mirror of
https://github.com/vanhoefm/fragattacks.git
synced 2024-11-29 10:48:22 -05:00
814f43cff5
Free the allocated structure in error cases to remove need for each EAP method to handle the error cases separately. Each registration function can simply do "return eap_server_method_register(eap);" in the end of the function. Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
573 lines
14 KiB
C
573 lines
14 KiB
C
/*
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* EAP-IKEv2 server (RFC 5106)
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* Copyright (c) 2007, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README 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_initiator_data ikev2;
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enum { MSG, FRAG_ACK, 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 u8 * eap_ikev2_get_shared_secret(void *ctx, const u8 *IDr,
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size_t IDr_len,
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size_t *secret_len)
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{
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struct eap_sm *sm = ctx;
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if (IDr == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: No IDr received - default "
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"to user identity from EAP-Identity");
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IDr = sm->identity;
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IDr_len = sm->identity_len;
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}
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if (eap_user_get(sm, IDr, IDr_len, 0) < 0 || sm->user == NULL ||
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sm->user->password == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: No user entry found");
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return NULL;
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}
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*secret_len = sm->user->password_len;
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return sm->user->password;
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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 MSG:
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return "MSG";
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case FRAG_ACK:
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return "FRAG_ACK";
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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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data = os_zalloc(sizeof(*data));
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if (data == NULL)
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return NULL;
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data->state = MSG;
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data->fragment_size = sm->fragment_size > 0 ? sm->fragment_size :
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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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/* TODO: make proposals configurable */
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data->ikev2.proposal.proposal_num = 1;
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data->ikev2.proposal.integ = AUTH_HMAC_SHA1_96;
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data->ikev2.proposal.prf = PRF_HMAC_SHA1;
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data->ikev2.proposal.encr = ENCR_AES_CBC;
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data->ikev2.proposal.dh = DH_GROUP2_1024BIT_MODP;
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data->ikev2.IDi = os_malloc(sm->server_id_len);
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if (data->ikev2.IDi == NULL)
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goto failed;
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os_memcpy(data->ikev2.IDi, sm->server_id, sm->server_id_len);
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data->ikev2.IDi_len = sm->server_id_len;
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data->ikev2.get_shared_secret = eap_ikev2_get_shared_secret;
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data->ikev2.cb_ctx = sm;
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return data;
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failed:
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ikev2_initiator_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_reset(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_initiator_deinit(&data->ikev2);
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bin_clear_free(data, sizeof(*data));
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}
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static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data, u8 id)
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{
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struct wpabuf *req;
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u8 flags;
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size_t send_len, plen, icv_len = 0;
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Request");
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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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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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req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
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EAP_CODE_REQUEST, id);
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if (req == NULL)
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return NULL;
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wpabuf_put_u8(req, flags); /* Flags */
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if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
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wpabuf_put_be32(req, wpabuf_len(data->out_buf));
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wpabuf_put_data(req, 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(req);
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size_t len = wpabuf_len(req);
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ikev2_integ_hash(data->ikev2.proposal.integ,
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data->ikev2.keys.SK_ai,
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data->ikev2.keys.SK_integ_len,
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msg, len, wpabuf_put(req, icv_len));
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}
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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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} 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 req;
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}
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static struct wpabuf * eap_ikev2_buildReq(struct eap_sm *sm, void *priv, u8 id)
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{
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struct eap_ikev2_data *data = priv;
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switch (data->state) {
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case MSG:
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if (data->out_buf == NULL) {
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data->out_buf = ikev2_initiator_build(&data->ikev2);
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if (data->out_buf == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
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"generate 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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/* pass through */
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case WAIT_FRAG_ACK:
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return eap_ikev2_build_msg(data, id);
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case FRAG_ACK:
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return eap_ikev2_build_frag_ack(id, EAP_CODE_REQUEST);
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default:
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected state %d in "
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"buildReq", data->state);
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return NULL;
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}
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}
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static Boolean eap_ikev2_check(struct eap_sm *sm, void *priv,
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struct wpabuf *respData)
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{
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const u8 *pos;
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size_t len;
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pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, respData,
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&len);
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if (pos == NULL) {
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wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid frame");
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return TRUE;
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}
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return FALSE;
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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 *respData,
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u8 flags, const u8 *pos, const u8 **end,
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int frag_ack)
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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, 0,
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respData, 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 && !frag_ack) {
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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 for %lu "
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"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 int eap_ikev2_process_fragment(struct eap_ikev2_data *data,
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u8 flags, 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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return -1;
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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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if (message_length > 50000) {
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/* Limit maximum memory allocation */
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wpa_printf(MSG_DEBUG,
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"EAP-IKEV2: Ignore too long message");
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return -1;
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}
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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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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 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 0;
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}
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static int eap_ikev2_server_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 derive "
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"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 void eap_ikev2_process(struct eap_sm *sm, void *priv,
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struct wpabuf *respData)
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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;
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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, respData,
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&len);
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if (pos == NULL)
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return; /* Should not happen; message already verified */
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start = pos;
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end = start + len;
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if (len == 0) {
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/* fragment ack */
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flags = 0;
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} else
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flags = *pos++;
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if (eap_ikev2_process_icv(data, respData, flags, pos, &end,
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data->state == WAIT_FRAG_ACK && len == 0) < 0)
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{
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eap_ikev2_state(data, FAIL);
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return;
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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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eap_ikev2_state(data, FAIL);
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return;
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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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eap_ikev2_state(data, FAIL);
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return;
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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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if (len != 0) {
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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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eap_ikev2_state(data, FAIL);
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return;
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}
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
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eap_ikev2_state(data, MSG);
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return;
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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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eap_ikev2_state(data, FAIL);
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return;
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}
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if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
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if (eap_ikev2_process_fragment(data, flags, message_length,
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pos, end - pos) < 0)
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eap_ikev2_state(data, FAIL);
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else
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eap_ikev2_state(data, FRAG_ACK);
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return;
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} else if (data->state == FRAG_ACK) {
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wpa_printf(MSG_DEBUG, "EAP-TNC: All fragments received");
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data->state = MSG;
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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_initiator_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;
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}
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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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if (data->state == FAIL)
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break;
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wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication completed "
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"successfully");
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if (eap_ikev2_server_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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default:
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break;
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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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}
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static Boolean eap_ikev2_isDone(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->state == FAIL;
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}
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static Boolean eap_ikev2_isSuccess(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->ikev2.state == IKEV2_DONE &&
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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)
|
|
{
|
|
struct eap_ikev2_data *data = priv;
|
|
u8 *key;
|
|
|
|
if (data->state != DONE || !data->keymat_ok)
|
|
return NULL;
|
|
|
|
key = os_malloc(EAP_MSK_LEN);
|
|
if (key) {
|
|
os_memcpy(key, data->keymat, EAP_MSK_LEN);
|
|
*len = EAP_MSK_LEN;
|
|
}
|
|
|
|
return key;
|
|
}
|
|
|
|
|
|
static u8 * eap_ikev2_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
|
|
{
|
|
struct eap_ikev2_data *data = priv;
|
|
u8 *key;
|
|
|
|
if (data->state != DONE || !data->keymat_ok)
|
|
return NULL;
|
|
|
|
key = os_malloc(EAP_EMSK_LEN);
|
|
if (key) {
|
|
os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
|
|
*len = EAP_EMSK_LEN;
|
|
}
|
|
|
|
return key;
|
|
}
|
|
|
|
|
|
static u8 * eap_ikev2_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
|
|
{
|
|
struct eap_ikev2_data *data = priv;
|
|
u8 *sid;
|
|
size_t sid_len;
|
|
size_t offset;
|
|
|
|
if (data->state != DONE || !data->keymat_ok)
|
|
return NULL;
|
|
|
|
sid_len = 1 + data->ikev2.i_nonce_len + data->ikev2.r_nonce_len;
|
|
sid = os_malloc(sid_len);
|
|
if (sid) {
|
|
offset = 0;
|
|
sid[offset] = EAP_TYPE_IKEV2;
|
|
offset++;
|
|
os_memcpy(sid + offset, data->ikev2.i_nonce,
|
|
data->ikev2.i_nonce_len);
|
|
offset += data->ikev2.i_nonce_len;
|
|
os_memcpy(sid + offset, data->ikev2.r_nonce,
|
|
data->ikev2.r_nonce_len);
|
|
*len = sid_len;
|
|
wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Derived Session-Id",
|
|
sid, sid_len);
|
|
}
|
|
|
|
return sid;
|
|
}
|
|
|
|
|
|
int eap_server_ikev2_register(void)
|
|
{
|
|
struct eap_method *eap;
|
|
|
|
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
|
|
EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
|
|
"IKEV2");
|
|
if (eap == NULL)
|
|
return -1;
|
|
|
|
eap->init = eap_ikev2_init;
|
|
eap->reset = eap_ikev2_reset;
|
|
eap->buildReq = eap_ikev2_buildReq;
|
|
eap->check = eap_ikev2_check;
|
|
eap->process = eap_ikev2_process;
|
|
eap->isDone = eap_ikev2_isDone;
|
|
eap->getKey = eap_ikev2_getKey;
|
|
eap->isSuccess = eap_ikev2_isSuccess;
|
|
eap->get_emsk = eap_ikev2_get_emsk;
|
|
eap->getSessionId = eap_ikev2_get_session_id;
|
|
|
|
return eap_server_method_register(eap);
|
|
}
|