/* * hostapd / EAP-PAX (draft-clancy-eap-pax-04.txt) server * Copyright (c) 2005, Jouni Malinen * * 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 #include #include #include #include "hostapd.h" #include "common.h" #include "eap_i.h" #include "eap_pax_common.h" /* * Note: only PAX_STD subprotocol is currently supported */ struct eap_pax_data { enum { PAX_STD_1, PAX_STD_3, SUCCESS, FAILURE } state; u8 mac_id; union { u8 e[2 * EAP_PAX_RAND_LEN]; struct { u8 x[EAP_PAX_RAND_LEN]; /* server rand */ u8 y[EAP_PAX_RAND_LEN]; /* client rand */ } r; } rand; u8 ak[EAP_PAX_AK_LEN]; u8 mk[EAP_PAX_MK_LEN]; u8 ck[EAP_PAX_CK_LEN]; u8 ick[EAP_PAX_ICK_LEN]; int keys_set; char *cid; size_t cid_len; }; static void * eap_pax_init(struct eap_sm *sm) { struct eap_pax_data *data; data = malloc(sizeof(*data)); if (data == NULL) return data; memset(data, 0, sizeof(*data)); data->state = PAX_STD_1; /* * TODO: make this configurable once EAP_PAX_MAC_AES_CBC_MAC_128 is * supported */ data->mac_id = EAP_PAX_MAC_HMAC_SHA1_128; return data; } static void eap_pax_reset(struct eap_sm *sm, void *priv) { struct eap_pax_data *data = priv; free(data->cid); free(data); } static u8 * eap_pax_build_std_1(struct eap_sm *sm, struct eap_pax_data *data, int id, size_t *reqDataLen) { struct eap_pax_hdr *req; u8 *pos; wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (sending)"); if (hostapd_get_rand(data->rand.r.x, EAP_PAX_RAND_LEN)) { wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data"); data->state = FAILURE; return NULL; } *reqDataLen = sizeof(*req) + 2 + EAP_PAX_RAND_LEN + EAP_PAX_ICV_LEN; req = malloc(*reqDataLen); if (req == NULL) { wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory " "request"); data->state = FAILURE; return NULL; } req->code = EAP_CODE_REQUEST; req->identifier = id; req->length = htons(*reqDataLen); req->type = EAP_TYPE_PAX; req->op_code = EAP_PAX_OP_STD_1; req->flags = 0; req->mac_id = data->mac_id; req->dh_group_id = EAP_PAX_DH_GROUP_NONE; req->public_key_id = EAP_PAX_PUBLIC_KEY_NONE; pos = (u8 *) (req + 1); *pos++ = 0; *pos++ = EAP_PAX_RAND_LEN; memcpy(pos, data->rand.r.x, EAP_PAX_RAND_LEN); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: A = X (server rand)", pos, EAP_PAX_RAND_LEN); pos += EAP_PAX_RAND_LEN; eap_pax_mac(data->mac_id, (u8 *) "", 0, (u8 *) req, *reqDataLen - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0, pos); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN); pos += EAP_PAX_ICV_LEN; return (u8 *) req; } static u8 * eap_pax_build_std_3(struct eap_sm *sm, struct eap_pax_data *data, int id, size_t *reqDataLen) { struct eap_pax_hdr *req; u8 *pos; wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (sending)"); *reqDataLen = sizeof(*req) + 2 + EAP_PAX_MAC_LEN + EAP_PAX_ICV_LEN; req = malloc(*reqDataLen); if (req == NULL) { wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory " "request"); data->state = FAILURE; return NULL; } req->code = EAP_CODE_REQUEST; req->identifier = id; req->length = htons(*reqDataLen); req->type = EAP_TYPE_PAX; req->op_code = EAP_PAX_OP_STD_3; req->flags = 0; req->mac_id = data->mac_id; req->dh_group_id = EAP_PAX_DH_GROUP_NONE; req->public_key_id = EAP_PAX_PUBLIC_KEY_NONE; pos = (u8 *) (req + 1); *pos++ = 0; *pos++ = EAP_PAX_MAC_LEN; eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN, data->rand.r.y, EAP_PAX_RAND_LEN, (u8 *) data->cid, data->cid_len, NULL, 0, pos); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)", pos, EAP_PAX_MAC_LEN); pos += EAP_PAX_MAC_LEN; eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN, (u8 *) req, *reqDataLen - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0, pos); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN); pos += EAP_PAX_ICV_LEN; return (u8 *) req; } static u8 * eap_pax_buildReq(struct eap_sm *sm, void *priv, int id, size_t *reqDataLen) { struct eap_pax_data *data = priv; switch (data->state) { case PAX_STD_1: return eap_pax_build_std_1(sm, data, id, reqDataLen); case PAX_STD_3: return eap_pax_build_std_3(sm, data, id, reqDataLen); default: wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown state %d in buildReq", data->state); break; } return NULL; } static Boolean eap_pax_check(struct eap_sm *sm, void *priv, u8 *respData, size_t respDataLen) { struct eap_pax_data *data = priv; struct eap_pax_hdr *resp; size_t len; u8 icvbuf[EAP_PAX_ICV_LEN], *icv; resp = (struct eap_pax_hdr *) respData; if (respDataLen < sizeof(*resp) || resp->type != EAP_TYPE_PAX || (len = ntohs(resp->length)) > respDataLen || len < sizeof(*resp) + EAP_PAX_ICV_LEN) { wpa_printf(MSG_INFO, "EAP-PAX: Invalid frame"); return TRUE; } wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x " "flags 0x%x mac_id 0x%x dh_group_id 0x%x " "public_key_id 0x%x", resp->op_code, resp->flags, resp->mac_id, resp->dh_group_id, resp->public_key_id); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload", (u8 *) (resp + 1), len - sizeof(*resp) - EAP_PAX_ICV_LEN); if (data->state == PAX_STD_1 && resp->op_code != EAP_PAX_OP_STD_2) { wpa_printf(MSG_DEBUG, "EAP-PAX: Expected PAX_STD-2 - " "ignore op %d", resp->op_code); return TRUE; } if (data->state == PAX_STD_3 && resp->op_code != EAP_PAX_OP_ACK) { wpa_printf(MSG_DEBUG, "EAP-PAX: Expected PAX-ACK - " "ignore op %d", resp->op_code); return TRUE; } if (resp->op_code != EAP_PAX_OP_STD_2 && resp->op_code != EAP_PAX_OP_ACK) { wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown op_code 0x%x", resp->op_code); } if (data->mac_id != resp->mac_id) { wpa_printf(MSG_DEBUG, "EAP-PAX: Expected MAC ID 0x%x, " "received 0x%x", data->mac_id, resp->mac_id); return TRUE; } if (resp->dh_group_id != EAP_PAX_DH_GROUP_NONE) { wpa_printf(MSG_INFO, "EAP-PAX: Expected DH Group ID 0x%x, " "received 0x%x", EAP_PAX_DH_GROUP_NONE, resp->dh_group_id); return TRUE; } if (resp->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) { wpa_printf(MSG_INFO, "EAP-PAX: Expected Public Key ID 0x%x, " "received 0x%x", EAP_PAX_PUBLIC_KEY_NONE, resp->public_key_id); return TRUE; } if (resp->flags & EAP_PAX_FLAGS_MF) { /* TODO: add support for reassembling fragments */ wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported"); return TRUE; } if (resp->flags & EAP_PAX_FLAGS_CE) { wpa_printf(MSG_INFO, "EAP-PAX: Unexpected CE flag"); return TRUE; } if (data->keys_set) { if (len - sizeof(*resp) < EAP_PAX_ICV_LEN) { wpa_printf(MSG_INFO, "EAP-PAX: No ICV in the packet"); return TRUE; } icv = respData + len - EAP_PAX_ICV_LEN; wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN); eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN, respData, len - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0, icvbuf); if (memcmp(icvbuf, icv, EAP_PAX_ICV_LEN) != 0) { wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV"); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV", icvbuf, EAP_PAX_ICV_LEN); return TRUE; } } return FALSE; } static void eap_pax_process_std_2(struct eap_sm *sm, struct eap_pax_data *data, u8 *respData, size_t respDataLen) { struct eap_pax_hdr *resp; u8 *pos, mac[EAP_PAX_MAC_LEN], icvbuf[EAP_PAX_ICV_LEN]; size_t len, left; int i; if (data->state != PAX_STD_1) return; wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX_STD-2"); resp = (struct eap_pax_hdr *) respData; len = ntohs(resp->length); pos = (u8 *) (resp + 1); left = len - sizeof(*resp); if (left < 2 + EAP_PAX_RAND_LEN || ((pos[0] << 8) | pos[1]) != EAP_PAX_RAND_LEN) { wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (B)"); return; } pos += 2; left -= 2; memcpy(data->rand.r.y, pos, EAP_PAX_RAND_LEN); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)", data->rand.r.y, EAP_PAX_RAND_LEN); pos += EAP_PAX_RAND_LEN; left -= EAP_PAX_RAND_LEN; if (left < 2 || 2 + ((pos[0] << 8) | pos[1]) > left) { wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (CID)"); return; } data->cid_len = (pos[0] << 8) | pos[1]; free(data->cid); data->cid = malloc(data->cid_len); if (data->cid == NULL) { wpa_printf(MSG_INFO, "EAP-PAX: Failed to allocate memory for " "CID"); return; } memcpy (data->cid, pos + 2, data->cid_len); pos += 2 + data->cid_len; left -= 2 + data->cid_len; wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID", (u8 *) data->cid, data->cid_len); if (left < 2 + EAP_PAX_MAC_LEN || ((pos[0] << 8) | pos[1]) != EAP_PAX_MAC_LEN) { wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (MAC_CK)"); return; } pos += 2; left -= 2; wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)", pos, EAP_PAX_MAC_LEN); if (eap_user_get(sm, (u8 *) data->cid, data->cid_len, 0) < 0) { wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: unknown CID", (u8 *) data->cid, data->cid_len); data->state = FAILURE; return; } for (i = 0; i < EAP_MAX_METHODS && sm->user->methods[i] != EAP_TYPE_NONE; i++) { if (sm->user->methods[i] == EAP_TYPE_PAX) break; } if (sm->user->methods[i] != EAP_TYPE_PAX) { wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: EAP-PAX not enabled for CID", (u8 *) data->cid, data->cid_len); data->state = FAILURE; return; } if (sm->user->password == NULL || sm->user->password_len != EAP_PAX_AK_LEN) { wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: invalid password in " "user database for CID", (u8 *) data->cid, data->cid_len); data->state = FAILURE; return; } memcpy(data->ak, sm->user->password, EAP_PAX_AK_LEN); if (eap_pax_initial_key_derivation(data->mac_id, data->ak, data->rand.e, data->mk, data->ck, data->ick) < 0) { wpa_printf(MSG_INFO, "EAP-PAX: Failed to complete initial " "key derivation"); data->state = FAILURE; return; } data->keys_set = 1; eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN, data->rand.r.x, EAP_PAX_RAND_LEN, data->rand.r.y, EAP_PAX_RAND_LEN, (u8 *) data->cid, data->cid_len, mac); if (memcmp(mac, pos, EAP_PAX_MAC_LEN) != 0) { wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(A, B, CID) in " "PAX_STD-2"); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected MAC_CK(A, B, CID)", mac, EAP_PAX_MAC_LEN); data->state = FAILURE; return; } pos += EAP_PAX_MAC_LEN; left -= EAP_PAX_MAC_LEN; if (left < EAP_PAX_ICV_LEN) { wpa_printf(MSG_INFO, "EAP-PAX: Too short ICV (%lu) in " "PAX_STD-2", (unsigned long) left); return; } wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN); eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN, respData, len - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0, icvbuf); if (memcmp(icvbuf, pos, EAP_PAX_ICV_LEN) != 0) { wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV in PAX_STD-2"); wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV", icvbuf, EAP_PAX_ICV_LEN); return; } pos += EAP_PAX_ICV_LEN; left -= EAP_PAX_ICV_LEN; if (left > 0) { wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload", pos, left); } data->state = PAX_STD_3; } static void eap_pax_process_ack(struct eap_sm *sm, struct eap_pax_data *data, u8 *respData, size_t respDataLen) { if (data->state != PAX_STD_3) return; wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX-ACK - authentication " "completed successfully"); data->state = SUCCESS; } static void eap_pax_process(struct eap_sm *sm, void *priv, u8 *respData, size_t respDataLen) { struct eap_pax_data *data = priv; struct eap_pax_hdr *resp; if (sm->user == NULL || sm->user->password == NULL) { wpa_printf(MSG_INFO, "EAP-PAX: Password not configured"); data->state = FAILURE; return; } resp = (struct eap_pax_hdr *) respData; switch (resp->op_code) { case EAP_PAX_OP_STD_2: eap_pax_process_std_2(sm, data, respData, respDataLen); break; case EAP_PAX_OP_ACK: eap_pax_process_ack(sm, data, respData, respDataLen); break; } } static Boolean eap_pax_isDone(struct eap_sm *sm, void *priv) { struct eap_pax_data *data = priv; return data->state == SUCCESS || data->state == FAILURE; } static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len) { struct eap_pax_data *data = priv; u8 *key; if (data->state != SUCCESS) return NULL; key = malloc(EAP_PAX_MSK_LEN); if (key == NULL) return NULL; *len = EAP_PAX_MSK_LEN; eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN, "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN, EAP_PAX_MSK_LEN, key); return key; } static Boolean eap_pax_isSuccess(struct eap_sm *sm, void *priv) { struct eap_pax_data *data = priv; return data->state == SUCCESS; } const struct eap_method eap_method_pax = { .method = EAP_TYPE_PAX, .name = "PAX", .init = eap_pax_init, .reset = eap_pax_reset, .buildReq = eap_pax_buildReq, .check = eap_pax_check, .process = eap_pax_process, .isDone = eap_pax_isDone, .getKey = eap_pax_getKey, .isSuccess = eap_pax_isSuccess, };