506 lines
12 KiB
C
506 lines
12 KiB
C
/*
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* EAP-IKEv2 peer (RFC 5106)
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* Copyright (c) 2007, Jouni Malinen <j@w1.fi>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Alternatively, this software may be distributed under the terms of BSD
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* license.
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*
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* See README and COPYING for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "eap_i.h"
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#include "eap_common/eap_ikev2_common.h"
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#include "ikev2.h"
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struct eap_ikev2_data {
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struct ikev2_responder_data ikev2;
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enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
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struct wpabuf *in_buf;
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struct wpabuf *out_buf;
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size_t out_used;
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size_t fragment_size;
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int keys_ready;
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u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
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int keymat_ok;
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};
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static const char * eap_ikev2_state_txt(int state)
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{
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switch (state) {
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case WAIT_START:
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return "WAIT_START";
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case PROC_MSG:
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return "PROC_MSG";
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case WAIT_FRAG_ACK:
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return "WAIT_FRAG_ACK";
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case DONE:
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return "DONE";
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case FAIL:
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return "FAIL";
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default:
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return "?";
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}
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}
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static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
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{
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
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eap_ikev2_state_txt(data->state),
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eap_ikev2_state_txt(state));
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data->state = state;
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}
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static void * eap_ikev2_init(struct eap_sm *sm)
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{
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struct eap_ikev2_data *data;
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const u8 *identity, *password;
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size_t identity_len, password_len;
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identity = eap_get_config_identity(sm, &identity_len);
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if (identity == NULL) {
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wpa_printf(MSG_INFO, "EAP-IKEV2: No identity available");
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return NULL;
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}
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data = os_zalloc(sizeof(*data));
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if (data == NULL)
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return NULL;
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data->state = WAIT_START;
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data->fragment_size = IKEV2_FRAGMENT_SIZE;
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data->ikev2.state = SA_INIT;
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data->ikev2.peer_auth = PEER_AUTH_SECRET;
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data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
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if (data->ikev2.key_pad == NULL)
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goto failed;
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data->ikev2.key_pad_len = 21;
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data->ikev2.IDr = os_malloc(identity_len);
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if (data->ikev2.IDr == NULL)
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goto failed;
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os_memcpy(data->ikev2.IDr, identity, identity_len);
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data->ikev2.IDr_len = identity_len;
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password = eap_get_config_password(sm, &password_len);
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if (password) {
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data->ikev2.shared_secret = os_malloc(password_len);
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if (data->ikev2.shared_secret == NULL)
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goto failed;
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os_memcpy(data->ikev2.shared_secret, password, password_len);
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data->ikev2.shared_secret_len = password_len;
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}
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return data;
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failed:
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ikev2_responder_deinit(&data->ikev2);
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os_free(data);
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return NULL;
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}
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static void eap_ikev2_deinit(struct eap_sm *sm, void *priv)
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{
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struct eap_ikev2_data *data = priv;
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wpabuf_free(data->in_buf);
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wpabuf_free(data->out_buf);
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ikev2_responder_deinit(&data->ikev2);
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os_free(data);
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}
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static int eap_ikev2_peer_keymat(struct eap_ikev2_data *data)
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{
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if (eap_ikev2_derive_keymat(
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data->ikev2.proposal.prf, &data->ikev2.keys,
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data->ikev2.i_nonce, data->ikev2.i_nonce_len,
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data->ikev2.r_nonce, data->ikev2.r_nonce_len,
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data->keymat) < 0) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
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"derive key material");
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return -1;
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}
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data->keymat_ok = 1;
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return 0;
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}
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static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data,
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struct eap_method_ret *ret, u8 id)
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{
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struct wpabuf *resp;
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u8 flags;
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size_t send_len, plen, icv_len = 0;
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ret->ignore = FALSE;
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Response");
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ret->allowNotifications = TRUE;
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flags = 0;
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send_len = wpabuf_len(data->out_buf) - data->out_used;
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if (1 + send_len > data->fragment_size) {
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send_len = data->fragment_size - 1;
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flags |= IKEV2_FLAGS_MORE_FRAGMENTS;
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if (data->out_used == 0) {
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flags |= IKEV2_FLAGS_LENGTH_INCLUDED;
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send_len -= 4;
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}
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}
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#ifdef CCNS_PL
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/* Some issues figuring out the length of the message if Message Length
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* field not included?! */
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if (!(flags & IKEV2_FLAGS_LENGTH_INCLUDED))
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flags |= IKEV2_FLAGS_LENGTH_INCLUDED;
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#endif /* CCNS_PL */
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plen = 1 + send_len;
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if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
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plen += 4;
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if (data->keys_ready) {
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const struct ikev2_integ_alg *integ;
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
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"Data");
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flags |= IKEV2_FLAGS_ICV_INCLUDED;
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integ = ikev2_get_integ(data->ikev2.proposal.integ);
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if (integ == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
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"transform / cannot generate ICV");
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return NULL;
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}
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icv_len = integ->hash_len;
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plen += icv_len;
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}
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resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
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EAP_CODE_RESPONSE, id);
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if (resp == NULL)
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return NULL;
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wpabuf_put_u8(resp, flags); /* Flags */
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if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
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wpabuf_put_be32(resp, wpabuf_len(data->out_buf));
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wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
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send_len);
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data->out_used += send_len;
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if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
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const u8 *msg = wpabuf_head(resp);
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size_t len = wpabuf_len(resp);
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ikev2_integ_hash(data->ikev2.proposal.integ,
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data->ikev2.keys.SK_ar,
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data->ikev2.keys.SK_integ_len,
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msg, len, wpabuf_put(resp, icv_len));
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}
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ret->methodState = METHOD_MAY_CONT;
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ret->decision = DECISION_FAIL;
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if (data->out_used == wpabuf_len(data->out_buf)) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
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"(message sent completely)",
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(unsigned long) send_len);
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wpabuf_free(data->out_buf);
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data->out_buf = NULL;
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data->out_used = 0;
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switch (data->ikev2.state) {
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case SA_AUTH:
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/* SA_INIT was sent out, so message have to be
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* integrity protected from now on. */
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data->keys_ready = 1;
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break;
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case IKEV2_DONE:
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ret->methodState = METHOD_DONE;
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if (data->state == FAIL)
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break;
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ret->decision = DECISION_COND_SUCC;
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
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"completed successfully");
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if (eap_ikev2_peer_keymat(data))
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break;
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eap_ikev2_state(data, DONE);
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break;
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case IKEV2_FAILED:
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
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"failed");
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ret->methodState = METHOD_DONE;
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ret->decision = DECISION_FAIL;
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break;
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default:
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break;
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}
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} else {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
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"(%lu more to send)", (unsigned long) send_len,
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(unsigned long) wpabuf_len(data->out_buf) -
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data->out_used);
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eap_ikev2_state(data, WAIT_FRAG_ACK);
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}
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return resp;
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}
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static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
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const struct wpabuf *reqData,
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u8 flags, const u8 *pos, const u8 **end)
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{
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if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
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int icv_len = eap_ikev2_validate_icv(
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data->ikev2.proposal.integ, &data->ikev2.keys, 1,
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reqData, pos, *end);
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if (icv_len < 0)
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return -1;
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/* Hide Integrity Checksum Data from further processing */
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*end -= icv_len;
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} else if (data->keys_ready) {
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wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
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"included integrity checksum");
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return -1;
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}
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return 0;
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}
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static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
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const u8 *buf, size_t len)
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{
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/* Process continuation of a pending message */
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if (len > wpabuf_tailroom(data->in_buf)) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
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eap_ikev2_state(data, FAIL);
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return -1;
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}
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wpabuf_put_data(data->in_buf, buf, len);
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting "
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"for %lu bytes more", (unsigned long) len,
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(unsigned long) wpabuf_tailroom(data->in_buf));
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return 0;
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}
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static struct wpabuf * eap_ikev2_process_fragment(struct eap_ikev2_data *data,
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struct eap_method_ret *ret,
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u8 id, u8 flags,
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u32 message_length,
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const u8 *buf, size_t len)
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{
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/* Process a fragment that is not the last one of the message */
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if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
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"a fragmented packet");
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ret->ignore = TRUE;
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return NULL;
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}
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if (data->in_buf == NULL) {
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/* First fragment of the message */
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data->in_buf = wpabuf_alloc(message_length);
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if (data->in_buf == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
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"message");
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ret->ignore = TRUE;
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return NULL;
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}
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wpabuf_put_data(data->in_buf, buf, len);
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
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"fragment, waiting for %lu bytes more",
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(unsigned long) len,
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(unsigned long) wpabuf_tailroom(data->in_buf));
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}
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return eap_ikev2_build_frag_ack(id, EAP_CODE_RESPONSE);
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}
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static struct wpabuf * eap_ikev2_process(struct eap_sm *sm, void *priv,
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struct eap_method_ret *ret,
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const struct wpabuf *reqData)
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{
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struct eap_ikev2_data *data = priv;
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const u8 *start, *pos, *end;
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size_t len;
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u8 flags, id;
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u32 message_length = 0;
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struct wpabuf tmpbuf;
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pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, reqData, &len);
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if (pos == NULL) {
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ret->ignore = TRUE;
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return NULL;
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}
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id = eap_get_id(reqData);
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start = pos;
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end = start + len;
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if (len == 0)
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flags = 0; /* fragment ack */
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else
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flags = *pos++;
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if (eap_ikev2_process_icv(data, reqData, flags, pos, &end) < 0) {
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ret->ignore = TRUE;
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return NULL;
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}
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if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
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if (end - pos < 4) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
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ret->ignore = TRUE;
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return NULL;
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}
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message_length = WPA_GET_BE32(pos);
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pos += 4;
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if (message_length < (u32) (end - pos)) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
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"Length (%d; %ld remaining in this msg)",
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message_length, (long) (end - pos));
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ret->ignore = TRUE;
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return NULL;
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}
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}
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
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"Message Length %u", flags, message_length);
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if (data->state == WAIT_FRAG_ACK) {
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#ifdef CCNS_PL
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if (len > 1) /* Empty Flags field included in ACK */
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#else /* CCNS_PL */
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if (len != 0)
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#endif /* CCNS_PL */
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{
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
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"in WAIT_FRAG_ACK state");
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ret->ignore = TRUE;
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return NULL;
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}
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
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eap_ikev2_state(data, PROC_MSG);
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return eap_ikev2_build_msg(data, ret, id);
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}
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if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
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ret->ignore = TRUE;
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return NULL;
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}
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if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
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return eap_ikev2_process_fragment(data, ret, id, flags,
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message_length, pos,
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end - pos);
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}
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if (data->in_buf == NULL) {
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/* Wrap unfragmented messages as wpabuf without extra copy */
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wpabuf_set(&tmpbuf, pos, end - pos);
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data->in_buf = &tmpbuf;
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}
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if (ikev2_responder_process(&data->ikev2, data->in_buf) < 0) {
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if (data->in_buf == &tmpbuf)
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data->in_buf = NULL;
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eap_ikev2_state(data, FAIL);
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return NULL;
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}
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if (data->in_buf != &tmpbuf)
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wpabuf_free(data->in_buf);
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data->in_buf = NULL;
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if (data->out_buf == NULL) {
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data->out_buf = ikev2_responder_build(&data->ikev2);
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if (data->out_buf == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to generate "
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"IKEv2 message");
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return NULL;
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}
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data->out_used = 0;
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}
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eap_ikev2_state(data, PROC_MSG);
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return eap_ikev2_build_msg(data, ret, id);
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}
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static Boolean eap_ikev2_isKeyAvailable(struct eap_sm *sm, void *priv)
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{
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struct eap_ikev2_data *data = priv;
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return data->state == DONE && data->keymat_ok;
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}
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static u8 * eap_ikev2_getKey(struct eap_sm *sm, void *priv, size_t *len)
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{
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struct eap_ikev2_data *data = priv;
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u8 *key;
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if (data->state != DONE || !data->keymat_ok)
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return NULL;
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key = os_malloc(EAP_MSK_LEN);
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if (key) {
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os_memcpy(key, data->keymat, EAP_MSK_LEN);
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*len = EAP_MSK_LEN;
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}
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return key;
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}
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static u8 * eap_ikev2_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
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{
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struct eap_ikev2_data *data = priv;
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u8 *key;
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if (data->state != DONE || !data->keymat_ok)
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return NULL;
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key = os_malloc(EAP_EMSK_LEN);
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if (key) {
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os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
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*len = EAP_EMSK_LEN;
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}
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return key;
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}
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int eap_peer_ikev2_register(void)
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{
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struct eap_method *eap;
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int ret;
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eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
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EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
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"IKEV2");
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if (eap == NULL)
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return -1;
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eap->init = eap_ikev2_init;
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|
eap->deinit = eap_ikev2_deinit;
|
|
eap->process = eap_ikev2_process;
|
|
eap->isKeyAvailable = eap_ikev2_isKeyAvailable;
|
|
eap->getKey = eap_ikev2_getKey;
|
|
eap->get_emsk = eap_ikev2_get_emsk;
|
|
|
|
ret = eap_peer_method_register(eap);
|
|
if (ret)
|
|
eap_peer_method_free(eap);
|
|
return ret;
|
|
}
|