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

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

34 files changed, 4216 insertions, 0 deletions

diff --git a/lib/isccc/Kyuafile b/lib/isccc/Kyuafile
new file mode 100644
index 0000000..c796010
--- /dev/null
+++ b/lib/isccc/Kyuafile
@@ -0,0 +1,15 @@
+-- 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.
+
+syntax(2)
+test_suite('bind9')
+
+include('tests/Kyuafile')
diff --git a/lib/isccc/Makefile.in b/lib/isccc/Makefile.in
new file mode 100644
index 0000000..b542441
--- /dev/null
+++ b/lib/isccc/Makefile.in
@@ -0,0 +1,81 @@
+# 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.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+VERSION=@BIND9_VERSION@
+
+@BIND9_MAKE_INCLUDES@
+
+CINCLUDES =	-I. ${DNS_INCLUDES} ${ISC_INCLUDES} \
+		${ISCCC_INCLUDES} \
+		${OPENSSL_CFLAGS}
+
+CDEFINES =
+CWARNINGS =
+
+ISCLIBS =	../../lib/isc/libisc.@A@ @NO_LIBTOOL_ISCLIBS@
+ISCCCLIBS =	../../lib/isccc/libisccc.@A@
+
+ISCDEPLIBS =	../../lib/isc/libisc.@A@
+ISCCCDEPLIBS =	libisccc.@A@
+
+LIBS =		@LIBS@
+
+SUBDIRS =	include
+
+# Alphabetically
+OBJS =		alist.@O@ base64.@O@ cc.@O@ ccmsg.@O@ \
+		result.@O@ sexpr.@O@ symtab.@O@ version.@O@
+
+# Alphabetically
+SRCS =		alist.c base64.c cc.c ccmsg.c \
+		result.c sexpr.c symtab.c version.c
+
+
+TARGETS = 	timestamp
+TESTDIRS =	@UNITTESTS@
+
+@BIND9_MAKE_RULES@
+
+version.@O@: version.c
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} \
+		-DVERSION=\"${VERSION}\" \
+		-c ${srcdir}/version.c
+
+libisccc.@SA@: ${OBJS}
+	${AR} ${ARFLAGS} $@ ${OBJS}
+	${RANLIB} $@
+
+libisccc.la: ${OBJS}
+	${LIBTOOL_MODE_LINK} \
+		${CC} ${ALL_CFLAGS} ${LDFLAGS} -o libisccc.la -rpath ${libdir} \
+		-release "${VERSION}" \
+		${OBJS} ${ISCLIBS} ${LIBS}
+
+timestamp: libisccc.@A@
+	touch timestamp
+
+testdirs: libisccc.@A@
+
+installdirs:
+	$(SHELL) ${top_srcdir}/mkinstalldirs ${DESTDIR}${libdir}
+
+install:: timestamp installdirs
+	${LIBTOOL_MODE_INSTALL} ${INSTALL_LIBRARY} libisccc.@A@ ${DESTDIR}${libdir}
+
+uninstall::
+	${LIBTOOL_MODE_UNINSTALL} rm -f ${DESTDIR}${libdir}/libisccc.@A@
+
+clean distclean::
+	rm -f libisccc.@A@ timestamp
diff --git a/lib/isccc/alist.c b/lib/isccc/alist.c
new file mode 100644
index 0000000..a39d4f9
--- /dev/null
+++ b/lib/isccc/alist.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/assertions.h>
+#include <isc/print.h>
+
+#include <isccc/alist.h>
+#include <isccc/result.h>
+#include <isccc/sexpr.h>
+#include <isccc/util.h>
+
+#define CAR(s) (s)->value.as_dottedpair.car
+#define CDR(s) (s)->value.as_dottedpair.cdr
+
+#define ALIST_TAG  "*alist*"
+#define MAX_INDENT 64
+
+static char spaces[MAX_INDENT + 1] = "                                         "
+				     "                       ";
+
+isccc_sexpr_t *
+isccc_alist_create(void) {
+	isccc_sexpr_t *alist, *tag;
+
+	tag = isccc_sexpr_fromstring(ALIST_TAG);
+	if (tag == NULL) {
+		return (NULL);
+	}
+	alist = isccc_sexpr_cons(tag, NULL);
+	if (alist == NULL) {
+		isccc_sexpr_free(&tag);
+		return (NULL);
+	}
+
+	return (alist);
+}
+
+bool
+isccc_alist_alistp(isccc_sexpr_t *alist) {
+	isccc_sexpr_t *car;
+
+	if (alist == NULL || alist->type != ISCCC_SEXPRTYPE_DOTTEDPAIR) {
+		return (false);
+	}
+	car = CAR(alist);
+	if (car == NULL || car->type != ISCCC_SEXPRTYPE_STRING) {
+		return (false);
+	}
+	if (strcmp(car->value.as_string, ALIST_TAG) != 0) {
+		return (false);
+	}
+	return (true);
+}
+
+bool
+isccc_alist_emptyp(isccc_sexpr_t *alist) {
+	REQUIRE(isccc_alist_alistp(alist));
+
+	if (CDR(alist) == NULL) {
+		return (true);
+	}
+	return (false);
+}
+
+isccc_sexpr_t *
+isccc_alist_first(isccc_sexpr_t *alist) {
+	REQUIRE(isccc_alist_alistp(alist));
+
+	return (CDR(alist));
+}
+
+isccc_sexpr_t *
+isccc_alist_assq(isccc_sexpr_t *alist, const char *key) {
+	isccc_sexpr_t *car, *caar;
+
+	REQUIRE(isccc_alist_alistp(alist));
+
+	/*
+	 * Skip alist type tag.
+	 */
+	alist = CDR(alist);
+
+	while (alist != NULL) {
+		INSIST(alist->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+		car = CAR(alist);
+		INSIST(car->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+		caar = CAR(car);
+		if (caar->type == ISCCC_SEXPRTYPE_STRING &&
+		    strcmp(caar->value.as_string, key) == 0)
+		{
+			return (car);
+		}
+		alist = CDR(alist);
+	}
+
+	return (NULL);
+}
+
+void
+isccc_alist_delete(isccc_sexpr_t *alist, const char *key) {
+	isccc_sexpr_t *car, *caar, *rest, *prev;
+
+	REQUIRE(isccc_alist_alistp(alist));
+
+	prev = alist;
+	rest = CDR(alist);
+	while (rest != NULL) {
+		INSIST(rest->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+		car = CAR(rest);
+		INSIST(car != NULL && car->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+		caar = CAR(car);
+		if (caar->type == ISCCC_SEXPRTYPE_STRING &&
+		    strcmp(caar->value.as_string, key) == 0)
+		{
+			CDR(prev) = CDR(rest);
+			CDR(rest) = NULL;
+			isccc_sexpr_free(&rest);
+			break;
+		}
+		prev = rest;
+		rest = CDR(rest);
+	}
+}
+
+isccc_sexpr_t *
+isccc_alist_define(isccc_sexpr_t *alist, const char *key,
+		   isccc_sexpr_t *value) {
+	isccc_sexpr_t *kv, *k, *elt;
+
+	kv = isccc_alist_assq(alist, key);
+	if (kv == NULL) {
+		/*
+		 * New association.
+		 */
+		k = isccc_sexpr_fromstring(key);
+		if (k == NULL) {
+			return (NULL);
+		}
+		kv = isccc_sexpr_cons(k, value);
+		if (kv == NULL) {
+			isccc_sexpr_free(&kv);
+			return (NULL);
+		}
+		elt = isccc_sexpr_addtolist(&alist, kv);
+		if (elt == NULL) {
+			isccc_sexpr_free(&kv);
+			return (NULL);
+		}
+	} else {
+		/*
+		 * We've already got an entry for this key.  Replace it.
+		 */
+		isccc_sexpr_free(&CDR(kv));
+		CDR(kv) = value;
+	}
+
+	return (kv);
+}
+
+isccc_sexpr_t *
+isccc_alist_definestring(isccc_sexpr_t *alist, const char *key,
+			 const char *str) {
+	isccc_sexpr_t *v, *kv;
+
+	v = isccc_sexpr_fromstring(str);
+	if (v == NULL) {
+		return (NULL);
+	}
+	kv = isccc_alist_define(alist, key, v);
+	if (kv == NULL) {
+		isccc_sexpr_free(&v);
+	}
+
+	return (kv);
+}
+
+isccc_sexpr_t *
+isccc_alist_definebinary(isccc_sexpr_t *alist, const char *key,
+			 isccc_region_t *r) {
+	isccc_sexpr_t *v, *kv;
+
+	v = isccc_sexpr_frombinary(r);
+	if (v == NULL) {
+		return (NULL);
+	}
+	kv = isccc_alist_define(alist, key, v);
+	if (kv == NULL) {
+		isccc_sexpr_free(&v);
+	}
+
+	return (kv);
+}
+
+isccc_sexpr_t *
+isccc_alist_lookup(isccc_sexpr_t *alist, const char *key) {
+	isccc_sexpr_t *kv;
+
+	kv = isccc_alist_assq(alist, key);
+	if (kv != NULL) {
+		return (CDR(kv));
+	}
+	return (NULL);
+}
+
+isc_result_t
+isccc_alist_lookupstring(isccc_sexpr_t *alist, const char *key, char **strp) {
+	isccc_sexpr_t *kv, *v;
+
+	kv = isccc_alist_assq(alist, key);
+	if (kv != NULL) {
+		v = CDR(kv);
+		if (isccc_sexpr_stringp(v)) {
+			if (strp != NULL) {
+				*strp = isccc_sexpr_tostring(v);
+			}
+			return (ISC_R_SUCCESS);
+		} else {
+			return (ISC_R_EXISTS);
+		}
+	}
+
+	return (ISC_R_NOTFOUND);
+}
+
+isc_result_t
+isccc_alist_lookupbinary(isccc_sexpr_t *alist, const char *key,
+			 isccc_region_t **r) {
+	isccc_sexpr_t *kv, *v;
+
+	kv = isccc_alist_assq(alist, key);
+	if (kv != NULL) {
+		v = CDR(kv);
+		if (isccc_sexpr_binaryp(v)) {
+			if (r != NULL) {
+				*r = isccc_sexpr_tobinary(v);
+			}
+			return (ISC_R_SUCCESS);
+		} else {
+			return (ISC_R_EXISTS);
+		}
+	}
+
+	return (ISC_R_NOTFOUND);
+}
+
+void
+isccc_alist_prettyprint(isccc_sexpr_t *sexpr, unsigned int indent,
+			FILE *stream) {
+	isccc_sexpr_t *elt, *kv, *k, *v;
+
+	if (isccc_alist_alistp(sexpr)) {
+		fprintf(stream, "{\n");
+		indent += 4;
+		for (elt = isccc_alist_first(sexpr); elt != NULL;
+		     elt = CDR(elt))
+		{
+			kv = CAR(elt);
+			INSIST(isccc_sexpr_listp(kv));
+			k = CAR(kv);
+			v = CDR(kv);
+			INSIST(isccc_sexpr_stringp(k));
+			fprintf(stream, "%.*s%s => ", (int)indent, spaces,
+				isccc_sexpr_tostring(k));
+			isccc_alist_prettyprint(v, indent, stream);
+			if (CDR(elt) != NULL) {
+				fprintf(stream, ",");
+			}
+			fprintf(stream, "\n");
+		}
+		indent -= 4;
+		fprintf(stream, "%.*s}", (int)indent, spaces);
+	} else if (isccc_sexpr_listp(sexpr)) {
+		fprintf(stream, "(\n");
+		indent += 4;
+		for (elt = sexpr; elt != NULL; elt = CDR(elt)) {
+			fprintf(stream, "%.*s", (int)indent, spaces);
+			isccc_alist_prettyprint(CAR(elt), indent, stream);
+			if (CDR(elt) != NULL) {
+				fprintf(stream, ",");
+			}
+			fprintf(stream, "\n");
+		}
+		indent -= 4;
+		fprintf(stream, "%.*s)", (int)indent, spaces);
+	} else {
+		isccc_sexpr_print(sexpr, stream);
+	}
+}
diff --git a/lib/isccc/base64.c b/lib/isccc/base64.c
new file mode 100644
index 0000000..344d96a
--- /dev/null
+++ b/lib/isccc/base64.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <isc/base64.h>
+#include <isc/buffer.h>
+#include <isc/region.h>
+#include <isc/result.h>
+
+#include <isccc/base64.h>
+#include <isccc/result.h>
+#include <isccc/util.h>
+
+isc_result_t
+isccc_base64_encode(isccc_region_t *source, int wordlength,
+		    const char *wordbreak, isccc_region_t *target) {
+	isc_region_t sr;
+	isc_buffer_t tb;
+	isc_result_t result;
+
+	sr.base = source->rstart;
+	sr.length = (unsigned int)(source->rend - source->rstart);
+	isc_buffer_init(&tb, target->rstart,
+			(unsigned int)(target->rend - target->rstart));
+
+	result = isc_base64_totext(&sr, wordlength, wordbreak, &tb);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	source->rstart = source->rend;
+	target->rstart = isc_buffer_used(&tb);
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_base64_decode(const char *cstr, isccc_region_t *target) {
+	isc_buffer_t b;
+	isc_result_t result;
+
+	isc_buffer_init(&b, target->rstart,
+			(unsigned int)(target->rend - target->rstart));
+	result = isc_base64_decodestring(cstr, &b);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	target->rstart = isc_buffer_used(&b);
+	return (ISC_R_SUCCESS);
+}
diff --git a/lib/isccc/cc.c b/lib/isccc/cc.c
new file mode 100644
index 0000000..5a716bd
--- /dev/null
+++ b/lib/isccc/cc.c
@@ -0,0 +1,1059 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/assertions.h>
+#include <isc/hmac.h>
+#include <isc/print.h>
+#include <isc/safe.h>
+
+#include <pk11/site.h>
+
+#include <isccc/alist.h>
+#include <isccc/base64.h>
+#include <isccc/cc.h>
+#include <isccc/result.h>
+#include <isccc/sexpr.h>
+#include <isccc/symtab.h>
+#include <isccc/symtype.h>
+#include <isccc/util.h>
+
+#define MAX_TAGS     256
+#define DUP_LIFETIME 900
+#ifndef ISCCC_MAXDEPTH
+#define ISCCC_MAXDEPTH \
+	10 /* Big enough for rndc which just sends a string each way. */
+#endif
+
+typedef isccc_sexpr_t *sexpr_ptr;
+
+static unsigned char auth_hmd5[] = {
+	0x05, 0x5f, 0x61, 0x75, 0x74, 0x68, /*%< len + _auth */
+	ISCCC_CCMSGTYPE_TABLE,		    /*%< message type */
+	0x00, 0x00, 0x00, 0x20,		    /*%< length == 32 */
+	0x04, 0x68, 0x6d, 0x64, 0x35,	    /*%< len + hmd5 */
+	ISCCC_CCMSGTYPE_BINARYDATA,	    /*%< message type */
+	0x00, 0x00, 0x00, 0x16,		    /*%< length == 22 */
+	/*
+	 * The base64 encoding of one of our HMAC-MD5 signatures is
+	 * 22 bytes.
+	 */
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+#define HMD5_OFFSET 21 /*%< 21 = 6 + 1 + 4 + 5 + 1 + 4 */
+#define HMD5_LENGTH 22
+
+static unsigned char auth_hsha[] = {
+	0x05, 0x5f, 0x61, 0x75, 0x74, 0x68, /*%< len + _auth */
+	ISCCC_CCMSGTYPE_TABLE,		    /*%< message type */
+	0x00, 0x00, 0x00, 0x63,		    /*%< length == 99 */
+	0x04, 0x68, 0x73, 0x68, 0x61,	    /*%< len + hsha */
+	ISCCC_CCMSGTYPE_BINARYDATA,	    /*%< message type */
+	0x00, 0x00, 0x00, 0x59,		    /*%< length == 89 */
+	0x00,				    /*%< algorithm */
+	/*
+	 * The base64 encoding of one of our HMAC-SHA* signatures is
+	 * 88 bytes.
+	 */
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00
+};
+
+#define HSHA_OFFSET 22 /*%< 21 = 6 + 1 + 4 + 5 + 1 + 4 + 1 */
+#define HSHA_LENGTH 88
+
+static isc_result_t
+table_towire(isccc_sexpr_t *alist, isc_buffer_t **buffer);
+
+static isc_result_t
+list_towire(isccc_sexpr_t *alist, isc_buffer_t **buffer);
+
+static isc_result_t
+value_towire(isccc_sexpr_t *elt, isc_buffer_t **buffer) {
+	unsigned int len;
+	isccc_region_t *vr;
+	isc_result_t result;
+
+	if (isccc_sexpr_binaryp(elt)) {
+		vr = isccc_sexpr_tobinary(elt);
+		len = REGION_SIZE(*vr);
+		result = isc_buffer_reserve(buffer, 1 + 4);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_NOSPACE);
+		}
+		isc_buffer_putuint8(*buffer, ISCCC_CCMSGTYPE_BINARYDATA);
+		isc_buffer_putuint32(*buffer, len);
+
+		result = isc_buffer_reserve(buffer, len);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_NOSPACE);
+		}
+		isc_buffer_putmem(*buffer, vr->rstart, len);
+	} else if (isccc_alist_alistp(elt)) {
+		unsigned int used;
+		isc_buffer_t b;
+
+		result = isc_buffer_reserve(buffer, 1 + 4);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_NOSPACE);
+		}
+		isc_buffer_putuint8(*buffer, ISCCC_CCMSGTYPE_TABLE);
+		/*
+		 * Emit a placeholder length.
+		 */
+		used = (*buffer)->used;
+		isc_buffer_putuint32(*buffer, 0);
+
+		/*
+		 * Emit the table.
+		 */
+		result = table_towire(elt, buffer);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+
+		len = (*buffer)->used - used;
+		/*
+		 * 'len' is 4 bytes too big, since it counts
+		 * the placeholder length too.	Adjust and
+		 * emit.
+		 */
+		INSIST(len >= 4U);
+		len -= 4;
+
+		isc_buffer_init(&b, (unsigned char *)(*buffer)->base + used, 4);
+		isc_buffer_putuint32(&b, len);
+	} else if (isccc_sexpr_listp(elt)) {
+		unsigned int used;
+		isc_buffer_t b;
+
+		result = isc_buffer_reserve(buffer, 1 + 4);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_NOSPACE);
+		}
+		isc_buffer_putuint8(*buffer, ISCCC_CCMSGTYPE_LIST);
+		/*
+		 * Emit a placeholder length.
+		 */
+		used = (*buffer)->used;
+		isc_buffer_putuint32(*buffer, 0);
+
+		/*
+		 * Emit the list.
+		 */
+		result = list_towire(elt, buffer);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+
+		len = (*buffer)->used - used;
+		/*
+		 * 'len' is 4 bytes too big, since it counts
+		 * the placeholder length too.	Adjust and
+		 * emit.
+		 */
+		INSIST(len >= 4U);
+		len -= 4;
+
+		isc_buffer_init(&b, (unsigned char *)(*buffer)->base + used, 4);
+		isc_buffer_putuint32(&b, len);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+table_towire(isccc_sexpr_t *alist, isc_buffer_t **buffer) {
+	isccc_sexpr_t *kv, *elt, *k, *v;
+	char *ks;
+	isc_result_t result;
+	unsigned int len;
+
+	for (elt = isccc_alist_first(alist); elt != NULL;
+	     elt = ISCCC_SEXPR_CDR(elt))
+	{
+		kv = ISCCC_SEXPR_CAR(elt);
+		k = ISCCC_SEXPR_CAR(kv);
+		ks = isccc_sexpr_tostring(k);
+		v = ISCCC_SEXPR_CDR(kv);
+		len = (unsigned int)strlen(ks);
+		INSIST(len <= 255U);
+		/*
+		 * Emit the key name.
+		 */
+		result = isc_buffer_reserve(buffer, 1 + len);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_NOSPACE);
+		}
+		isc_buffer_putuint8(*buffer, (uint8_t)len);
+		isc_buffer_putmem(*buffer, (const unsigned char *)ks, len);
+		/*
+		 * Emit the value.
+		 */
+		result = value_towire(v, buffer);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+list_towire(isccc_sexpr_t *list, isc_buffer_t **buffer) {
+	isc_result_t result;
+
+	while (list != NULL) {
+		result = value_towire(ISCCC_SEXPR_CAR(list), buffer);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		list = ISCCC_SEXPR_CDR(list);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+sign(unsigned char *data, unsigned int length, unsigned char *hmac,
+     uint32_t algorithm, isccc_region_t *secret) {
+	const isc_md_type_t *md_type;
+	isc_result_t result;
+	isccc_region_t source, target;
+	unsigned char digest[ISC_MAX_MD_SIZE];
+	unsigned int digestlen;
+	unsigned char digestb64[HSHA_LENGTH + 4];
+
+	source.rstart = digest;
+
+	switch (algorithm) {
+	case ISCCC_ALG_HMACMD5:
+		md_type = ISC_MD_MD5;
+		break;
+	case ISCCC_ALG_HMACSHA1:
+		md_type = ISC_MD_SHA1;
+		break;
+	case ISCCC_ALG_HMACSHA224:
+		md_type = ISC_MD_SHA224;
+		break;
+	case ISCCC_ALG_HMACSHA256:
+		md_type = ISC_MD_SHA256;
+		break;
+	case ISCCC_ALG_HMACSHA384:
+		md_type = ISC_MD_SHA384;
+		break;
+	case ISCCC_ALG_HMACSHA512:
+		md_type = ISC_MD_SHA512;
+		break;
+	default:
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	result = isc_hmac(md_type, secret->rstart, REGION_SIZE(*secret), data,
+			  length, digest, &digestlen);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	source.rend = digest + digestlen;
+
+	memset(digestb64, 0, sizeof(digestb64));
+	target.rstart = digestb64;
+	target.rend = digestb64 + sizeof(digestb64);
+	result = isccc_base64_encode(&source, 64, "", &target);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	if (algorithm == ISCCC_ALG_HMACMD5) {
+		PUT_MEM(digestb64, HMD5_LENGTH, hmac);
+	} else {
+		PUT_MEM(digestb64, HSHA_LENGTH, hmac);
+	}
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_cc_towire(isccc_sexpr_t *alist, isc_buffer_t **buffer, uint32_t algorithm,
+		isccc_region_t *secret) {
+	unsigned int hmac_base, signed_base;
+	isc_result_t result;
+
+	result = isc_buffer_reserve(buffer,
+				    4 + ((algorithm == ISCCC_ALG_HMACMD5)
+						 ? sizeof(auth_hmd5)
+						 : sizeof(auth_hsha)));
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOSPACE);
+	}
+
+	/*
+	 * Emit protocol version.
+	 */
+	isc_buffer_putuint32(*buffer, 1);
+
+	if (secret != NULL) {
+		/*
+		 * Emit _auth section with zeroed HMAC signature.
+		 * We'll replace the zeros with the real signature once
+		 * we know what it is.
+		 */
+		if (algorithm == ISCCC_ALG_HMACMD5) {
+			hmac_base = (*buffer)->used + HMD5_OFFSET;
+			isc_buffer_putmem(*buffer, auth_hmd5,
+					  sizeof(auth_hmd5));
+		} else {
+			unsigned char *hmac_alg;
+
+			hmac_base = (*buffer)->used + HSHA_OFFSET;
+			hmac_alg = (unsigned char *)isc_buffer_used(*buffer) +
+				   HSHA_OFFSET - 1;
+			isc_buffer_putmem(*buffer, auth_hsha,
+					  sizeof(auth_hsha));
+			*hmac_alg = algorithm;
+		}
+	} else {
+		hmac_base = 0;
+	}
+	signed_base = (*buffer)->used;
+	/*
+	 * Delete any existing _auth section so that we don't try
+	 * to encode it.
+	 */
+	isccc_alist_delete(alist, "_auth");
+	/*
+	 * Emit the message.
+	 */
+	result = table_towire(alist, buffer);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	if (secret != NULL) {
+		return (sign((unsigned char *)(*buffer)->base + signed_base,
+			     (*buffer)->used - signed_base,
+			     (unsigned char *)(*buffer)->base + hmac_base,
+			     algorithm, secret));
+	}
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+verify(isccc_sexpr_t *alist, unsigned char *data, unsigned int length,
+       uint32_t algorithm, isccc_region_t *secret) {
+	const isc_md_type_t *md_type;
+	isccc_region_t source;
+	isccc_region_t target;
+	isc_result_t result;
+	isccc_sexpr_t *_auth, *hmac;
+	unsigned char digest[ISC_MAX_MD_SIZE];
+	unsigned int digestlen;
+	unsigned char digestb64[HSHA_LENGTH * 4];
+
+	/*
+	 * Extract digest.
+	 */
+	_auth = isccc_alist_lookup(alist, "_auth");
+	if (!isccc_alist_alistp(_auth)) {
+		return (ISC_R_FAILURE);
+	}
+	if (algorithm == ISCCC_ALG_HMACMD5) {
+		hmac = isccc_alist_lookup(_auth, "hmd5");
+	} else {
+		hmac = isccc_alist_lookup(_auth, "hsha");
+	}
+	if (!isccc_sexpr_binaryp(hmac)) {
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * Compute digest.
+	 */
+	source.rstart = digest;
+
+	switch (algorithm) {
+	case ISCCC_ALG_HMACMD5:
+		md_type = ISC_MD_MD5;
+		break;
+	case ISCCC_ALG_HMACSHA1:
+		md_type = ISC_MD_SHA1;
+		break;
+	case ISCCC_ALG_HMACSHA224:
+		md_type = ISC_MD_SHA224;
+		break;
+	case ISCCC_ALG_HMACSHA256:
+		md_type = ISC_MD_SHA256;
+		break;
+	case ISCCC_ALG_HMACSHA384:
+		md_type = ISC_MD_SHA384;
+		break;
+	case ISCCC_ALG_HMACSHA512:
+		md_type = ISC_MD_SHA512;
+		break;
+	default:
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	result = isc_hmac(md_type, secret->rstart, REGION_SIZE(*secret), data,
+			  length, digest, &digestlen);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	source.rend = digest + digestlen;
+
+	target.rstart = digestb64;
+	target.rend = digestb64 + sizeof(digestb64);
+	memset(digestb64, 0, sizeof(digestb64));
+	result = isccc_base64_encode(&source, 64, "", &target);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	/*
+	 * Verify.
+	 */
+	if (algorithm == ISCCC_ALG_HMACMD5) {
+		isccc_region_t *region;
+		unsigned char *value;
+
+		region = isccc_sexpr_tobinary(hmac);
+		if ((region->rend - region->rstart) != HMD5_LENGTH) {
+			return (ISCCC_R_BADAUTH);
+		}
+		value = region->rstart;
+		if (!isc_safe_memequal(value, digestb64, HMD5_LENGTH)) {
+			return (ISCCC_R_BADAUTH);
+		}
+	} else {
+		isccc_region_t *region;
+		unsigned char *value;
+		uint32_t valalg;
+
+		region = isccc_sexpr_tobinary(hmac);
+
+		/*
+		 * Note: with non-MD5 algorithms, there's an extra octet
+		 * to identify which algorithm is in use.
+		 */
+		if ((region->rend - region->rstart) != HSHA_LENGTH + 1) {
+			return (ISCCC_R_BADAUTH);
+		}
+		value = region->rstart;
+		GET8(valalg, value);
+		if ((valalg != algorithm) ||
+		    !isc_safe_memequal(value, digestb64, HSHA_LENGTH))
+		{
+			return (ISCCC_R_BADAUTH);
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+table_fromwire(isccc_region_t *source, isccc_region_t *secret,
+	       uint32_t algorithm, unsigned int depth, isccc_sexpr_t **alistp);
+
+static isc_result_t
+list_fromwire(isccc_region_t *source, unsigned int depth,
+	      isccc_sexpr_t **listp);
+
+static isc_result_t
+value_fromwire(isccc_region_t *source, unsigned int depth,
+	       isccc_sexpr_t **valuep) {
+	unsigned int msgtype;
+	uint32_t len;
+	isccc_sexpr_t *value;
+	isccc_region_t active;
+	isc_result_t result;
+
+	if (depth > ISCCC_MAXDEPTH) {
+		return (ISCCC_R_MAXDEPTH);
+	}
+
+	if (REGION_SIZE(*source) < 1 + 4) {
+		return (ISC_R_UNEXPECTEDEND);
+	}
+	GET8(msgtype, source->rstart);
+	GET32(len, source->rstart);
+	if (REGION_SIZE(*source) < len) {
+		return (ISC_R_UNEXPECTEDEND);
+	}
+	active.rstart = source->rstart;
+	active.rend = active.rstart + len;
+	source->rstart = active.rend;
+	if (msgtype == ISCCC_CCMSGTYPE_BINARYDATA) {
+		value = isccc_sexpr_frombinary(&active);
+		if (value != NULL) {
+			*valuep = value;
+			result = ISC_R_SUCCESS;
+		} else {
+			result = ISC_R_NOMEMORY;
+		}
+	} else if (msgtype == ISCCC_CCMSGTYPE_TABLE) {
+		result = table_fromwire(&active, NULL, 0, depth + 1, valuep);
+	} else if (msgtype == ISCCC_CCMSGTYPE_LIST) {
+		result = list_fromwire(&active, depth + 1, valuep);
+	} else {
+		result = ISCCC_R_SYNTAX;
+	}
+
+	return (result);
+}
+
+static isc_result_t
+table_fromwire(isccc_region_t *source, isccc_region_t *secret,
+	       uint32_t algorithm, unsigned int depth, isccc_sexpr_t **alistp) {
+	char key[256];
+	uint32_t len;
+	isc_result_t result;
+	isccc_sexpr_t *alist, *value;
+	bool first_tag;
+	unsigned char *checksum_rstart;
+
+	REQUIRE(alistp != NULL && *alistp == NULL);
+
+	if (depth > ISCCC_MAXDEPTH) {
+		return (ISCCC_R_MAXDEPTH);
+	}
+
+	checksum_rstart = NULL;
+	first_tag = true;
+	alist = isccc_alist_create();
+	if (alist == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	while (!REGION_EMPTY(*source)) {
+		GET8(len, source->rstart);
+		if (REGION_SIZE(*source) < len) {
+			result = ISC_R_UNEXPECTEDEND;
+			goto bad;
+		}
+		GET_MEM(key, len, source->rstart);
+		key[len] = '\0'; /* Ensure NUL termination. */
+		value = NULL;
+		result = value_fromwire(source, depth + 1, &value);
+		if (result != ISC_R_SUCCESS) {
+			goto bad;
+		}
+		if (isccc_alist_define(alist, key, value) == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto bad;
+		}
+		if (first_tag && secret != NULL && strcmp(key, "_auth") == 0) {
+			checksum_rstart = source->rstart;
+		}
+		first_tag = false;
+	}
+
+	if (secret != NULL) {
+		if (checksum_rstart != NULL) {
+			result = verify(
+				alist, checksum_rstart,
+				(unsigned int)(source->rend - checksum_rstart),
+				algorithm, secret);
+		} else {
+			result = ISCCC_R_BADAUTH;
+		}
+	} else {
+		result = ISC_R_SUCCESS;
+	}
+
+bad:
+	if (result == ISC_R_SUCCESS) {
+		*alistp = alist;
+	} else {
+		isccc_sexpr_free(&alist);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+list_fromwire(isccc_region_t *source, unsigned int depth,
+	      isccc_sexpr_t **listp) {
+	isccc_sexpr_t *list, *value;
+	isc_result_t result;
+
+	if (depth > ISCCC_MAXDEPTH) {
+		return (ISCCC_R_MAXDEPTH);
+	}
+
+	list = NULL;
+	while (!REGION_EMPTY(*source)) {
+		value = NULL;
+		result = value_fromwire(source, depth + 1, &value);
+		if (result != ISC_R_SUCCESS) {
+			isccc_sexpr_free(&list);
+			return (result);
+		}
+		if (isccc_sexpr_addtolist(&list, value) == NULL) {
+			isccc_sexpr_free(&value);
+			isccc_sexpr_free(&list);
+			return (ISC_R_NOMEMORY);
+		}
+	}
+
+	*listp = list;
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_cc_fromwire(isccc_region_t *source, isccc_sexpr_t **alistp,
+		  uint32_t algorithm, isccc_region_t *secret) {
+	unsigned int size;
+	uint32_t version;
+
+	size = REGION_SIZE(*source);
+	if (size < 4) {
+		return (ISC_R_UNEXPECTEDEND);
+	}
+	GET32(version, source->rstart);
+	if (version != 1) {
+		return (ISCCC_R_UNKNOWNVERSION);
+	}
+
+	return (table_fromwire(source, secret, algorithm, 0, alistp));
+}
+
+static isc_result_t
+createmessage(uint32_t version, const char *from, const char *to,
+	      uint32_t serial, isccc_time_t now, isccc_time_t expires,
+	      isccc_sexpr_t **alistp, bool want_expires) {
+	isccc_sexpr_t *alist, *_ctrl, *_data;
+	isc_result_t result;
+
+	REQUIRE(alistp != NULL && *alistp == NULL);
+
+	if (version != 1) {
+		return (ISCCC_R_UNKNOWNVERSION);
+	}
+
+	alist = isccc_alist_create();
+	if (alist == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	result = ISC_R_NOMEMORY;
+
+	_ctrl = isccc_alist_create();
+	if (_ctrl == NULL) {
+		goto bad;
+	}
+	if (isccc_alist_define(alist, "_ctrl", _ctrl) == NULL) {
+		isccc_sexpr_free(&_ctrl);
+		goto bad;
+	}
+
+	_data = isccc_alist_create();
+	if (_data == NULL) {
+		goto bad;
+	}
+	if (isccc_alist_define(alist, "_data", _data) == NULL) {
+		isccc_sexpr_free(&_data);
+		goto bad;
+	}
+
+	if (isccc_cc_defineuint32(_ctrl, "_ser", serial) == NULL ||
+	    isccc_cc_defineuint32(_ctrl, "_tim", now) == NULL ||
+	    (want_expires &&
+	     isccc_cc_defineuint32(_ctrl, "_exp", expires) == NULL))
+	{
+		goto bad;
+	}
+	if (from != NULL && isccc_cc_definestring(_ctrl, "_frm", from) == NULL)
+	{
+		goto bad;
+	}
+	if (to != NULL && isccc_cc_definestring(_ctrl, "_to", to) == NULL) {
+		goto bad;
+	}
+
+	*alistp = alist;
+
+	return (ISC_R_SUCCESS);
+
+bad:
+	isccc_sexpr_free(&alist);
+
+	return (result);
+}
+
+isc_result_t
+isccc_cc_createmessage(uint32_t version, const char *from, const char *to,
+		       uint32_t serial, isccc_time_t now, isccc_time_t expires,
+		       isccc_sexpr_t **alistp) {
+	return (createmessage(version, from, to, serial, now, expires, alistp,
+			      true));
+}
+
+isc_result_t
+isccc_cc_createack(isccc_sexpr_t *message, bool ok, isccc_sexpr_t **ackp) {
+	char *_frm, *_to;
+	uint32_t serial;
+	isccc_sexpr_t *ack, *_ctrl;
+	isc_result_t result;
+	isccc_time_t t;
+
+	REQUIRE(ackp != NULL && *ackp == NULL);
+
+	_ctrl = isccc_alist_lookup(message, "_ctrl");
+	if (!isccc_alist_alistp(_ctrl) ||
+	    isccc_cc_lookupuint32(_ctrl, "_ser", &serial) != ISC_R_SUCCESS ||
+	    isccc_cc_lookupuint32(_ctrl, "_tim", &t) != ISC_R_SUCCESS)
+	{
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * _frm and _to are optional.
+	 */
+	_frm = NULL;
+	(void)isccc_cc_lookupstring(_ctrl, "_frm", &_frm);
+	_to = NULL;
+	(void)isccc_cc_lookupstring(_ctrl, "_to", &_to);
+	/*
+	 * Create the ack.
+	 */
+	ack = NULL;
+	result = createmessage(1, _to, _frm, serial, t, 0, &ack, false);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	_ctrl = isccc_alist_lookup(ack, "_ctrl");
+	if (_ctrl == NULL) {
+		result = ISC_R_FAILURE;
+		goto bad;
+	}
+	if (isccc_cc_definestring(ack, "_ack", (ok) ? "1" : "0") == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto bad;
+	}
+
+	*ackp = ack;
+
+	return (ISC_R_SUCCESS);
+
+bad:
+	isccc_sexpr_free(&ack);
+
+	return (result);
+}
+
+bool
+isccc_cc_isack(isccc_sexpr_t *message) {
+	isccc_sexpr_t *_ctrl;
+
+	_ctrl = isccc_alist_lookup(message, "_ctrl");
+	if (!isccc_alist_alistp(_ctrl)) {
+		return (false);
+	}
+	if (isccc_cc_lookupstring(_ctrl, "_ack", NULL) == ISC_R_SUCCESS) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_cc_isreply(isccc_sexpr_t *message) {
+	isccc_sexpr_t *_ctrl;
+
+	_ctrl = isccc_alist_lookup(message, "_ctrl");
+	if (!isccc_alist_alistp(_ctrl)) {
+		return (false);
+	}
+	if (isccc_cc_lookupstring(_ctrl, "_rpl", NULL) == ISC_R_SUCCESS) {
+		return (true);
+	}
+	return (false);
+}
+
+isc_result_t
+isccc_cc_createresponse(isccc_sexpr_t *message, isccc_time_t now,
+			isccc_time_t expires, isccc_sexpr_t **alistp) {
+	char *_frm, *_to, *type = NULL;
+	uint32_t serial;
+	isccc_sexpr_t *alist, *_ctrl, *_data;
+	isc_result_t result;
+
+	REQUIRE(alistp != NULL && *alistp == NULL);
+
+	_ctrl = isccc_alist_lookup(message, "_ctrl");
+	_data = isccc_alist_lookup(message, "_data");
+	if (!isccc_alist_alistp(_ctrl) || !isccc_alist_alistp(_data) ||
+	    isccc_cc_lookupuint32(_ctrl, "_ser", &serial) != ISC_R_SUCCESS ||
+	    isccc_cc_lookupstring(_data, "type", &type) != ISC_R_SUCCESS)
+	{
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * _frm and _to are optional.
+	 */
+	_frm = NULL;
+	(void)isccc_cc_lookupstring(_ctrl, "_frm", &_frm);
+	_to = NULL;
+	(void)isccc_cc_lookupstring(_ctrl, "_to", &_to);
+	/*
+	 * Create the response.
+	 */
+	alist = NULL;
+	result = isccc_cc_createmessage(1, _to, _frm, serial, now, expires,
+					&alist);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	_ctrl = isccc_alist_lookup(alist, "_ctrl");
+	if (_ctrl == NULL) {
+		result = ISC_R_FAILURE;
+		goto bad;
+	}
+
+	_data = isccc_alist_lookup(alist, "_data");
+	if (_data == NULL) {
+		result = ISC_R_FAILURE;
+		goto bad;
+	}
+
+	if (isccc_cc_definestring(_ctrl, "_rpl", "1") == NULL ||
+	    isccc_cc_definestring(_data, "type", type) == NULL)
+	{
+		result = ISC_R_NOMEMORY;
+		goto bad;
+	}
+
+	*alistp = alist;
+
+	return (ISC_R_SUCCESS);
+
+bad:
+	isccc_sexpr_free(&alist);
+	return (result);
+}
+
+isccc_sexpr_t *
+isccc_cc_definestring(isccc_sexpr_t *alist, const char *key, const char *str) {
+	size_t len;
+	isccc_region_t r;
+
+	len = strlen(str);
+	DE_CONST(str, r.rstart);
+	r.rend = r.rstart + len;
+
+	return (isccc_alist_definebinary(alist, key, &r));
+}
+
+isccc_sexpr_t *
+isccc_cc_defineuint32(isccc_sexpr_t *alist, const char *key, uint32_t i) {
+	char b[100];
+	size_t len;
+	isccc_region_t r;
+
+	snprintf(b, sizeof(b), "%u", i);
+	len = strlen(b);
+	r.rstart = (unsigned char *)b;
+	r.rend = (unsigned char *)b + len;
+
+	return (isccc_alist_definebinary(alist, key, &r));
+}
+
+isc_result_t
+isccc_cc_lookupstring(isccc_sexpr_t *alist, const char *key, char **strp) {
+	isccc_sexpr_t *kv, *v;
+
+	REQUIRE(strp == NULL || *strp == NULL);
+
+	kv = isccc_alist_assq(alist, key);
+	if (kv != NULL) {
+		v = ISCCC_SEXPR_CDR(kv);
+		if (isccc_sexpr_binaryp(v)) {
+			if (strp != NULL) {
+				*strp = isccc_sexpr_tostring(v);
+			}
+			return (ISC_R_SUCCESS);
+		} else {
+			return (ISC_R_EXISTS);
+		}
+	}
+
+	return (ISC_R_NOTFOUND);
+}
+
+isc_result_t
+isccc_cc_lookupuint32(isccc_sexpr_t *alist, const char *key, uint32_t *uintp) {
+	isccc_sexpr_t *kv, *v;
+
+	kv = isccc_alist_assq(alist, key);
+	if (kv != NULL) {
+		v = ISCCC_SEXPR_CDR(kv);
+		if (isccc_sexpr_binaryp(v)) {
+			if (uintp != NULL) {
+				*uintp = (uint32_t)strtoul(
+					isccc_sexpr_tostring(v), NULL, 10);
+			}
+			return (ISC_R_SUCCESS);
+		} else {
+			return (ISC_R_EXISTS);
+		}
+	}
+
+	return (ISC_R_NOTFOUND);
+}
+
+static void
+symtab_undefine(char *key, unsigned int type, isccc_symvalue_t value,
+		void *arg) {
+	UNUSED(type);
+	UNUSED(value);
+	UNUSED(arg);
+
+	free(key);
+}
+
+static bool
+symtab_clean(char *key, unsigned int type, isccc_symvalue_t value, void *arg) {
+	isccc_time_t *now;
+
+	UNUSED(key);
+	UNUSED(type);
+
+	now = arg;
+
+	if (*now < value.as_uinteger) {
+		return (false);
+	}
+	if ((*now - value.as_uinteger) < DUP_LIFETIME) {
+		return (false);
+	}
+	return (true);
+}
+
+isc_result_t
+isccc_cc_createsymtab(isccc_symtab_t **symtabp) {
+	return (isccc_symtab_create(11897, symtab_undefine, NULL, false,
+				    symtabp));
+}
+
+void
+isccc_cc_cleansymtab(isccc_symtab_t *symtab, isccc_time_t now) {
+	isccc_symtab_foreach(symtab, symtab_clean, &now);
+}
+
+static bool
+has_whitespace(const char *str) {
+	char c;
+
+	if (str == NULL) {
+		return (false);
+	}
+	while ((c = *str++) != '\0') {
+		if (c == ' ' || c == '\t' || c == '\n') {
+			return (true);
+		}
+	}
+	return (false);
+}
+
+isc_result_t
+isccc_cc_checkdup(isccc_symtab_t *symtab, isccc_sexpr_t *message,
+		  isccc_time_t now) {
+	const char *_frm;
+	const char *_to;
+	char *_ser = NULL, *_tim = NULL, *tmp;
+	isc_result_t result;
+	char *key;
+	size_t len;
+	isccc_symvalue_t value;
+	isccc_sexpr_t *_ctrl;
+
+	_ctrl = isccc_alist_lookup(message, "_ctrl");
+	if (!isccc_alist_alistp(_ctrl) ||
+	    isccc_cc_lookupstring(_ctrl, "_ser", &_ser) != ISC_R_SUCCESS ||
+	    isccc_cc_lookupstring(_ctrl, "_tim", &_tim) != ISC_R_SUCCESS)
+	{
+		return (ISC_R_FAILURE);
+	}
+
+	INSIST(_ser != NULL);
+	INSIST(_tim != NULL);
+
+	/*
+	 * _frm and _to are optional.
+	 */
+	tmp = NULL;
+	if (isccc_cc_lookupstring(_ctrl, "_frm", &tmp) != ISC_R_SUCCESS) {
+		_frm = "";
+	} else {
+		_frm = tmp;
+	}
+	tmp = NULL;
+	if (isccc_cc_lookupstring(_ctrl, "_to", &tmp) != ISC_R_SUCCESS) {
+		_to = "";
+	} else {
+		_to = tmp;
+	}
+	/*
+	 * Ensure there is no newline in any of the strings.  This is so
+	 * we can write them to a file later.
+	 */
+	if (has_whitespace(_frm) || has_whitespace(_to) ||
+	    has_whitespace(_ser) || has_whitespace(_tim))
+	{
+		return (ISC_R_FAILURE);
+	}
+	len = strlen(_frm) + strlen(_to) + strlen(_ser) + strlen(_tim) + 4;
+	key = malloc(len);
+	if (key == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+	snprintf(key, len, "%s;%s;%s;%s", _frm, _to, _ser, _tim);
+	value.as_uinteger = now;
+	result = isccc_symtab_define(symtab, key, ISCCC_SYMTYPE_CCDUP, value,
+				     isccc_symexists_reject);
+	if (result != ISC_R_SUCCESS) {
+		free(key);
+		return (result);
+	}
+
+	return (ISC_R_SUCCESS);
+}
diff --git a/lib/isccc/ccmsg.c b/lib/isccc/ccmsg.c
new file mode 100644
index 0000000..bb60a53
--- /dev/null
+++ b/lib/isccc/ccmsg.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+
+#include <isc/mem.h>
+#include <isc/result.h>
+#include <isc/task.h>
+#include <isc/util.h>
+
+#include <isccc/ccmsg.h>
+#include <isccc/events.h>
+
+#define CCMSG_MAGIC	 ISC_MAGIC('C', 'C', 'm', 's')
+#define VALID_CCMSG(foo) ISC_MAGIC_VALID(foo, CCMSG_MAGIC)
+
+static void
+recv_length(isc_task_t *, isc_event_t *);
+static void
+recv_message(isc_task_t *, isc_event_t *);
+
+static void
+recv_length(isc_task_t *task, isc_event_t *ev_in) {
+	isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
+	isc_event_t *dev;
+	isccc_ccmsg_t *ccmsg = ev_in->ev_arg;
+	isc_region_t region;
+	isc_result_t result;
+
+	INSIST(VALID_CCMSG(ccmsg));
+
+	dev = &ccmsg->event;
+
+	if (ev->result != ISC_R_SUCCESS) {
+		ccmsg->result = ev->result;
+		goto send_and_free;
+	}
+
+	/*
+	 * Success.
+	 */
+	ccmsg->size = ntohl(ccmsg->size);
+	if (ccmsg->size == 0) {
+		ccmsg->result = ISC_R_UNEXPECTEDEND;
+		goto send_and_free;
+	}
+	if (ccmsg->size > ccmsg->maxsize) {
+		ccmsg->result = ISC_R_RANGE;
+		goto send_and_free;
+	}
+
+	region.base = isc_mem_get(ccmsg->mctx, ccmsg->size);
+	region.length = ccmsg->size;
+	if (region.base == NULL) {
+		ccmsg->result = ISC_R_NOMEMORY;
+		goto send_and_free;
+	}
+
+	isc_buffer_init(&ccmsg->buffer, region.base, region.length);
+	result = isc_socket_recv(ccmsg->sock, &region, 0, task, recv_message,
+				 ccmsg);
+	if (result != ISC_R_SUCCESS) {
+		ccmsg->result = result;
+		goto send_and_free;
+	}
+
+	isc_event_free(&ev_in);
+	return;
+
+send_and_free:
+	isc_task_send(ccmsg->task, &dev);
+	ccmsg->task = NULL;
+	isc_event_free(&ev_in);
+	return;
+}
+
+static void
+recv_message(isc_task_t *task, isc_event_t *ev_in) {
+	isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
+	isc_event_t *dev;
+	isccc_ccmsg_t *ccmsg = ev_in->ev_arg;
+
+	(void)task;
+
+	INSIST(VALID_CCMSG(ccmsg));
+
+	dev = &ccmsg->event;
+
+	if (ev->result != ISC_R_SUCCESS) {
+		ccmsg->result = ev->result;
+		goto send_and_free;
+	}
+
+	ccmsg->result = ISC_R_SUCCESS;
+	isc_buffer_add(&ccmsg->buffer, ev->n);
+	ccmsg->address = ev->address;
+
+send_and_free:
+	isc_task_send(ccmsg->task, &dev);
+	ccmsg->task = NULL;
+	isc_event_free(&ev_in);
+}
+
+void
+isccc_ccmsg_init(isc_mem_t *mctx, isc_socket_t *sock, isccc_ccmsg_t *ccmsg) {
+	REQUIRE(mctx != NULL);
+	REQUIRE(sock != NULL);
+	REQUIRE(ccmsg != NULL);
+
+	ccmsg->magic = CCMSG_MAGIC;
+	ccmsg->size = 0;
+	ccmsg->buffer.base = NULL;
+	ccmsg->buffer.length = 0;
+	ccmsg->maxsize = 4294967295U; /* Largest message possible. */
+	ccmsg->mctx = mctx;
+	ccmsg->sock = sock;
+	ccmsg->task = NULL;		  /* None yet. */
+	ccmsg->result = ISC_R_UNEXPECTED; /* None yet. */
+					  /*
+					   * Should probably initialize the
+					   *event here, but it can wait.
+					   */
+}
+
+void
+isccc_ccmsg_setmaxsize(isccc_ccmsg_t *ccmsg, unsigned int maxsize) {
+	REQUIRE(VALID_CCMSG(ccmsg));
+
+	ccmsg->maxsize = maxsize;
+}
+
+isc_result_t
+isccc_ccmsg_readmessage(isccc_ccmsg_t *ccmsg, isc_task_t *task,
+			isc_taskaction_t action, void *arg) {
+	isc_result_t result;
+	isc_region_t region;
+
+	REQUIRE(VALID_CCMSG(ccmsg));
+	REQUIRE(task != NULL);
+	REQUIRE(ccmsg->task == NULL); /* not currently in use */
+
+	if (ccmsg->buffer.base != NULL) {
+		isc_mem_put(ccmsg->mctx, ccmsg->buffer.base,
+			    ccmsg->buffer.length);
+		ccmsg->buffer.base = NULL;
+		ccmsg->buffer.length = 0;
+	}
+
+	ccmsg->task = task;
+	ccmsg->action = action;
+	ccmsg->arg = arg;
+	ccmsg->result = ISC_R_UNEXPECTED; /* unknown right now */
+
+	ISC_EVENT_INIT(&ccmsg->event, sizeof(isc_event_t), 0, 0,
+		       ISCCC_EVENT_CCMSG, action, arg, ccmsg, NULL, NULL);
+
+	region.base = (unsigned char *)&ccmsg->size;
+	region.length = 4; /* uint32_t */
+	result = isc_socket_recv(ccmsg->sock, &region, 0, ccmsg->task,
+				 recv_length, ccmsg);
+
+	if (result != ISC_R_SUCCESS) {
+		ccmsg->task = NULL;
+	}
+
+	return (result);
+}
+
+void
+isccc_ccmsg_cancelread(isccc_ccmsg_t *ccmsg) {
+	REQUIRE(VALID_CCMSG(ccmsg));
+
+	isc_socket_cancel(ccmsg->sock, NULL, ISC_SOCKCANCEL_RECV);
+}
+
+#if 0
+void
+isccc_ccmsg_freebuffer(isccc_ccmsg_t*ccmsg) {
+	REQUIRE(VALID_CCMSG(ccmsg));
+
+	if (ccmsg->buffer.base == NULL) {
+		return;
+	}
+
+	isc_mem_put(ccmsg->mctx,ccmsg->buffer.base,ccmsg->buffer.length);
+	ccmsg->buffer.base = NULL;
+	ccmsg->buffer.length = 0;
+}
+#endif /* if 0 */
+
+void
+isccc_ccmsg_invalidate(isccc_ccmsg_t *ccmsg) {
+	REQUIRE(VALID_CCMSG(ccmsg));
+
+	ccmsg->magic = 0;
+
+	if (ccmsg->buffer.base != NULL) {
+		isc_mem_put(ccmsg->mctx, ccmsg->buffer.base,
+			    ccmsg->buffer.length);
+		ccmsg->buffer.base = NULL;
+		ccmsg->buffer.length = 0;
+	}
+}
diff --git a/lib/isccc/include/.clang-format b/lib/isccc/include/.clang-format
new file mode 120000
index 0000000..0e62f72
--- /dev/null
+++ b/lib/isccc/include/.clang-format
@@ -0,0 +1 @@
+../../../.clang-format.headers
\ No newline at end of file
diff --git a/lib/isccc/include/Makefile.in b/lib/isccc/include/Makefile.in
new file mode 100644
index 0000000..09c4dd7
--- /dev/null
+++ b/lib/isccc/include/Makefile.in
@@ -0,0 +1,19 @@
+# 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.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+SUBDIRS =	isccc
+TARGETS =
+
+@BIND9_MAKE_RULES@
diff --git a/lib/isccc/include/isccc/Makefile.in b/lib/isccc/include/isccc/Makefile.in
new file mode 100644
index 0000000..af4ddf3
--- /dev/null
+++ b/lib/isccc/include/isccc/Makefile.in
@@ -0,0 +1,41 @@
+# 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.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+VERSION=@BIND9_VERSION@
+
+#
+# Only list headers that are to be installed and are not
+# machine generated.  The latter are handled specially in the
+# install target below.
+#
+HEADERS =	alist.h base64.h cc.h ccmsg.h events.h result.h \
+		sexpr.h symtab.h symtype.h types.h util.h version.h
+SUBDIRS =
+TARGETS =
+
+@BIND9_MAKE_RULES@
+
+installdirs:
+	$(SHELL) ${top_srcdir}/mkinstalldirs ${DESTDIR}${includedir}/isccc
+
+install:: installdirs
+	for i in ${HEADERS}; do \
+		${INSTALL_DATA} ${srcdir}/$$i ${DESTDIR}${includedir}/isccc || exit 1; \
+	done
+
+uninstall::
+	for i in ${HEADERS}; do \
+		rm -f ${DESTDIR}${includedir}/isccc/$$i || exit 1; \
+	done
diff --git a/lib/isccc/include/isccc/alist.h b/lib/isccc/include/isccc/alist.h
new file mode 100644
index 0000000..558378b
--- /dev/null
+++ b/lib/isccc/include/isccc/alist.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_ALIST_H
+#define ISCCC_ALIST_H 1
+
+/*! \file isccc/alist.h */
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <isc/lang.h>
+
+#include <isccc/types.h>
+
+ISC_LANG_BEGINDECLS
+
+isccc_sexpr_t *
+isccc_alist_create(void);
+
+bool
+isccc_alist_alistp(isccc_sexpr_t *alist);
+
+bool
+isccc_alist_emptyp(isccc_sexpr_t *alist);
+
+isccc_sexpr_t *
+isccc_alist_first(isccc_sexpr_t *alist);
+
+isccc_sexpr_t *
+isccc_alist_assq(isccc_sexpr_t *alist, const char *key);
+
+void
+isccc_alist_delete(isccc_sexpr_t *alist, const char *key);
+
+isccc_sexpr_t *
+isccc_alist_define(isccc_sexpr_t *alist, const char *key, isccc_sexpr_t *value);
+
+isccc_sexpr_t *
+isccc_alist_definestring(isccc_sexpr_t *alist, const char *key,
+			 const char *str);
+
+isccc_sexpr_t *
+isccc_alist_definebinary(isccc_sexpr_t *alist, const char *key,
+			 isccc_region_t *r);
+
+isccc_sexpr_t *
+isccc_alist_lookup(isccc_sexpr_t *alist, const char *key);
+
+isc_result_t
+isccc_alist_lookupstring(isccc_sexpr_t *alist, const char *key, char **strp);
+
+isc_result_t
+isccc_alist_lookupbinary(isccc_sexpr_t *alist, const char *key,
+			 isccc_region_t **r);
+
+void
+isccc_alist_prettyprint(isccc_sexpr_t *sexpr, unsigned int indent,
+			FILE *stream);
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_ALIST_H */
diff --git a/lib/isccc/include/isccc/base64.h b/lib/isccc/include/isccc/base64.h
new file mode 100644
index 0000000..2eba95c
--- /dev/null
+++ b/lib/isccc/include/isccc/base64.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_BASE64_H
+#define ISCCC_BASE64_H 1
+
+/*! \file isccc/base64.h */
+
+#include <isc/lang.h>
+
+#include <isccc/types.h>
+
+ISC_LANG_BEGINDECLS
+
+/***
+ *** Functions
+ ***/
+
+isc_result_t
+isccc_base64_encode(isccc_region_t *source, int wordlength,
+		    const char *wordbreak, isccc_region_t *target);
+/*%<
+ * Convert data into base64 encoded text.
+ *
+ * Notes:
+ *\li	The base64 encoded text in 'target' will be divided into
+ *	words of at most 'wordlength' characters, separated by
+ * 	the 'wordbreak' string.  No parentheses will surround
+ *	the text.
+ *
+ * Requires:
+ *\li	'source' is a region containing binary data.
+ *\li	'target' is a text region containing available space.
+ *\li	'wordbreak' points to a null-terminated string of
+ *		zero or more whitespace characters.
+ */
+
+isc_result_t
+isccc_base64_decode(const char *cstr, isccc_region_t *target);
+/*%<
+ * Decode a null-terminated base64 string.
+ *
+ * Requires:
+ *\li	'cstr' is non-null.
+ *\li	'target' is a valid region.
+ *
+ * Returns:
+ *\li	#ISC_R_SUCCESS	-- the entire decoded representation of 'cstring'
+ *			   fit in 'target'.
+ *\li	#ISC_R_BADBASE64 -- 'cstr' is not a valid base64 encoding.
+ *\li	#ISC_R_NOSPACE	-- 'target' is not big enough.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_BASE64_H */
diff --git a/lib/isccc/include/isccc/cc.h b/lib/isccc/include/isccc/cc.h
new file mode 100644
index 0000000..9b19904
--- /dev/null
+++ b/lib/isccc/include/isccc/cc.h
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_CC_H
+#define ISCCC_CC_H 1
+
+/*! \file isccc/cc.h */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/buffer.h>
+#include <isc/lang.h>
+
+#include <isccc/types.h>
+
+ISC_LANG_BEGINDECLS
+
+/*% from lib/dns/include/dst/dst.h */
+
+#define ISCCC_ALG_UNKNOWN    0
+#define ISCCC_ALG_HMACMD5    157
+#define ISCCC_ALG_HMACSHA1   161
+#define ISCCC_ALG_HMACSHA224 162
+#define ISCCC_ALG_HMACSHA256 163
+#define ISCCC_ALG_HMACSHA384 164
+#define ISCCC_ALG_HMACSHA512 165
+
+/*% Maximum Datagram Package */
+#define ISCCC_CC_MAXDGRAMPACKET 4096
+
+/*% Message Type String */
+#define ISCCC_CCMSGTYPE_STRING 0x00
+/*% Message Type Binary Data */
+#define ISCCC_CCMSGTYPE_BINARYDATA 0x01
+/*% Message Type Table */
+#define ISCCC_CCMSGTYPE_TABLE 0x02
+/*% Message Type List */
+#define ISCCC_CCMSGTYPE_LIST 0x03
+
+/*% Send to Wire */
+isc_result_t
+isccc_cc_towire(isccc_sexpr_t *alist, isc_buffer_t **buffer, uint32_t algorithm,
+		isccc_region_t *secret);
+
+/*% Get From Wire */
+isc_result_t
+isccc_cc_fromwire(isccc_region_t *source, isccc_sexpr_t **alistp,
+		  uint32_t algorithm, isccc_region_t *secret);
+
+/*% Create Message */
+isc_result_t
+isccc_cc_createmessage(uint32_t version, const char *from, const char *to,
+		       uint32_t serial, isccc_time_t now, isccc_time_t expires,
+		       isccc_sexpr_t **alistp);
+
+/*% Create Acknowledgment */
+isc_result_t
+isccc_cc_createack(isccc_sexpr_t *message, bool ok, isccc_sexpr_t **ackp);
+
+/*% Is Ack? */
+bool
+isccc_cc_isack(isccc_sexpr_t *message);
+
+/*% Is Reply? */
+bool
+isccc_cc_isreply(isccc_sexpr_t *message);
+
+/*% Create Response */
+isc_result_t
+isccc_cc_createresponse(isccc_sexpr_t *message, isccc_time_t now,
+			isccc_time_t expires, isccc_sexpr_t **alistp);
+
+/*% Define String */
+isccc_sexpr_t *
+isccc_cc_definestring(isccc_sexpr_t *alist, const char *key, const char *str);
+
+/*% Define uint 32 */
+isccc_sexpr_t *
+isccc_cc_defineuint32(isccc_sexpr_t *alist, const char *key, uint32_t i);
+
+/*% Lookup String */
+isc_result_t
+isccc_cc_lookupstring(isccc_sexpr_t *alist, const char *key, char **strp);
+
+/*% Lookup uint 32 */
+isc_result_t
+isccc_cc_lookupuint32(isccc_sexpr_t *alist, const char *key, uint32_t *uintp);
+
+/*% Create Symbol Table */
+isc_result_t
+isccc_cc_createsymtab(isccc_symtab_t **symtabp);
+
+/*% Clean up Symbol Table */
+void
+isccc_cc_cleansymtab(isccc_symtab_t *symtab, isccc_time_t now);
+
+/*% Check for Duplicates */
+isc_result_t
+isccc_cc_checkdup(isccc_symtab_t *symtab, isccc_sexpr_t *message,
+		  isccc_time_t now);
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_CC_H */
diff --git a/lib/isccc/include/isccc/ccmsg.h b/lib/isccc/include/isccc/ccmsg.h
new file mode 100644
index 0000000..db64fcf
--- /dev/null
+++ b/lib/isccc/include/isccc/ccmsg.h
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_CCMSG_H
+#define ISCCC_CCMSG_H 1
+
+/*! \file isccc/ccmsg.h */
+
+#include <inttypes.h>
+
+#include <isc/buffer.h>
+#include <isc/lang.h>
+#include <isc/socket.h>
+
+/*% ISCCC Message Structure */
+typedef struct isccc_ccmsg {
+	/* private (don't touch!) */
+	unsigned int	 magic;
+	uint32_t	 size;
+	isc_buffer_t	 buffer;
+	unsigned int	 maxsize;
+	isc_mem_t	*mctx;
+	isc_socket_t	*sock;
+	isc_task_t	*task;
+	isc_taskaction_t action;
+	void		*arg;
+	isc_event_t	 event;
+	/* public (read-only) */
+	isc_result_t   result;
+	isc_sockaddr_t address;
+} isccc_ccmsg_t;
+
+ISC_LANG_BEGINDECLS
+
+void
+isccc_ccmsg_init(isc_mem_t *mctx, isc_socket_t *sock, isccc_ccmsg_t *ccmsg);
+/*%
+ * Associate a cc message state with a given memory context and
+ * TCP socket.
+ *
+ * Requires:
+ *
+ *\li	"mctx" and "sock" be non-NULL and valid types.
+ *
+ *\li	"sock" be a read/write TCP socket.
+ *
+ *\li	"ccmsg" be non-NULL and an uninitialized or invalidated structure.
+ *
+ * Ensures:
+ *
+ *\li	"ccmsg" is a valid structure.
+ */
+
+void
+isccc_ccmsg_setmaxsize(isccc_ccmsg_t *ccmsg, unsigned int maxsize);
+/*%
+ * Set the maximum packet size to "maxsize"
+ *
+ * Requires:
+ *
+ *\li	"ccmsg" be valid.
+ *
+ *\li	512 <= "maxsize" <= 4294967296
+ */
+
+isc_result_t
+isccc_ccmsg_readmessage(isccc_ccmsg_t *ccmsg, isc_task_t *task,
+			isc_taskaction_t action, void *arg);
+/*%
+ * Schedule an event to be delivered when a command channel message is
+ * readable, or when an error occurs on the socket.
+ *
+ * Requires:
+ *
+ *\li	"ccmsg" be valid.
+ *
+ *\li	"task", "taskaction", and "arg" be valid.
+ *
+ * Returns:
+ *
+ *\li	#ISC_R_SUCCESS		-- no error
+ *\li	Anything that the isc_socket_recv() call can return.  XXXMLG
+ *
+ * Notes:
+ *
+ *\li	The event delivered is a fully generic event.  It will contain no
+ *	actual data.  The sender will be a pointer to the isccc_ccmsg_t.
+ *	The result code inside that structure should be checked to see
+ *	what the final result was.
+ */
+
+void
+isccc_ccmsg_cancelread(isccc_ccmsg_t *ccmsg);
+/*%
+ * Cancel a readmessage() call.  The event will still be posted with a
+ * CANCELED result code.
+ *
+ * Requires:
+ *
+ *\li	"ccmsg" be valid.
+ */
+
+void
+isccc_ccmsg_invalidate(isccc_ccmsg_t *ccmsg);
+/*%
+ * Clean up all allocated state, and invalidate the structure.
+ *
+ * Requires:
+ *
+ *\li	"ccmsg" be valid.
+ *
+ * Ensures:
+ *
+ *\li	"ccmsg" is invalidated and disassociated with all memory contexts,
+ *	sockets, etc.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_CCMSG_H */
diff --git a/lib/isccc/include/isccc/events.h b/lib/isccc/include/isccc/events.h
new file mode 100644
index 0000000..78ee02d
--- /dev/null
+++ b/lib/isccc/include/isccc/events.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_EVENTS_H
+#define ISCCC_EVENTS_H 1
+
+/*! \file isccc/events.h */
+
+#include <isc/eventclass.h>
+
+/*%
+ * Registry of ISCCC event numbers.
+ */
+
+#define ISCCC_EVENT_CCMSG (ISC_EVENTCLASS_ISCCC + 0)
+
+#define ISCCC_EVENT_FIRSTEVENT (ISC_EVENTCLASS_ISCCC + 0)
+#define ISCCC_EVENT_LASTEVENT  (ISC_EVENTCLASS_ISCCC + 65535)
+
+#endif /* ISCCC_EVENTS_H */
diff --git a/lib/isccc/include/isccc/result.h b/lib/isccc/include/isccc/result.h
new file mode 100644
index 0000000..56f9c38
--- /dev/null
+++ b/lib/isccc/include/isccc/result.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ * 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.
+ */
+
+#ifndef ISCCC_RESULT_H
+#define ISCCC_RESULT_H 1
+
+/*! \file isccc/result.h */
+
+#include <isc/lang.h>
+#include <isc/result.h>
+#include <isc/resultclass.h>
+
+#include <isccc/types.h>
+
+/*% Unknown Version */
+#define ISCCC_R_UNKNOWNVERSION (ISC_RESULTCLASS_ISCCC + 0)
+/*% Syntax Error */
+#define ISCCC_R_SYNTAX (ISC_RESULTCLASS_ISCCC + 1)
+/*% Bad Authorization */
+#define ISCCC_R_BADAUTH (ISC_RESULTCLASS_ISCCC + 2)
+/*% Expired */
+#define ISCCC_R_EXPIRED (ISC_RESULTCLASS_ISCCC + 3)
+/*% Clock Skew */
+#define ISCCC_R_CLOCKSKEW (ISC_RESULTCLASS_ISCCC + 4)
+/*% Duplicate */
+#define ISCCC_R_DUPLICATE (ISC_RESULTCLASS_ISCCC + 5)
+/*% Maximum recursion depth */
+#define ISCCC_R_MAXDEPTH (ISC_RESULTCLASS_ISCCC + 6)
+
+#define ISCCC_R_NRESULTS 7 /*%< Number of results */
+
+ISC_LANG_BEGINDECLS
+
+const char *
+isccc_result_totext(isc_result_t result);
+/*%
+ * Convert a isccc_result_t into a string message describing the result.
+ */
+
+void
+isccc_result_register(void);
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_RESULT_H */
diff --git a/lib/isccc/include/isccc/sexpr.h b/lib/isccc/include/isccc/sexpr.h
new file mode 100644
index 0000000..dae9906
--- /dev/null
+++ b/lib/isccc/include/isccc/sexpr.h
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_SEXPR_H
+#define ISCCC_SEXPR_H 1
+
+/*! \file isccc/sexpr.h */
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <isc/lang.h>
+
+#include <isccc/types.h>
+
+ISC_LANG_BEGINDECLS
+
+/*% dotted pair structure */
+struct isccc_dottedpair {
+	isccc_sexpr_t *car;
+	isccc_sexpr_t *cdr;
+};
+
+/*% iscc_sexpr structure */
+struct isccc_sexpr {
+	unsigned int type;
+	union {
+		char		  *as_string;
+		isccc_dottedpair_t as_dottedpair;
+		isccc_region_t	   as_region;
+	} value;
+};
+
+#define ISCCC_SEXPRTYPE_NONE	   0x00 /*%< Illegal. */
+#define ISCCC_SEXPRTYPE_T	   0x01
+#define ISCCC_SEXPRTYPE_STRING	   0x02
+#define ISCCC_SEXPRTYPE_DOTTEDPAIR 0x03
+#define ISCCC_SEXPRTYPE_BINARY	   0x04
+
+#define ISCCC_SEXPR_CAR(s) (s)->value.as_dottedpair.car
+#define ISCCC_SEXPR_CDR(s) (s)->value.as_dottedpair.cdr
+
+isccc_sexpr_t *
+isccc_sexpr_cons(isccc_sexpr_t *car, isccc_sexpr_t *cdr);
+
+isccc_sexpr_t *
+isccc_sexpr_tconst(void);
+
+isccc_sexpr_t *
+isccc_sexpr_fromstring(const char *str);
+
+isccc_sexpr_t *
+isccc_sexpr_frombinary(const isccc_region_t *region);
+
+void
+isccc_sexpr_free(isccc_sexpr_t **sexprp);
+
+void
+isccc_sexpr_print(isccc_sexpr_t *sexpr, FILE *stream);
+
+isccc_sexpr_t *
+isccc_sexpr_car(isccc_sexpr_t *list);
+
+isccc_sexpr_t *
+isccc_sexpr_cdr(isccc_sexpr_t *list);
+
+void
+isccc_sexpr_setcar(isccc_sexpr_t *pair, isccc_sexpr_t *car);
+
+void
+isccc_sexpr_setcdr(isccc_sexpr_t *pair, isccc_sexpr_t *cdr);
+
+isccc_sexpr_t *
+isccc_sexpr_addtolist(isccc_sexpr_t **l1p, isccc_sexpr_t *l2);
+
+bool
+isccc_sexpr_listp(isccc_sexpr_t *sexpr);
+
+bool
+isccc_sexpr_emptyp(isccc_sexpr_t *sexpr);
+
+bool
+isccc_sexpr_stringp(isccc_sexpr_t *sexpr);
+
+bool
+isccc_sexpr_binaryp(isccc_sexpr_t *sexpr);
+
+char *
+isccc_sexpr_tostring(isccc_sexpr_t *sexpr);
+
+isccc_region_t *
+isccc_sexpr_tobinary(isccc_sexpr_t *sexpr);
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_SEXPR_H */
diff --git a/lib/isccc/include/isccc/symtab.h b/lib/isccc/include/isccc/symtab.h
new file mode 100644
index 0000000..ff978b2
--- /dev/null
+++ b/lib/isccc/include/isccc/symtab.h
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_SYMTAB_H
+#define ISCCC_SYMTAB_H 1
+
+/*****
+***** Module Info
+*****/
+
+/*! \file isccc/symtab.h
+ * \brief
+ * Provides a simple memory-based symbol table.
+ *
+ * Keys are C strings.  A type may be specified when looking up,
+ * defining, or undefining.  A type value of 0 means "match any type";
+ * any other value will only match the given type.
+ *
+ * It's possible that a client will attempt to define a <key, type,
+ * value> tuple when a tuple with the given key and type already
+ * exists in the table.  What to do in this case is specified by the
+ * client.  Possible policies are:
+ *
+ *\li	isccc_symexists_reject	Disallow the define, returning #ISC_R_EXISTS
+ *\li	isccc_symexists_replace	Replace the old value with the new.  The
+ *				undefine action (if provided) will be called
+ *				with the old <key, type, value> tuple.
+ *\li	isccc_symexists_add	Add the new tuple, leaving the old tuple in
+ *				the table.  Subsequent lookups will retrieve
+ *				the most-recently-defined tuple.
+ *
+ * A lookup of a key using type 0 will return the most-recently
+ * defined symbol with that key.  An undefine of a key using type 0
+ * will undefine the most-recently defined symbol with that key.
+ * Trying to define a key with type 0 is illegal.
+ *
+ * The symbol table library does not make a copy the key field, so the
+ * caller must ensure that any key it passes to isccc_symtab_define()
+ * will not change until it calls isccc_symtab_undefine() or
+ * isccc_symtab_destroy().
+ *
+ * A user-specified action will be called (if provided) when a symbol
+ * is undefined.  It can be used to free memory associated with keys
+ * and/or values.
+ */
+
+/***
+ *** Imports.
+ ***/
+
+#include <stdbool.h>
+
+#include <isc/lang.h>
+
+#include <isccc/types.h>
+
+/***
+ *** Symbol Tables.
+ ***/
+
+typedef union isccc_symvalue {
+	void	    *as_pointer;
+	int	     as_integer;
+	unsigned int as_uinteger;
+} isccc_symvalue_t;
+
+typedef void (*isccc_symtabundefaction_t)(char *key, unsigned int type,
+					  isccc_symvalue_t value,
+					  void		  *userarg);
+
+typedef bool (*isccc_symtabforeachaction_t)(char *key, unsigned int type,
+					    isccc_symvalue_t value,
+					    void	    *userarg);
+
+typedef enum {
+	isccc_symexists_reject = 0,
+	isccc_symexists_replace = 1,
+	isccc_symexists_add = 2
+} isccc_symexists_t;
+
+ISC_LANG_BEGINDECLS
+
+isc_result_t
+isccc_symtab_create(unsigned int	      size,
+		    isccc_symtabundefaction_t undefine_action,
+		    void *undefine_arg, bool case_sensitive,
+		    isccc_symtab_t **symtabp);
+
+void
+isccc_symtab_destroy(isccc_symtab_t **symtabp);
+
+isc_result_t
+isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
+		    isccc_symvalue_t *value);
+
+isc_result_t
+isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
+		    isccc_symvalue_t value, isccc_symexists_t exists_policy);
+
+isc_result_t
+isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key,
+		      unsigned int type);
+
+void
+isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
+		     void *arg);
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISCCC_SYMTAB_H */
diff --git a/lib/isccc/include/isccc/symtype.h b/lib/isccc/include/isccc/symtype.h
new file mode 100644
index 0000000..9003683
--- /dev/null
+++ b/lib/isccc/include/isccc/symtype.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_SYMTYPE_H
+#define ISCCC_SYMTYPE_H 1
+
+/*! \file isccc/symtype.h */
+
+#define ISCCC_SYMTYPE_ZONESTATS	   0x0001
+#define ISCCC_SYMTYPE_CCDUP	   0x0002
+#define ISCCC_SYMTYPE_TELLSERVICE  0x0003
+#define ISCCC_SYMTYPE_TELLRESPONSE 0x0004
+
+#endif /* ISCCC_SYMTYPE_H */
diff --git a/lib/isccc/include/isccc/types.h b/lib/isccc/include/isccc/types.h
new file mode 100644
index 0000000..477e2df
--- /dev/null
+++ b/lib/isccc/include/isccc/types.h
@@ -0,0 +1,55 @@
+/*
+ * Portions Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_TYPES_H
+#define ISCCC_TYPES_H 1
+
+/*! \file isccc/types.h */
+
+#include <inttypes.h>
+
+#include <isc/result.h>
+
+/*% isccc_time_t typedef */
+typedef uint32_t isccc_time_t;
+
+/*% isccc_sexpr_t typedef */
+typedef struct isccc_sexpr isccc_sexpr_t;
+/*% isccc_dottedpair_t typedef */
+typedef struct isccc_dottedpair isccc_dottedpair_t;
+/*% isccc_symtab_t typedef */
+typedef struct isccc_symtab isccc_symtab_t;
+
+/*% iscc region structure */
+typedef struct isccc_region {
+	unsigned char *rstart;
+	unsigned char *rend;
+} isccc_region_t;
+
+#endif /* ISCCC_TYPES_H */
diff --git a/lib/isccc/include/isccc/util.h b/lib/isccc/include/isccc/util.h
new file mode 100644
index 0000000..546423d
--- /dev/null
+++ b/lib/isccc/include/isccc/util.h
@@ -0,0 +1,229 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISCCC_UTIL_H
+#define ISCCC_UTIL_H 1
+
+#include <inttypes.h>
+
+#include <isc/util.h>
+
+/*! \file isccc/util.h
+ * \brief
+ * Macros for dealing with unaligned numbers.
+ *
+ * \note no side effects are allowed when invoking these macros!
+ */
+
+#define GET8(v, w)      \
+	do {            \
+		v = *w; \
+		w++;    \
+	} while (0)
+
+#define GET16(v, w)                          \
+	do {                                 \
+		v = (unsigned int)w[0] << 8; \
+		v |= (unsigned int)w[1];     \
+		w += 2;                      \
+	} while (0)
+
+#define GET24(v, w)                           \
+	do {                                  \
+		v = (unsigned int)w[0] << 16; \
+		v |= (unsigned int)w[1] << 8; \
+		v |= (unsigned int)w[2];      \
+		w += 3;                       \
+	} while (0)
+
+#define GET32(v, w)                            \
+	do {                                   \
+		v = (unsigned int)w[0] << 24;  \
+		v |= (unsigned int)w[1] << 16; \
+		v |= (unsigned int)w[2] << 8;  \
+		v |= (unsigned int)w[3];       \
+		w += 4;                        \
+	} while (0)
+
+#define GET64(v, w)                        \
+	do {                               \
+		v = (uint64_t)w[0] << 56;  \
+		v |= (uint64_t)w[1] << 48; \
+		v |= (uint64_t)w[2] << 40; \
+		v |= (uint64_t)w[3] << 32; \
+		v |= (uint64_t)w[4] << 24; \
+		v |= (uint64_t)w[5] << 16; \
+		v |= (uint64_t)w[6] << 8;  \
+		v |= (uint64_t)w[7];       \
+		w += 8;                    \
+	} while (0)
+
+#define GETC16(v, w, d)                      \
+	do {                                 \
+		GET8(v, w);                  \
+		if (v == 0) {                \
+			d = ISCCC_TRUE;      \
+		} else {                     \
+			d = ISCCC_FALSE;     \
+			if (v == 255)        \
+				GET16(v, w); \
+		}                            \
+	} while (0)
+
+#define GETC32(v, w)                  \
+	do {                          \
+		GET24(v, w);          \
+		if (v == 0xffffffu) { \
+			GET32(v, w);  \
+		}                     \
+	} while (0)
+
+#define GET_OFFSET(v, w) GET32(v, w)
+
+#define GET_MEM(v, c, w)          \
+	do {                      \
+		memmove(v, w, c); \
+		w += c;           \
+	} while (0)
+
+#define GET_TYPE(v, w)                                                        \
+	do {                                                                  \
+		GET8(v, w);                                                   \
+		if (v > 127) {                                                \
+			if (v < 255) {                                        \
+				v = ((v & 0x7f) << 16) | ISCCC_RDATATYPE_SIG; \
+			} else {                                              \
+				GET32(v, w);                                  \
+			}                                                     \
+		}                                                             \
+	} while (0)
+
+#define PUT8(v, w)                      \
+	do {                            \
+		*w = (v & 0x000000ffU); \
+		w++;                    \
+	} while (0)
+
+#define PUT16(v, w)                            \
+	do {                                   \
+		w[0] = (v & 0x0000ff00U) >> 8; \
+		w[1] = (v & 0x000000ffU);      \
+		w += 2;                        \
+	} while (0)
+
+#define PUT24(v, w)                             \
+	do {                                    \
+		w[0] = (v & 0x00ff0000U) >> 16; \
+		w[1] = (v & 0x0000ff00U) >> 8;  \
+		w[2] = (v & 0x000000ffU);       \
+		w += 3;                         \
+	} while (0)
+
+#define PUT32(v, w)                             \
+	do {                                    \
+		w[0] = (v & 0xff000000U) >> 24; \
+		w[1] = (v & 0x00ff0000U) >> 16; \
+		w[2] = (v & 0x0000ff00U) >> 8;  \
+		w[3] = (v & 0x000000ffU);       \
+		w += 4;                         \
+	} while (0)
+
+#define PUT64(v, w)                                       \
+	do {                                              \
+		w[0] = (v & 0xff00000000000000ULL) >> 56; \
+		w[1] = (v & 0x00ff000000000000ULL) >> 48; \
+		w[2] = (v & 0x0000ff0000000000ULL) >> 40; \
+		w[3] = (v & 0x000000ff00000000ULL) >> 32; \
+		w[4] = (v & 0x00000000ff000000ULL) >> 24; \
+		w[5] = (v & 0x0000000000ff0000ULL) >> 16; \
+		w[6] = (v & 0x000000000000ff00ULL) >> 8;  \
+		w[7] = (v & 0x00000000000000ffULL);       \
+		w += 8;                                   \
+	} while (0)
+
+#define PUTC16(v, w)                    \
+	do {                            \
+		if (v > 0 && v < 255) { \
+			PUT8(v, w);     \
+		} else {                \
+			PUT8(255, w);   \
+			PUT16(v, w);    \
+		}                       \
+	} while (0)
+
+#define PUTC32(v, w)                         \
+	do {                                 \
+		if (v < 0xffffffU) {         \
+			PUT24(v, w);         \
+		} else {                     \
+			PUT24(0xffffffU, w); \
+			PUT32(v, w);         \
+		}                            \
+	} while (0)
+
+#define PUT_OFFSET(v, w) PUT32(v, w)
+
+#include <string.h>
+
+#define PUT_MEM(s, c, w)          \
+	do {                      \
+		memmove(w, s, c); \
+		w += c;           \
+	} while (0)
+
+/*
+ * Regions.
+ */
+#define REGION_SIZE(r)	((unsigned int)((r).rend - (r).rstart))
+#define REGION_EMPTY(r) ((r).rstart == (r).rend)
+#define REGION_FROMSTRING(r, s)                    \
+	do {                                       \
+		(r).rstart = (unsigned char *)s;   \
+		(r).rend = (r).rstart + strlen(s); \
+	} while (0)
+
+/*%
+ * Use this to remove the const qualifier of a variable to assign it to
+ * a non-const variable or pass it as a non-const function argument ...
+ * but only when you are sure it won't then be changed!
+ * This is necessary to sometimes shut up some compilers
+ * (as with gcc -Wcast-qual) when there is just no other good way to avoid the
+ * situation.
+ */
+#define DE_CONST(konst, var)           \
+	do {                           \
+		union {                \
+			const void *k; \
+			void	   *v; \
+		} _u;                  \
+		_u.k = konst;          \
+		var = _u.v;            \
+	} while (0)
+
+#endif /* ISCCC_UTIL_H */
diff --git a/lib/isccc/include/isccc/version.h b/lib/isccc/include/isccc/version.h
new file mode 100644
index 0000000..9dc1a6d
--- /dev/null
+++ b/lib/isccc/include/isccc/version.h
@@ -0,0 +1,18 @@
+/*
+ * 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.
+ */
+
+/*! \file isccc/version.h */
+
+#include <isc/platform.h>
+
+LIBISCCC_EXTERNAL_DATA extern const char isccc_version[];
diff --git a/lib/isccc/result.c b/lib/isccc/result.c
new file mode 100644
index 0000000..127dd77
--- /dev/null
+++ b/lib/isccc/result.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ * 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.
+ */
+
+/*! \file */
+
+#include <isc/once.h>
+#include <isc/util.h>
+
+#include <isccc/result.h>
+
+static const char *text[ISCCC_R_NRESULTS] = {
+	"unknown version", /* 1 */
+	"syntax error",	   /* 2 */
+	"bad auth",	   /* 3 */
+	"expired",	   /* 4 */
+	"clock skew",	   /* 5 */
+	"duplicate",	   /* 6 */
+	"max depth"	   /* 7 */
+};
+
+static const char *ids[ISCCC_R_NRESULTS] = {
+	"ISCCC_R_UNKNOWNVERSION", "ISCCC_R_SYNTAX",    "ISCCC_R_BADAUTH",
+	"ISCCC_R_EXPIRED",	  "ISCCC_R_CLOCKSKEW", "ISCCC_R_DUPLICATE",
+	"ISCCC_R_MAXDEPTH"
+};
+
+#define ISCCC_RESULT_RESULTSET 2
+
+static isc_once_t once = ISC_ONCE_INIT;
+
+static void
+initialize_action(void) {
+	isc_result_t result;
+
+	result = isc_result_register(ISC_RESULTCLASS_ISCCC, ISCCC_R_NRESULTS,
+				     text, ISCCC_RESULT_RESULTSET);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_result_register() failed: %u", result);
+	}
+
+	result = isc_result_registerids(ISC_RESULTCLASS_ISCCC, ISCCC_R_NRESULTS,
+					ids, ISCCC_RESULT_RESULTSET);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_result_registerids() failed: %u", result);
+	}
+}
+
+static void
+initialize(void) {
+	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);
+}
+
+const char *
+isccc_result_totext(isc_result_t result) {
+	initialize();
+
+	return (isc_result_totext(result));
+}
+
+void
+isccc_result_register(void) {
+	initialize();
+}
diff --git a/lib/isccc/sexpr.c b/lib/isccc/sexpr.c
new file mode 100644
index 0000000..62c80c4
--- /dev/null
+++ b/lib/isccc/sexpr.c
@@ -0,0 +1,317 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/assertions.h>
+#include <isc/print.h>
+
+#include <isccc/sexpr.h>
+#include <isccc/util.h>
+
+static isccc_sexpr_t sexpr_t = { ISCCC_SEXPRTYPE_T, { NULL } };
+
+#define CAR(s) (s)->value.as_dottedpair.car
+#define CDR(s) (s)->value.as_dottedpair.cdr
+
+isccc_sexpr_t *
+isccc_sexpr_cons(isccc_sexpr_t *car, isccc_sexpr_t *cdr) {
+	isccc_sexpr_t *sexpr;
+
+	sexpr = malloc(sizeof(*sexpr));
+	if (sexpr == NULL) {
+		return (NULL);
+	}
+	sexpr->type = ISCCC_SEXPRTYPE_DOTTEDPAIR;
+	CAR(sexpr) = car;
+	CDR(sexpr) = cdr;
+
+	return (sexpr);
+}
+
+isccc_sexpr_t *
+isccc_sexpr_tconst(void) {
+	return (&sexpr_t);
+}
+
+isccc_sexpr_t *
+isccc_sexpr_fromstring(const char *str) {
+	isccc_sexpr_t *sexpr;
+
+	sexpr = malloc(sizeof(*sexpr));
+	if (sexpr == NULL) {
+		return (NULL);
+	}
+	sexpr->type = ISCCC_SEXPRTYPE_STRING;
+	sexpr->value.as_string = strdup(str);
+	if (sexpr->value.as_string == NULL) {
+		free(sexpr);
+		return (NULL);
+	}
+
+	return (sexpr);
+}
+
+isccc_sexpr_t *
+isccc_sexpr_frombinary(const isccc_region_t *region) {
+	isccc_sexpr_t *sexpr;
+	unsigned int region_size;
+
+	sexpr = malloc(sizeof(*sexpr));
+	if (sexpr == NULL) {
+		return (NULL);
+	}
+	sexpr->type = ISCCC_SEXPRTYPE_BINARY;
+	region_size = REGION_SIZE(*region);
+	/*
+	 * We add an extra byte when we malloc so we can NUL terminate
+	 * the binary data.  This allows the caller to use it as a C
+	 * string.  It's up to the caller to ensure this is safe.  We don't
+	 * add 1 to the length of the binary region, because the NUL is
+	 * not part of the binary data.
+	 */
+	sexpr->value.as_region.rstart = malloc(region_size + 1);
+	if (sexpr->value.as_region.rstart == NULL) {
+		free(sexpr);
+		return (NULL);
+	}
+	sexpr->value.as_region.rend = sexpr->value.as_region.rstart +
+				      region_size;
+	memmove(sexpr->value.as_region.rstart, region->rstart, region_size);
+	/*
+	 * NUL terminate.
+	 */
+	sexpr->value.as_region.rstart[region_size] = '\0';
+
+	return (sexpr);
+}
+
+void
+isccc_sexpr_free(isccc_sexpr_t **sexprp) {
+	isccc_sexpr_t *sexpr;
+	isccc_sexpr_t *item;
+
+	sexpr = *sexprp;
+	*sexprp = NULL;
+	if (sexpr == NULL) {
+		return;
+	}
+	switch (sexpr->type) {
+	case ISCCC_SEXPRTYPE_STRING:
+		free(sexpr->value.as_string);
+		break;
+	case ISCCC_SEXPRTYPE_DOTTEDPAIR:
+		item = CAR(sexpr);
+		if (item != NULL) {
+			isccc_sexpr_free(&item);
+		}
+		item = CDR(sexpr);
+		if (item != NULL) {
+			isccc_sexpr_free(&item);
+		}
+		break;
+	case ISCCC_SEXPRTYPE_BINARY:
+		free(sexpr->value.as_region.rstart);
+		break;
+	}
+	free(sexpr);
+}
+
+static bool
+printable(isccc_region_t *r) {
+	unsigned char *curr;
+
+	curr = r->rstart;
+	while (curr != r->rend) {
+		if (!isprint(*curr)) {
+			return (false);
+		}
+		curr++;
+	}
+
+	return (true);
+}
+
+void
+isccc_sexpr_print(isccc_sexpr_t *sexpr, FILE *stream) {
+	isccc_sexpr_t *cdr;
+	unsigned int size, i;
+	unsigned char *curr;
+
+	if (sexpr == NULL) {
+		fprintf(stream, "nil");
+		return;
+	}
+
+	switch (sexpr->type) {
+	case ISCCC_SEXPRTYPE_T:
+		fprintf(stream, "t");
+		break;
+	case ISCCC_SEXPRTYPE_STRING:
+		fprintf(stream, "\"%s\"", sexpr->value.as_string);
+		break;
+	case ISCCC_SEXPRTYPE_DOTTEDPAIR:
+		fprintf(stream, "(");
+		do {
+			isccc_sexpr_print(CAR(sexpr), stream);
+			cdr = CDR(sexpr);
+			if (cdr != NULL) {
+				fprintf(stream, " ");
+				if (cdr->type != ISCCC_SEXPRTYPE_DOTTEDPAIR) {
+					fprintf(stream, ". ");
+					isccc_sexpr_print(cdr, stream);
+					cdr = NULL;
+				}
+			}
+			sexpr = cdr;
+		} while (sexpr != NULL);
+		fprintf(stream, ")");
+		break;
+	case ISCCC_SEXPRTYPE_BINARY:
+		size = REGION_SIZE(sexpr->value.as_region);
+		curr = sexpr->value.as_region.rstart;
+		if (printable(&sexpr->value.as_region)) {
+			fprintf(stream, "'%.*s'", (int)size, curr);
+		} else {
+			fprintf(stream, "0x");
+			for (i = 0; i < size; i++) {
+				fprintf(stream, "%02x", *curr++);
+			}
+		}
+		break;
+	default:
+		UNREACHABLE();
+	}
+}
+
+isccc_sexpr_t *
+isccc_sexpr_car(isccc_sexpr_t *list) {
+	REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	return (CAR(list));
+}
+
+isccc_sexpr_t *
+isccc_sexpr_cdr(isccc_sexpr_t *list) {
+	REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	return (CDR(list));
+}
+
+void
+isccc_sexpr_setcar(isccc_sexpr_t *pair, isccc_sexpr_t *car) {
+	REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	CAR(pair) = car;
+}
+
+void
+isccc_sexpr_setcdr(isccc_sexpr_t *pair, isccc_sexpr_t *cdr) {
+	REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	CDR(pair) = cdr;
+}
+
+isccc_sexpr_t *
+isccc_sexpr_addtolist(isccc_sexpr_t **l1p, isccc_sexpr_t *l2) {
+	isccc_sexpr_t *last, *elt, *l1;
+
+	REQUIRE(l1p != NULL);
+	l1 = *l1p;
+	REQUIRE(l1 == NULL || l1->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	elt = isccc_sexpr_cons(l2, NULL);
+	if (elt == NULL) {
+		return (NULL);
+	}
+	if (l1 == NULL) {
+		*l1p = elt;
+		return (elt);
+	}
+	for (last = l1; CDR(last) != NULL; last = CDR(last)) {
+		/* Nothing */
+	}
+	CDR(last) = elt;
+
+	return (elt);
+}
+
+bool
+isccc_sexpr_listp(isccc_sexpr_t *sexpr) {
+	if (sexpr == NULL || sexpr->type == ISCCC_SEXPRTYPE_DOTTEDPAIR) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_sexpr_emptyp(isccc_sexpr_t *sexpr) {
+	if (sexpr == NULL) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_sexpr_stringp(isccc_sexpr_t *sexpr) {
+	if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_STRING) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_sexpr_binaryp(isccc_sexpr_t *sexpr) {
+	if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY) {
+		return (true);
+	}
+	return (false);
+}
+
+char *
+isccc_sexpr_tostring(isccc_sexpr_t *sexpr) {
+	REQUIRE(sexpr != NULL && (sexpr->type == ISCCC_SEXPRTYPE_STRING ||
+				  sexpr->type == ISCCC_SEXPRTYPE_BINARY));
+
+	if (sexpr->type == ISCCC_SEXPRTYPE_BINARY) {
+		return ((char *)sexpr->value.as_region.rstart);
+	}
+	return (sexpr->value.as_string);
+}
+
+isccc_region_t *
+isccc_sexpr_tobinary(isccc_sexpr_t *sexpr) {
+	REQUIRE(sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY);
+	return (&sexpr->value.as_region);
+}
diff --git a/lib/isccc/symtab.c b/lib/isccc/symtab.c
new file mode 100644
index 0000000..2ab969a
--- /dev/null
+++ b/lib/isccc/symtab.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * 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.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <isc/assertions.h>
+#include <isc/magic.h>
+#include <isc/string.h>
+
+#include <isccc/result.h>
+#include <isccc/symtab.h>
+#include <isccc/util.h>
+
+typedef struct elt {
+	char *key;
+	unsigned int type;
+	isccc_symvalue_t value;
+	ISC_LINK(struct elt) link;
+} elt_t;
+
+typedef ISC_LIST(elt_t) eltlist_t;
+
+#define SYMTAB_MAGIC	 ISC_MAGIC('S', 'y', 'm', 'T')
+#define VALID_SYMTAB(st) ISC_MAGIC_VALID(st, SYMTAB_MAGIC)
+
+struct isccc_symtab {
+	unsigned int magic;
+	unsigned int size;
+	eltlist_t *table;
+	isccc_symtabundefaction_t undefine_action;
+	void *undefine_arg;
+	bool case_sensitive;
+};
+
+isc_result_t
+isccc_symtab_create(unsigned int size,
+		    isccc_symtabundefaction_t undefine_action,
+		    void *undefine_arg, bool case_sensitive,
+		    isccc_symtab_t **symtabp) {
+	isccc_symtab_t *symtab;
+	unsigned int i;
+
+	REQUIRE(symtabp != NULL && *symtabp == NULL);
+	REQUIRE(size > 0); /* Should be prime. */
+
+	symtab = malloc(sizeof(*symtab));
+	if (symtab == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+	symtab->table = malloc(size * sizeof(eltlist_t));
+	if (symtab->table == NULL) {
+		free(symtab);
+		return (ISC_R_NOMEMORY);
+	}
+	for (i = 0; i < size; i++) {
+		ISC_LIST_INIT(symtab->table[i]);
+	}
+	symtab->size = size;
+	symtab->undefine_action = undefine_action;
+	symtab->undefine_arg = undefine_arg;
+	symtab->case_sensitive = case_sensitive;
+	symtab->magic = SYMTAB_MAGIC;
+
+	*symtabp = symtab;
+
+	return (ISC_R_SUCCESS);
+}
+
+static void
+free_elt(isccc_symtab_t *symtab, unsigned int bucket, elt_t *elt) {
+	ISC_LIST_UNLINK(symtab->table[bucket], elt, link);
+	if (symtab->undefine_action != NULL) {
+		(symtab->undefine_action)(elt->key, elt->type, elt->value,
+					  symtab->undefine_arg);
+	}
+	free(elt);
+}
+
+void
+isccc_symtab_destroy(isccc_symtab_t **symtabp) {
+	isccc_symtab_t *symtab;
+	unsigned int i;
+	elt_t *elt, *nelt;
+
+	REQUIRE(symtabp != NULL);
+	symtab = *symtabp;
+	*symtabp = NULL;
+	REQUIRE(VALID_SYMTAB(symtab));
+
+	for (i = 0; i < symtab->size; i++) {
+		for (elt = ISC_LIST_HEAD(symtab->table[i]); elt != NULL;
+		     elt = nelt)
+		{
+			nelt = ISC_LIST_NEXT(elt, link);
+			free_elt(symtab, i, elt);
+		}
+	}
+	free(symtab->table);
+	symtab->magic = 0;
+	free(symtab);
+}
+
+static unsigned int
+hash(const char *key, bool case_sensitive) {
+	const char *s;
+	unsigned int h = 0;
+	unsigned int g;
+	int c;
+
+	/*
+	 * P. J. Weinberger's hash function, adapted from p. 436 of
+	 * _Compilers: Principles, Techniques, and Tools_, Aho, Sethi
+	 * and Ullman, Addison-Wesley, 1986, ISBN 0-201-10088-6.
+	 */
+
+	if (case_sensitive) {
+		for (s = key; *s != '\0'; s++) {
+			h = (h << 4) + *s;
+			if ((g = (h & 0xf0000000)) != 0) {
+				h = h ^ (g >> 24);
+				h = h ^ g;
+			}
+		}
+	} else {
+		for (s = key; *s != '\0'; s++) {
+			c = *s;
+			c = tolower((unsigned char)c);
+			h = (h << 4) + c;
+			if ((g = (h & 0xf0000000)) != 0) {
+				h = h ^ (g >> 24);
+				h = h ^ g;
+			}
+		}
+	}
+
+	return (h);
+}
+
+#define FIND(s, k, t, b, e)                                       \
+	b = hash((k), (s)->case_sensitive) % (s)->size;           \
+	if ((s)->case_sensitive) {                                \
+		for (e = ISC_LIST_HEAD((s)->table[b]); e != NULL; \
+		     e = ISC_LIST_NEXT(e, link))                  \
+		{                                                 \
+			if (((t) == 0 || e->type == (t)) &&       \
+			    strcmp(e->key, (k)) == 0)             \
+				break;                            \
+		}                                                 \
+	} else {                                                  \
+		for (e = ISC_LIST_HEAD((s)->table[b]); e != NULL; \
+		     e = ISC_LIST_NEXT(e, link))                  \
+		{                                                 \
+			if (((t) == 0 || e->type == (t)) &&       \
+			    strcasecmp(e->key, (k)) == 0)         \
+				break;                            \
+		}                                                 \
+	}
+
+isc_result_t
+isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
+		    isccc_symvalue_t *value) {
+	unsigned int bucket;
+	elt_t *elt;
+
+	REQUIRE(VALID_SYMTAB(symtab));
+	REQUIRE(key != NULL);
+
+	FIND(symtab, key, type, bucket, elt);
+
+	if (elt == NULL) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	if (value != NULL) {
+		*value = elt->value;
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
+		    isccc_symvalue_t value, isccc_symexists_t exists_policy) {
+	unsigned int bucket;
+	elt_t *elt;
+
+	REQUIRE(VALID_SYMTAB(symtab));
+	REQUIRE(key != NULL);
+	REQUIRE(type != 0);
+
+	FIND(symtab, key, type, bucket, elt);
+
+	if (exists_policy != isccc_symexists_add && elt != NULL) {
+		if (exists_policy == isccc_symexists_reject) {
+			return (ISC_R_EXISTS);
+		}
+		INSIST(exists_policy == isccc_symexists_replace);
+		ISC_LIST_UNLINK(symtab->table[bucket], elt, link);
+		if (symtab->undefine_action != NULL) {
+			(symtab->undefine_action)(elt->key, elt->type,
+						  elt->value,
+						  symtab->undefine_arg);
+		}
+	} else {
+		elt = malloc(sizeof(*elt));
+		if (elt == NULL) {
+			return (ISC_R_NOMEMORY);
+		}
+		ISC_LINK_INIT(elt, link);
+	}
+
+	elt->key = key;
+	elt->type = type;
+	elt->value = value;
+
+	/*
+	 * We prepend so that the most recent definition will be found.
+	 */
+	ISC_LIST_PREPEND(symtab->table[bucket], elt, link);
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key,
+		      unsigned int type) {
+	unsigned int bucket;
+	elt_t *elt;
+
+	REQUIRE(VALID_SYMTAB(symtab));
+	REQUIRE(key != NULL);
+
+	FIND(symtab, key, type, bucket, elt);
+
+	if (elt == NULL) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	free_elt(symtab, bucket, elt);
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
+		     void *arg) {
+	unsigned int i;
+	elt_t *elt, *nelt;
+
+	REQUIRE(VALID_SYMTAB(symtab));
+	REQUIRE(action != NULL);
+
+	for (i = 0; i < symtab->size; i++) {
+		for (elt = ISC_LIST_HEAD(symtab->table[i]); elt != NULL;
+		     elt = nelt)
+		{
+			nelt = ISC_LIST_NEXT(elt, link);
+			if ((action)(elt->key, elt->type, elt->value, arg)) {
+				free_elt(symtab, i, elt);
+			}
+		}
+	}
+}
diff --git a/lib/isccc/tests/Kyuafile b/lib/isccc/tests/Kyuafile
new file mode 100644
index 0000000..79c8b3c
--- /dev/null
+++ b/lib/isccc/tests/Kyuafile
@@ -0,0 +1,15 @@
+-- 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.
+
+syntax(2)
+test_suite('bind9')
+
+tap_test_program{name='result_test'}
diff --git a/lib/isccc/tests/Makefile.in b/lib/isccc/tests/Makefile.in
new file mode 100644
index 0000000..f9f1968
--- /dev/null
+++ b/lib/isccc/tests/Makefile.in
@@ -0,0 +1,51 @@
+# 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.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+# Attempt to disable parallel processing.
+.NOTPARALLEL:
+.NO_PARALLEL:
+
+VERSION=@BIND9_VERSION@
+
+@BIND9_MAKE_INCLUDES@
+
+CINCLUDES =	-I. -Iinclude ${ISCCC_INCLUDES} ${ISC_INCLUDES} @CMOCKA_CFLAGS@
+CDEFINES =
+
+ISCLIBS =	../../isc/libisc.@A@
+ISCDEPLIBS =	../../isc/libisc.@A@
+ISCCCLIBS =	../libisccc.@A@
+ISCCCDEPLIBS =	../libisccc.@A@
+
+LIBS =		@LIBS@ @CMOCKA_LIBS@
+
+OBJS =
+SRCS =		result_test.c
+SUBDIRS =
+TARGETS =	result_test@EXEEXT@
+
+@BIND9_MAKE_RULES@
+
+result_test@EXEEXT@: result_test.@O@ ${ISCDEPLIBS} ${ISCCCDEPLIBS}
+	${LIBTOOL_MODE_LINK} ${PURIFY} ${CC} ${CFLAGS} \
+		${LDFLAGS} -o $@ result_test.@O@ \
+		${ISCCCLIBS} ${ISCLIBS} ${LIBS}
+
+unit::
+	sh ${top_builddir}/unit/unittest.sh
+
+clean distclean::
+	rm -f ${TARGETS}
+	rm -f atf.out
diff --git a/lib/isccc/tests/result_test.c b/lib/isccc/tests/result_test.c
new file mode 100644
index 0000000..b27ee22
--- /dev/null
+++ b/lib/isccc/tests/result_test.c
@@ -0,0 +1,84 @@
+/*
+ * 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.
+ */
+
+#if HAVE_CMOCKA
+
+#include <setjmp.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define UNIT_TESTING
+#include <cmocka.h>
+
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <isccc/result.h>
+
+/*
+ * Check tables are populated.
+ */
+static void
+tables(void **state) {
+	const char *str;
+	isc_result_t result;
+
+	UNUSED(state);
+
+	isccc_result_register();
+
+	for (result = ISC_RESULTCLASS_ISCCC;
+	     result < (ISC_RESULTCLASS_ISCCC + ISCCC_R_NRESULTS); result++)
+	{
+		str = isc_result_toid(result);
+		assert_non_null(str);
+		assert_string_not_equal(str, "(result code text not "
+					     "available)");
+
+		str = isc_result_totext(result);
+		assert_non_null(str);
+		assert_string_not_equal(str, "(result code text not "
+					     "available)");
+	}
+
+	str = isc_result_toid(result);
+	assert_non_null(str);
+	assert_string_equal(str, "(result code text not available)");
+
+	str = isc_result_totext(result);
+	assert_non_null(str);
+	assert_string_equal(str, "(result code text not available)");
+}
+
+int
+main(void) {
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(tables),
+	};
+
+	return (cmocka_run_group_tests(tests, NULL, NULL));
+}
+
+#else /* HAVE_CMOCKA */
+
+#include <stdio.h>
+
+int
+main(void) {
+	printf("1..0 # Skipped: cmocka not available\n");
+	return (SKIPPED_TEST_EXIT_CODE);
+}
+
+#endif /* if HAVE_CMOCKA */
diff --git a/lib/isccc/version.c b/lib/isccc/version.c
new file mode 100644
index 0000000..95f9ee2
--- /dev/null
+++ b/lib/isccc/version.c
@@ -0,0 +1,18 @@
+/*
+ * 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.
+ */
+
+/*! \file */
+
+#include <isccc/version.h>
+
+const char isccc_version[] = VERSION;
diff --git a/lib/isccc/win32/DLLMain.c b/lib/isccc/win32/DLLMain.c
new file mode 100644
index 0000000..62c6e53
--- /dev/null
+++ b/lib/isccc/win32/DLLMain.c
@@ -0,0 +1,49 @@
+/*
+ * 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 <signal.h>
+#include <windows.h>
+
+/*
+ * Called when we enter the DLL
+ */
+__declspec(dllexport) BOOL WINAPI
+	DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) {
+	switch (fdwReason) {
+	/*
+	 * The DLL is loading due to process
+	 * initialization or a call to LoadLibrary.
+	 */
+	case DLL_PROCESS_ATTACH:
+		break;
+
+	/* The attached process creates a new thread.  */
+	case DLL_THREAD_ATTACH:
+		break;
+
+	/* The thread of the attached process terminates. */
+	case DLL_THREAD_DETACH:
+		break;
+
+	/*
+	 * The DLL is unloading from a process due to
+	 * process termination or a call to FreeLibrary.
+	 */
+	case DLL_PROCESS_DETACH:
+		break;
+
+	default:
+		break;
+	}
+	return (TRUE);
+}
diff --git a/lib/isccc/win32/libisccc.def b/lib/isccc/win32/libisccc.def
new file mode 100644
index 0000000..5cb5662
--- /dev/null
+++ b/lib/isccc/win32/libisccc.def
@@ -0,0 +1,65 @@
+LIBRARY libisccc
+
+; Exported Functions
+EXPORTS
+
+isccc_alist_create
+isccc_alist_alistp
+isccc_alist_emptyp
+isccc_alist_first
+isccc_alist_assq
+isccc_alist_delete
+isccc_alist_define
+isccc_alist_definestring
+isccc_alist_definebinary
+isccc_alist_lookup
+isccc_alist_lookupstring
+isccc_alist_lookupbinary
+isccc_alist_prettyprint
+isccc_base64_encode
+isccc_base64_decode
+isccc_cc_towire
+isccc_cc_fromwire
+isccc_cc_createmessage
+isccc_cc_createack
+isccc_cc_isack
+isccc_cc_isreply
+isccc_cc_createresponse
+isccc_cc_definestring
+isccc_cc_defineuint32
+isccc_cc_lookupstring
+isccc_cc_lookupuint32
+isccc_cc_createsymtab
+isccc_cc_cleansymtab
+isccc_cc_checkdup
+isccc_ccmsg_init
+isccc_ccmsg_setmaxsize
+isccc_ccmsg_readmessage
+isccc_ccmsg_cancelread
+isccc_ccmsg_invalidate
+isccc_result_totext
+isccc_result_register
+isccc_sexpr_cons
+isccc_sexpr_tconst
+isccc_sexpr_fromstring
+isccc_sexpr_frombinary
+isccc_sexpr_free
+isccc_sexpr_print
+isccc_sexpr_car
+isccc_sexpr_cdr
+isccc_sexpr_setcar
+isccc_sexpr_setcdr
+isccc_sexpr_addtolist
+isccc_sexpr_listp
+isccc_sexpr_emptyp
+isccc_sexpr_stringp
+isccc_sexpr_binaryp
+isccc_sexpr_tostring
+isccc_sexpr_tobinary
+isccc_symtab_destroy
+isccc_symtab_create
+isccc_symtab_destroy
+isccc_symtab_lookup
+isccc_symtab_define
+isccc_symtab_undefine
+isccc_symtab_foreach
diff --git a/lib/isccc/win32/libisccc.vcxproj.filters.in b/lib/isccc/win32/libisccc.vcxproj.filters.in
new file mode 100644
index 0000000..1d1ff10
--- /dev/null
+++ b/lib/isccc/win32/libisccc.vcxproj.filters.in
@@ -0,0 +1,87 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="Source Files">
+      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
+      <Extensions>cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
+    </Filter>
+    <Filter Include="Header Files">
+      <UniqueIdentifier>{93995380-89BD-4b04-88EB-625FBE52EBFB}</UniqueIdentifier>
+      <Extensions>h;hpp;hxx;hm;inl;inc;xsd</Extensions>
+    </Filter>
+    <Filter Include="Resource Files">
+      <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
+      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="libisccc.def" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="DLLMain.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="version.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\alist.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\base64.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\cc.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\ccmsg.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\result.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\sexpr.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\symtab.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\include\isccc\alist.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\base64.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\cc.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\ccmsg.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\events.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\result.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\sexpr.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\symtab.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\symtype.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\types.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\util.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\isccc\version.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+  </ItemGroup>
+</Project>
diff --git a/lib/isccc/win32/libisccc.vcxproj.in b/lib/isccc/win32/libisccc.vcxproj.in
new file mode 100644
index 0000000..86de718
--- /dev/null
+++ b/lib/isccc/win32/libisccc.vcxproj.in
@@ -0,0 +1,148 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="@TOOLS_VERSION@" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|@PLATFORM@">
+      <Configuration>Debug</Configuration>
+      <Platform>@PLATFORM@</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|@PLATFORM@">
+      <Configuration>Release</Configuration>
+      <Platform>@PLATFORM@</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{B556705F-1920-4400-878A-B259D3556047}</ProjectGuid>
+    <Keyword>Win32Proj</Keyword>
+    <RootNamespace>libisccc</RootNamespace>
+    @WINDOWS_TARGET_PLATFORM_VERSION@
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>MultiByte</CharacterSet>
+    @PLATFORM_TOOLSET@
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>MultiByte</CharacterSet>
+    @PLATFORM_TOOLSET@
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'">
+    <LinkIncremental>true</LinkIncremental>
+    <OutDir>..\..\..\Build\$(Configuration)\</OutDir>
+    <IntDir>.\$(Configuration)\</IntDir>
+    <IntDirSharingDetected>None</IntDirSharingDetected>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'">
+    <LinkIncremental>false</LinkIncremental>
+    <OutDir>..\..\..\Build\$(Configuration)\</OutDir>
+    <IntDir>.\$(Configuration)\</IntDir>
+    <IntDirSharingDetected>None</IntDirSharingDetected>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'">
+    <ClCompile>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <TreatWarningAsError>false</TreatWarningAsError>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;LIBISCCC_EXPORTS;%(PreprocessorDefinitions);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ForcedIncludeFiles>..\..\..\config.h</ForcedIncludeFiles>
+      <AdditionalIncludeDirectories>.\;..\..\..\;@LIBXML2_INC@@OPENSSL_INC@include;..\include;..\..\isc\win32;..\..\isc\win32\include;..\..\isc\include;..\..\dns\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>.\$(Configuration)\$(TargetName).pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>.\$(Configuration)\</AssemblerListingLocation>
+      <ObjectFileName>.\$(Configuration)\</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)$(TargetName).pdb</ProgramDataBaseFileName>
+      <BrowseInformation>true</BrowseInformation>
+      <CompileAs>CompileAsC</CompileAs>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <OutputFile>..\..\..\Build\$(Configuration)\$(TargetName)$(TargetExt)</OutputFile>
+      <AdditionalLibraryDirectories>..\..\isc\win32\$(Configuration);%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>@OPENSSL_LIBCRYPTO@@OPENSSL_LIBSSL@libisc.lib;ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <ModuleDefinitionFile>$(ProjectName).def</ModuleDefinitionFile>
+      <ImportLibrary>.\$(Configuration)\$(ProjectName).lib</ImportLibrary>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'">
+    <ClCompile>
+      <WarningLevel>Level1</WarningLevel>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>@INTRINSIC@</IntrinsicFunctions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;LIBISCCC_EXPORTS;%(PreprocessorDefinitions);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ForcedIncludeFiles>..\..\..\config.h</ForcedIncludeFiles>
+      <AdditionalIncludeDirectories>.\;..\..\..\;@LIBXML2_INC@@OPENSSL_INC@include;..\include;..\..\isc\win32;..\..\isc\win32\include;..\..\isc\include;..\..\dns\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <StringPooling>true</StringPooling>
+      <PrecompiledHeaderOutputFile>.\$(Configuration)\$(TargetName).pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>.\$(Configuration)\</AssemblerListingLocation>
+      <ObjectFileName>.\$(Configuration)\</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)$(TargetName).pdb</ProgramDataBaseFileName>
+      <WholeProgramOptimization>false</WholeProgramOptimization>
+      <CompileAs>CompileAsC</CompileAs>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <OutputFile>..\..\..\Build\$(Configuration)\$(TargetName)$(TargetExt)</OutputFile>
+      <AdditionalLibraryDirectories>..\..\isc\win32\$(Configuration);%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>@OPENSSL_LIBCRYPTO@@OPENSSL_LIBSSL@libisc.lib;ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <ModuleDefinitionFile>$(ProjectName).def</ModuleDefinitionFile>
+      <ImportLibrary>.\$(Configuration)\$(ProjectName).lib</ImportLibrary>
+      <LinkTimeCodeGeneration>Default</LinkTimeCodeGeneration>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <None Include="libisccc.def" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\alist.c" />
+    <ClCompile Include="..\base64.c" />
+    <ClCompile Include="..\cc.c" />
+    <ClCompile Include="..\ccmsg.c" />
+    <ClCompile Include="..\result.c" />
+    <ClCompile Include="..\sexpr.c" />
+    <ClCompile Include="..\symtab.c" />
+    <ClCompile Include="DLLMain.c" />
+    <ClCompile Include="version.c" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\include\isccc\alist.h" />
+    <ClInclude Include="..\include\isccc\base64.h" />
+    <ClInclude Include="..\include\isccc\cc.h" />
+    <ClInclude Include="..\include\isccc\ccmsg.h" />
+    <ClInclude Include="..\include\isccc\events.h" />
+    <ClInclude Include="..\include\isccc\result.h" />
+    <ClInclude Include="..\include\isccc\sexpr.h" />
+    <ClInclude Include="..\include\isccc\symtab.h" />
+    <ClInclude Include="..\include\isccc\symtype.h" />
+    <ClInclude Include="..\include\isccc\types.h" />
+    <ClInclude Include="..\include\isccc\util.h" />
+    <ClInclude Include="..\include\isccc\version.h" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
diff --git a/lib/isccc/win32/libisccc.vcxproj.user b/lib/isccc/win32/libisccc.vcxproj.user
new file mode 100644
index 0000000..ace9a86
--- /dev/null
+++ b/lib/isccc/win32/libisccc.vcxproj.user
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+</Project>
\ No newline at end of file
diff --git a/lib/isccc/win32/version.c b/lib/isccc/win32/version.c
new file mode 100644
index 0000000..6576b52
--- /dev/null
+++ b/lib/isccc/win32/version.c
@@ -0,0 +1,18 @@
+/*
+ * 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 <versions.h>
+
+#include <isccc/version.h>
+
+LIBISCCC_EXTERNAL_DATA const char isccc_version[] = VERSION;