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-rw-r--r--keyexchange/isakmpd-20041012/dnssec.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/keyexchange/isakmpd-20041012/dnssec.c b/keyexchange/isakmpd-20041012/dnssec.c
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+++ b/keyexchange/isakmpd-20041012/dnssec.c
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+/* $OpenBSD: dnssec.c,v 1.20 2004/06/14 09:55:41 ho Exp $ */
+
+/*
+ * Copyright (c) 2001 Håkan Olsson. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <arpa/inet.h>
+#include <stdlib.h>
+
+#include <openssl/rsa.h>
+
+#ifdef LWRES
+#include <lwres/netdb.h>
+#include <dns/keyvalues.h>
+#else
+#include <netdb.h>
+#endif
+
+#include "sysdep.h"
+
+#include "dnssec.h"
+#include "exchange.h"
+#include "ipsec_num.h"
+#include "libcrypto.h"
+#include "log.h"
+#include "message.h"
+#include "transport.h"
+#include "util.h"
+
+#ifndef DNS_UFQDN_SEPARATOR
+#define DNS_UFQDN_SEPARATOR "._ipsec."
+#endif
+
+/* adapted from <dns/rdatastruct.h> / RFC 2535 */
+struct dns_rdata_key {
+ u_int16_t flags;
+ u_int8_t protocol;
+ u_int8_t algorithm;
+ u_int16_t datalen;
+ unsigned char *data;
+};
+
+void *
+dns_get_key(int type, struct message *msg, int *keylen)
+{
+ struct exchange *exchange = msg->exchange;
+ struct rrsetinfo *rr;
+ struct dns_rdata_key key_rr;
+ char name[MAXHOSTNAMELEN];
+ in_addr_t ip4;
+ u_int8_t algorithm, *id, *umark;
+ size_t id_len;
+ int ret, i;
+
+ switch (type) {
+ case IKE_AUTH_RSA_SIG:
+ algorithm = DNS_KEYALG_RSA;
+ break;
+
+ case IKE_AUTH_RSA_ENC:
+ case IKE_AUTH_RSA_ENC_REV:
+ /* XXX Not yet. */
+ /* algorithm = DNS_KEYALG_RSA; */
+ return 0;
+
+ case IKE_AUTH_DSS:
+ /* XXX Not yet. */
+ /* algorithm = DNS_KEYALG_DSS; */
+ return 0;
+
+ case IKE_AUTH_PRE_SHARED:
+ default:
+ return 0;
+ }
+
+ id = exchange->initiator ? exchange->id_r : exchange->id_i;
+ id_len = exchange->initiator ? exchange->id_r_len : exchange->id_i_len;
+ memset(name, 0, sizeof name);
+
+ if (!id || id_len == 0) {
+ log_print("dns_get_key: ID is missing");
+ return 0;
+ }
+ /* Exchanges (and SAs) don't carry the ID in ISAKMP form */
+ id -= ISAKMP_GEN_SZ;
+ id_len += ISAKMP_GEN_SZ - ISAKMP_ID_DATA_OFF;
+
+ switch (GET_ISAKMP_ID_TYPE(id)) {
+ case IPSEC_ID_IPV4_ADDR:
+ /* We want to lookup a KEY RR in the reverse zone. */
+ if (id_len < sizeof ip4)
+ return 0;
+ memcpy(&ip4, id + ISAKMP_ID_DATA_OFF, sizeof ip4);
+ snprintf(name, sizeof name, "%d.%d.%d.%d.in-addr.arpa.", ip4
+ >> 24, (ip4 >> 16) & 0xFF, (ip4 >> 8) & 0xFF, ip4 & 0xFF);
+ break;
+
+ case IPSEC_ID_IPV6_ADDR:
+ /* XXX Not yet. */
+ return 0;
+ break;
+
+ case IPSEC_ID_FQDN:
+ if ((id_len + 1) >= sizeof name)
+ return 0;
+ /* ID is not NULL-terminated. Add trailing dot and NULL. */
+ memcpy(name, id + ISAKMP_ID_DATA_OFF, id_len);
+ *(name + id_len) = '.';
+ *(name + id_len + 1) = '\0';
+ break;
+
+ case IPSEC_ID_USER_FQDN:
+ /*
+ * Some special handling here. We want to convert the ID
+ * 'user@host.domain' string into 'user._ipsec.host.domain.'.
+ */
+ if ((id_len + sizeof(DNS_UFQDN_SEPARATOR)) >= sizeof name)
+ return 0;
+ /* Look for the '@' separator. */
+ for (umark = id + ISAKMP_ID_DATA_OFF; (umark - id) < id_len;
+ umark++)
+ if (*umark == '@')
+ break;
+ if (*umark != '@') {
+ LOG_DBG((LOG_MISC, 50, "dns_get_key: bad UFQDN ID"));
+ return 0;
+ }
+ *umark++ = '\0';
+ /* id is now terminated. 'umark', however, is not. */
+ snprintf(name, sizeof name, "%s%s", id + ISAKMP_ID_DATA_OFF,
+ DNS_UFQDN_SEPARATOR);
+ memcpy(name + strlen(name), umark, id_len - strlen(id) - 1);
+ *(name + id_len + sizeof(DNS_UFQDN_SEPARATOR) - 2) = '.';
+ *(name + id_len + sizeof(DNS_UFQDN_SEPARATOR) - 1) = '\0';
+ break;
+
+ default:
+ return 0;
+ }
+
+ LOG_DBG((LOG_MISC, 50, "dns_get_key: trying KEY RR for %s", name));
+ ret = getrrsetbyname(name, C_IN, T_KEY, 0, &rr);
+
+ if (ret) {
+ LOG_DBG((LOG_MISC, 30, "dns_get_key: no DNS responses "
+ "(error %d)", ret));
+ return 0;
+ }
+ LOG_DBG((LOG_MISC, 80,
+ "dns_get_key: rrset class %d type %d ttl %d nrdatas %d nrsigs %d",
+ rr->rri_rdclass, rr->rri_rdtype, rr->rri_ttl, rr->rri_nrdatas,
+ rr->rri_nsigs));
+
+ /* We don't accept unvalidated data. */
+ if (!(rr->rri_flags & RRSET_VALIDATED)) {
+ LOG_DBG((LOG_MISC, 10, "dns_get_key: "
+ "got unvalidated response"));
+ freerrset(rr);
+ return 0;
+ }
+ /* Sanity. */
+ if (rr->rri_nrdatas == 0 || rr->rri_rdtype != T_KEY) {
+ LOG_DBG((LOG_MISC, 30, "dns_get_key: no KEY RRs received"));
+ freerrset(rr);
+ return 0;
+ }
+ memset(&key_rr, 0, sizeof key_rr);
+
+ /*
+ * Find a key with the wanted algorithm, if any.
+ * XXX If there are several keys present, we currently only find the
+ * first.
+ */
+ for (i = 0; i < rr->rri_nrdatas && key_rr.datalen == 0; i++) {
+ key_rr.flags = ntohs((u_int16_t) * rr->rri_rdatas[i].rdi_data);
+ key_rr.protocol = *(rr->rri_rdatas[i].rdi_data + 2);
+ key_rr.algorithm = *(rr->rri_rdatas[i].rdi_data + 3);
+
+ if (key_rr.protocol != DNS_KEYPROTO_IPSEC) {
+ LOG_DBG((LOG_MISC, 50, "dns_get_key: ignored "
+ "non-IPsec key"));
+ continue;
+ }
+ if (key_rr.algorithm != algorithm) {
+ LOG_DBG((LOG_MISC, 50, "dns_get_key: ignored "
+ "key with other alg"));
+ continue;
+ }
+ key_rr.datalen = rr->rri_rdatas[i].rdi_length - 4;
+ if (key_rr.datalen <= 0) {
+ LOG_DBG((LOG_MISC, 50, "dns_get_key: "
+ "ignored bad key"));
+ key_rr.datalen = 0;
+ continue;
+ }
+ /* This key seems to fit our requirements... */
+ key_rr.data = (char *)malloc(key_rr.datalen);
+ if (!key_rr.data) {
+ log_error("dns_get_key: malloc (%d) failed",
+ key_rr.datalen);
+ freerrset(rr);
+ return 0;
+ }
+ memcpy(key_rr.data, rr->rri_rdatas[i].rdi_data + 4,
+ key_rr.datalen);
+ *keylen = key_rr.datalen;
+ }
+
+ freerrset(rr);
+
+ if (key_rr.datalen)
+ return key_rr.data;
+ return 0;
+}
+
+int
+dns_RSA_dns_to_x509(u_int8_t *key, int keylen, RSA **rsa_key)
+{
+ RSA *rsa;
+ int key_offset;
+ u_int8_t e_len;
+
+ if (!key || keylen <= 0) {
+ log_print("dns_RSA_dns_to_x509: invalid public key");
+ return -1;
+ }
+ rsa = RSA_new();
+ if (rsa == NULL) {
+ log_error("dns_RSA_dns_to_x509: "
+ "failed to allocate new RSA struct");
+ return -1;
+ }
+ e_len = *key;
+ key_offset = 1;
+
+ if (e_len == 0) {
+ if (keylen < 3) {
+ log_print("dns_RSA_dns_to_x509: invalid public key");
+ RSA_free(rsa);
+ return -1;
+ }
+ e_len = *(key + key_offset++) << 8;
+ e_len += *(key + key_offset++);
+ }
+ if (e_len > (keylen - key_offset)) {
+ log_print("dns_RSA_dns_to_x509: invalid public key");
+ RSA_free(rsa);
+ return -1;
+ }
+ rsa->e = BN_bin2bn(key + key_offset, e_len, NULL);
+ key_offset += e_len;
+
+ /* XXX if (keylen <= key_offset) -> "invalid public key" ? */
+
+ rsa->n = BN_bin2bn(key + key_offset, keylen - key_offset, NULL);
+
+ *rsa_key = rsa;
+
+ LOG_DBG((LOG_MISC, 30, "dns_RSA_dns_to_x509: got %d bits RSA key",
+ BN_num_bits(rsa->n)));
+ return 0;
+}
+
+#if notyet
+int
+dns_RSA_x509_to_dns(RSA *rsa_key, u_int8_t *key, int *keylen)
+{
+ return 0;
+}
+#endif
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