eap_ikev2_common.c

Go to the documentation of this file.

/*
 * EAP-IKEv2 common routines
 * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eap_defs.h"
#include "eap_common.h"
#include "ikev2_common.h"
#include "eap_ikev2_common.h"


int eap_ikev2_derive_keymat(int prf, struct ikev2_keys *keys,
                            const u8 *i_nonce, size_t i_nonce_len,
                            const u8 *r_nonce, size_t r_nonce_len,
                            u8 *keymat)
{
        u8 *nonces;
        size_t nlen;

        /* KEYMAT = prf+(SK_d, Ni | Nr) */
        if (keys->SK_d == NULL || i_nonce == NULL || r_nonce == NULL)
                return -1;

        nlen = i_nonce_len + r_nonce_len;
        nonces = os_malloc(nlen);
        if (nonces == NULL)
                return -1;
        os_memcpy(nonces, i_nonce, i_nonce_len);
        os_memcpy(nonces + i_nonce_len, r_nonce, r_nonce_len);

        if (ikev2_prf_plus(prf, keys->SK_d, keys->SK_d_len, nonces, nlen,
                           keymat, EAP_MSK_LEN + EAP_EMSK_LEN)) {
                os_free(nonces);
                return -1;
        }
        os_free(nonces);

        wpa_hexdump_key(MSG_DEBUG, "EAP-IKEV2: KEYMAT",
                        keymat, EAP_MSK_LEN + EAP_EMSK_LEN);

        return 0;
}


struct wpabuf * eap_ikev2_build_frag_ack(u8 id, u8 code)
{
        struct wpabuf *msg;

#ifdef CCNS_PL
        msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, 1, code, id);
        if (msg == NULL) {
                wpa_printf(MSG_ERROR, "EAP-IKEV2: Failed to allocate memory "
                           "for fragment ack");
                return NULL;
        }
        wpabuf_put_u8(msg, 0); /* Flags */
#else /* CCNS_PL */
        msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, 0, code, id);
        if (msg == NULL) {
                wpa_printf(MSG_ERROR, "EAP-IKEV2: Failed to allocate memory "
                           "for fragment ack");
                return NULL;
        }
#endif /* CCNS_PL */

        wpa_printf(MSG_DEBUG, "EAP-IKEV2: Send fragment ack");

        return msg;
}


int eap_ikev2_validate_icv(int integ_alg, struct ikev2_keys *keys,
                           int initiator, const struct wpabuf *msg,
                           const u8 *pos, const u8 *end)
{
        const struct ikev2_integ_alg *integ;
        size_t icv_len;
        u8 icv[IKEV2_MAX_HASH_LEN];
        const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;

        integ = ikev2_get_integ(integ_alg);
        if (integ == NULL) {
                wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
                           "transform / cannot validate ICV");
                return -1;
        }
        icv_len = integ->hash_len;

        if (end - pos < (int) icv_len) {
                wpa_printf(MSG_DEBUG, "EAP-IKEV2: Not enough room in the "
                           "message for Integrity Checksum Data");
                return -1;
        }

        if (SK_a == NULL) {
                wpa_printf(MSG_DEBUG, "EAP-IKEV2: No SK_a for ICV validation");
                return -1;
        }

        if (ikev2_integ_hash(integ_alg, SK_a, keys->SK_integ_len,
                             wpabuf_head(msg),
                             wpabuf_len(msg) - icv_len, icv) < 0) {
                wpa_printf(MSG_INFO, "EAP-IKEV2: Could not calculate ICV");
                return -1;
        }

        if (os_memcmp(icv, end - icv_len, icv_len) != 0) {
                wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid ICV");
                wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Calculated ICV",
                            icv, icv_len);
                wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Received ICV",
                            end - icv_len, icv_len);
                return -1;
        }

        wpa_printf(MSG_DEBUG, "EAP-IKEV2: Valid Integrity Checksum Data in "
                   "the received message");

        return icv_len;
}