- import of strongswan-2.7.0

- applied patch for charon
2006-04-28 07:14:48 +00:00
parent 52923c9acb
commit 997358a6c4
2043 changed files with 346842 additions and 0 deletions
@@ -0,0 +1,459 @@
+/* IKE modular algorithm handling interface
+ * Author: JuanJo Ciarlante <[email protected]>
+ *
+ * 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.
+ *
+ * RCSID $Id: ike_alg.c,v 1.6 2004/09/17 21:29:50 as Exp $
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/queue.h>
+
+#include <freeswan.h>
+#include <freeswan/ipsec_policy.h>
+
+#include "constants.h"
+#include "defs.h"
+#include "sha1.h"
+#include "md5.h"
+#include "crypto.h"
+
+#include "state.h"
+#include "packet.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)
+{
+    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->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_encrypter(u_int alg)
+{
+    return (struct encrypt_desc *) ike_alg_find(IKE_ALG_ENCRYPT, alg, 0);
+}
+
+/*
+ * check if IKE hash algorithm is present
+ */
+bool
+ike_alg_hash_present(u_int halg)
+{
+    return ike_alg_get_hasher(halg) != NULL;
+}
+
+/*
+ * check if IKE encryption algorithm is present
+ */
+bool
+ike_alg_enc_present(u_int ealg)
+{
+    return ike_alg_get_encrypter(ealg) != NULL;
+}
+
+/*
+ * Validate and register IKE hash algorithm object
+ */
+int
+ike_alg_register_hash(struct hash_desc *hash_desc)
+{
+    const char *alg_name = NULL;
+    int ret = 0;
+
+    if (hash_desc->algo_id > OAKLEY_HASH_MAX)
+    {
+	plog ("ike_alg: hash alg=%d > max=%d"
+		, hash_desc->algo_id, OAKLEY_HASH_MAX);
+	return_on(ret,-EINVAL);
+    }
+
+    if (hash_desc->hash_ctx_size > sizeof (union hash_ctx))
+    {
+	plog ("ike_alg: hash alg=%d has ctx_size=%d > hash_ctx=%d"
+	      , hash_desc->algo_id
+	      , (int)hash_desc->hash_ctx_size
+	      , (int)sizeof (union hash_ctx));
+	return_on(ret,-EOVERFLOW);
+    }
+
+    if (!(hash_desc->hash_init && hash_desc->hash_update && hash_desc->hash_final))
+    {
+	plog ("ike_alg: hash alg=%d needs hash_init(), hash_update() and hash_final()"
+	      , hash_desc->algo_id);
+	return_on(ret,-EINVAL);
+    }
+	
+    alg_name = enum_name(&oakley_hash_names, hash_desc->algo_id);
+    if (!alg_name)
+    {
+	plog ("ike_alg: hash alg=%d not found in constants.c:oakley_hash_names"
+	      , hash_desc->algo_id);
+	alg_name = "<NULL>";
+    }
+
+return_out:
+    if (ret == 0)
+	ret = ike_alg_add((struct ike_alg *)hash_desc);
+
+    plog("ike_alg: Activating %s hash: %s"
+	,alg_name, ret == 0 ? "Ok" : "FAILED");
+
+    return ret;
+}
+
+/*
+ * Validate and register IKE encryption algorithm object
+ */
+int
+ike_alg_register_enc(struct encrypt_desc *enc_desc)
+{
+    int ret = ike_alg_add((struct ike_alg *)enc_desc);
+
+    const char *alg_name = enum_name(&oakley_enc_names, enc_desc->algo_id);
+
+    char alg_number[20];
+    
+    /* algorithm is not listed in oakley_enc_names */
+    if (alg_name == NULL)
+    {
+	snprintf(alg_number, sizeof(alg_number), "OAKLEY_ID_%d"
+	    , enc_desc->algo_id);
+	alg_name = alg_number;
+    }
+
+    plog("ike_alg: Activating %s encryption: %s"
+	, alg_name, ret == 0 ? "Ok" : "FAILED");
+
+    return ret;
+}
+
+/*
+ * Get pfsgroup for this connection
+ */
+const struct oakley_group_desc *
+ike_alg_pfsgroup(struct connection *c, lset_t policy)
+{
+    const struct oakley_group_desc * ret = NULL;
+
+    if ((policy & POLICY_PFS)
+    && c->alg_info_esp
+    && c->alg_info_esp->esp_pfsgroup)
+	ret = lookup_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(struct alg_info_ike *ai , lset_t policy)
+{
+    struct db_context *db_ctx = NULL;
+    struct ike_info *ike_info;
+    u_int ealg, halg, modp, eklen = 0;
+    struct encrypt_desc *enc_desc;
+    int i;
+
+    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_enc_present(ealg))
+	{
+	    DBG_log("ike_alg: ike enc ealg=%d not present"
+		    , ealg);
+	    continue;
+	}
+
+	if (!ike_alg_hash_present(halg)) 
+	{
+	    DBG_log("ike_alg: ike hash halg=%d not present"
+		    , halg);
+	    continue;
+	}
+
+	enc_desc = ike_alg_get_encrypter(ealg);
+	passert(enc_desc != NULL);
+
+	if (eklen
+	&& (eklen < enc_desc->keyminlen || eklen >  enc_desc->keymaxlen))
+	{
+	    DBG_log("ike_alg: ealg=%d (specified) keylen:%d, not valid min=%d, max=%d"
+		    , ealg
+		    , eklen
+		    , enc_desc->keyminlen
+		    , enc_desc->keymaxlen
+	    );
+	    continue;
+	}
+
+	if (policy & POLICY_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, OAKLEY_RSA_SIG);
+	    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 (ike_info->ike_eklen)
+		db_attr_add_values(db_ctx, OAKLEY_KEY_LENGTH, ike_info->ike_eklen);
+	    db_attr_add_values(db_ctx, OAKLEY_AUTHENTICATION_METHOD, OAKLEY_PRESHARED_KEY);
+	    db_attr_add_values(db_ctx, OAKLEY_GROUP_DESCRIPTION, modp);
+	}
+    }
+fail:
+    return db_ctx;
+}
+
+/*
+ * Show registered IKE algorithms
+ */
+void
+ike_alg_list(void)
+{
+    u_int i;
+    struct ike_alg *a;
+
+    whack_log(RC_COMMENT, " ");
+    whack_log(RC_COMMENT, "List of registered IKE Encryption Algorithms:");
+    whack_log(RC_COMMENT, " ");
+
+    for (a = ike_alg_base[IKE_ALG_ENCRYPT]; a != NULL; a = a->algo_next)
+    {
+        struct encrypt_desc *desc = (struct encrypt_desc*)a;
+
+	whack_log(RC_COMMENT, "#%-5d %s, blocksize: %d, keylen: %d-%d-%d"
+	    , a->algo_id
+	    , enum_name(&oakley_enc_names, a->algo_id)
+	    , (int)desc->enc_blocksize*BITS_PER_BYTE
+	    , desc->keyminlen
+	    , desc->keydeflen
+	    , desc->keymaxlen
+	);
+    }
+
+    whack_log(RC_COMMENT, " ");
+    whack_log(RC_COMMENT, "List of registered IKE Hash Algorithms:");
+    whack_log(RC_COMMENT, " ");
+
+    for (a = ike_alg_base[IKE_ALG_HASH]; a != NULL; a = a->algo_next)
+    {
+	whack_log(RC_COMMENT, "#%-5d %s, hashsize: %d"
+	    , a->algo_id
+	    , enum_name(&oakley_hash_names, a->algo_id)
+	    , (int)((struct hash_desc *)a)->hash_digest_size*BITS_PER_BYTE
+	);
+    }
+
+    whack_log(RC_COMMENT, " ");
+    whack_log(RC_COMMENT, "List of registered IKE DH Groups:");
+    whack_log(RC_COMMENT, " ");
+
+    for (i = 0; i < elemsof(oakley_group); i++)
+    {
+	const struct oakley_group_desc *gdesc=oakley_group + i;
+
+	whack_log(RC_COMMENT, "#%-5d %s, groupsize: %d"
+	    , gdesc->group
+	    , enum_name(&oakley_group_names, gdesc->group)
+	    , (int)gdesc->bytes*BITS_PER_BYTE
+	);
+    }
+}
+
+/*  Show IKE algorithms for
+ *    - this connection (result from ike= string)
+ *    - newest SA
+ */
+void
+ike_alg_show_connection(struct connection *c, const char *instance)
+{
+    char buf[256];
+    struct state *st;
+
+    if (c->alg_info_ike)
+    {
+	alg_info_snprint(buf, sizeof(buf)-1, (struct alg_info *)c->alg_info_ike);
+	whack_log(RC_COMMENT
+		, "\"%s\"%s:   IKE algorithms wanted: %s"
+		, c->name
+		, instance
+		, buf
+	);
+
+	alg_info_snprint_ike(buf, sizeof(buf)-1, c->alg_info_ike);
+	whack_log(RC_COMMENT
+		, "\"%s\"%s:   IKE algorithms found:  %s"
+		, c->name
+		, instance
+		, buf
+	);
+    }
+
+    st = state_with_serialno(c->newest_isakmp_sa);
+    if (st)
+	whack_log(RC_COMMENT
+		, "\"%s\"%s:   IKE algorithm newest: %s_%d-%s-%s"
+		, c->name
+		, instance
+		, enum_show(&oakley_enc_names, st->st_oakley.encrypt)
+		+7 /* strlen("OAKLEY_") */
+		/* , st->st_oakley.encrypter->keydeflen */
+		, st->st_oakley.enckeylen
+		, enum_show(&oakley_hash_names, st->st_oakley.hash)
+		+7 /* strlen("OAKLEY_") */
+		, enum_show(&oakley_group_names, st->st_oakley.group->group)
+		+13 /* strlen("OAKLEY_GROUP_") */
+	);
+}
+
+/*
+ * 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;
+}
+