strongswan/src/pluto/ike_alg.c

453 lines
11 KiB
C

/* IKE modular algorithm handling interface
* Copyright (C) JuanJo Ciarlante <jjo-ipsec@mendoza.gov.ar>
* Copyright (C) 2009 Andreas Steffen - Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/queue.h>
#include <freeswan.h>
#include <library.h>
#include <debug.h>
#include <credentials/keys/public_key.h>
#include <credentials/keys/private_key.h>
#include <crypto/hashers/hasher.h>
#include <crypto/crypters/crypter.h>
#include <crypto/prfs/prf.h>
#include "constants.h"
#include "defs.h"
#include "crypto.h"
#include "state.h"
#include "packet.h"
#include "keys.h"
#include "log.h"
#include "whack.h"
#include "spdb.h"
#include "alg_info.h"
#include "ike_alg.h"
#include "db_ops.h"
#include "connections.h"
#include "kernel.h"
#define return_on(var, val) do { var=val;goto return_out; } while(0);
/**
* IKE algorithm list handling - registration and lookup
*/
/* Modular IKE algorithm storage structure */
static struct ike_alg *ike_alg_base[IKE_ALG_MAX+1] = {NULL, NULL};
/**
* Return ike_algo object by {type, id}
*/
static struct ike_alg *ike_alg_find(u_int algo_type, u_int algo_id,
u_int keysize __attribute__((unused)))
{
struct ike_alg *e = ike_alg_base[algo_type];
while (e != NULL && algo_id > e->algo_id)
{
e = e->algo_next;
}
return (e != NULL && e->algo_id == algo_id) ? e : NULL;
}
/**
* "raw" ike_alg list adding function
*/
int ike_alg_add(struct ike_alg* a, const char *plugin_name)
{
if (a->algo_type > IKE_ALG_MAX)
{
plog("ike_alg: Not added, invalid algorithm type");
return -EINVAL;
}
if (ike_alg_find(a->algo_type, a->algo_id, 0) != NULL)
{
plog("ike_alg: Not added, algorithm already exists");
return -EEXIST;
}
{
struct ike_alg **ep = &ike_alg_base[a->algo_type];
struct ike_alg *e = *ep;
while (e != NULL && a->algo_id > e->algo_id)
{
ep = &e->algo_next;
e = *ep;
}
*ep = a;
a->plugin_name = plugin_name;
a->algo_next = e;
return 0;
}
}
/**
* Get IKE hash algorithm
*/
struct hash_desc *ike_alg_get_hasher(u_int alg)
{
return (struct hash_desc *) ike_alg_find(IKE_ALG_HASH, alg, 0);
}
/**
* Get IKE encryption algorithm
*/
struct encrypt_desc *ike_alg_get_crypter(u_int alg)
{
return (struct encrypt_desc *) ike_alg_find(IKE_ALG_ENCRYPT, alg, 0);
}
/**
* Get IKE dh group
*/
struct dh_desc *ike_alg_get_dh_group(u_int alg)
{
return (struct dh_desc *) ike_alg_find(IKE_ALG_DH_GROUP, alg, 0);
}
/**
* Get pfsgroup for this connection
*/
const struct dh_desc *ike_alg_pfsgroup(connection_t *c, lset_t policy)
{
const struct dh_desc *ret = NULL;
if ((policy & POLICY_PFS) &&
c->alg_info_esp && c->alg_info_esp->esp_pfsgroup)
{
ret = ike_alg_get_dh_group(c->alg_info_esp->esp_pfsgroup);
}
return ret;
}
/**
* Create an OAKLEY proposal based on alg_info and policy
*/
struct db_context *ike_alg_db_new(connection_t *c, lset_t policy)
{
struct alg_info_ike *ai = c->alg_info_ike;
struct db_context *db_ctx = NULL;
struct ike_info *ike_info;
u_int ealg, halg, modp, eklen = 0;
int i;
bool is_xauth_server = (policy & POLICY_XAUTH_SERVER) != LEMPTY;
if (!ai)
{
whack_log(RC_LOG_SERIOUS, "no IKE algorithms "
"for this connection "
"(check ike algorithm string)");
goto fail;
}
policy &= POLICY_ID_AUTH_MASK;
db_ctx = db_prop_new(PROTO_ISAKMP, 8, 8 * 5);
/* for each group */
ALG_INFO_IKE_FOREACH(ai, ike_info, i)
{
ealg = ike_info->ike_ealg;
halg = ike_info->ike_halg;
modp = ike_info->ike_modp;
eklen= ike_info->ike_eklen;
if (!ike_alg_get_crypter(ealg))
{
plog("ike alg: crypter %s not present",
enum_show(&oakley_enc_names, ealg));
continue;
}
if (!ike_alg_get_hasher(halg))
{
plog("ike alg: hasher %s not present",
enum_show(&oakley_hash_names, halg));
continue;
}
if (!ike_alg_get_dh_group(modp))
{
plog("ike alg: dh group %s not present",
enum_show(&oakley_group_names, modp));
continue;
}
if (policy & POLICY_PUBKEY)
{
int auth_method = 0, key_size = 0;
key_type_t key_type = KEY_ANY;
if (c->spd.this.cert)
{
certificate_t *certificate = c->spd.this.cert->cert;
public_key_t *key = certificate->get_public_key(certificate);
if (key == NULL)
{
plog("ike alg: unable to retrieve my public key");
continue;
}
key_type = key->get_type(key);
key_size = key->get_keysize(key);
key->destroy(key);
}
else
{
private_key_t *key = get_private_key(c);
if (key == NULL)
{
plog("ike alg: unable to retrieve my private key");
continue;
}
key_type = key->get_type(key);
key_size = key->get_keysize(key);
}
switch (key_type)
{
case KEY_RSA:
auth_method = OAKLEY_RSA_SIG;
break;
case KEY_ECDSA:
switch (key_size)
{
case 256:
auth_method = OAKLEY_ECDSA_256;
break;
case 384:
auth_method = OAKLEY_ECDSA_384;
break;
case 521:
auth_method = OAKLEY_ECDSA_521;
break;
default:
continue;
}
break;
default:
continue;
}
db_trans_add(db_ctx, KEY_IKE);
db_attr_add_values(db_ctx, OAKLEY_ENCRYPTION_ALGORITHM, ealg);
db_attr_add_values(db_ctx, OAKLEY_HASH_ALGORITHM, halg);
if (eklen)
{
db_attr_add_values(db_ctx, OAKLEY_KEY_LENGTH, eklen);
}
db_attr_add_values(db_ctx, OAKLEY_AUTHENTICATION_METHOD, auth_method);
db_attr_add_values(db_ctx, OAKLEY_GROUP_DESCRIPTION, modp);
}
if (policy & POLICY_PSK)
{
db_trans_add(db_ctx, KEY_IKE);
db_attr_add_values(db_ctx, OAKLEY_ENCRYPTION_ALGORITHM, ealg);
db_attr_add_values(db_ctx, OAKLEY_HASH_ALGORITHM, halg);
if (eklen)
{
db_attr_add_values(db_ctx, OAKLEY_KEY_LENGTH, eklen);
}
db_attr_add_values(db_ctx, OAKLEY_AUTHENTICATION_METHOD, OAKLEY_PRESHARED_KEY);
db_attr_add_values(db_ctx, OAKLEY_GROUP_DESCRIPTION, modp);
}
if (policy & POLICY_XAUTH_RSASIG)
{
db_trans_add(db_ctx, KEY_IKE);
db_attr_add_values(db_ctx, OAKLEY_ENCRYPTION_ALGORITHM, ealg);
db_attr_add_values(db_ctx, OAKLEY_HASH_ALGORITHM, halg);
if (eklen)
{
db_attr_add_values(db_ctx, OAKLEY_KEY_LENGTH, eklen);
}
db_attr_add_values(db_ctx, OAKLEY_AUTHENTICATION_METHOD
, is_xauth_server ? XAUTHRespRSA : XAUTHInitRSA);
db_attr_add_values(db_ctx, OAKLEY_GROUP_DESCRIPTION, modp);
}
if (policy & POLICY_XAUTH_PSK)
{
db_trans_add(db_ctx, KEY_IKE);
db_attr_add_values(db_ctx, OAKLEY_ENCRYPTION_ALGORITHM, ealg);
db_attr_add_values(db_ctx, OAKLEY_HASH_ALGORITHM, halg);
if (eklen)
{
db_attr_add_values(db_ctx, OAKLEY_KEY_LENGTH, eklen);
}
db_attr_add_values(db_ctx, OAKLEY_AUTHENTICATION_METHOD
, is_xauth_server ? XAUTHRespPreShared : XAUTHInitPreShared);
db_attr_add_values(db_ctx, OAKLEY_GROUP_DESCRIPTION, modp);
}
}
fail:
return db_ctx;
}
/**
* Print the name of an algorithm plus the name of the plugin that registered it
*/
static void print_alg(char *buf, int *len, enum_names *alg_names, int alg_type,
const char *plugin_name)
{
char alg_name[BUF_LEN];
int alg_name_len;
alg_name_len = sprintf(alg_name, " %s[%s]", enum_name(alg_names, alg_type),
plugin_name);
if (*len + alg_name_len > CRYPTO_MAX_ALG_LINE)
{
whack_log(RC_COMMENT, "%s", buf);
*len = sprintf(buf, " ");
}
sprintf(buf + *len, "%s", alg_name);
*len += alg_name_len;
}
/**
* Show registered IKE algorithms
*/
void ike_alg_list(void)
{
rng_quality_t quality;
enumerator_t *enumerator;
const char *plugin_name;
char buf[BUF_LEN];
int len;
struct ike_alg *a;
whack_log(RC_COMMENT, " ");
whack_log(RC_COMMENT, "List of registered IKEv1 Algorithms:");
whack_log(RC_COMMENT, " ");
len = sprintf(buf, " encryption:");
for (a = ike_alg_base[IKE_ALG_ENCRYPT]; a != NULL; a = a->algo_next)
{
print_alg(buf, &len, &oakley_enc_names, a->algo_id, a->plugin_name);
}
whack_log(RC_COMMENT, "%s", buf);
len = sprintf(buf, " integrity: ");
for (a = ike_alg_base[IKE_ALG_HASH]; a != NULL; a = a->algo_next)
{
print_alg(buf, &len, &oakley_hash_names, a->algo_id, a->plugin_name);
}
whack_log(RC_COMMENT, "%s", buf);
len = sprintf(buf, " dh-group: ");
for (a = ike_alg_base[IKE_ALG_DH_GROUP]; a != NULL; a = a->algo_next)
{
print_alg(buf, &len, &oakley_group_names, a->algo_id, a->plugin_name);
}
whack_log(RC_COMMENT, "%s", buf);
len = sprintf(buf, " random-gen:");
enumerator = lib->crypto->create_rng_enumerator(lib->crypto);
while (enumerator->enumerate(enumerator, &quality, &plugin_name))
{
len += sprintf(buf + len, " %N[%s]", rng_quality_names, quality,
plugin_name);
}
enumerator->destroy(enumerator);
whack_log(RC_COMMENT, "%s", buf);
}
/**
* Show IKE algorithms for this connection (result from ike= string)
* and newest SA
*/
void ike_alg_show_connection(connection_t *c, const char *instance)
{
struct state *st = state_with_serialno(c->newest_isakmp_sa);
if (st)
{
if (st->st_oakley.encrypt == OAKLEY_3DES_CBC)
{
whack_log(RC_COMMENT,
"\"%s\"%s: IKE proposal: %s/%s/%s",
c->name, instance,
enum_show(&oakley_enc_names, st->st_oakley.encrypt),
enum_show(&oakley_hash_names, st->st_oakley.hash),
enum_show(&oakley_group_names, st->st_oakley.group->algo_id)
);
}
else
{
whack_log(RC_COMMENT,
"\"%s\"%s: IKE proposal: %s_%u/%s/%s",
c->name, instance,
enum_show(&oakley_enc_names, st->st_oakley.encrypt),
st->st_oakley.enckeylen,
enum_show(&oakley_hash_names, st->st_oakley.hash),
enum_show(&oakley_group_names, st->st_oakley.group->algo_id)
);
}
}
}
/**
* ML: make F_STRICT logic consider enc,hash/auth,modp algorithms
*/
bool ike_alg_ok_final(u_int ealg, u_int key_len, u_int aalg, u_int group,
struct alg_info_ike *alg_info_ike)
{
/*
* simple test to discard low key_len, will accept it only
* if specified in "esp" string
*/
bool ealg_insecure = (key_len < 128);
if (ealg_insecure
|| (alg_info_ike && alg_info_ike->alg_info_flags & ALG_INFO_F_STRICT))
{
int i;
struct ike_info *ike_info;
if (alg_info_ike)
{
ALG_INFO_IKE_FOREACH(alg_info_ike, ike_info, i)
{
if (ike_info->ike_ealg == ealg
&& (ike_info->ike_eklen == 0 || key_len == 0 || ike_info->ike_eklen == key_len)
&& ike_info->ike_halg == aalg
&& ike_info->ike_modp == group)
{
if (ealg_insecure)
loglog(RC_LOG_SERIOUS, "You should NOT use insecure IKE algorithms (%s)!"
, enum_name(&oakley_enc_names, ealg));
return TRUE;
}
}
}
plog("Oakley Transform [%s (%d), %s, %s] refused due to %s"
, enum_name(&oakley_enc_names, ealg), key_len
, enum_name(&oakley_hash_names, aalg)
, enum_name(&oakley_group_names, group)
, ealg_insecure ?
"insecure key_len and enc. alg. not listed in \"ike\" string" : "strict flag"
);
return FALSE;
}
return TRUE;
}