From 6585e5ad764ee2414d9b01f30784b6549bc8f58e Mon Sep 17 00:00:00 2001 From: Othmar Gsenger Date: Mon, 30 Jul 2007 19:37:53 +0000 Subject: added keyexchange --- keyexchange/isakmpd-20041012/dnssec.c | 293 ++++++++++++++++++++++++++++++++++ 1 file changed, 293 insertions(+) create mode 100644 keyexchange/isakmpd-20041012/dnssec.c (limited to 'keyexchange/isakmpd-20041012/dnssec.c') diff --git a/keyexchange/isakmpd-20041012/dnssec.c b/keyexchange/isakmpd-20041012/dnssec.c new file mode 100644 index 0000000..b7ee75f --- /dev/null +++ b/keyexchange/isakmpd-20041012/dnssec.c @@ -0,0 +1,293 @@ +/* $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 +#include +#include +#include +#include + +#include + +#ifdef LWRES +#include +#include +#else +#include +#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 / 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 -- cgit v1.2.3