Merge branch 'ondrej-add-dns_message_checktsig-fuzzer' into 'main'

Add dns_message_checksig() fuzzer

See merge request isc-projects/bind9!5923

CHANGES

@@ -1,3 +1,10 @@
+5982.	[func]		Extend dig to allow requests to be signed using SIG(0)
+			as well as providing a mechanism to specify the signing
+			time. [GL !5923]
+
+5981.	[test]		Add dns_message_checksig fuzzer to check messages
+			signed using TSIG or SIG(0). [GL !5923]
+
 5980.	[func]		The internal isc_entropy API provider has been
 			changed from OpenSSL RAND_bytes() to uv_random()
 			to use system provided entropy. [GL !6803]

bin/dig/dig.c

@@ -1522,8 +1522,31 @@ plus_option(char *option, bool is_batchfile, bool *need_clone,
 		}
 		break;
 	case 'f': /* fail */
-		FULLCHECK("fail");
-		lookup->servfail_stops = state;
+		switch (cmd[1]) {
+		case 'a':
+			FULLCHECK("fail");
+			lookup->servfail_stops = state;
+			break;
+		case 'u':
+			FULLCHECK("fuzztime");
+			lookup->fuzzing = state;
+			if (lookup->fuzzing) {
+				if (value == NULL) {
+					lookup->fuzztime = 0x622acce1;
+					break;
+				}
+				result = parse_uint(&num, value, 0xffffffff,
+						    "fuzztime");
+				if (result != ISC_R_SUCCESS) {
+					warn("Couldn't parse fuzztime");
+					goto exit_or_usage;
+				}
+				lookup->fuzztime = num;
+			}
+			break;
+		default:
+			goto invalid_option;
+		}
 		break;
 	case 'h':
 		switch (cmd[1]) {

bin/dig/dig.rst

@@ -132,12 +132,14 @@ Options
 
 .. option:: -k keyfile
 
-   This option tells :iscman:`named` to sign queries using TSIG using a key read from the given file. Key
-   files can be generated using :iscman:`tsig-keygen`. When using TSIG
-   authentication with :program:`dig`, the name server that is queried needs to
-   know the key and algorithm that is being used. In BIND, this is done
-   by providing appropriate ``key`` and ``server`` statements in
-   :iscman:`named.conf`.
+   This option tells :program:`dig` to sign queries using TSIG or
+   SIG(0) using a key read from the given file. Key files can be
+   generated using :iscman:`tsig-keygen`. When using TSIG authentication
+   with :program:`dig`, the name server that is queried needs to
+   know the key and algorithm that is being used. In BIND, this is
+   done by providing appropriate ``key`` and ``server`` statements
+   in :iscman:`named.conf` for TSIG and by looking up the KEY record
+   in zone data for SIG(0).
 
 .. option:: -m
 
@@ -386,6 +388,14 @@ abbreviation is unambiguous; for example, :option:`+cd` is equivalent to
    to not try the next server, which is the reverse of normal stub
    resolver behavior.
 
+.. option:: +fuzztime[=value], +nofuzztime
+
+   This option allows the signing time to be specified when generating
+   signed messages.  If a value is specified it is the seconds since
+   00:00:00 January 1, 1970 UTC ignoring leap seconds.  If no value
+   is specified 1646972129 (Fri 11 Mar 2022 04:15:29 UTC) is used.
+   The default is ``+nofuzztime`` and the current time is used.
+
 .. option:: +header-only, +noheader-only
 
    This option sends a query with a DNS header without a question section. The

bin/dig/dighost.c

@@ -143,6 +143,7 @@ const dns_name_t *hmacname = NULL;
 unsigned int digestbits = 0;
 isc_buffer_t *namebuf = NULL;
 dns_tsigkey_t *tsigkey = NULL;
+dst_key_t *sig0key = NULL;
 bool validated = true;
 bool debugging = false;
 bool debugtiming = false;
@@ -794,6 +795,8 @@ clone_lookup(dig_lookup_t *lookold, bool servers) {
 	looknew->done_as_is = lookold->done_as_is;
 	looknew->dscp = lookold->dscp;
 	looknew->rrcomments = lookold->rrcomments;
+	looknew->fuzzing = lookold->fuzzing;
+	looknew->fuzztime = lookold->fuzztime;
 
 	if (lookold->ecs_addr != NULL) {
 		size_t len = sizeof(isc_sockaddr_t);
@@ -1141,6 +1144,10 @@ setup_file_key(void) {
 
 	debug("setup_file_key()");
 
+	if (sig0key != NULL) {
+		dst_key_free(&sig0key);
+	}
+
 	/* Try reading the key from a K* pair */
 	result = dst_key_fromnamedfile(
 		keyfile, NULL, DST_TYPE_PRIVATE | DST_TYPE_KEY, mctx, &dstkey);
@@ -1178,18 +1185,20 @@ setup_file_key(void) {
 	case DST_ALG_HMACSHA512:
 		hmacname = DNS_TSIG_HMACSHA512_NAME;
 		break;
-	default:
-		printf(";; Couldn't create key %s: bad algorithm\n",
-		       keynametext);
-		goto failure;
 	}
-	result = dns_tsigkey_createfromkey(dst_key_name(dstkey), hmacname,
-					   dstkey, false, NULL, 0, 0, mctx,
-					   NULL, &tsigkey);
-	if (result != ISC_R_SUCCESS) {
-		printf(";; Couldn't create key %s: %s\n", keynametext,
-		       isc_result_totext(result));
-		goto failure;
+
+	if (hmacname != NULL) {
+		result = dns_tsigkey_createfromkey(
+			dst_key_name(dstkey), hmacname, dstkey, false, NULL, 0,
+			0, mctx, NULL, &tsigkey);
+		if (result != ISC_R_SUCCESS) {
+			printf(";; Couldn't create key %s: %s\n", keynametext,
+			       isc_result_totext(result));
+			goto failure;
+		}
+	} else {
+		dst_key_attach(dstkey, &sig0key);
+		dst_key_free(&dstkey);
 	}
 failure:
 	if (dstkey != NULL) {
@@ -2425,6 +2434,15 @@ setup_lookup(dig_lookup_t *lookup) {
 		debug("initializing keys");
 		result = dns_message_settsigkey(lookup->sendmsg, tsigkey);
 		check_result(result, "dns_message_settsigkey");
+	} else if (sig0key != NULL) {
+		debug("initializing keys");
+		result = dns_message_setsig0key(lookup->sendmsg, sig0key);
+		check_result(result, "dns_message_setsig0key");
+	}
+
+	if (lookup->fuzzing) {
+		lookup->sendmsg->fuzzing = true;
+		lookup->sendmsg->fuzztime = lookup->fuzztime;
 	}
 
 	lookup->sendspace = isc_mem_get(mctx, COMMSIZE);
@@ -4654,10 +4672,17 @@ destroy_libs(void) {
 	clear_searchlist();
 
 	if (tsigkey != NULL) {
-		debug("freeing key %p", tsigkey);
+		debug("freeing TSIG key %p", tsigkey);
 		dns_tsigkey_detach(&tsigkey);
 	}
+
+	if (sig0key != NULL) {
+		debug("freeing SIG(0) key %p", sig0key);
+		dst_key_free(&sig0key);
+	}
+
 	if (namebuf != NULL) {
+		debug("freeing key %p", tsigkey);
 		isc_buffer_free(&namebuf);
 	}
 

bin/dig/dighost.h

@@ -108,10 +108,11 @@ struct dig_lookup {
 	isc_refcount_t references;
 	bool aaonly, adflag, badcookie, besteffort, cdflag, cleared, comments,
 		dns64prefix, dnssec, doing_xfr, done_as_is, ednsneg, expandaaaa,
-		expire, header_only, identify, /*%< Append an "on server <foo>"
-						  message */
-		identify_previous_line,	       /*% Prepend a "Nameserver <foo>:"
-						  message, with newline and tab */
+		expire, fuzzing, header_only, identify, /*%< Append an "on
+							   server <foo>" message
+							 */
+		identify_previous_line, /*% Prepend a "Nameserver <foo>:"
+					   message, with newline and tab */
 		idnin, idnout, ignore, multiline, need_search, new_search,
 		noclass, nocrypto, nottl, ns_search_only, /*%< dig +nssearch,
 							     host -C */
@@ -188,6 +189,7 @@ struct dig_lookup {
 		char *tls_key_file;
 		isc_tlsctx_cache_t *tls_ctx_cache;
 	};
+	isc_stdtime_t fuzztime;
 };
 
 /*% The dig_query structure */

doc/man/dig.1in

@@ -153,12 +153,14 @@ Print a usage summary.
 .INDENT 0.0
 .TP
 .B \-k keyfile
-This option tells \fI\%named\fP to sign queries using TSIG using a key read from the given file. Key
-files can be generated using \fI\%tsig\-keygen\fP\&. When using TSIG
-authentication with \fBdig\fP, the name server that is queried needs to
-know the key and algorithm that is being used. In BIND, this is done
-by providing appropriate \fBkey\fP and \fBserver\fP statements in
-\fI\%named.conf\fP\&.
+This option tells \fBdig\fP to sign queries using TSIG or
+SIG(0) using a key read from the given file. Key files can be
+generated using \fI\%tsig\-keygen\fP\&. When using TSIG authentication
+with \fBdig\fP, the name server that is queried needs to
+know the key and algorithm that is being used. In BIND, this is
+done by providing appropriate \fBkey\fP and \fBserver\fP statements
+in \fI\%named.conf\fP for TSIG and by looking up the KEY record
+in zone data for SIG(0).
 .UNINDENT
 .INDENT 0.0
 .TP
@@ -448,6 +450,15 @@ resolver behavior.
 .UNINDENT
 .INDENT 0.0
 .TP
+.B +fuzztime[=value], +nofuzztime
+This option allows the signing time to be specified when generating
+signed messages.  If a value is specified it is the seconds since
+00:00:00 January 1, 1970 UTC ignoring leap seconds.  If no value
+is specified 1646972129 (Fri 11 Mar 2022 04:15:29 UTC) is used.
+The default is \fB+nofuzztime\fP and the current time is used.
+.UNINDENT
+.INDENT 0.0
+.TP
 .B +header\-only, +noheader\-only
 This option sends a query with a DNS header without a question section. The
 default is to add a question section. The query type and query name

fuzz/.gitignore

@@ -1,6 +1,7 @@
 /*.dSYM/
 /*.out/
 /dns_master_load
+/dns_message_checksig
 /dns_message_parse
 /dns_name_fromtext_target
 /dns_rdata_fromtext

fuzz/Makefile.am

@@ -23,6 +23,7 @@ libfuzzmain_la_SOURCES =		\
 
 check_PROGRAMS =			\
 	dns_master_load			\
+	dns_message_checksig		\
 	dns_message_parse		\
 	dns_name_fromtext_target	\
 	dns_rdata_fromtext		\
@@ -32,6 +33,7 @@ check_PROGRAMS =			\
 
 EXTRA_DIST =				\
 	dns_master_load.in		\
+	dns_message_checksig.in		\
 	dns_message_parse.in		\
 	dns_name_fromtext_target.in	\
 	dns_rdata_fromtext.in		\

fuzz/dns_message_checksig.c

@@ -0,0 +1,413 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <isc/buffer.h>
+#include <isc/commandline.h>
+#include <isc/file.h>
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/fixedname.h>
+#include <dns/message.h>
+#include <dns/name.h>
+#include <dns/rcode.h>
+#include <dns/tsig.h>
+#include <dns/view.h>
+#include <dns/zone.h>
+
+#include "fuzz.h"
+
+bool debug = false;
+
+static isc_mem_t *mctx = NULL;
+
+/*
+ *	Packet dumps of validily signed request ./IN/SOA
+ *	requests.
+ *
+ *	TSIG:
+ *
+ *	0x0000:  600b 0900 006a 1140 0000 0000 0000 0000
+ *	0x0010:  0000 0000 0000 0001 0000 0000 0000 0000
+ *	0x0020:  0000 0000 0000 0001 cc88 0035 006a 007d
+ *	0x0030:  1dfa 0000 0001 0000 0000 0001 0000 0600
+ *	0x0040:  0108 7473 6967 2d6b 6579 0000 fa00 ff00
+ *	0x0050:  0000 0000 3d0b 686d 6163 2d73 6861 3235
+ *	0x0060:  3600 0000 622a cce1 012c 0020 224d 5807
+ *	0x0070:  648d 1400 9d8e fc1c d049 55e9 cc90 2187
+ *	0x0080:  3b5f af5c 8899 dc27 c8df b34b 1dfa 0000
+ *	0x0090:  0000
+ *
+ *	SIG(0):
+ *
+ *	0x0000:  6004 0e00 013f 1140 0000 0000 0000 0000
+ *	0x0010:  0000 0000 0000 0001 0000 0000 0000 0000
+ *	0x0020:  0000 0000 0000 0001 c0a7 0035 013f 0152
+ *	0x0030:  0000 0000 0001 0000 0000 0001 0000 0600
+ *	0x0040:  0100 0018 00ff 0000 0000 011b 0000 0800
+ *	0x0050:  0000 0000 622a ce0d 622a cbb5 da71 0773
+ *	0x0060:  6967 306b 6579 0068 988b 27bf 5c89 5270
+ *	0x0070:  c5ba ea8b 2e10 0512 9b44 48d3 69de b7ec
+ *	0x0080:  7c67 15f3 6bc7 b0dc 277b e8f1 6979 4c89
+ *	0x0090:  149a 0203 30a1 c0b7 a711 ee8a 8d90 ebb9
+ *	0x00a0:  9e33 dd65 33d5 5d1d 90db cf9c bb6a b346
+ *	0x00b0:  568f a399 71d7 c877 616d 2fb7 0f86 963f
+ *	0x00c0:  aa00 850d 180a 9f83 cd4b d115 c79f 64c9
+ *	0x00d0:  ff05 e751 6810 28b3 2249 c4ba 2d8d 57ba
+ *	0x00e0:  9aad f1fc b34e c237 9465 04fd fe4d 19c9
+ *	0x00f0:  2368 ec8e 7097 eaea e067 2b9c 06eb c383
+ *	0x0100:  e901 a11e 606b 4cce c12a 0e57 8c09 b7cb
+ *	0x0110:  23bb ec05 b68b 1852 9288 b665 fe89 cf62
+ *	0x0120:  0a41 5e5a acbe 6903 cbb7 e7b6 cab4 e4a2
+ *	0x0130:  b98f 884f c09d 5b39 c695 c84c 9a92 f110
+ *	0x0140:  ccc3 f2ee 313f a2a1 1cda 5aa2 faec d593
+ *	0x0150:  4514 724a 868f 94b9 0547 4dc9 7b73 c85e
+ *	0x0160:  544c 73d4 e892 f9
+ */
+
+#define HMACSHA256 "\x0bhmac-sha256"
+
+static isc_stdtime_t fuzztime = 0x622acce1;
+static dns_view_t *view = NULL;
+static dns_tsigkey_t *tsigkey = NULL;
+static dns_tsig_keyring_t *ring = NULL;
+static dns_tsig_keyring_t *emptyring = NULL;
+
+static void
+cleanup(void) {
+	if (view != NULL) {
+		dns_view_detach(&view);
+	}
+	if (tsigkey != NULL) {
+		dns_tsigkey_detach(&tsigkey);
+	}
+	if (ring != NULL) {
+		dns_tsigkeyring_detach(&ring);
+	}
+	if (emptyring != NULL) {
+		dns_tsigkeyring_detach(&emptyring);
+	}
+	if (mctx != NULL) {
+		isc_mem_detach(&mctx);
+	}
+}
+
+int
+LLVMFuzzerInitialize(int *argc __attribute__((unused)),
+		     char ***argv __attribute__((unused))) {
+	isc_result_t result;
+	dns_fixedname_t fixed;
+	dns_name_t *name = dns_fixedname_initname(&fixed);
+	unsigned char secret[16] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+				     0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+				     0xff, 0xff, 0xff, 0xff };
+	dns_zone_t *zone = NULL;
+
+	atexit(cleanup);
+
+	isc_mem_create(&mctx);
+
+	result = dst_lib_init(mctx, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_view_create(mctx, dns_rdataclass_in, "view", &view);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_tsigkeyring_create(mctx, &ring);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_tsigkeyring_create(mctx, &emptyring);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_name_fromstring(name, "tsig-key", 0, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_tsigkey_create(name, dns_tsig_hmacsha256_name, secret,
+				    sizeof(secret), false, NULL, 0, 0, mctx,
+				    ring, &tsigkey);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_name_fromstring(name, "sig0key", 0, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_zone_create(&zone, mctx, 0);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_zone_setorigin(zone, name);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	dns_zone_setclass(zone, view->rdclass);
+	dns_zone_settype(zone, dns_zone_primary);
+
+	result = dns_zone_setkeydirectory(zone, "dns_message_checksig.data");
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_zone_setfile(zone, "dns_message_checksig.data/sig0key.db",
+				  dns_masterformat_text,
+				  &dns_master_style_default);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_zone_load(zone, false);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	result = dns_view_addzone(view, zone);
+	if (result != ISC_R_SUCCESS) {
+		return (1);
+	}
+
+	dns_view_freeze(view);
+
+	dns_zone_detach(&zone);
+
+	return (0);
+}
+
+static isc_result_t
+create_message(dns_message_t **messagep, const uint8_t *data, size_t size,
+	       bool addasig, bool addtsig) {
+	isc_result_t result;
+	dns_message_t *message = NULL;
+	isc_buffer_t b;
+	unsigned char buf[65535];
+
+	isc_buffer_init(&b, buf, sizeof(buf));
+
+	/* Message ID */
+	isc_buffer_putuint16(&b, 0);
+
+	/* QR, Opcode, other flags = 0, rcode = 0 */
+	isc_buffer_putuint16(&b, (*data & 0x1f) << 11);
+	/* Counts */
+	isc_buffer_putuint16(&b, 1);
+	isc_buffer_putuint16(&b, 0);
+	isc_buffer_putuint16(&b, 0);
+	isc_buffer_putuint16(&b, addasig ? 1 : 0);
+
+	/* Question ./IN/SOA */
+	isc_buffer_putuint8(&b, 0);
+	isc_buffer_putuint16(&b, 6);
+	isc_buffer_putuint16(&b, 1);
+
+	if (addasig) {
+		/* Signature */
+		if (addtsig) {
+			const unsigned char keyname[] = "\x08tsig-key";
+			isc_buffer_putmem(&b, keyname, sizeof(keyname));
+			isc_buffer_putuint16(&b, dns_rdatatype_tsig);
+			isc_buffer_putuint16(&b, dns_rdataclass_any);
+		} else {
+			isc_buffer_putuint8(&b, 0); /* '.' */
+			isc_buffer_putuint16(&b, dns_rdatatype_sig);
+			isc_buffer_putuint16(&b, dns_rdataclass_in);
+		}
+		isc_buffer_putuint32(&b, 0); /* ttl */
+		data++;
+		size--;
+		if (size > isc_buffer_availablelength(&b) - 2) {
+			size = isc_buffer_availablelength(&b) - 2;
+		}
+		isc_buffer_putuint16(&b, size);
+		isc_buffer_putmem(&b, data, size);
+	}
+
+	dns_message_create(mctx, DNS_MESSAGE_INTENTPARSE, &message);
+
+	result = dns_message_parse(message, &b, 0);
+	if (debug) {
+		fprintf(stderr, "dns_message_parse => %s\n",
+			isc_result_totext(result));
+	}
+	if (result != ISC_R_SUCCESS) {
+		dns_message_detach(&message);
+	} else {
+		if (debug) {
+			char text[200000];
+			isc_buffer_init(&b, text, sizeof(text));
+
+			result = dns_message_totext(
+				message, &dns_master_style_debug, 0, &b);
+			if (result == ISC_R_SUCCESS) {
+				fprintf(stderr, "%.*s", (int)b.used, text);
+			} else {
+				fprintf(stderr, "dns_message_totext => %s\n",
+					isc_result_totext(result));
+			}
+		}
+		*messagep = message;
+	}
+	return (result);
+}
+
+int
+LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+	isc_result_t result;
+	dns_message_t *message = NULL;
+	unsigned char query_tsig[23 + 32 + 6] = { 0 };
+	bool addasig = false;
+	bool addtime = false;
+	bool addtsig = false;
+	bool setquerytsig = false;
+	bool settsigkey = false;
+	bool subtime = false;
+	bool withring = false;
+	bool withview = false;
+
+	/*
+	 * The first 2 octets affect setup.
+	 * Octet 1 determines whether a signature is added and which type
+	 * (addasig, addtsig), whether time should be adjusted (addtime,
+	 * subtime), whether dns_message_setquerytsig and dns_message_settsigkey
+	 * have been called, whether there is a keyring available with the
+	 * TSIG key or a view is defined.
+	 *
+	 * The second octet defines if the message is a response and the
+	 * opcode.
+	 */
+	if (size > 65535 || size < 2) {
+		return (0);
+	}
+
+	addasig = (*data & 0x80) != 0;
+	addtime = (*data & 0x40) != 0;
+	addtsig = (*data & 0x20) != 0;
+	setquerytsig = (*data & 0x10) != 0;
+	settsigkey = (*data & 0x08) != 0;
+	subtime = (*data & 0x04) != 0;
+	withring = (*data & 0x02) != 0;
+	withview = (*data & 0x01) != 0;
+
+	data++;
+	size--;
+
+	if (debug) {
+		fprintf(stderr,
+			"addasig=%u addtime=%u addtsig=%u setquerytsig=%u "
+			"settsigkey=%u subtime=%u withring=%u\nwithview=%u\n",
+			addasig, addtime, addtsig, setquerytsig, settsigkey,
+			subtime, withring, withview);
+	}
+
+	result = create_message(&message, data, size, addasig, addtsig);
+	if (result != ISC_R_SUCCESS) {
+		return (0);
+	}
+
+	/*
+	 * Make time calculations consistent.
+	 */
+	message->fuzzing = 1;
+	message->fuzztime = fuzztime;
+	if (addtime) {
+		message->fuzztime += 1200;
+	}
+	if (subtime) {
+		message->fuzztime -= 1200;
+	}
+
+	if ((message->flags & DNS_MESSAGEFLAG_QR) != 0) {
+		if (setquerytsig) {
+			isc_buffer_t b;
+			unsigned char hmacname[] = HMACSHA256;
+			unsigned char hmac[32] = {
+				0x22, 0x4d, 0x58, 0x07, 0x64, 0x8d, 0x14, 0x00,
+				0x9d, 0x8e, 0xfc, 0x1c, 0xd0, 0x49, 0x55, 0xe9,
+				0xcc, 0x90, 0x21, 0x87, 0x3b, 0x5f, 0xaf, 0x5c,
+				0x88, 0x99, 0xdc, 0x27, 0xc8, 0xdf, 0xb3, 0x4b
+			};
+
+			/*
+			 * Valid TSIG rdata for tsig-key over a plain
+			 * DNS QUERY for ./SOA/IN with no flags set.
+			 */
+			isc_buffer_init(&b, query_tsig, sizeof(query_tsig));
+			isc_buffer_putmem(&b, hmacname, sizeof(hmacname));
+			isc_buffer_putuint16(&b, 0);	      /* time high */
+			isc_buffer_putuint32(&b, 0x622abec0); /* time low */
+			isc_buffer_putuint16(&b, 300);	      /* Fudge */
+			isc_buffer_putuint16(&b, 32);	      /* Mac Length */
+			/* Mac */
+			isc_buffer_putmem(&b, hmac, 32);
+			isc_buffer_putuint16(&b, 7674); /* Original Id */
+			isc_buffer_putuint16(&b, 0);	/* Error */
+			isc_buffer_putuint16(&b, 0);	/* Other len */
+
+			dns_message_setquerytsig(message, &b);
+		}
+	}
+
+	if (settsigkey) {
+		result = dns_message_settsigkey(message, tsigkey);
+		if (debug) {
+			fprintf(stderr, "dns_message_settsigkey => %s\n",
+				isc_result_totext(result));
+		}
+	}
+
+	dns_view_setkeyring(view, withring ? ring : emptyring);
+
+	result = dns_message_checksig(message, withview ? view : NULL);
+	if (debug) {
+		char textbuf[64];
+		isc_buffer_t b;
+
+		fprintf(stderr, "dns_message_checksig => %s\n",
+			isc_result_totext(result));
+		isc_buffer_init(&b, textbuf, sizeof(textbuf));
+		dns_tsigrcode_totext(message->tsigstatus, &b);
+		fprintf(stderr, "tsigstatus=%.*s\n", (int)b.used, textbuf);
+		isc_buffer_init(&b, textbuf, sizeof(textbuf));
+		dns_tsigrcode_totext(message->sig0status, &b);
+		fprintf(stderr, "sig0status=%.*s\n", (int)b.used, textbuf);
+	}
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
+cleanup:
+	if (message != NULL) {
+		dns_message_detach(&message);
+	}
+
+	return (0);
+}

fuzz/dns_message_checksig.data/Ksig0key.+008+55921.key

@@ -0,0 +1 @@
+sig0key. IN KEY 512 3 8 AwEAAa22lgHi1vAbQvu5ETdTrm2H8rwga9tvyMa6LFiSDyevLvSv0Uo5 uvfrXnxaLdtBMts6e1Ly2piSH9JRbOGMNibOK4EXWhWAn8MII4SWgQAs bFwtiz4HyPn2wScrUQdo8DocKiQJBanesr7vDO8fdA6Rg1e0yAtSeNti e8avx46/HJa6CFs3CoE0sf6oOFSxM954AgCBTXOGNBt1Nt3Bhfqt2qyA TLFii5K1jLDTZDVkoiyDXL1M7wcTwKf9METgj1eQmH3GGlRM/OJ/j8xk ZiFGbL3cipWdiH48031jiV2hlc92mKn8Ya0d9AN6c44piza/JSFydZXw sY32nxzjDbs=

fuzz/dns_message_checksig.data/Ksig0key.+008+55921.private

@@ -0,0 +1,13 @@
+Private-key-format: v1.3
+Algorithm: 8 (RSASHA256)
+Modulus: rbaWAeLW8BtC+7kRN1OubYfyvCBr22/IxrosWJIPJ68u9K/RSjm69+tefFot20Ey2zp7UvLamJIf0lFs4Yw2Js4rgRdaFYCfwwgjhJaBACxsXC2LPgfI+fbBJytRB2jwOhwqJAkFqd6yvu8M7x90DpGDV7TIC1J422J7xq/Hjr8clroIWzcKgTSx/qg4VLEz3ngCAIFNc4Y0G3U23cGF+q3arIBMsWKLkrWMsNNkNWSiLINcvUzvBxPAp/0wROCPV5CYfcYaVEz84n+PzGRmIUZsvdyKlZ2IfjzTfWOJXaGVz3aYqfxhrR30A3pzjimLNr8lIXJ1lfCxjfafHOMNuw==
+PublicExponent: AQAB
+PrivateExponent: GDfclFkR5ToFGH9rMTRMnP73Q5dzjLgkx4vyHcuzKtxcvAans4+hNj+NazckAy2E+mpzV2j95TJ4wZjSM2RvB5xLwBIc4Dg6oyAHL6Ikoae6gw64cHFOaYb808n8CyqWqfX+QWAz9sRSVZXnTuPViX3A+svR7ejVak9Bzr1NTDm0DFlrhaKVCYA++dKVZerfuNiXT/jQvrc4wMCa7WWsfLsFO8aTNkEhqUnmS9c5VYgr7MkCV4ENDBcISpQc9wElI0hl12QPaSj8iSdk9liYp+HTiOxOyp6BGGuecKAoQijMwrZy4qExdOxvowptll8+nZLtwGRn/un/xvIZY5OLAQ==
+Prime1: ww3C6jwnrLQik/zxSgC0KuqgHq68cCjiRjwK2/euzs7NkMevFpXvV0cWO8x1/wKC1mszVLsUaKTvH6fzRsXfz5MPihzNzUYFwvobKVLserSxEwHNk+FKUU+q07Kf8WWnCqX5nX9QzVG1q4J8Q44N49I5S480jHLGYbyLZrEYMQE=
+Prime2: 4/3Ozq/8vRgcO4bieFs4CbZR7C98HiTi65SiLBIKY09mDfCleZI0uurAYBluZJgHS5AC5cdyHFuJr3uKxvD+Mgdlru40U6cSCEdK7HAhyUGZUndWl28wyMEB6Kke1/owxVn0S4RKLPOgFI2668H6JObaqXf0wyY89RdVQP6VQrs=
+Exponent1: Tbr9MyVX1j5PDVSev5P6OKQZvUB7PeM9ESo6VaCl3CqTxx+cic6ke86LcLcxSrewdkxwP1LydiVMWfwvOcP/RhRf+/Uwmp5OC35qNpSiQuAhNObiCw2b9T1fYU/s52FQKTEtgXNMOxZV5IxyguVoaaLMTG08TsAqiKZ/kyP99QE=
+Exponent2: Q4qSNKrwLbixzHS2LL+hR0dK17RtiaSV0QKUVIf3qdoAusp6yxwkIOegnBeMm6JqLtl38kh2pq37iRAJWcxVEc8dMYiB2fJZpjgwmwDREYUsfcC611vqUN7UyO8pIwSMZDq045ZKPyzhVJV0NZmemEYHq0LNMO7oCheiewGwiDc=
+Coefficient: T2u/J4NgyO+OqoLpXBIpTBzqrvDk8tb0feYgsp5d16hHvbXxNkMUR8cI07RdbI9HnEldtmhAnbQ6SvFiy2YYjpw/1Fz2WwdxRqLaDV7UlhrT+CqltvU9d/N/xThBNKDa23Wf5Vat+HRiLHSgzsY1PseVCWN+g4azuK2D8+DLeHE=
+Created: 20220311073606
+Publish: 20220311073606
+Activate: 20220311073606

fuzz/dns_message_checksig.data/sig0key.db

@@ -0,0 +1,14 @@
+; 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.
+
+sig0key. 0 IN SOA . . 0 0 0 0 0
+sig0key. 0 IN NS .
+sig0key. 0 IN KEY 512 3 8 AwEAAa22lgHi1vAbQvu5ETdTrm2H8rwga9tvyMa6LFiSDyevLvSv0Uo5 uvfrXnxaLdtBMts6e1Ly2piSH9JRbOGMNibOK4EXWhWAn8MII4SWgQAs bFwtiz4HyPn2wScrUQdo8DocKiQJBanesr7vDO8fdA6Rg1e0yAtSeNti e8avx46/HJa6CFs3CoE0sf6oOFSxM954AgCBTXOGNBt1Nt3Bhfqt2qyA TLFii5K1jLDTZDVkoiyDXL1M7wcTwKf9METgj1eQmH3GGlRM/OJ/j8xk ZiFGbL3cipWdiH48031jiV2hlc92mKn8Ya0d9AN6c44piza/JSFydZXw sY32nxzjDbs=

lib/dns/dnssec.c

@@ -967,7 +967,11 @@ dns_dnssec_signmessage(dns_message_t *msg, dst_key_t *key) {
 	sig.labels = 0; /* the root name */
 	sig.originalttl = 0;
 
-	isc_stdtime_get(&now);
+	if (msg->fuzzing) {
+		now = msg->fuzztime;
+	} else {
+		isc_stdtime_get(&now);
+	}
 	sig.timesigned = now - DNS_TSIG_FUDGE;
 	sig.timeexpire = now + DNS_TSIG_FUDGE;
 
@@ -1111,7 +1115,12 @@ dns_dnssec_verifymessage(isc_buffer_t *source, dns_message_t *msg,
 		goto failure;
 	}
 
-	isc_stdtime_get(&now);
+	if (msg->fuzzing) {
+		now = msg->fuzztime;
+	} else {
+		isc_stdtime_get(&now);
+	}
+
 	if (isc_serial_lt((uint32_t)now, sig.timesigned)) {
 		result = DNS_R_SIGFUTURE;
 		msg->sig0status = dns_tsigerror_badtime;

lib/dns/include/dns/message.h

@@ -281,6 +281,7 @@ struct dns_message {
 	unsigned int cc_bad	      : 1;
 	unsigned int tkey	      : 1;
 	unsigned int rdclass_set      : 1;
+	unsigned int fuzzing	      : 1;
 
 	unsigned int opt_reserved;
 	unsigned int sig_reserved;
@@ -323,6 +324,11 @@ struct dns_message {
 	isc_region_t query;
 	isc_region_t saved;
 
+	/*
+	 * Time to be used when fuzzing.
+	 */
+	isc_stdtime_t fuzztime;
+
 	dns_rdatasetorderfunc_t order;
 	dns_sortlist_arg_t	order_arg;
 

lib/dns/tsig.c

@@ -795,7 +795,12 @@ dns_tsig_sign(dns_message_t *msg) {
 	dns_name_init(&tsig.algorithm, NULL);
 	dns_name_clone(key->algorithm, &tsig.algorithm);
 
-	isc_stdtime_get(&now);
+	if (msg->fuzzing) {
+		now = msg->fuzztime;
+	} else {
+		isc_stdtime_get(&now);
+	}
+
 	tsig.timesigned = now + msg->timeadjust;
 	tsig.fudge = DNS_TSIG_FUDGE;
 
@@ -1143,7 +1148,11 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
 	/*
 	 * Get the current time.
 	 */
-	isc_stdtime_get(&now);
+	if (msg->fuzzing) {
+		now = msg->fuzztime;
+	} else {
+		isc_stdtime_get(&now);
+	}
 
 	/*
 	 * Find dns_tsigkey_t based on keyname.
@@ -1636,7 +1645,11 @@ tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
 		/*
 		 * Is the time ok?
 		 */
-		isc_stdtime_get(&now);
+		if (msg->fuzzing) {
+			now = msg->fuzztime;
+		} else {
+			isc_stdtime_get(&now);
+		}
 
 		if (now + msg->timeadjust > tsig.timesigned + tsig.fudge) {
 			msg->tsigstatus = dns_tsigerror_badtime;