Example #1
0
static isc_result_t
process_dhtkey(dns_message_t *msg, dns_name_t *signer, dns_name_t *name,
	       dns_rdata_tkey_t *tkeyin, dns_tkeyctx_t *tctx,
	       dns_rdata_tkey_t *tkeyout,
	       dns_tsig_keyring_t *ring, dns_namelist_t *namelist)
{
	isc_result_t result = ISC_R_SUCCESS;
	dns_name_t *keyname, ourname;
	dns_rdataset_t *keyset = NULL;
	dns_rdata_t keyrdata = DNS_RDATA_INIT, ourkeyrdata = DNS_RDATA_INIT;
	isc_boolean_t found_key = ISC_FALSE, found_incompatible = ISC_FALSE;
	dst_key_t *pubkey = NULL;
	isc_buffer_t ourkeybuf, *shared = NULL;
	isc_region_t r, r2, ourkeyr;
	unsigned char keydata[DST_KEY_MAXSIZE];
	unsigned int sharedsize;
	isc_buffer_t secret;
	unsigned char *randomdata = NULL, secretdata[256];
	dns_ttl_t ttl = 0;

	if (tctx->dhkey == NULL) {
		tkey_log("process_dhtkey: tkey-dhkey not defined");
		tkeyout->error = dns_tsigerror_badalg;
		return (DNS_R_REFUSED);
	}

	if (!dns_name_equal(&tkeyin->algorithm, DNS_TSIG_HMACMD5_NAME)) {
		tkey_log("process_dhtkey: algorithms other than "
			 "hmac-md5 are not supported");
		tkeyout->error = dns_tsigerror_badalg;
		return (ISC_R_SUCCESS);
	}

	/*
	 * Look for a DH KEY record that will work with ours.
	 */
	for (result = dns_message_firstname(msg, DNS_SECTION_ADDITIONAL);
	     result == ISC_R_SUCCESS && !found_key;
	     result = dns_message_nextname(msg, DNS_SECTION_ADDITIONAL)) {
		keyname = NULL;
		dns_message_currentname(msg, DNS_SECTION_ADDITIONAL, &keyname);
		keyset = NULL;
		result = dns_message_findtype(keyname, dns_rdatatype_key, 0,
					      &keyset);
		if (result != ISC_R_SUCCESS)
			continue;

		for (result = dns_rdataset_first(keyset);
		     result == ISC_R_SUCCESS && !found_key;
		     result = dns_rdataset_next(keyset)) {
			dns_rdataset_current(keyset, &keyrdata);
			pubkey = NULL;
			result = dns_dnssec_keyfromrdata(keyname, &keyrdata,
							 msg->mctx, &pubkey);
			if (result != ISC_R_SUCCESS) {
				dns_rdata_reset(&keyrdata);
				continue;
			}
			if (dst_key_alg(pubkey) == DNS_KEYALG_DH) {
				if (dst_key_paramcompare(pubkey, tctx->dhkey))
				{
					found_key = ISC_TRUE;
					ttl = keyset->ttl;
					break;
				} else
					found_incompatible = ISC_TRUE;
			}
			dst_key_free(&pubkey);
			dns_rdata_reset(&keyrdata);
		}
	}

	if (!found_key) {
		if (found_incompatible) {
			tkey_log("process_dhtkey: found an incompatible key");
			tkeyout->error = dns_tsigerror_badkey;
			return (ISC_R_SUCCESS);
		} else {
			tkey_log("process_dhtkey: failed to find a key");
			return (DNS_R_FORMERR);
		}
	}

	RETERR(add_rdata_to_list(msg, keyname, &keyrdata, ttl, namelist));

	isc_buffer_init(&ourkeybuf, keydata, sizeof(keydata));
	RETERR(dst_key_todns(tctx->dhkey, &ourkeybuf));
	isc_buffer_usedregion(&ourkeybuf, &ourkeyr);
	dns_rdata_fromregion(&ourkeyrdata, dns_rdataclass_any,
			     dns_rdatatype_key, &ourkeyr);

	dns_name_init(&ourname, NULL);
	dns_name_clone(dst_key_name(tctx->dhkey), &ourname);

	/*
	 * XXXBEW The TTL should be obtained from the database, if it exists.
	 */
	RETERR(add_rdata_to_list(msg, &ourname, &ourkeyrdata, 0, namelist));

	RETERR(dst_key_secretsize(tctx->dhkey, &sharedsize));
	RETERR(isc_buffer_allocate(msg->mctx, &shared, sharedsize));

	result = dst_key_computesecret(pubkey, tctx->dhkey, shared);
	if (result != ISC_R_SUCCESS) {
		tkey_log("process_dhtkey: failed to compute shared secret: %s",
			 isc_result_totext(result));
		goto failure;
	}
	dst_key_free(&pubkey);

	isc_buffer_init(&secret, secretdata, sizeof(secretdata));

	randomdata = isc_mem_get(tkeyout->mctx, TKEY_RANDOM_AMOUNT);
	if (randomdata == NULL)
		goto failure;

	result = dst__entropy_getdata(randomdata, TKEY_RANDOM_AMOUNT,
				      ISC_FALSE);
	if (result != ISC_R_SUCCESS) {
		tkey_log("process_dhtkey: failed to obtain entropy: %s",
			 isc_result_totext(result));
		goto failure;
	}

	r.base = randomdata;
	r.length = TKEY_RANDOM_AMOUNT;
	r2.base = tkeyin->key;
	r2.length = tkeyin->keylen;
	RETERR(compute_secret(shared, &r2, &r, &secret));
	isc_buffer_free(&shared);

	RETERR(dns_tsigkey_create(name, &tkeyin->algorithm,
				  isc_buffer_base(&secret),
				  isc_buffer_usedlength(&secret),
				  ISC_TRUE, signer, tkeyin->inception,
				  tkeyin->expire, ring->mctx, ring, NULL));

	/* This key is good for a long time */
	tkeyout->inception = tkeyin->inception;
	tkeyout->expire = tkeyin->expire;

	tkeyout->key = randomdata;
	tkeyout->keylen = TKEY_RANDOM_AMOUNT;

	return (ISC_R_SUCCESS);

 failure:
	if (!ISC_LIST_EMPTY(*namelist))
		free_namelist(msg, namelist);
	if (shared != NULL)
		isc_buffer_free(&shared);
	if (pubkey != NULL)
		dst_key_free(&pubkey);
	if (randomdata != NULL)
		isc_mem_put(tkeyout->mctx, randomdata, TKEY_RANDOM_AMOUNT);
	return (result);
}
Example #2
0
isc_result_t
dns_dnssec_findzonekeys2(dns_db_t *db, dns_dbversion_t *ver,
			 dns_dbnode_t *node, dns_name_t *name,
			 const char *directory, isc_mem_t *mctx,
			 unsigned int maxkeys, dst_key_t **keys,
			 unsigned int *nkeys)
{
	dns_rdataset_t rdataset;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	isc_result_t result;
	dst_key_t *pubkey = NULL;
	unsigned int count = 0;

	REQUIRE(nkeys != NULL);
	REQUIRE(keys != NULL);

	*nkeys = 0;
	dns_rdataset_init(&rdataset);
	RETERR(dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey, 0, 0,
				   &rdataset, NULL));
	RETERR(dns_rdataset_first(&rdataset));
	while (result == ISC_R_SUCCESS && count < maxkeys) {
		pubkey = NULL;
		dns_rdataset_current(&rdataset, &rdata);
		RETERR(dns_dnssec_keyfromrdata(name, &rdata, mctx, &pubkey));
		if (!is_zone_key(pubkey) ||
		    (dst_key_flags(pubkey) & DNS_KEYTYPE_NOAUTH) != 0)
			goto next;
		keys[count] = NULL;
		result = dst_key_fromfile(dst_key_name(pubkey),
					  dst_key_id(pubkey),
					  dst_key_alg(pubkey),
					  DST_TYPE_PUBLIC|DST_TYPE_PRIVATE,
					  directory,
					  mctx, &keys[count]);
		if (result == ISC_R_FILENOTFOUND) {
			keys[count] = pubkey;
			pubkey = NULL;
			count++;
			goto next;
		}
		if (result != ISC_R_SUCCESS)
			goto failure;
		if ((dst_key_flags(keys[count]) & DNS_KEYTYPE_NOAUTH) != 0) {
			/* We should never get here. */
			dst_key_free(&keys[count]);
			goto next;
		}
		count++;
 next:
		if (pubkey != NULL)
			dst_key_free(&pubkey);
		dns_rdata_reset(&rdata);
		result = dns_rdataset_next(&rdataset);
	}
	if (result != ISC_R_NOMORE)
		goto failure;
	if (count == 0)
		result = ISC_R_NOTFOUND;
	else
		result = ISC_R_SUCCESS;

 failure:
	if (dns_rdataset_isassociated(&rdataset))
		dns_rdataset_disassociate(&rdataset);
	if (pubkey != NULL)
		dst_key_free(&pubkey);
	if (result != ISC_R_SUCCESS)
		while (count > 0)
			dst_key_free(&keys[--count]);
	*nkeys = count;
	return (result);
}