bool ns_exists, dname_exists;
+
+			if (oldver != NULL) {
+				CHECK(rrset_exists(db, oldver, &t->name,
+						   dns_rdatatype_ns, 0,
+						   &ns_existed));
+			} else {
+				ns_existed = false;
+			}
+			if (oldver != NULL) {
+				CHECK(rrset_exists(db, oldver, &t->name,
+						   dns_rdatatype_dname, 0,
+						   &dname_existed));
+			} else {
+				dname_existed = false;
+			}
+			CHECK(rrset_exists(db, newver, &t->name,
+					   dns_rdatatype_ns, 0, &ns_exists));
+			CHECK(rrset_exists(db, newver, &t->name,
+					   dns_rdatatype_dname, 0,
+					   &dname_exists));
+			if ((ns_exists || dname_exists) ==
+			    (ns_existed || dname_existed))
+			{
+				continue;
+			}
+			/*
+			 * There was a delegation change.  Mark all subdomains
+			 * of t->name as potentially needing a NSEC update.
+			 */
+			CHECK(namelist_append_subdomain(db, &t->name,
+							&state->affected));
+		}
+		ISC_LIST_APPENDLIST(state->affected.tuples,
+				    state->diffnames.tuples, link);
+		INSIST(ISC_LIST_EMPTY(state->diffnames.tuples));
+
+		CHECK(uniqify_name_list(&state->affected));
+
+		FALLTHROUGH;
+	case process_nsec:
+		state->state = process_nsec;
+
+		/*
+		 * Determine which names should have NSECs, and delete/create
+		 * NSECs to make it so.  We don't know the final NSEC targets
+		 * yet, so we just create placeholder NSECs with arbitrary
+		 * contents to indicate that their respective owner names
+		 * should be part of the NSEC chain.
+		 */
+		while ((t = ISC_LIST_HEAD(state->affected.tuples)) != NULL) {
+			bool exists;
+			dns_name_t *name = &t->name;
+
+			CHECK(name_exists(db, newver, name, &exists));
+			if (!exists) {
+				goto unlink;
+			}
+			CHECK(is_active(db, newver, name, &flag, &cut, NULL));
+			if (!flag) {
+				/*
+				 * This name is obscured.  Delete any
+				 * existing NSEC record.
+				 */
+				CHECK(delete_if(true_p, db, newver, name,
+						dns_rdatatype_nsec, 0, NULL,
+						&state->nsec_diff));
+				CHECK(delete_if(rrsig_p, db, newver, name,
+						dns_rdatatype_any, 0, NULL,
+						diff));
+			} else {
+				/*
+				 * This name is not obscured.  It needs to have
+				 * a NSEC unless it is the at the origin, in
+				 * which case it should already exist if there
+				 * is a complete NSEC chain and if there isn't
+				 * a complete NSEC chain we don't want to add
+				 * one as that would signal that there is a
+				 * complete NSEC chain.
+				 */
+				if (!dns_name_equal(name, dns_db_origin(db))) {
+					CHECK(rrset_exists(db, newver, name,
+							   dns_rdatatype_nsec,
+							   0, &flag));
+					if (!flag) {
+						CHECK(add_placeholder_nsec(
+							db, newver, name,
+							diff));
+					}
+				}
+				CHECK(add_exposed_sigs(
+					log, zone, db, newver, name, cut,
+					&state->sig_diff, state->zone_keys,
+					state->nkeys, state->inception,
+					state->expire, state->check_ksk,
+					state->keyset_kskonly, &sigs));
+			}
+		unlink:
+			ISC_LIST_UNLINK(state->affected.tuples, t, link);
+			ISC_LIST_APPEND(state->work.tuples, t, link);
+			if (state != &mystate && sigs > maxsigs) {
+				return (DNS_R_CONTINUE);
+			}
+		}
+		ISC_LIST_APPENDLIST(state->affected.tuples, state->work.tuples,
+				    link);
+
+		/*
+		 * Now we know which names are part of the NSEC chain.
+		 * Make them all point at their correct targets.
+		 */
+		for (t = ISC_LIST_HEAD(state->affected.tuples); t != NULL;
+		     t = ISC_LIST_NEXT(t, link))
+		{
+			CHECK(rrset_exists(db, newver, &t->name,
+					   dns_rdatatype_nsec, 0, &flag));
+			if (flag) {
+				/*
+				 * There is a NSEC, but we don't know if it
+				 * is correct. Delete it and create a correct
+				 * one to be sure. If the update was
+				 * unnecessary, the diff minimization
+				 * will take care of eliminating it from the
+				 * journal, IXFRs, etc.
+				 *
+				 * The RRSIG bit should always be set in the
+				 * NSECs we generate, because they will all
+				 * get RRSIG NSECs.
+				 * (XXX what if the zone keys are missing?).
+				 * Because the RRSIG NSECs have not necessarily
+				 * been created yet, the correctness of the
+				 * bit mask relies on the assumption that NSECs
+				 * are only created if there is other data, and
+				 * if there is other data, there are other
+				 * RRSIGs.
+				 */
+				CHECK(add_nsec(log, zone, db, newver, &t->name,
+					       state->nsecttl,
+					       &state->nsec_diff));
+			}
+		}
+
+		/*
+		 * Minimize the set of NSEC updates so that we don't
+		 * have to regenerate the RRSIG NSECs for NSECs that were
+		 * replaced with identical ones.
+		 */
+		while ((t = ISC_LIST_HEAD(state->nsec_diff.tuples)) != NULL) {
+			ISC_LIST_UNLINK(state->nsec_diff.tuples, t, link);
+			dns_diff_appendminimal(&state->nsec_mindiff, &t);
+		}
+
+		update_log(log, zone, ISC_LOG_DEBUG(3),
+			   "signing rebuilt NSEC chain");
+
+		FALLTHROUGH;
+	case sign_nsec:
+		state->state = sign_nsec;
+		/* Update RRSIG NSECs. */
+		while ((t = ISC_LIST_HEAD(state->nsec_mindiff.tuples)) != NULL)
+		{
+			if (t->op == DNS_DIFFOP_DEL) {
+				CHECK(delete_if(true_p, db, newver, &t->name,
+						dns_rdatatype_rrsig,
+						dns_rdatatype_nsec, NULL,
+						&state->sig_diff));
+			} else if (t->op == DNS_DIFFOP_ADD) {
+				CHECK(add_sigs(log, zone, db, newver, &t->name,
+					       dns_rdatatype_nsec,
+					       &state->sig_diff,
+					       state->zone_keys, state->nkeys,
+					       state->inception, state->expire,
+					       state->check_ksk,
+					       state->keyset_kskonly));
+				sigs++;
+			} else {
+				UNREACHABLE();
+			}
+			ISC_LIST_UNLINK(state->nsec_mindiff.tuples, t, link);
+			ISC_LIST_APPEND(state->work.tuples, t, link);
+			if (state != &mystate && sigs > maxsigs) {
+				return (DNS_R_CONTINUE);
+			}
+		}
+		ISC_LIST_APPENDLIST(state->nsec_mindiff.tuples,
+				    state->work.tuples, link);
+		FALLTHROUGH;
+	case update_nsec3:
+		state->state = update_nsec3;
+
+		/* Record our changes for the journal. */
+		while ((t = ISC_LIST_HEAD(state->sig_diff.tuples)) != NULL) {
+			ISC_LIST_UNLINK(state->sig_diff.tuples, t, link);
+			dns_diff_appendminimal(diff, &t);
+		}
+		while ((t = ISC_LIST_HEAD(state->nsec_mindiff.tuples)) != NULL)
+		{
+			ISC_LIST_UNLINK(state->nsec_mindiff.tuples, t, link);
+			dns_diff_appendminimal(diff, &t);
+		}
+
+		INSIST(ISC_LIST_EMPTY(state->sig_diff.tuples));
+		INSIST(ISC_LIST_EMPTY(state->nsec_diff.tuples));
+		INSIST(ISC_LIST_EMPTY(state->nsec_mindiff.tuples));
+
+		if (!state->build_nsec3) {
+			update_log(log, zone, ISC_LOG_DEBUG(3),
+				   "no NSEC3 chains to rebuild");
+			goto failure;
+		}
+
+		update_log(log, zone, ISC_LOG_DEBUG(3),
+			   "rebuilding NSEC3 chains");
+
+		dns_diff_clear(&state->diffnames);
+		dns_diff_clear(&state->affected);
+
+		CHECK(dns_diff_sort(diff, temp_order));
+
+		/*
+		 * Find names potentially affected by delegation changes
+		 * (obscured by adding an NS or DNAME, or unobscured by
+		 * removing one).
+		 */
+		t = ISC_LIST_HEAD(diff->tuples);
+		while (t != NULL) {
+			dns_name_t *name = &t->name;
+
+			bool ns_existed, dname_existed;
+			bool ns_exists, dname_exists;
+			bool exists, existed;
+
+			if (t->rdata.type == dns_rdatatype_nsec ||
+			    t->rdata.type == dns_rdatatype_rrsig)
+			{
+				t = ISC_LIST_NEXT(t, link);
+				continue;
+			}
+
+			CHECK(namelist_append_name(&state->affected, name));
+
+			if (oldver != NULL) {
+				CHECK(rrset_exists(db, oldver, name,
+						   dns_rdatatype_ns, 0,
+						   &ns_existed));
+			} else {
+				ns_existed = false;
+			}
+			if (oldver != NULL) {
+				CHECK(rrset_exists(db, oldver, name,
+						   dns_rdatatype_dname, 0,
+						   &dname_existed));
+			} else {
+				dname_existed = false;
+			}
+			CHECK(rrset_exists(db, newver, name, dns_rdatatype_ns,
+					   0, &ns_exists));
+			CHECK(rrset_exists(db, newver, name,
+					   dns_rdatatype_dname, 0,
+					   &dname_exists));
+
+			exists = ns_exists || dname_exists;
+			existed = ns_existed || dname_existed;
+			if (exists == existed) {
+				goto nextname;
+			}
+			/*
+			 * There was a delegation change.  Mark all subdomains
+			 * of t->name as potentially needing a NSEC3 update.
+			 */
+			CHECK(namelist_append_subdomain(db, name,
+							&state->affected));
+
+		nextname:
+			while (t != NULL && dns_name_equal(&t->name, name)) {
+				t = ISC_LIST_NEXT(t, link);
+			}
+		}
+
+		FALLTHROUGH;
+	case process_nsec3:
+		state->state = process_nsec3;
+		while ((t = ISC_LIST_HEAD(state->affected.tuples)) != NULL) {
+			dns_name_t *name = &t->name;
+
+			unsecure = false; /* Silence compiler warning. */
+			CHECK(is_active(db, newver, name, &flag, &cut,
+					&unsecure));
+
+			if (!flag) {
+				CHECK(delete_if(rrsig_p, db, newver, name,
+						dns_rdatatype_any, 0, NULL,
+						diff));
+				CHECK(dns_nsec3_delnsec3sx(db, newver, name,
+							   privatetype,
+							   &state->nsec_diff));
+			} else {
+				CHECK(add_exposed_sigs(
+					log, zone, db, newver, name, cut,
+					&state->sig_diff, state->zone_keys,
+					state->nkeys, state->inception,
+					state->expire, state->check_ksk,
+					state->keyset_kskonly, &sigs));
+				CHECK(dns_nsec3_addnsec3sx(
+					db, newver, name, state->nsecttl,
+					unsecure, privatetype,
+					&state->nsec_diff));
+			}
+			ISC_LIST_UNLINK(state->affected.tuples, t, link);
+			ISC_LIST_APPEND(state->work.tuples, t, link);
+			if (state != &mystate && sigs > maxsigs) {
+				return (DNS_R_CONTINUE);
+			}
+		}
+		ISC_LIST_APPENDLIST(state->affected.tuples, state->work.tuples,
+				    link);
+
+		/*
+		 * Minimize the set of NSEC3 updates so that we don't
+		 * have to regenerate the RRSIG NSEC3s for NSEC3s that were
+		 * replaced with identical ones.
+		 */
+		while ((t = ISC_LIST_HEAD(state->nsec_diff.tuples)) != NULL) {
+			ISC_LIST_UNLINK(state->nsec_diff.tuples, t, link);
+			dns_diff_appendminimal(&state->nsec_mindiff, &t);
+		}
+
+		update_log(log, zone, ISC_LOG_DEBUG(3),
+			   "signing rebuilt NSEC3 chain");
+
+		FALLTHROUGH;
+	case sign_nsec3:
+		state->state = sign_nsec3;
+		/* Update RRSIG NSEC3s. */
+		while ((t = ISC_LIST_HEAD(state->nsec_mindiff.tuples)) != NULL)
+		{
+			if (t->op == DNS_DIFFOP_DEL) {
+				CHECK(delete_if(true_p, db, newver, &t->name,
+						dns_rdatatype_rrsig,
+						dns_rdatatype_nsec3, NULL,
+						&state->sig_diff));
+			} else if (t->op == DNS_DIFFOP_ADD) {
+				CHECK(add_sigs(log, zone, db, newver, &t->name,
+					       dns_rdatatype_nsec3,
+					       &state->sig_diff,
+					       state->zone_keys, state->nkeys,
+					       state->inception, state->expire,
+					       state->check_ksk,
+					       state->keyset_kskonly));
+				sigs++;
+			} else {
+				UNREACHABLE();
+			}
+			ISC_LIST_UNLINK(state->nsec_mindiff.tuples, t, link);
+			ISC_LIST_APPEND(state->work.tuples, t, link);
+			if (state != &mystate && sigs > maxsigs) {
+				return (DNS_R_CONTINUE);
+			}
+		}
+		ISC_LIST_APPENDLIST(state->nsec_mindiff.tuples,
+				    state->work.tuples, link);
+
+		/* Record our changes for the journal. */
+		while ((t = ISC_LIST_HEAD(state->sig_diff.tuples)) != NULL) {
+			ISC_LIST_UNLINK(state->sig_diff.tuples, t, link);
+			dns_diff_appendminimal(diff, &t);
+		}
+		while ((t = ISC_LIST_HEAD(state->nsec_mindiff.tuples)) != NULL)
+		{
+			ISC_LIST_UNLINK(state->nsec_mindiff.tuples, t, link);
+			dns_diff_appendminimal(diff, &t);
+		}
+
+		INSIST(ISC_LIST_EMPTY(state->sig_diff.tuples));
+		INSIST(ISC_LIST_EMPTY(state->nsec_diff.tuples));
+		INSIST(ISC_LIST_EMPTY(state->nsec_mindiff.tuples));
+		break;
+	default:
+		UNREACHABLE();
+	}
+
+failure:
+	if (node != NULL) {
+		dns_db_detachnode(db, &node);
+	}
+
+	dns_diff_clear(&state->sig_diff);
+	dns_diff_clear(&state->nsec_diff);
+	dns_diff_clear(&state->nsec_mindiff);
+
+	dns_diff_clear(&state->affected);
+	dns_diff_clear(&state->diffnames);
+	dns_diff_clear(&state->work);
+
+	for (i = 0; i < state->nkeys; i++) {
+		dst_key_free(&state->zone_keys[i]);
+	}
+
+	if (state != &mystate) {
+		*statep = NULL;
+		state->magic = 0;
+		isc_mem_put(diff->mctx, state, sizeof(*state));
+	}
+
+	return (result);
+}
+
+static isc_stdtime_t
+epoch_to_yyyymmdd(time_t when) {
+	struct tm t, *tm = localtime_r(&when, &t);
+	if (tm == NULL) {
+		return (0);
+	}
+	return (((tm->tm_year + 1900) * 10000) + ((tm->tm_mon + 1) * 100) +
+		tm->tm_mday);
+}
+
+static uint32_t
+dns__update_soaserial(uint32_t serial, dns_updatemethod_t method) {
+	isc_stdtime_t now;
+
+	switch (method) {
+	case dns_updatemethod_none:
+		return (serial);
+	case dns_updatemethod_unixtime:
+		isc_stdtime_get(&now);
+		return (now);
+	case dns_updatemethod_date:
+		isc_stdtime_get(&now);
+		return (epoch_to_yyyymmdd((time_t)now) * 100);
+	case dns_updatemethod_increment:
+		/* RFC1982 */
+		serial = (serial + 1) & 0xFFFFFFFF;
+		if (serial == 0) {
+			return (1);
+		}
+		return (serial);
+	default:
+		UNREACHABLE();
+	}
+}
+
+uint32_t
+dns_update_soaserial(uint32_t serial, dns_updatemethod_t method,
+		     dns_updatemethod_t *used) {
+	uint32_t new_serial = dns__update_soaserial(serial, method);
+	switch (method) {
+	case dns_updatemethod_none:
+	case dns_updatemethod_increment:
+		break;
+	case dns_updatemethod_unixtime:
+	case dns_updatemethod_date:
+		if (!(new_serial != 0 && isc_serial_gt(new_serial, serial))) {
+			/*
+			 * If the new date serial following YYYYMMDD00 is equal
+			 * to or smaller than the current serial, but YYYYMMDD99
+			 * would be larger, pretend we have used the
+			 * "dns_updatemethod_date" method.
+			 */
+			if (method == dns_updatemethod_unixtime ||
+			    !isc_serial_gt(new_serial + 99, serial))
+			{
+				method = dns_updatemethod_increment;
+			}
+			new_serial = dns__update_soaserial(
+				serial, dns_updatemethod_increment);
+		}
+		break;
+	default:
+		UNREACHABLE();
+	}
+
+	if (used != NULL) {
+		*used = method;
+	}
+
+	return (new_serial);
+}