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Diffstat (limited to '')
| -rw-r--r-- | bin/dnssec/dnssec-cds.c | 1361 |
1 files changed, 1361 insertions, 0 deletions
diff --git a/bin/dnssec/dnssec-cds.c b/bin/dnssec/dnssec-cds.c new file mode 100644 index 0000000..06b1f8c --- /dev/null +++ b/bin/dnssec/dnssec-cds.c @@ -0,0 +1,1361 @@ +/* + * 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. + */ + +/* + * Written by Tony Finch <dot@dotat.at> <fanf2@cam.ac.uk> + * at Cambridge University Information Services + */ + +/*! \file */ + +#include <errno.h> +#include <inttypes.h> +#include <stdbool.h> +#include <stdlib.h> + +#include <isc/attributes.h> +#include <isc/buffer.h> +#include <isc/commandline.h> +#include <isc/dir.h> +#include <isc/file.h> +#include <isc/hash.h> +#include <isc/mem.h> +#include <isc/print.h> +#include <isc/result.h> +#include <isc/serial.h> +#include <isc/string.h> +#include <isc/time.h> +#include <isc/util.h> + +#include <dns/callbacks.h> +#include <dns/db.h> +#include <dns/dbiterator.h> +#include <dns/dnssec.h> +#include <dns/ds.h> +#include <dns/fixedname.h> +#include <dns/keyvalues.h> +#include <dns/log.h> +#include <dns/master.h> +#include <dns/name.h> +#include <dns/rdata.h> +#include <dns/rdataclass.h> +#include <dns/rdatalist.h> +#include <dns/rdataset.h> +#include <dns/rdatasetiter.h> +#include <dns/rdatatype.h> +#include <dns/time.h> + +#include <dst/dst.h> + +#include "dnssectool.h" + +const char *program = "dnssec-cds"; + +/* + * Infrastructure + */ +static isc_log_t *lctx = NULL; +static isc_mem_t *mctx = NULL; + +/* + * The domain we are working on + */ +static const char *namestr = NULL; +static dns_fixedname_t fixed; +static dns_name_t *name = NULL; +static dns_rdataclass_t rdclass = dns_rdataclass_in; + +static const char *startstr = NULL; /* from which we derive notbefore */ +static isc_stdtime_t notbefore = 0; /* restrict sig inception times */ +static dns_rdata_rrsig_t oldestsig; /* for recording inception time */ + +static int nkey; /* number of child zone DNSKEY records */ + +/* + * The validation strategy of this program is top-down. + * + * We start with an implicitly trusted authoritative dsset. + * + * The child DNSKEY RRset is scanned to find out which keys are + * authenticated by DS records, and the result is recorded in a key + * table as described later in this comment. + * + * The key table is used up to three times to verify the signatures on + * the child DNSKEY, CDNSKEY, and CDS RRsets. In this program, only keys + * that have matching DS records are used for validating signatures. + * + * For replay attack protection, signatures are ignored if their inception + * time is before the previously recorded inception time. We use the earliest + * signature so that another run of dnssec-cds with the same records will + * still accept all the signatures. + * + * A key table is an array of nkey keyinfo structures, like + * + * keyinfo_t key_tbl[nkey]; + * + * Each key is decoded into more useful representations, held in + * keyinfo->rdata + * keyinfo->dst + * + * If a key has no matching DS record then keyinfo->dst is NULL. + * + * The key algorithm and ID are saved in keyinfo->algo and + * keyinfo->tag for quicky skipping DS and RRSIG records that can't + * match. + */ +typedef struct keyinfo { + dns_rdata_t rdata; + dst_key_t *dst; + dns_secalg_t algo; + dns_keytag_t tag; +} keyinfo_t; + +/* A replaceable function that can generate a DS RRset from some input */ +typedef isc_result_t +ds_maker_func_t(isc_buffer_t *buf, dns_rdata_t *ds, dns_dsdigest_t dt, + dns_rdata_t *crdata); + +static dns_rdataset_t cdnskey_set = DNS_RDATASET_INIT; +static dns_rdataset_t cdnskey_sig = DNS_RDATASET_INIT; +static dns_rdataset_t cds_set = DNS_RDATASET_INIT; +static dns_rdataset_t cds_sig = DNS_RDATASET_INIT; +static dns_rdataset_t dnskey_set = DNS_RDATASET_INIT; +static dns_rdataset_t dnskey_sig = DNS_RDATASET_INIT; +static dns_rdataset_t old_ds_set = DNS_RDATASET_INIT; +static dns_rdataset_t new_ds_set = DNS_RDATASET_INIT; + +static keyinfo_t *old_key_tbl = NULL, *new_key_tbl = NULL; + +isc_buffer_t *new_ds_buf = NULL; /* backing store for new_ds_set */ + +static dns_db_t *child_db = NULL; +static dns_dbnode_t *child_node = NULL; +static dns_db_t *parent_db = NULL; +static dns_dbnode_t *parent_node = NULL; +static dns_db_t *update_db = NULL; +static dns_dbnode_t *update_node = NULL; +static dns_dbversion_t *update_version = NULL; +static bool cleanup_dst = false; +static bool print_mem_stats = false; + +static void +verbose_time(int level, const char *msg, isc_stdtime_t time) { + isc_result_t result; + isc_buffer_t timebuf; + char timestr[32]; + + if (verbose < level) { + return; + } + + isc_buffer_init(&timebuf, timestr, sizeof(timestr)); + result = dns_time64_totext(time, &timebuf); + check_result(result, "dns_time64_totext()"); + isc_buffer_putuint8(&timebuf, 0); + if (verbose < 3) { + vbprintf(level, "%s %s\n", msg, timestr); + } else { + vbprintf(level, "%s %s (%" PRIu32 ")\n", msg, timestr, time); + } +} + +static void +initname(char *setname) { + isc_result_t result; + isc_buffer_t buf; + + name = dns_fixedname_initname(&fixed); + namestr = setname; + + isc_buffer_init(&buf, setname, strlen(setname)); + isc_buffer_add(&buf, strlen(setname)); + result = dns_name_fromtext(name, &buf, dns_rootname, 0, NULL); + if (result != ISC_R_SUCCESS) { + fatal("could not initialize name %s", setname); + } +} + +static void +findset(dns_db_t *db, dns_dbnode_t *node, dns_rdatatype_t type, + dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { + isc_result_t result; + + dns_rdataset_init(rdataset); + if (sigrdataset != NULL) { + dns_rdataset_init(sigrdataset); + } + result = dns_db_findrdataset(db, node, NULL, type, 0, 0, rdataset, + sigrdataset); + if (result != ISC_R_NOTFOUND) { + check_result(result, "dns_db_findrdataset()"); + } +} + +static void +freeset(dns_rdataset_t *rdataset) { + if (dns_rdataset_isassociated(rdataset)) { + dns_rdataset_disassociate(rdataset); + } +} + +static void +freelist(dns_rdataset_t *rdataset) { + dns_rdatalist_t *rdlist; + dns_rdata_t *rdata; + + if (!dns_rdataset_isassociated(rdataset)) { + return; + } + + dns_rdatalist_fromrdataset(rdataset, &rdlist); + + for (rdata = ISC_LIST_HEAD(rdlist->rdata); rdata != NULL; + rdata = ISC_LIST_HEAD(rdlist->rdata)) + { + ISC_LIST_UNLINK(rdlist->rdata, rdata, link); + isc_mem_put(mctx, rdata, sizeof(*rdata)); + } + isc_mem_put(mctx, rdlist, sizeof(*rdlist)); + dns_rdataset_disassociate(rdataset); +} + +static void +free_all_sets(void) { + freeset(&cdnskey_set); + freeset(&cdnskey_sig); + freeset(&cds_set); + freeset(&cds_sig); + freeset(&dnskey_set); + freeset(&dnskey_sig); + freeset(&old_ds_set); + freelist(&new_ds_set); + if (new_ds_buf != NULL) { + isc_buffer_free(&new_ds_buf); + } +} + +static void +load_db(const char *filename, dns_db_t **dbp, dns_dbnode_t **nodep) { + isc_result_t result; + + result = dns_db_create(mctx, "rbt", name, dns_dbtype_zone, rdclass, 0, + NULL, dbp); + check_result(result, "dns_db_create()"); + + result = dns_db_load(*dbp, filename, dns_masterformat_text, + DNS_MASTER_HINT); + if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) { + fatal("can't load %s: %s", filename, isc_result_totext(result)); + } + + result = dns_db_findnode(*dbp, name, false, nodep); + if (result != ISC_R_SUCCESS) { + fatal("can't find %s node in %s", namestr, filename); + } +} + +static void +free_db(dns_db_t **dbp, dns_dbnode_t **nodep, dns_dbversion_t **versionp) { + if (*dbp != NULL) { + if (*nodep != NULL) { + dns_db_detachnode(*dbp, nodep); + } + if (versionp != NULL && *versionp != NULL) { + dns_db_closeversion(*dbp, versionp, false); + } + dns_db_detach(dbp); + } +} + +static void +load_child_sets(const char *file) { + load_db(file, &child_db, &child_node); + findset(child_db, child_node, dns_rdatatype_dnskey, &dnskey_set, + &dnskey_sig); + findset(child_db, child_node, dns_rdatatype_cdnskey, &cdnskey_set, + &cdnskey_sig); + findset(child_db, child_node, dns_rdatatype_cds, &cds_set, &cds_sig); + free_db(&child_db, &child_node, NULL); +} + +static void +get_dsset_name(char *filename, size_t size, const char *path, + const char *suffix) { + isc_result_t result; + isc_buffer_t buf; + size_t len; + + isc_buffer_init(&buf, filename, size); + + len = strlen(path); + + /* allow room for a trailing slash */ + if (isc_buffer_availablelength(&buf) <= len) { + fatal("%s: pathname too long", path); + } + isc_buffer_putstr(&buf, path); + + if (isc_file_isdirectory(path) == ISC_R_SUCCESS) { + const char *prefix = "dsset-"; + + if (path[len - 1] != '/') { + isc_buffer_putstr(&buf, "/"); + } + + if (isc_buffer_availablelength(&buf) < strlen(prefix)) { + fatal("%s: pathname too long", path); + } + isc_buffer_putstr(&buf, prefix); + + result = dns_name_tofilenametext(name, false, &buf); + check_result(result, "dns_name_tofilenametext()"); + if (isc_buffer_availablelength(&buf) == 0) { + fatal("%s: pathname too long", path); + } + } + /* allow room for a trailing nul */ + if (isc_buffer_availablelength(&buf) <= strlen(suffix)) { + fatal("%s: pathname too long", path); + } + isc_buffer_putstr(&buf, suffix); + isc_buffer_putuint8(&buf, 0); +} + +static void +load_parent_set(const char *path) { + isc_result_t result; + isc_time_t modtime; + char filename[PATH_MAX + 1]; + + get_dsset_name(filename, sizeof(filename), path, ""); + + result = isc_file_getmodtime(filename, &modtime); + if (result != ISC_R_SUCCESS) { + fatal("could not get modification time of %s: %s", filename, + isc_result_totext(result)); + } + notbefore = isc_time_seconds(&modtime); + if (startstr != NULL) { + isc_stdtime_t now; + isc_stdtime_get(&now); + notbefore = strtotime(startstr, now, notbefore, NULL); + } + verbose_time(1, "child records must not be signed before", notbefore); + + load_db(filename, &parent_db, &parent_node); + findset(parent_db, parent_node, dns_rdatatype_ds, &old_ds_set, NULL); + + if (!dns_rdataset_isassociated(&old_ds_set)) { + fatal("could not find DS records for %s in %s", namestr, + filename); + } + + free_db(&parent_db, &parent_node, NULL); +} + +#define MAX_CDS_RDATA_TEXT_SIZE DNS_RDATA_MAXLENGTH * 2 + +static isc_buffer_t * +formatset(dns_rdataset_t *rdataset) { + isc_result_t result; + isc_buffer_t *buf = NULL; + dns_master_style_t *style = NULL; + unsigned int styleflags; + + styleflags = (rdataset->ttl == 0) ? DNS_STYLEFLAG_NO_TTL : 0; + + /* + * This style is for consistency with the output of dnssec-dsfromkey + * which just separates fields with spaces. The huge tab stop width + * eliminates any tab characters. + */ + result = dns_master_stylecreate(&style, styleflags, 0, 0, 0, 0, 0, + 1000000, 0, mctx); + check_result(result, "dns_master_stylecreate2 failed"); + + isc_buffer_allocate(mctx, &buf, MAX_CDS_RDATA_TEXT_SIZE); + result = dns_master_rdatasettotext(name, rdataset, style, NULL, buf); + dns_master_styledestroy(&style, mctx); + + if ((result == ISC_R_SUCCESS) && isc_buffer_availablelength(buf) < 1) { + result = ISC_R_NOSPACE; + } + + if (result != ISC_R_SUCCESS) { + isc_buffer_free(&buf); + check_result(result, "dns_rdataset_totext()"); + } + + isc_buffer_putuint8(buf, 0); + return (buf); +} + +static void +write_parent_set(const char *path, const char *inplace, bool nsupdate, + dns_rdataset_t *rdataset) { + isc_result_t result; + isc_buffer_t *buf = NULL; + isc_region_t r; + isc_time_t filetime; + char backname[PATH_MAX + 1]; + char filename[PATH_MAX + 1]; + char tmpname[PATH_MAX + 1]; + FILE *fp = NULL; + + if (nsupdate && inplace == NULL) { + return; + } + + buf = formatset(rdataset); + isc_buffer_usedregion(buf, &r); + + /* + * Try to ensure a write error doesn't make a zone go insecure! + */ + if (inplace == NULL) { + printf("%s", (char *)r.base); + isc_buffer_free(&buf); + if (fflush(stdout) == EOF) { + fatal("error writing to stdout: %s", strerror(errno)); + } + return; + } + + if (inplace[0] != '\0') { + get_dsset_name(backname, sizeof(backname), path, inplace); + } + get_dsset_name(filename, sizeof(filename), path, ""); + get_dsset_name(tmpname, sizeof(tmpname), path, "-XXXXXXXXXX"); + + result = isc_file_openunique(tmpname, &fp); + if (result != ISC_R_SUCCESS) { + isc_buffer_free(&buf); + fatal("open %s: %s", tmpname, isc_result_totext(result)); + } + fprintf(fp, "%s", (char *)r.base); + isc_buffer_free(&buf); + if (fclose(fp) == EOF) { + int err = errno; + isc_file_remove(tmpname); + fatal("error writing to %s: %s", tmpname, strerror(err)); + } + + isc_time_set(&filetime, oldestsig.timesigned, 0); + result = isc_file_settime(tmpname, &filetime); + if (result != ISC_R_SUCCESS) { + isc_file_remove(tmpname); + fatal("can't set modification time of %s: %s", tmpname, + isc_result_totext(result)); + } + + if (inplace[0] != '\0') { + isc_file_rename(filename, backname); + } + isc_file_rename(tmpname, filename); +} + +typedef enum { LOOSE, TIGHT } strictness_t; + +/* + * Find out if any (C)DS record matches a particular (C)DNSKEY. + */ +static bool +match_key_dsset(keyinfo_t *ki, dns_rdataset_t *dsset, strictness_t strictness) { + isc_result_t result; + unsigned char dsbuf[DNS_DS_BUFFERSIZE]; + + for (result = dns_rdataset_first(dsset); result == ISC_R_SUCCESS; + result = dns_rdataset_next(dsset)) + { + dns_rdata_ds_t ds; + dns_rdata_t dsrdata = DNS_RDATA_INIT; + dns_rdata_t newdsrdata = DNS_RDATA_INIT; + bool c; + + dns_rdataset_current(dsset, &dsrdata); + result = dns_rdata_tostruct(&dsrdata, &ds, NULL); + check_result(result, "dns_rdata_tostruct(DS)"); + + if (ki->tag != ds.key_tag || ki->algo != ds.algorithm) { + continue; + } + + result = dns_ds_buildrdata(name, &ki->rdata, ds.digest_type, + dsbuf, &newdsrdata); + if (result != ISC_R_SUCCESS) { + vbprintf(3, + "dns_ds_buildrdata(" + "keytag=%d, algo=%d, digest=%d): %s\n", + ds.key_tag, ds.algorithm, ds.digest_type, + isc_result_totext(result)); + continue; + } + /* allow for both DS and CDS */ + c = dsrdata.type != dns_rdatatype_ds; + dsrdata.type = dns_rdatatype_ds; + if (dns_rdata_compare(&dsrdata, &newdsrdata) == 0) { + vbprintf(1, "found matching %s %d %d %d\n", + c ? "CDS" : "DS", ds.key_tag, ds.algorithm, + ds.digest_type); + return (true); + } else if (strictness == TIGHT) { + vbprintf(0, + "key does not match %s %d %d %d " + "when it looks like it should\n", + c ? "CDS" : "DS", ds.key_tag, ds.algorithm, + ds.digest_type); + return (false); + } + } + + vbprintf(1, "no matching %s for %s %d %d\n", + dsset->type == dns_rdatatype_cds ? "CDS" : "DS", + ki->rdata.type == dns_rdatatype_cdnskey ? "CDNSKEY" : "DNSKEY", + ki->tag, ki->algo); + + return (false); +} + +/* + * Find which (C)DNSKEY records match a (C)DS RRset. + * This creates a keyinfo_t key_tbl[nkey] array. + */ +static keyinfo_t * +match_keyset_dsset(dns_rdataset_t *keyset, dns_rdataset_t *dsset, + strictness_t strictness) { + isc_result_t result; + keyinfo_t *keytable, *ki; + int i; + + nkey = dns_rdataset_count(keyset); + + keytable = isc_mem_get(mctx, sizeof(keyinfo_t) * nkey); + + for (result = dns_rdataset_first(keyset), i = 0, ki = keytable; + result == ISC_R_SUCCESS; + result = dns_rdataset_next(keyset), i++, ki++) + { + dns_rdata_dnskey_t dnskey; + dns_rdata_t *keyrdata; + isc_region_t r; + + INSIST(i < nkey); + keyrdata = &ki->rdata; + + dns_rdata_init(keyrdata); + dns_rdataset_current(keyset, keyrdata); + + result = dns_rdata_tostruct(keyrdata, &dnskey, NULL); + check_result(result, "dns_rdata_tostruct(DNSKEY)"); + ki->algo = dnskey.algorithm; + + dns_rdata_toregion(keyrdata, &r); + ki->tag = dst_region_computeid(&r); + + ki->dst = NULL; + if (!match_key_dsset(ki, dsset, strictness)) { + continue; + } + + result = dns_dnssec_keyfromrdata(name, keyrdata, mctx, + &ki->dst); + if (result != ISC_R_SUCCESS) { + vbprintf(3, + "dns_dnssec_keyfromrdata(" + "keytag=%d, algo=%d): %s\n", + ki->tag, ki->algo, isc_result_totext(result)); + } + } + + return (keytable); +} + +static void +free_keytable(keyinfo_t **keytable_p) { + keyinfo_t *keytable = *keytable_p; + *keytable_p = NULL; + keyinfo_t *ki; + int i; + + REQUIRE(keytable != NULL); + + for (i = 0, ki = keytable; i < nkey; i++, ki++) { + if (ki->dst != NULL) { + dst_key_free(&ki->dst); + } + } + + isc_mem_put(mctx, keytable, sizeof(keyinfo_t) * nkey); +} + +/* + * Find out which keys have signed an RRset. Keys that do not match a + * DS record are skipped. + * + * The return value is an array with nkey elements, one for each key, + * either zero if the key was skipped or did not sign the RRset, or + * otherwise the key algorithm. This is used by the signature coverage + * check functions below. + */ +static dns_secalg_t * +matching_sigs(keyinfo_t *keytbl, dns_rdataset_t *rdataset, + dns_rdataset_t *sigset) { + isc_result_t result; + dns_secalg_t *algo; + int i; + + REQUIRE(keytbl != NULL); + + algo = isc_mem_get(mctx, nkey); + memset(algo, 0, nkey); + + for (result = dns_rdataset_first(sigset); result == ISC_R_SUCCESS; + result = dns_rdataset_next(sigset)) + { + dns_rdata_t sigrdata = DNS_RDATA_INIT; + dns_rdata_rrsig_t sig; + + dns_rdataset_current(sigset, &sigrdata); + result = dns_rdata_tostruct(&sigrdata, &sig, NULL); + check_result(result, "dns_rdata_tostruct(RRSIG)"); + + /* + * Replay attack protection: check against current age limit + */ + if (isc_serial_lt(sig.timesigned, notbefore)) { + vbprintf(1, "skip RRSIG by key %d: too old\n", + sig.keyid); + continue; + } + + for (i = 0; i < nkey; i++) { + keyinfo_t *ki = &keytbl[i]; + if (sig.keyid != ki->tag || sig.algorithm != ki->algo || + !dns_name_equal(&sig.signer, name)) + { + continue; + } + if (ki->dst == NULL) { + vbprintf(1, + "skip RRSIG by key %d:" + " no matching (C)DS\n", + sig.keyid); + continue; + } + + result = dns_dnssec_verify(name, rdataset, ki->dst, + false, 0, mctx, &sigrdata, + NULL); + + if (result != ISC_R_SUCCESS && + result != DNS_R_FROMWILDCARD) + { + vbprintf(1, + "skip RRSIG by key %d:" + " verification failed: %s\n", + sig.keyid, isc_result_totext(result)); + continue; + } + + vbprintf(1, "found RRSIG by key %d\n", ki->tag); + algo[i] = sig.algorithm; + + /* + * Replay attack protection: work out next age limit, + * only after the signature has been verified + */ + if (oldestsig.timesigned == 0 || + isc_serial_lt(sig.timesigned, oldestsig.timesigned)) + { + verbose_time(2, "this is the oldest so far", + sig.timesigned); + oldestsig = sig; + } + } + } + + return (algo); +} + +/* + * Consume the result of matching_sigs(). When checking records + * fetched from the child zone, any working signature is enough. + */ +static bool +signed_loose(dns_secalg_t *algo) { + bool ok = false; + int i; + for (i = 0; i < nkey; i++) { + if (algo[i] != 0) { + ok = true; + } + } + isc_mem_put(mctx, algo, nkey); + return (ok); +} + +/* + * Consume the result of matching_sigs(). To ensure that the new DS + * RRset does not break the chain of trust to the DNSKEY RRset, every + * key algorithm in the DS RRset must have a signature in the DNSKEY + * RRset. + */ +static bool +signed_strict(dns_rdataset_t *dsset, dns_secalg_t *algo) { + isc_result_t result; + bool all_ok = true; + + for (result = dns_rdataset_first(dsset); result == ISC_R_SUCCESS; + result = dns_rdataset_next(dsset)) + { + dns_rdata_t dsrdata = DNS_RDATA_INIT; + dns_rdata_ds_t ds; + bool ds_ok; + int i; + + dns_rdataset_current(dsset, &dsrdata); + result = dns_rdata_tostruct(&dsrdata, &ds, NULL); + check_result(result, "dns_rdata_tostruct(DS)"); + + ds_ok = false; + for (i = 0; i < nkey; i++) { + if (algo[i] == ds.algorithm) { + ds_ok = true; + } + } + if (!ds_ok) { + vbprintf(0, + "missing signature for algorithm %d " + "(key %d)\n", + ds.algorithm, ds.key_tag); + all_ok = false; + } + } + + isc_mem_put(mctx, algo, nkey); + return (all_ok); +} + +/* + * This basically copies the rdata into the buffer, but going via the + * unpacked struct lets us change the rdatatype. (The dns_rdata_cds_t + * and dns_rdata_ds_t types are aliases.) + */ +static isc_result_t +ds_from_cds(isc_buffer_t *buf, dns_rdata_t *rds, dns_dsdigest_t dt, + dns_rdata_t *cds) { + isc_result_t result; + dns_rdata_ds_t ds; + + REQUIRE(buf != NULL); + + result = dns_rdata_tostruct(cds, &ds, NULL); + check_result(result, "dns_rdata_tostruct(CDS)"); + ds.common.rdtype = dns_rdatatype_ds; + + if (ds.digest_type != dt) { + return (ISC_R_IGNORE); + } + + return (dns_rdata_fromstruct(rds, rdclass, dns_rdatatype_ds, &ds, buf)); +} + +static isc_result_t +ds_from_cdnskey(isc_buffer_t *buf, dns_rdata_t *ds, dns_dsdigest_t dt, + dns_rdata_t *cdnskey) { + isc_result_t result; + isc_region_t r; + + REQUIRE(buf != NULL); + + isc_buffer_availableregion(buf, &r); + if (r.length < DNS_DS_BUFFERSIZE) { + return (ISC_R_NOSPACE); + } + + result = dns_ds_buildrdata(name, cdnskey, dt, r.base, ds); + if (result == ISC_R_SUCCESS) { + isc_buffer_add(buf, DNS_DS_BUFFERSIZE); + } + + return (result); +} + +static isc_result_t +append_new_ds_set(ds_maker_func_t *ds_from_rdata, isc_buffer_t *buf, + dns_rdatalist_t *dslist, dns_dsdigest_t dt, + dns_rdataset_t *crdset) { + isc_result_t result; + + for (result = dns_rdataset_first(crdset); result == ISC_R_SUCCESS; + result = dns_rdataset_next(crdset)) + { + dns_rdata_t crdata = DNS_RDATA_INIT; + dns_rdata_t *ds = NULL; + + dns_rdataset_current(crdset, &crdata); + + ds = isc_mem_get(mctx, sizeof(*ds)); + dns_rdata_init(ds); + + result = ds_from_rdata(buf, ds, dt, &crdata); + + switch (result) { + case ISC_R_SUCCESS: + ISC_LIST_APPEND(dslist->rdata, ds, link); + break; + case ISC_R_IGNORE: + isc_mem_put(mctx, ds, sizeof(*ds)); + continue; + case ISC_R_NOSPACE: + isc_mem_put(mctx, ds, sizeof(*ds)); + return (result); + default: + isc_mem_put(mctx, ds, sizeof(*ds)); + check_result(result, "ds_from_rdata()"); + } + } + + return (ISC_R_SUCCESS); +} + +static void +make_new_ds_set(ds_maker_func_t *ds_from_rdata, uint32_t ttl, + dns_rdataset_t *crdset) { + isc_result_t result; + dns_rdatalist_t *dslist; + unsigned int size = 16; + unsigned i, n; + + for (;;) { + dslist = isc_mem_get(mctx, sizeof(*dslist)); + dns_rdatalist_init(dslist); + dslist->rdclass = rdclass; + dslist->type = dns_rdatatype_ds; + dslist->ttl = ttl; + + dns_rdataset_init(&new_ds_set); + result = dns_rdatalist_tordataset(dslist, &new_ds_set); + check_result(result, "dns_rdatalist_tordataset(dslist)"); + + isc_buffer_allocate(mctx, &new_ds_buf, size); + + n = sizeof(dtype) / sizeof(dtype[0]); + for (i = 0; i < n && dtype[i] != 0; i++) { + result = append_new_ds_set(ds_from_rdata, new_ds_buf, + dslist, dtype[i], crdset); + if (result != ISC_R_SUCCESS) { + break; + } + } + if (result == ISC_R_SUCCESS) { + return; + } + + vbprintf(2, "doubling DS list buffer size from %u\n", size); + freelist(&new_ds_set); + isc_buffer_free(&new_ds_buf); + size *= 2; + } +} + +static int +rdata_cmp(const void *rdata1, const void *rdata2) { + return (dns_rdata_compare((const dns_rdata_t *)rdata1, + (const dns_rdata_t *)rdata2)); +} + +/* + * Ensure that every key identified by the DS RRset has the same set of + * digest types. + */ +static bool +consistent_digests(dns_rdataset_t *dsset) { + isc_result_t result; + dns_rdata_t *arrdata; + dns_rdata_ds_t *ds; + dns_keytag_t key_tag; + dns_secalg_t algorithm; + bool match; + int i, j, n, d; + + /* + * First sort the dsset. DS rdata fields are tag, algorithm, + * digest, so sorting them brings together all the records for + * each key. + */ + + n = dns_rdataset_count(dsset); + + arrdata = isc_mem_get(mctx, n * sizeof(dns_rdata_t)); + + for (result = dns_rdataset_first(dsset), i = 0; result == ISC_R_SUCCESS; + result = dns_rdataset_next(dsset), i++) + { + dns_rdata_init(&arrdata[i]); + dns_rdataset_current(dsset, &arrdata[i]); + } + + qsort(arrdata, n, sizeof(dns_rdata_t), rdata_cmp); + + /* + * Convert sorted arrdata to more accessible format + */ + ds = isc_mem_get(mctx, n * sizeof(dns_rdata_ds_t)); + + for (i = 0; i < n; i++) { + result = dns_rdata_tostruct(&arrdata[i], &ds[i], NULL); + check_result(result, "dns_rdata_tostruct(DS)"); + } + + /* + * Count number of digest types (d) for first key + */ + key_tag = ds[0].key_tag; + algorithm = ds[0].algorithm; + for (d = 0, i = 0; i < n; i++, d++) { + if (ds[i].key_tag != key_tag || ds[i].algorithm != algorithm) { + break; + } + } + + /* + * Check subsequent keys match the first one + */ + match = true; + while (i < n) { + key_tag = ds[i].key_tag; + algorithm = ds[i].algorithm; + for (j = 0; j < d && i + j < n; j++) { + if (ds[i + j].key_tag != key_tag || + ds[i + j].algorithm != algorithm || + ds[i + j].digest_type != ds[j].digest_type) + { + match = false; + } + } + i += d; + } + + /* + * Done! + */ + isc_mem_put(mctx, ds, n * sizeof(dns_rdata_ds_t)); + isc_mem_put(mctx, arrdata, n * sizeof(dns_rdata_t)); + + return (match); +} + +static void +print_diff(const char *cmd, dns_rdataset_t *rdataset) { + isc_buffer_t *buf; + isc_region_t r; + unsigned char *nl; + size_t len; + + buf = formatset(rdataset); + isc_buffer_usedregion(buf, &r); + + while ((nl = memchr(r.base, '\n', r.length)) != NULL) { + len = nl - r.base + 1; + printf("update %s %.*s", cmd, (int)len, (char *)r.base); + isc_region_consume(&r, len); + } + + isc_buffer_free(&buf); +} + +static void +update_diff(const char *cmd, uint32_t ttl, dns_rdataset_t *addset, + dns_rdataset_t *delset) { + isc_result_t result; + dns_rdataset_t diffset; + uint32_t save; + + result = dns_db_create(mctx, "rbt", name, dns_dbtype_zone, rdclass, 0, + NULL, &update_db); + check_result(result, "dns_db_create()"); + + result = dns_db_newversion(update_db, &update_version); + check_result(result, "dns_db_newversion()"); + + result = dns_db_findnode(update_db, name, true, &update_node); + check_result(result, "dns_db_findnode()"); + + dns_rdataset_init(&diffset); + + result = dns_db_addrdataset(update_db, update_node, update_version, 0, + addset, DNS_DBADD_MERGE, NULL); + check_result(result, "dns_db_addrdataset()"); + + result = dns_db_subtractrdataset(update_db, update_node, update_version, + delset, 0, &diffset); + if (result == DNS_R_UNCHANGED) { + save = addset->ttl; + addset->ttl = ttl; + print_diff(cmd, addset); + addset->ttl = save; + } else if (result != DNS_R_NXRRSET) { + check_result(result, "dns_db_subtractrdataset()"); + diffset.ttl = ttl; + print_diff(cmd, &diffset); + dns_rdataset_disassociate(&diffset); + } + + free_db(&update_db, &update_node, &update_version); +} + +static void +nsdiff(uint32_t ttl, dns_rdataset_t *oldset, dns_rdataset_t *newset) { + if (ttl == 0) { + vbprintf(1, "warning: no TTL in nsupdate script\n"); + } + update_diff("add", ttl, newset, oldset); + update_diff("del", 0, oldset, newset); + if (verbose > 0) { + printf("show\nsend\nanswer\n"); + } else { + printf("send\n"); + } + if (fflush(stdout) == EOF) { + fatal("write stdout: %s", strerror(errno)); + } +} + +noreturn static void +usage(void); + +static void +usage(void) { + fprintf(stderr, "Usage:\n"); + fprintf(stderr, + " %s options [options] -f <file> -d <path> <domain>\n", + program); + fprintf(stderr, "Version: %s\n", PACKAGE_VERSION); + fprintf(stderr, "Options:\n" + " -a <algorithm> digest algorithm (SHA-1 / " + "SHA-256 / SHA-384)\n" + " -c <class> of domain (default IN)\n" + " -D prefer CDNSKEY records instead " + "of CDS\n" + " -d <file|dir> where to find parent dsset- " + "file\n" + " -f <file> child DNSKEY+CDNSKEY+CDS+RRSIG " + "records\n" + " -i[extension] update dsset- file in place\n" + " -s <start-time> oldest permitted child " + "signatures\n" + " -u emit nsupdate script\n" + " -T <ttl> TTL of DS records\n" + " -V print version\n" + " -v <verbosity>\n"); + exit(1); +} + +static void +cleanup(void) { + free_db(&child_db, &child_node, NULL); + free_db(&parent_db, &parent_node, NULL); + free_db(&update_db, &update_node, &update_version); + if (old_key_tbl != NULL) { + free_keytable(&old_key_tbl); + } + if (new_key_tbl != NULL) { + free_keytable(&new_key_tbl); + } + free_all_sets(); + if (lctx != NULL) { + cleanup_logging(&lctx); + } + if (cleanup_dst) { + dst_lib_destroy(); + } + if (mctx != NULL) { + if (print_mem_stats && verbose > 10) { + isc_mem_stats(mctx, stdout); + } + isc_mem_destroy(&mctx); + } +} + +int +main(int argc, char *argv[]) { + const char *child_path = NULL; + const char *ds_path = NULL; + const char *inplace = NULL; + isc_result_t result; + bool prefer_cdnskey = false; + bool nsupdate = false; + uint32_t ttl = 0; + int ch; + char *endp; + + setfatalcallback(cleanup); + + isc_mem_create(&mctx); + + isc_commandline_errprint = false; + +#define OPTIONS "a:c:Dd:f:i:ms:T:uv:V" + while ((ch = isc_commandline_parse(argc, argv, OPTIONS)) != -1) { + switch (ch) { + case 'a': + add_dtype(strtodsdigest(isc_commandline_argument)); + break; + case 'c': + rdclass = strtoclass(isc_commandline_argument); + break; + case 'D': + prefer_cdnskey = true; + break; + case 'd': + ds_path = isc_commandline_argument; + break; + case 'f': + child_path = isc_commandline_argument; + break; + case 'i': + /* + * This is a bodge to make the argument + * optional, so that it works just like sed(1). + */ + if (isc_commandline_argument == + argv[isc_commandline_index - 1]) + { + isc_commandline_index--; + inplace = ""; + } else { + inplace = isc_commandline_argument; + } + break; + case 'm': + isc_mem_debugging = ISC_MEM_DEBUGTRACE | + ISC_MEM_DEBUGRECORD; + break; + case 's': + startstr = isc_commandline_argument; + break; + case 'T': + ttl = strtottl(isc_commandline_argument); + break; + case 'u': + nsupdate = true; + break; + case 'V': + /* Does not return. */ + version(program); + break; + case 'v': + verbose = strtoul(isc_commandline_argument, &endp, 0); + if (*endp != '\0') { + fatal("-v must be followed by a number"); + } + break; + default: + usage(); + break; + } + } + argv += isc_commandline_index; + argc -= isc_commandline_index; + + if (argc != 1) { + usage(); + } + initname(argv[0]); + + /* + * Default digest type if none specified. + */ + if (dtype[0] == 0) { + dtype[0] = DNS_DSDIGEST_SHA256; + } + + setup_logging(mctx, &lctx); + + result = dst_lib_init(mctx, NULL); + if (result != ISC_R_SUCCESS) { + fatal("could not initialize dst: %s", + isc_result_totext(result)); + } + cleanup_dst = true; + + if (ds_path == NULL) { + fatal("missing -d DS pathname"); + } + load_parent_set(ds_path); + + /* + * Preserve the TTL if it wasn't overridden. + */ + if (ttl == 0) { + ttl = old_ds_set.ttl; + } + + if (child_path == NULL) { + fatal("path to file containing child data must be specified"); + } + + load_child_sets(child_path); + + /* + * Check child records have accompanying RRSIGs and DNSKEYs + */ + + if (!dns_rdataset_isassociated(&dnskey_set) || + !dns_rdataset_isassociated(&dnskey_sig)) + { + fatal("could not find signed DNSKEY RRset for %s", namestr); + } + + if (dns_rdataset_isassociated(&cdnskey_set) && + !dns_rdataset_isassociated(&cdnskey_sig)) + { + fatal("missing RRSIG CDNSKEY records for %s", namestr); + } + if (dns_rdataset_isassociated(&cds_set) && + !dns_rdataset_isassociated(&cds_sig)) + { + fatal("missing RRSIG CDS records for %s", namestr); + } + + vbprintf(1, "which child DNSKEY records match parent DS records?\n"); + old_key_tbl = match_keyset_dsset(&dnskey_set, &old_ds_set, LOOSE); + + /* + * We have now identified the keys that are allowed to + * authenticate the DNSKEY RRset (RFC 4035 section 5.2 bullet + * 2), and CDNSKEY and CDS RRsets (RFC 7344 section 4.1 bullet + * 2). + */ + + vbprintf(1, "verify DNSKEY signature(s)\n"); + if (!signed_loose(matching_sigs(old_key_tbl, &dnskey_set, &dnskey_sig))) + { + fatal("could not validate child DNSKEY RRset for %s", namestr); + } + + if (dns_rdataset_isassociated(&cdnskey_set)) { + vbprintf(1, "verify CDNSKEY signature(s)\n"); + if (!signed_loose(matching_sigs(old_key_tbl, &cdnskey_set, + &cdnskey_sig))) + { + fatal("could not validate child CDNSKEY RRset for %s", + namestr); + } + } + if (dns_rdataset_isassociated(&cds_set)) { + vbprintf(1, "verify CDS signature(s)\n"); + if (!signed_loose( + matching_sigs(old_key_tbl, &cds_set, &cds_sig))) + { + fatal("could not validate child CDS RRset for %s", + namestr); + } + } + + free_keytable(&old_key_tbl); + + /* + * Report the result of the replay attack protection checks + * used for the output file timestamp + */ + if (oldestsig.timesigned != 0 && verbose > 0) { + char type[32]; + dns_rdatatype_format(oldestsig.covered, type, sizeof(type)); + verbose_time(1, "child signature inception time", + oldestsig.timesigned); + vbprintf(2, "from RRSIG %s by key %d\n", type, oldestsig.keyid); + } + + /* + * Successfully do nothing if there's neither CDNSKEY nor CDS + * RFC 7344 section 4.1 first paragraph + */ + if (!dns_rdataset_isassociated(&cdnskey_set) && + !dns_rdataset_isassociated(&cds_set)) + { + vbprintf(1, "%s has neither CDS nor CDNSKEY records\n", + namestr); + write_parent_set(ds_path, inplace, nsupdate, &old_ds_set); + goto cleanup; + } + + /* + * Make DS records from the CDS or CDNSKEY records + * Prefer CDS if present, unless run with -D + */ + if (prefer_cdnskey && dns_rdataset_isassociated(&cdnskey_set)) { + make_new_ds_set(ds_from_cdnskey, ttl, &cdnskey_set); + } else if (dns_rdataset_isassociated(&cds_set)) { + make_new_ds_set(ds_from_cds, ttl, &cds_set); + } else { + make_new_ds_set(ds_from_cdnskey, ttl, &cdnskey_set); + } + + /* + * Try to use CDNSKEY records if the CDS records are missing + * or did not match. + */ + if (dns_rdataset_count(&new_ds_set) == 0 && + dns_rdataset_isassociated(&cdnskey_set)) + { + vbprintf(1, "CDS records have no allowed digest types; " + "using CDNSKEY instead\n"); + freelist(&new_ds_set); + isc_buffer_free(&new_ds_buf); + make_new_ds_set(ds_from_cdnskey, ttl, &cdnskey_set); + } + if (dns_rdataset_count(&new_ds_set) == 0) { + fatal("CDS records at %s do not match any -a digest types", + namestr); + } + + /* + * Now we have a candidate DS RRset, we need to check it + * won't break the delegation. + */ + vbprintf(1, "which child DNSKEY records match new DS records?\n"); + new_key_tbl = match_keyset_dsset(&dnskey_set, &new_ds_set, TIGHT); + + if (!consistent_digests(&new_ds_set)) { + fatal("CDS records at %s do not cover each key " + "with the same set of digest types", + namestr); + } + + vbprintf(1, "verify DNSKEY signature(s)\n"); + if (!signed_strict(&new_ds_set, matching_sigs(new_key_tbl, &dnskey_set, + &dnskey_sig))) + { + fatal("could not validate child DNSKEY RRset " + "with new DS records for %s", + namestr); + } + + free_keytable(&new_key_tbl); + + /* + * OK, it's all good! + */ + if (nsupdate) { + nsdiff(ttl, &old_ds_set, &new_ds_set); + } + + write_parent_set(ds_path, inplace, nsupdate, &new_ds_set); + +cleanup: + print_mem_stats = true; + cleanup(); + exit(0); +} |