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src/sbin/isakmpd/ike_auth.c

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/* $OpenBSD: ike_auth.c,v 1.118 2020/07/07 17:33:40 tobhe Exp $ */
/* $EOM: ike_auth.c,v 1.59 2000/11/21 00:21:31 angelos Exp $ */
/*
* Copyright (c) 1998, 1999, 2000, 2001 Niklas Hallqvist. All rights reserved.
* Copyright (c) 1999 Niels Provos. All rights reserved.
* Copyright (c) 1999 Angelos D. Keromytis. All rights reserved.
* Copyright (c) 2000, 2001, 2003 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.
*/
/*
* This code was written under funding by Ericsson Radio Systems.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <regex.h>
#include <keynote.h>
#include <policy.h>
#include "cert.h"
#include "conf.h"
#include "constants.h"
#if defined (USE_DNSSEC)
#include "dnssec.h"
#endif
#include "exchange.h"
#include "hash.h"
#include "ike_auth.h"
#include "ipsec.h"
#include "ipsec_doi.h"
#include "libcrypto.h"
#include "log.h"
#include "message.h"
#include "monitor.h"
#include "prf.h"
#include "transport.h"
#include "util.h"
#include "key.h"
#include "x509.h"
#ifdef notyet
static u_int8_t *enc_gen_skeyid(struct exchange *, size_t *);
#endif
static u_int8_t *pre_shared_gen_skeyid(struct exchange *, size_t *);
static int pre_shared_decode_hash(struct message *);
static int pre_shared_encode_hash(struct message *);
static u_int8_t *sig_gen_skeyid(struct exchange *, size_t *);
static int rsa_sig_decode_hash(struct message *);
static int rsa_sig_encode_hash(struct message *);
static int get_raw_key_from_file(int, u_int8_t *, size_t, RSA **);
static int ike_auth_hash(struct exchange *, u_int8_t *);
static struct ike_auth ike_auth[] = {
{
IKE_AUTH_PRE_SHARED, pre_shared_gen_skeyid,
pre_shared_decode_hash,
pre_shared_encode_hash
},
#ifdef notdef
{
IKE_AUTH_DSS, sig_gen_skeyid,
pre_shared_decode_hash,
pre_shared_encode_hash
},
#endif
{
IKE_AUTH_RSA_SIG, sig_gen_skeyid,
rsa_sig_decode_hash,
rsa_sig_encode_hash
},
#ifdef notdef
{
IKE_AUTH_RSA_ENC, enc_gen_skeyid,
pre_shared_decode_hash,
pre_shared_encode_hash
},
{
IKE_AUTH_RSA_ENC_REV, enc_gen_skeyid,
pre_shared_decode_hash,
pre_shared_encode_hash
},
#endif
};
struct ike_auth *
ike_auth_get(u_int16_t id)
{
size_t i;
for (i = 0; i < sizeof ike_auth / sizeof ike_auth[0]; i++)
if (id == ike_auth[i].id)
return &ike_auth[i];
return 0;
}
/*
* Find and decode the configured key (pre-shared or public) for the
* peer denoted by ID. Stash the len in KEYLEN.
*/
static void *
ike_auth_get_key(int type, char *id, char *local_id, size_t *keylen)
{
char *key, *buf;
char *keyfile, *privkeyfile;
FILE *keyfp;
RSA *rsakey;
size_t fsize, pkflen;
int fd;
switch (type) {
case IKE_AUTH_PRE_SHARED:
/* Get the pre-shared key for our peer. */
key = conf_get_str(id, "Authentication");
if (!key && local_id)
key = conf_get_str(local_id, "Authentication");
if (!key) {
log_print("ike_auth_get_key: "
"no key found for peer \"%s\" or local ID \"%s\"",
id, local_id ? local_id : "<none>");
return 0;
}
/* If the key starts with 0x it is in hex format. */
if (strncasecmp(key, "0x", 2) == 0) {
*keylen = (strlen(key) - 1) / 2;
buf = malloc(*keylen);
if (!buf) {
log_error("ike_auth_get_key: malloc (%lu) "
"failed", (unsigned long)*keylen);
return 0;
}
if (hex2raw(key + 2, (unsigned char *)buf, *keylen)) {
free(buf);
log_print("ike_auth_get_key: invalid hex key "
"%s", key);
return 0;
}
key = buf;
} else {
buf = key;
key = strdup(buf);
if (!key) {
log_error("ike_auth_get_key: strdup() failed");
return 0;
}
*keylen = strlen(key);
}
break;
case IKE_AUTH_RSA_SIG:
if (local_id && (keyfile = conf_get_str("KeyNote",
"Credential-directory")) != 0) {
struct stat sb;
struct keynote_deckey dc;
char *privkeyfile, *buf2;
size_t size;
if (asprintf(&privkeyfile, "%s/%s/%s", keyfile,
local_id, PRIVATE_KEY_FILE) == -1) {
log_print("ike_auth_get_key: failed to asprintf()");
return 0;
}
keyfile = privkeyfile;
fd = monitor_open(keyfile, O_RDONLY, 0);
if (fd < 0) {
free(keyfile);
goto ignorekeynote;
}
if (fstat(fd, &sb) == -1) {
log_print("ike_auth_get_key: fstat failed");
free(keyfile);
close(fd);
return 0;
}
size = (size_t)sb.st_size;
buf = calloc(size + 1, sizeof(char));
if (!buf) {
log_print("ike_auth_get_key: failed allocating"
" %lu bytes", (unsigned long)size + 1);
free(keyfile);
close(fd);
return 0;
}
if (read(fd, buf, size) != (ssize_t)size) {
free(buf);
log_print("ike_auth_get_key: "
"failed reading %lu bytes from \"%s\"",
(unsigned long)size, keyfile);
free(keyfile);
close(fd);
return 0;
}
close(fd);
/* Parse private key string */
buf2 = kn_get_string(buf);
free(buf);
if (!buf2 || kn_decode_key(&dc, buf2,
KEYNOTE_PRIVATE_KEY) == -1) {
free(buf2);
log_print("ike_auth_get_key: failed decoding "
"key in \"%s\"", keyfile);
free(keyfile);
return 0;
}
free(buf2);
if (dc.dec_algorithm != KEYNOTE_ALGORITHM_RSA) {
log_print("ike_auth_get_key: wrong algorithm "
"type %d in \"%s\"", dc.dec_algorithm,
keyfile);
free(keyfile);
kn_free_key(&dc);
return 0;
}
free(keyfile);
return dc.dec_key;
}
ignorekeynote:
/* Otherwise, try X.509 */
privkeyfile = keyfile = NULL;
fd = -1;
if (local_id) {
/* Look in Private-key-directory. */
keyfile = conf_get_str("X509-certificates",
"Private-key-directory");
pkflen = strlen(keyfile) + strlen(local_id) + sizeof "/";
privkeyfile = calloc(pkflen, sizeof(char));
if (!privkeyfile) {
log_print("ike_auth_get_key: failed to "
"allocate %lu bytes", (unsigned long)pkflen);
return 0;
}
snprintf(privkeyfile, pkflen, "%s/%s", keyfile,
local_id);
keyfile = privkeyfile;
fd = monitor_open(keyfile, O_RDONLY, 0);
if (fd == -1 && errno != ENOENT) {
log_print("ike_auth_get_key: failed opening "
"\"%s\"", keyfile);
free(privkeyfile);
privkeyfile = NULL;
keyfile = NULL;
}
}
if (fd == -1) {
/* No key found, try default key. */
keyfile = conf_get_str("X509-certificates",
"Private-key");
fd = monitor_open(keyfile, O_RDONLY, 0);
if (fd == -1) {
log_print("ike_auth_get_key: failed opening "
"\"%s\"", keyfile);
return 0;
}
}
if (check_file_secrecy_fd(fd, keyfile, &fsize)) {
free(privkeyfile);
close(fd);
return 0;
}
if ((keyfp = fdopen(fd, "r")) == NULL) {
log_print("ike_auth_get_key: fdopen failed");
free(privkeyfile);
close(fd);
return 0;
}
#if SSLEAY_VERSION_NUMBER >= 0x00904100L
rsakey = PEM_read_RSAPrivateKey(keyfp, NULL, NULL, NULL);
#else
rsakey = PEM_read_RSAPrivateKey(keyfp, NULL, NULL);
#endif
fclose(keyfp);
free(privkeyfile);
if (!rsakey) {
log_print("ike_auth_get_key: "
"PEM_read_bio_RSAPrivateKey failed");
return 0;
}
return rsakey;
default:
log_print("ike_auth_get_key: unknown key type %d", type);
return 0;
}
return key;
}
static u_int8_t *
pre_shared_gen_skeyid(struct exchange *exchange, size_t *sz)
{
struct prf *prf;
struct ipsec_exch *ie = exchange->data;
u_int8_t *skeyid, *buf = 0;
unsigned char *key;
size_t keylen;
/*
* If we're the responder and have the initiator's ID (which is the
* case in Aggressive mode), try to find the preshared key in the
* section of the initiator's Phase 1 ID. This allows us to do
* mobile user support with preshared keys.
*/
if (!exchange->initiator && exchange->id_i) {
switch (exchange->id_i[0]) {
case IPSEC_ID_IPV4_ADDR:
case IPSEC_ID_IPV6_ADDR:
util_ntoa((char **) &buf,
exchange->id_i[0] == IPSEC_ID_IPV4_ADDR ? AF_INET :
AF_INET6, exchange->id_i + ISAKMP_ID_DATA_OFF -
ISAKMP_GEN_SZ);
if (!buf)
return 0;
break;
case IPSEC_ID_FQDN:
case IPSEC_ID_USER_FQDN:
buf = calloc(exchange->id_i_len - ISAKMP_ID_DATA_OFF +
ISAKMP_GEN_SZ + 1, sizeof(char));
if (!buf) {
log_print("pre_shared_gen_skeyid: malloc (%lu"
") failed",
(unsigned long)exchange->id_i_len -
ISAKMP_ID_DATA_OFF + ISAKMP_GEN_SZ + 1);
return 0;
}
memcpy(buf,
exchange->id_i + ISAKMP_ID_DATA_OFF -
ISAKMP_GEN_SZ,
exchange->id_i_len - ISAKMP_ID_DATA_OFF +
ISAKMP_GEN_SZ);
break;
/* XXX Support more ID types ? */
default:
break;
}
}
/*
* Get the pre-shared key for our peer. This will work even if the key
* has been passed to us through a mechanism like PFKEYv2.
*/
key = ike_auth_get_key(IKE_AUTH_PRE_SHARED, exchange->name,
(char *)buf, &keylen);
free(buf);
/* Fail if no key could be found. */
if (!key)
return 0;
/* Store the secret key for later policy processing. */
exchange->recv_key = calloc(keylen + 1, sizeof(char));
exchange->recv_keytype = ISAKMP_KEY_PASSPHRASE;
if (!exchange->recv_key) {
log_error("pre_shared_gen_skeyid: malloc (%lu) failed",
(unsigned long)keylen);
free(key);
return 0;
}
memcpy(exchange->recv_key, key, keylen);
exchange->recv_certtype = ISAKMP_CERTENC_NONE;
free(key);
prf = prf_alloc(ie->prf_type, ie->hash->type, exchange->recv_key,
keylen);
if (!prf)
return 0;
*sz = prf->blocksize;
skeyid = malloc(*sz);
if (!skeyid) {
log_error("pre_shared_gen_skeyid: malloc (%lu) failed",
(unsigned long)*sz);
prf_free(prf);
return 0;
}
prf->Init(prf->prfctx);
prf->Update(prf->prfctx, exchange->nonce_i, exchange->nonce_i_len);
prf->Update(prf->prfctx, exchange->nonce_r, exchange->nonce_r_len);
prf->Final(skeyid, prf->prfctx);
prf_free(prf);
return skeyid;
}
/* Both DSS & RSA signature authentication use this algorithm. */
static u_int8_t *
sig_gen_skeyid(struct exchange *exchange, size_t *sz)
{
struct prf *prf;
struct ipsec_exch *ie = exchange->data;
u_int8_t *skeyid;
unsigned char *key;
key = malloc(exchange->nonce_i_len + exchange->nonce_r_len);
if (!key)
return 0;
memcpy(key, exchange->nonce_i, exchange->nonce_i_len);
memcpy(key + exchange->nonce_i_len, exchange->nonce_r,
exchange->nonce_r_len);
LOG_DBG((LOG_NEGOTIATION, 80, "sig_gen_skeyid: PRF type %d, hash %d",
ie->prf_type, ie->hash->type));
LOG_DBG_BUF((LOG_NEGOTIATION, 80,
"sig_gen_skeyid: SKEYID initialized with",
(u_int8_t *)key, exchange->nonce_i_len + exchange->nonce_r_len));
prf = prf_alloc(ie->prf_type, ie->hash->type, key,
exchange->nonce_i_len + exchange->nonce_r_len);
free(key);
if (!prf)
return 0;
*sz = prf->blocksize;
skeyid = malloc(*sz);
if (!skeyid) {
log_error("sig_gen_skeyid: malloc (%lu) failed",
(unsigned long)*sz);
prf_free(prf);
return 0;
}
LOG_DBG((LOG_NEGOTIATION, 80, "sig_gen_skeyid: g^xy length %lu",
(unsigned long)ie->g_xy_len));
LOG_DBG_BUF((LOG_NEGOTIATION, 80,
"sig_gen_skeyid: SKEYID fed with g^xy", ie->g_xy, ie->g_xy_len));
prf->Init(prf->prfctx);
prf->Update(prf->prfctx, ie->g_xy, ie->g_xy_len);
prf->Final(skeyid, prf->prfctx);
prf_free(prf);
return skeyid;
}
#ifdef notdef
/*
* Both standard and revised RSA encryption authentication use this SKEYID
* computation.
*/
static u_int8_t *
enc_gen_skeyid(struct exchange *exchange, size_t *sz)
{
struct prf *prf;
struct ipsec_exch *ie = exchange->data;
struct hash *hash = ie->hash;
u_int8_t *skeyid;
hash->Init(hash->ctx);
hash->Update(hash->ctx, exchange->nonce_i, exchange->nonce_i_len);
hash->Update(hash->ctx, exchange->nonce_r, exchange->nonce_r_len);
hash->Final(hash->digest, hash->ctx);
prf = prf_alloc(ie->prf_type, hash->type, hash->digest, *sz);
if (!prf)
return 0;
*sz = prf->blocksize;
skeyid = malloc(*sz);
if (!skeyid) {
log_error("enc_gen_skeyid: malloc (%d) failed", *sz);
prf_free(prf);
return 0;
}
prf->Init(prf->prfctx);
prf->Update(prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN);
prf->Final(skeyid, prf->prfctx);
prf_free(prf);
return skeyid;
}
#endif /* notdef */
static int
pre_shared_decode_hash(struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct ipsec_exch *ie = exchange->data;
struct payload *payload;
size_t hashsize = ie->hash->hashsize;
char header[80];
int initiator = exchange->initiator;
u_int8_t **hash_p;
/* Choose the right fields to fill-in. */
hash_p = initiator ? &ie->hash_r : &ie->hash_i;
payload = payload_first(msg, ISAKMP_PAYLOAD_HASH);
if (!payload) {
log_print("pre_shared_decode_hash: no HASH payload found");
return -1;
}
/* Check that the hash is of the correct size. */
if (GET_ISAKMP_GEN_LENGTH(payload->p) - ISAKMP_GEN_SZ != hashsize)
return -1;
/* XXX Need this hash be in the SA? */
*hash_p = malloc(hashsize);
if (!*hash_p) {
log_error("pre_shared_decode_hash: malloc (%lu) failed",
(unsigned long)hashsize);
return -1;
}
memcpy(*hash_p, payload->p + ISAKMP_HASH_DATA_OFF, hashsize);
snprintf(header, sizeof header, "pre_shared_decode_hash: HASH_%c",
initiator ? 'R' : 'I');
LOG_DBG_BUF((LOG_MISC, 80, header, *hash_p, hashsize));
payload->flags |= PL_MARK;
return 0;
}
/* Decrypt the HASH in SIG, we already need a parsed ID payload. */
static int
rsa_sig_decode_hash(struct message *msg)
{
struct cert_handler *handler;
struct exchange *exchange = msg->exchange;
struct ipsec_exch *ie = exchange->data;
struct payload *p;
void *cert = 0;
u_int8_t *rawcert = 0, **hash_p, **id_cert, *id;
u_int32_t rawcertlen, *id_cert_len;
RSA *key = 0;
size_t hashsize = ie->hash->hashsize, id_len;
char header[80];
int len, initiator = exchange->initiator;
int found = 0, n, i, id_found;
#if defined (USE_DNSSEC)
u_int8_t *rawkey = 0;
u_int32_t rawkeylen;
#endif
/* Choose the right fields to fill-in. */
hash_p = initiator ? &ie->hash_r : &ie->hash_i;
id = initiator ? exchange->id_r : exchange->id_i;
id_len = initiator ? exchange->id_r_len : exchange->id_i_len;
if (!id || id_len == 0) {
log_print("rsa_sig_decode_hash: ID is missing");
return -1;
}
/*
* XXX Assume we should use the same kind of certification as the
* remote... moreover, just use the first CERT payload to decide what
* to use.
*/
p = payload_first(msg, ISAKMP_PAYLOAD_CERT);
if (!p)
handler = cert_get(ISAKMP_CERTENC_KEYNOTE);
else
handler = cert_get(GET_ISAKMP_CERT_ENCODING(p->p));
if (!handler) {
log_print("rsa_sig_decode_hash: cert_get (%d) failed",
p ? GET_ISAKMP_CERT_ENCODING(p->p) : -1);
return -1;
}
/*
* We need the policy session initialized now, so we can add
* credentials etc.
*/
exchange->policy_id = kn_init();
if (exchange->policy_id == -1) {
log_print("rsa_sig_decode_hash: failed to initialize policy "
"session");
return -1;
}
/* Obtain a certificate from our certificate storage. */
if (handler->cert_obtain(id, id_len, 0, &rawcert, &rawcertlen)) {
if (handler->id == ISAKMP_CERTENC_X509_SIG) {
cert = handler->cert_get(rawcert, rawcertlen);
if (!cert)
LOG_DBG((LOG_CRYPTO, 50, "rsa_sig_decode_hash:"
" certificate malformed"));
else {
if (!handler->cert_get_key(cert, &key)) {
log_print("rsa_sig_decode_hash: "
"decoding certificate failed");
handler->cert_free(cert);
} else {
found++;
LOG_DBG((LOG_CRYPTO, 40,
"rsa_sig_decode_hash: using cert "
"of type %d", handler->id));
exchange->recv_cert = cert;
exchange->recv_certtype = handler->id;
x509_generate_kn(exchange->policy_id,
cert);
}
}
} else if (handler->id == ISAKMP_CERTENC_KEYNOTE)
handler->cert_insert(exchange->policy_id, rawcert);
free(rawcert);
}
/*
* Walk over potential CERT payloads in this message.
* XXX I believe this is the wrong spot for this. CERTs can appear
* anytime.
*/
TAILQ_FOREACH(p, &msg->payload[ISAKMP_PAYLOAD_CERT], link) {
p->flags |= PL_MARK;
/*
* When we have found a key, just walk over the rest, marking
* them.
*/
if (found)
continue;
handler = cert_get(GET_ISAKMP_CERT_ENCODING(p->p));
if (!handler) {
LOG_DBG((LOG_MISC, 30, "rsa_sig_decode_hash: "
"no handler for %s CERT encoding",
constant_name(isakmp_certenc_cst,
GET_ISAKMP_CERT_ENCODING(p->p))));
continue;
}
cert = handler->cert_get(p->p + ISAKMP_CERT_DATA_OFF,
GET_ISAKMP_GEN_LENGTH(p->p) - ISAKMP_CERT_DATA_OFF);
if (!cert) {
log_print("rsa_sig_decode_hash: "
"can not get data from CERT");
continue;
}
if (!handler->cert_validate(cert)) {
handler->cert_free(cert);
log_print("rsa_sig_decode_hash: received CERT can't "
"be validated");
continue;
}
if (GET_ISAKMP_CERT_ENCODING(p->p) ==
ISAKMP_CERTENC_X509_SIG) {
if (!handler->cert_get_subjects(cert, &n, &id_cert,
&id_cert_len)) {
handler->cert_free(cert);
log_print("rsa_sig_decode_hash: can not get "
"subject from CERT");
continue;
}
id_found = 0;
for (i = 0; i < n; i++)
if (id_cert_len[i] == id_len &&
id[0] == id_cert[i][0] &&
memcmp(id + 4, id_cert[i] + 4, id_len - 4)
== 0) {
id_found++;
break;
}
if (!id_found) {
handler->cert_free(cert);
log_print("rsa_sig_decode_hash: no CERT "
"subject match the ID");
free(id_cert);
continue;
}
cert_free_subjects(n, id_cert, id_cert_len);
}
if (!handler->cert_get_key(cert, &key)) {
handler->cert_free(cert);
log_print("rsa_sig_decode_hash: decoding payload CERT "
"failed");
continue;
}
/* We validated the cert, cache it for later use. */
handler->cert_insert(exchange->policy_id, cert);
exchange->recv_cert = cert;
exchange->recv_certtype = GET_ISAKMP_CERT_ENCODING(p->p);
if (exchange->recv_certtype == ISAKMP_CERTENC_KEYNOTE) {
struct keynote_deckey dc;
char *pp;
dc.dec_algorithm = KEYNOTE_ALGORITHM_RSA;
dc.dec_key = key;
pp = kn_encode_key(&dc, INTERNAL_ENC_PKCS1,
ENCODING_HEX, KEYNOTE_PUBLIC_KEY);
if (pp == NULL) {
kn_free_key(&dc);
log_print("rsa_sig_decode_hash: failed to "
"ASCII-encode key");
return -1;
}
if (asprintf(&exchange->keynote_key, "rsa-hex:%s",
pp) == -1) {
free(pp);
kn_free_key(&dc);
log_print("rsa_sig_decode_hash: failed to asprintf()");
return -1;
}
free(pp);
}
found++;
}
#if defined (USE_DNSSEC)
/*
* If no certificate provided a key, try to find a validated DNSSEC
* KEY.
*/
if (!found) {
rawkey = dns_get_key(IKE_AUTH_RSA_SIG, msg, &rawkeylen);
/* We need to convert 'void *rawkey' into 'RSA *key'. */
if (dns_RSA_dns_to_x509(rawkey, rawkeylen, &key) == 0)
found++;
else
log_print("rsa_sig_decode_hash: KEY to RSA key "
"conversion failed");
free(rawkey);
}
#endif /* USE_DNSSEC */
/* If we still have not found a key, try to read it from a file. */
if (!found)
if (get_raw_key_from_file(IKE_AUTH_RSA_SIG, id, id_len, &key)
!= -1)
found++;
if (!found) {
log_print("rsa_sig_decode_hash: no public key found");
return -1;
}
p = payload_first(msg, ISAKMP_PAYLOAD_SIG);
if (!p) {
log_print("rsa_sig_decode_hash: missing signature payload");
RSA_free(key);
return -1;
}
/* Check that the sig is of the correct size. */
len = GET_ISAKMP_GEN_LENGTH(p->p) - ISAKMP_SIG_SZ;
if (len != RSA_size(key)) {
RSA_free(key);
log_print("rsa_sig_decode_hash: "
"SIG payload length does not match public key");
return -1;
}
*hash_p = malloc(len);
if (!*hash_p) {
RSA_free(key);
log_error("rsa_sig_decode_hash: malloc (%d) failed", len);
return -1;
}
len = RSA_public_decrypt(len, p->p + ISAKMP_SIG_DATA_OFF, *hash_p, key,
RSA_PKCS1_PADDING);
if (len == -1) {
RSA_free(key);
log_print("rsa_sig_decode_hash: RSA_public_decrypt () failed");
return -1;
}
/* Store key for later use */
exchange->recv_key = key;
exchange->recv_keytype = ISAKMP_KEY_RSA;
if (len != (int)hashsize) {
free(*hash_p);
*hash_p = 0;
log_print("rsa_sig_decode_hash: len %lu != hashsize %lu",
(unsigned long)len, (unsigned long)hashsize);
return -1;
}
snprintf(header, sizeof header, "rsa_sig_decode_hash: HASH_%c",
initiator ? 'R' : 'I');
LOG_DBG_BUF((LOG_MISC, 80, header, *hash_p, hashsize));
p->flags |= PL_MARK;
return 0;
}
static int
pre_shared_encode_hash(struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct ipsec_exch *ie = exchange->data;
size_t hashsize = ie->hash->hashsize;
char header[80];
int initiator = exchange->initiator;
u_int8_t *buf;
buf = ipsec_add_hash_payload(msg, hashsize);
if (!buf)
return -1;
if (ike_auth_hash(exchange, buf + ISAKMP_HASH_DATA_OFF) == -1)
return -1;
snprintf(header, sizeof header, "pre_shared_encode_hash: HASH_%c",
initiator ? 'I' : 'R');
LOG_DBG_BUF((LOG_MISC, 80, header, buf + ISAKMP_HASH_DATA_OFF,
hashsize));
return 0;
}
/* Encrypt the HASH into a SIG type. */
static int
rsa_sig_encode_hash(struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct ipsec_exch *ie = exchange->data;
size_t hashsize = ie->hash->hashsize, id_len;
struct cert_handler *handler;
char header[80];
int initiator = exchange->initiator, idtype;
u_int8_t *buf, *data, *buf2, *id;
u_int32_t datalen;
int32_t sigsize;
void *sent_key;
id = initiator ? exchange->id_i : exchange->id_r;
id_len = initiator ? exchange->id_i_len : exchange->id_r_len;
/* We may have been provided these by the kernel */
buf = (u_int8_t *)conf_get_str(exchange->name, "Credentials");
if (buf && (idtype = conf_get_num(exchange->name, "Credential_Type",
-1)) != -1) {
exchange->sent_certtype = idtype;
handler = cert_get(idtype);
if (!handler) {
log_print("rsa_sig_encode_hash: cert_get (%d) failed",
idtype);
return -1;
}
exchange->sent_cert =
handler->cert_from_printable((char *)buf);
if (!exchange->sent_cert) {
log_print("rsa_sig_encode_hash: failed to retrieve "
"certificate");
return -1;
}
handler->cert_serialize(exchange->sent_cert, &data, &datalen);
if (!data) {
log_print("rsa_sig_encode_hash: cert serialization "
"failed");
return -1;
}
goto aftercert; /* Skip all the certificate discovery */
}
/* XXX This needs to be configurable. */
idtype = ISAKMP_CERTENC_KEYNOTE;
/* Find a certificate with subjectAltName = id. */
handler = cert_get(idtype);
if (!handler) {
idtype = ISAKMP_CERTENC_X509_SIG;
handler = cert_get(idtype);
if (!handler) {
log_print("rsa_sig_encode_hash: cert_get(%d) failed",
idtype);
return -1;
}
}
if (handler->cert_obtain(id, id_len, 0, &data, &datalen) == 0) {
if (idtype == ISAKMP_CERTENC_KEYNOTE) {
idtype = ISAKMP_CERTENC_X509_SIG;
handler = cert_get(idtype);
if (!handler) {
log_print("rsa_sig_encode_hash: cert_get(%d) "
"failed", idtype);
return -1;
}
if (handler->cert_obtain(id, id_len, 0, &data,
&datalen) == 0) {
LOG_DBG((LOG_MISC, 10, "rsa_sig_encode_hash: "
"no certificate to send for id %s",
ipsec_id_string(id, id_len)));
goto skipcert;
}
} else {
LOG_DBG((LOG_MISC, 10,
"rsa_sig_encode_hash: no certificate to send"
" for id %s", ipsec_id_string(id, id_len)));
goto skipcert;
}
}
/* Let's store the certificate we are going to use */
exchange->sent_certtype = idtype;
exchange->sent_cert = handler->cert_get(data, datalen);
if (!exchange->sent_cert) {
free(data);
log_print("rsa_sig_encode_hash: failed to get certificate "
"from wire encoding");
return -1;
}
aftercert:
buf = realloc(data, ISAKMP_CERT_SZ + datalen);
if (!buf) {
log_error("rsa_sig_encode_hash: realloc (%p, %d) failed", data,
ISAKMP_CERT_SZ + datalen);
free(data);
return -1;
}
memmove(buf + ISAKMP_CERT_SZ, buf, datalen);
SET_ISAKMP_CERT_ENCODING(buf, idtype);
if (message_add_payload(msg, ISAKMP_PAYLOAD_CERT, buf,
ISAKMP_CERT_SZ + datalen, 1)) {
free(buf);
return -1;
}
skipcert:
/* Again, we may have these from the kernel */
buf = (u_int8_t *)conf_get_str(exchange->name, "PKAuthentication");
if (buf) {
key_from_printable(ISAKMP_KEY_RSA, ISAKMP_KEYTYPE_PRIVATE,
(char *)buf, &data, &datalen);
if (!data) {
log_print("rsa_sig_encode_hash: badly formatted RSA "
"private key");
return 0;
}
sent_key = key_internalize(ISAKMP_KEY_RSA,
ISAKMP_KEYTYPE_PRIVATE, data, datalen);
if (!sent_key) {
log_print("rsa_sig_encode_hash: bad RSA private key "
"from dynamic SA acquisition subsystem");
return 0;
}
} else {
/* Try through the regular means. */
switch (id[ISAKMP_ID_TYPE_OFF - ISAKMP_GEN_SZ]) {
case IPSEC_ID_IPV4_ADDR:
case IPSEC_ID_IPV6_ADDR:
util_ntoa((char **)&buf2,
id[ISAKMP_ID_TYPE_OFF - ISAKMP_GEN_SZ] ==
IPSEC_ID_IPV4_ADDR ? AF_INET : AF_INET6,
id + ISAKMP_ID_DATA_OFF - ISAKMP_GEN_SZ);
if (!buf2)
return 0;
break;
case IPSEC_ID_FQDN:
case IPSEC_ID_USER_FQDN:
buf2 = calloc(id_len - ISAKMP_ID_DATA_OFF +
ISAKMP_GEN_SZ + 1, sizeof(char));
if (!buf2) {
log_print("rsa_sig_encode_hash: malloc (%lu) "
"failed", (unsigned long)id_len -
ISAKMP_ID_DATA_OFF + ISAKMP_GEN_SZ + 1);
return 0;
}
memcpy(buf2, id + ISAKMP_ID_DATA_OFF - ISAKMP_GEN_SZ,
id_len - ISAKMP_ID_DATA_OFF + ISAKMP_GEN_SZ);
break;
/* XXX Support more ID types? */
default:
buf2 = 0;
return 0;
}
sent_key = ike_auth_get_key(IKE_AUTH_RSA_SIG, exchange->name,
(char *)buf2, 0);
free(buf2);
/* Did we find a key? */
if (!sent_key) {
log_print("rsa_sig_encode_hash: "
"could not get private key");
return -1;
}
}
/* Enable RSA blinding. */
if (RSA_blinding_on(sent_key, NULL) != 1) {
log_error("rsa_sig_encode_hash: RSA_blinding_on () failed.");
RSA_free(sent_key);
return -1;
}
/* XXX hashsize is not necessarily prf->blocksize. */
buf = malloc(hashsize);
if (!buf) {
log_error("rsa_sig_encode_hash: malloc (%lu) failed",
(unsigned long)hashsize);
RSA_free(sent_key);
return -1;
}
if (ike_auth_hash(exchange, buf) == -1) {
free(buf);
RSA_free(sent_key);
return -1;
}
snprintf(header, sizeof header, "rsa_sig_encode_hash: HASH_%c",
initiator ? 'I' : 'R');
LOG_DBG_BUF((LOG_MISC, 80, header, buf, hashsize));
data = malloc(RSA_size(sent_key));
if (!data) {
log_error("rsa_sig_encode_hash: malloc (%d) failed",
RSA_size(sent_key));
free(buf);
RSA_free(sent_key);
return -1;
}
sigsize = RSA_private_encrypt(hashsize, buf, data, sent_key,
RSA_PKCS1_PADDING);
if (sigsize == -1) {
log_print("rsa_sig_encode_hash: "
"RSA_private_encrypt () failed");
free(data);
free(buf);
RSA_free(sent_key);
return -1;
}
datalen = (u_int32_t) sigsize;
free(buf);
RSA_free(sent_key);
buf = realloc(data, ISAKMP_SIG_SZ + datalen);
if (!buf) {
log_error("rsa_sig_encode_hash: realloc (%p, %d) failed", data,
ISAKMP_SIG_SZ + datalen);
free(data);
return -1;
}
memmove(buf + ISAKMP_SIG_SZ, buf, datalen);
snprintf(header, sizeof header, "rsa_sig_encode_hash: SIG_%c",
initiator ? 'I' : 'R');
LOG_DBG_BUF((LOG_MISC, 80, header, buf + ISAKMP_SIG_DATA_OFF,
datalen));
if (message_add_payload(msg, ISAKMP_PAYLOAD_SIG, buf,
ISAKMP_SIG_SZ + datalen, 1)) {
free(buf);
return -1;
}
return 0;
}
int
ike_auth_hash(struct exchange *exchange, u_int8_t *buf)
{
struct ipsec_exch *ie = exchange->data;
struct prf *prf;
struct hash *hash = ie->hash;
int initiator = exchange->initiator;
u_int8_t *id;
size_t id_len;
/* Choose the right fields to fill-in. */
id = initiator ? exchange->id_i : exchange->id_r;
id_len = initiator ? exchange->id_i_len : exchange->id_r_len;
/* Allocate the prf and start calculating our HASH. */
prf = prf_alloc(ie->prf_type, hash->type, ie->skeyid, ie->skeyid_len);
if (!prf)
return -1;
prf->Init(prf->prfctx);
prf->Update(prf->prfctx, initiator ? ie->g_xi : ie->g_xr, ie->g_x_len);
prf->Update(prf->prfctx, initiator ? ie->g_xr : ie->g_xi, ie->g_x_len);
prf->Update(prf->prfctx, exchange->cookies +
(initiator ? ISAKMP_HDR_ICOOKIE_OFF : ISAKMP_HDR_RCOOKIE_OFF),
ISAKMP_HDR_ICOOKIE_LEN);
prf->Update(prf->prfctx, exchange->cookies +
(initiator ? ISAKMP_HDR_RCOOKIE_OFF : ISAKMP_HDR_ICOOKIE_OFF),
ISAKMP_HDR_ICOOKIE_LEN);
prf->Update(prf->prfctx, ie->sa_i_b, ie->sa_i_b_len);
prf->Update(prf->prfctx, id, id_len);
prf->Final(buf, prf->prfctx);
prf_free(prf);
return 0;
}
static int
get_raw_key_from_file(int type, u_int8_t *id, size_t id_len, RSA **rsa)
{
char filename[FILENAME_MAX];
char *fstr;
FILE *keyfp;
if (type != IKE_AUTH_RSA_SIG) { /* XXX More types? */
LOG_DBG((LOG_NEGOTIATION, 20, "get_raw_key_from_file: "
"invalid auth type %d\n", type));
return -1;
}
*rsa = 0;
fstr = conf_get_str("General", "Pubkey-directory");
if (!fstr)
fstr = CONF_DFLT_PUBKEY_DIR;
if (snprintf(filename, sizeof filename, "%s/", fstr) >
(int)sizeof filename - 1)
return -1;
fstr = ipsec_id_string(id, id_len);
if (!fstr) {
LOG_DBG((LOG_NEGOTIATION, 50, "get_raw_key_from_file: "
"ipsec_id_string failed"));
return -1;
}
strlcat(filename, fstr, sizeof filename - strlen(filename));
free(fstr);
/* If the file does not exist, fail silently. */
keyfp = monitor_fopen(filename, "r");
if (keyfp) {
*rsa = PEM_read_RSA_PUBKEY(keyfp, NULL, NULL, NULL);
if (!*rsa) {
rewind(keyfp);
*rsa = PEM_read_RSAPublicKey(keyfp, NULL, NULL, NULL);
}
if (!*rsa)
log_print("get_raw_key_from_file: failed to get "
"public key %s", filename);
fclose(keyfp);
} else if (errno != ENOENT) {
log_error("get_raw_key_from_file: monitor_fopen "
"(\"%s\", \"r\") failed", filename);
return -1;
} else
LOG_DBG((LOG_NEGOTIATION, 50,
"get_raw_key_from_file: file %s not found", filename));
return (*rsa ? 0 : -1);
}
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