| /* |
| * EAP-IKEv2 peer (RFC 5106) |
| * Copyright (c) 2007-2014, Jouni Malinen <j@w1.fi> |
| * |
| * This software may be distributed under the terms of the BSD license. |
| * See README for more details. |
| */ |
| |
| #include "includes.h" |
| |
| #include "common.h" |
| #include "eap_i.h" |
| #include "eap_common/eap_ikev2_common.h" |
| #include "ikev2.h" |
| |
| |
| struct eap_ikev2_data { |
| struct ikev2_responder_data ikev2; |
| enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state; |
| struct wpabuf *in_buf; |
| struct wpabuf *out_buf; |
| size_t out_used; |
| size_t fragment_size; |
| int keys_ready; |
| u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN]; |
| int keymat_ok; |
| }; |
| |
| |
| static const char * eap_ikev2_state_txt(int state) |
| { |
| switch (state) { |
| case WAIT_START: |
| return "WAIT_START"; |
| case PROC_MSG: |
| return "PROC_MSG"; |
| case WAIT_FRAG_ACK: |
| return "WAIT_FRAG_ACK"; |
| case DONE: |
| return "DONE"; |
| case FAIL: |
| return "FAIL"; |
| default: |
| return "?"; |
| } |
| } |
| |
| |
| static void eap_ikev2_state(struct eap_ikev2_data *data, int state) |
| { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s", |
| eap_ikev2_state_txt(data->state), |
| eap_ikev2_state_txt(state)); |
| data->state = state; |
| } |
| |
| |
| static void * eap_ikev2_init(struct eap_sm *sm) |
| { |
| struct eap_ikev2_data *data; |
| const u8 *identity, *password; |
| size_t identity_len, password_len; |
| int fragment_size; |
| |
| identity = eap_get_config_identity(sm, &identity_len); |
| if (identity == NULL) { |
| wpa_printf(MSG_INFO, "EAP-IKEV2: No identity available"); |
| return NULL; |
| } |
| |
| data = os_zalloc(sizeof(*data)); |
| if (data == NULL) |
| return NULL; |
| data->state = WAIT_START; |
| fragment_size = eap_get_config_fragment_size(sm); |
| if (fragment_size <= 0) |
| data->fragment_size = IKEV2_FRAGMENT_SIZE; |
| else |
| data->fragment_size = fragment_size; |
| data->ikev2.state = SA_INIT; |
| data->ikev2.peer_auth = PEER_AUTH_SECRET; |
| data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2"); |
| if (data->ikev2.key_pad == NULL) |
| goto failed; |
| data->ikev2.key_pad_len = 21; |
| data->ikev2.IDr = os_memdup(identity, identity_len); |
| if (data->ikev2.IDr == NULL) |
| goto failed; |
| data->ikev2.IDr_len = identity_len; |
| |
| password = eap_get_config_password(sm, &password_len); |
| if (password) { |
| data->ikev2.shared_secret = os_memdup(password, password_len); |
| if (data->ikev2.shared_secret == NULL) |
| goto failed; |
| data->ikev2.shared_secret_len = password_len; |
| } |
| |
| return data; |
| |
| failed: |
| ikev2_responder_deinit(&data->ikev2); |
| os_free(data); |
| return NULL; |
| } |
| |
| |
| static void eap_ikev2_deinit(struct eap_sm *sm, void *priv) |
| { |
| struct eap_ikev2_data *data = priv; |
| wpabuf_free(data->in_buf); |
| wpabuf_free(data->out_buf); |
| ikev2_responder_deinit(&data->ikev2); |
| bin_clear_free(data, sizeof(*data)); |
| } |
| |
| |
| static int eap_ikev2_peer_keymat(struct eap_ikev2_data *data) |
| { |
| if (eap_ikev2_derive_keymat( |
| data->ikev2.proposal.prf, &data->ikev2.keys, |
| data->ikev2.i_nonce, data->ikev2.i_nonce_len, |
| data->ikev2.r_nonce, data->ikev2.r_nonce_len, |
| data->keymat) < 0) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to " |
| "derive key material"); |
| return -1; |
| } |
| data->keymat_ok = 1; |
| return 0; |
| } |
| |
| |
| static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data, |
| struct eap_method_ret *ret, u8 id) |
| { |
| struct wpabuf *resp; |
| u8 flags; |
| size_t send_len, plen, icv_len = 0; |
| |
| ret->ignore = false; |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Response"); |
| ret->allowNotifications = true; |
| |
| flags = 0; |
| send_len = wpabuf_len(data->out_buf) - data->out_used; |
| if (1 + send_len > data->fragment_size) { |
| send_len = data->fragment_size - 1; |
| flags |= IKEV2_FLAGS_MORE_FRAGMENTS; |
| if (data->out_used == 0) { |
| flags |= IKEV2_FLAGS_LENGTH_INCLUDED; |
| send_len -= 4; |
| } |
| } |
| |
| plen = 1 + send_len; |
| if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) |
| plen += 4; |
| if (data->keys_ready) { |
| const struct ikev2_integ_alg *integ; |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum " |
| "Data"); |
| flags |= IKEV2_FLAGS_ICV_INCLUDED; |
| integ = ikev2_get_integ(data->ikev2.proposal.integ); |
| if (integ == NULL) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG " |
| "transform / cannot generate ICV"); |
| return NULL; |
| } |
| icv_len = integ->hash_len; |
| |
| plen += icv_len; |
| } |
| resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen, |
| EAP_CODE_RESPONSE, id); |
| if (resp == NULL) |
| return NULL; |
| |
| wpabuf_put_u8(resp, flags); /* Flags */ |
| if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) |
| wpabuf_put_be32(resp, wpabuf_len(data->out_buf)); |
| |
| wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used, |
| send_len); |
| data->out_used += send_len; |
| |
| if (flags & IKEV2_FLAGS_ICV_INCLUDED) { |
| const u8 *msg = wpabuf_head(resp); |
| size_t len = wpabuf_len(resp); |
| ikev2_integ_hash(data->ikev2.proposal.integ, |
| data->ikev2.keys.SK_ar, |
| data->ikev2.keys.SK_integ_len, |
| msg, len, wpabuf_put(resp, icv_len)); |
| } |
| |
| ret->methodState = METHOD_MAY_CONT; |
| ret->decision = DECISION_FAIL; |
| |
| if (data->out_used == wpabuf_len(data->out_buf)) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes " |
| "(message sent completely)", |
| (unsigned long) send_len); |
| wpabuf_free(data->out_buf); |
| data->out_buf = NULL; |
| data->out_used = 0; |
| switch (data->ikev2.state) { |
| case SA_AUTH: |
| /* SA_INIT was sent out, so message have to be |
| * integrity protected from now on. */ |
| data->keys_ready = 1; |
| break; |
| case IKEV2_DONE: |
| ret->methodState = METHOD_DONE; |
| if (data->state == FAIL) |
| break; |
| ret->decision = DECISION_COND_SUCC; |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication " |
| "completed successfully"); |
| if (eap_ikev2_peer_keymat(data)) |
| break; |
| eap_ikev2_state(data, DONE); |
| break; |
| case IKEV2_FAILED: |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication " |
| "failed"); |
| ret->methodState = METHOD_DONE; |
| ret->decision = DECISION_FAIL; |
| break; |
| default: |
| break; |
| } |
| } else { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes " |
| "(%lu more to send)", (unsigned long) send_len, |
| (unsigned long) wpabuf_len(data->out_buf) - |
| data->out_used); |
| eap_ikev2_state(data, WAIT_FRAG_ACK); |
| } |
| |
| return resp; |
| } |
| |
| |
| static int eap_ikev2_process_icv(struct eap_ikev2_data *data, |
| const struct wpabuf *reqData, |
| u8 flags, const u8 *pos, const u8 **end, |
| int frag_ack) |
| { |
| if (flags & IKEV2_FLAGS_ICV_INCLUDED) { |
| int icv_len = eap_ikev2_validate_icv( |
| data->ikev2.proposal.integ, &data->ikev2.keys, 1, |
| reqData, pos, *end); |
| if (icv_len < 0) |
| return -1; |
| /* Hide Integrity Checksum Data from further processing */ |
| *end -= icv_len; |
| } else if (data->keys_ready && !frag_ack) { |
| wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have " |
| "included integrity checksum"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int eap_ikev2_process_cont(struct eap_ikev2_data *data, |
| const u8 *buf, size_t len) |
| { |
| /* Process continuation of a pending message */ |
| if (len > wpabuf_tailroom(data->in_buf)) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow"); |
| eap_ikev2_state(data, FAIL); |
| return -1; |
| } |
| |
| wpabuf_put_data(data->in_buf, buf, len); |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting " |
| "for %lu bytes more", (unsigned long) len, |
| (unsigned long) wpabuf_tailroom(data->in_buf)); |
| |
| return 0; |
| } |
| |
| |
| static struct wpabuf * eap_ikev2_process_fragment(struct eap_ikev2_data *data, |
| struct eap_method_ret *ret, |
| u8 id, u8 flags, |
| u32 message_length, |
| const u8 *buf, size_t len) |
| { |
| /* Process a fragment that is not the last one of the message */ |
| if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in " |
| "a fragmented packet"); |
| ret->ignore = true; |
| return NULL; |
| } |
| |
| if (data->in_buf == NULL) { |
| /* First fragment of the message */ |
| if (message_length > 50000) { |
| /* Limit maximum memory allocation */ |
| wpa_printf(MSG_DEBUG, |
| "EAP-IKEV2: Ignore too long message"); |
| ret->ignore = true; |
| return NULL; |
| } |
| data->in_buf = wpabuf_alloc(message_length); |
| if (data->in_buf == NULL) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for " |
| "message"); |
| ret->ignore = true; |
| return NULL; |
| } |
| wpabuf_put_data(data->in_buf, buf, len); |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first " |
| "fragment, waiting for %lu bytes more", |
| (unsigned long) len, |
| (unsigned long) wpabuf_tailroom(data->in_buf)); |
| } |
| |
| ret->ignore = false; |
| return eap_ikev2_build_frag_ack(id, EAP_CODE_RESPONSE); |
| } |
| |
| |
| static struct wpabuf * eap_ikev2_process(struct eap_sm *sm, void *priv, |
| struct eap_method_ret *ret, |
| const struct wpabuf *reqData) |
| { |
| struct eap_ikev2_data *data = priv; |
| const u8 *start, *pos, *end; |
| size_t len; |
| u8 flags, id; |
| u32 message_length = 0; |
| struct wpabuf tmpbuf; |
| |
| pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, reqData, &len); |
| if (pos == NULL) { |
| ret->ignore = true; |
| return NULL; |
| } |
| |
| id = eap_get_id(reqData); |
| |
| start = pos; |
| end = start + len; |
| |
| if (len == 0) |
| flags = 0; /* fragment ack */ |
| else |
| flags = *pos++; |
| |
| if (eap_ikev2_process_icv(data, reqData, flags, pos, &end, |
| data->state == WAIT_FRAG_ACK && len == 0) < 0) |
| { |
| ret->ignore = true; |
| return NULL; |
| } |
| |
| if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) { |
| if (end - pos < 4) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow"); |
| ret->ignore = true; |
| return NULL; |
| } |
| message_length = WPA_GET_BE32(pos); |
| pos += 4; |
| |
| if (message_length < (u32) (end - pos)) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message " |
| "Length (%d; %ld remaining in this msg)", |
| message_length, (long) (end - pos)); |
| ret->ignore = true; |
| return NULL; |
| } |
| } |
| |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x " |
| "Message Length %u", flags, message_length); |
| |
| if (data->state == WAIT_FRAG_ACK) { |
| if (len != 0) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload " |
| "in WAIT_FRAG_ACK state"); |
| ret->ignore = true; |
| return NULL; |
| } |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged"); |
| eap_ikev2_state(data, PROC_MSG); |
| return eap_ikev2_build_msg(data, ret, id); |
| } |
| |
| if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) { |
| ret->ignore = true; |
| return NULL; |
| } |
| |
| if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) { |
| return eap_ikev2_process_fragment(data, ret, id, flags, |
| message_length, pos, |
| end - pos); |
| } |
| |
| if (data->in_buf == NULL) { |
| /* Wrap unfragmented messages as wpabuf without extra copy */ |
| wpabuf_set(&tmpbuf, pos, end - pos); |
| data->in_buf = &tmpbuf; |
| } |
| |
| if (ikev2_responder_process(&data->ikev2, data->in_buf) < 0) { |
| if (data->in_buf == &tmpbuf) |
| data->in_buf = NULL; |
| eap_ikev2_state(data, FAIL); |
| return NULL; |
| } |
| |
| if (data->in_buf != &tmpbuf) |
| wpabuf_free(data->in_buf); |
| data->in_buf = NULL; |
| |
| if (data->out_buf == NULL) { |
| data->out_buf = ikev2_responder_build(&data->ikev2); |
| if (data->out_buf == NULL) { |
| wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to generate " |
| "IKEv2 message"); |
| return NULL; |
| } |
| data->out_used = 0; |
| } |
| |
| eap_ikev2_state(data, PROC_MSG); |
| return eap_ikev2_build_msg(data, ret, id); |
| } |
| |
| |
| static bool eap_ikev2_isKeyAvailable(struct eap_sm *sm, void *priv) |
| { |
| struct eap_ikev2_data *data = priv; |
| return data->state == DONE && data->keymat_ok; |
| } |
| |
| |
| 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_peer_ikev2_register(void) |
| { |
| struct eap_method *eap; |
| |
| eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION, |
| EAP_VENDOR_IETF, EAP_TYPE_IKEV2, |
| "IKEV2"); |
| if (eap == NULL) |
| return -1; |
| |
| eap->init = eap_ikev2_init; |
| 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; |
| eap->getSessionId = eap_ikev2_get_session_id; |
| |
| return eap_peer_method_register(eap); |
| } |