3642c4313a
This commit adds a new wrapper, random_get_bytes(), that is currently defined to use os_get_random() as is. The places using random_get_bytes() depend on the returned value being strong random number, i.e., something that is infeasible for external device to figure out. These values are used either directly as a key or as nonces/challenges that are used as input for key derivation or authentication. The remaining direct uses of os_get_random() do not need as strong random numbers to function correctly.
531 lines
14 KiB
C
531 lines
14 KiB
C
/*
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* EAP peer method: EAP-PAX (RFC 4746)
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* Copyright (c) 2005-2008, 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 "crypto/random.h"
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#include "eap_common/eap_pax_common.h"
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#include "eap_i.h"
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/*
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* Note: only PAX_STD subprotocol is currently supported
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*
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* TODO: Add support with PAX_SEC with the mandatory to implement ciphersuite
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* (HMAC_SHA1_128, IANA DH Group 14 (2048 bits), RSA-PKCS1-V1_5) and
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* recommended ciphersuite (HMAC_SHA256_128, IANA DH Group 15 (3072 bits),
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* RSAES-OAEP).
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*/
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struct eap_pax_data {
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enum { PAX_INIT, PAX_STD_2_SENT, PAX_DONE } state;
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u8 mac_id, dh_group_id, public_key_id;
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union {
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u8 e[2 * EAP_PAX_RAND_LEN];
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struct {
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u8 x[EAP_PAX_RAND_LEN]; /* server rand */
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u8 y[EAP_PAX_RAND_LEN]; /* client rand */
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} r;
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} rand;
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char *cid;
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size_t cid_len;
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u8 ak[EAP_PAX_AK_LEN];
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u8 mk[EAP_PAX_MK_LEN];
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u8 ck[EAP_PAX_CK_LEN];
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u8 ick[EAP_PAX_ICK_LEN];
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};
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static void eap_pax_deinit(struct eap_sm *sm, void *priv);
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static void * eap_pax_init(struct eap_sm *sm)
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{
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struct eap_pax_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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password = eap_get_config_password(sm, &password_len);
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if (!identity || !password) {
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wpa_printf(MSG_INFO, "EAP-PAX: CID (nai) or key (password) "
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"not configured");
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return NULL;
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}
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if (password_len != EAP_PAX_AK_LEN) {
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wpa_printf(MSG_INFO, "EAP-PAX: Invalid PSK length");
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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 = PAX_INIT;
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data->cid = os_malloc(identity_len);
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if (data->cid == NULL) {
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eap_pax_deinit(sm, data);
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return NULL;
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}
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os_memcpy(data->cid, identity, identity_len);
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data->cid_len = identity_len;
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os_memcpy(data->ak, password, EAP_PAX_AK_LEN);
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return data;
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}
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static void eap_pax_deinit(struct eap_sm *sm, void *priv)
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{
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struct eap_pax_data *data = priv;
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os_free(data->cid);
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os_free(data);
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}
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static struct wpabuf * eap_pax_alloc_resp(const struct eap_pax_hdr *req,
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u8 id, u8 op_code, size_t plen)
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{
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struct wpabuf *resp;
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struct eap_pax_hdr *pax;
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resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
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sizeof(*pax) + plen, EAP_CODE_RESPONSE, id);
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if (resp == NULL)
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return NULL;
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pax = wpabuf_put(resp, sizeof(*pax));
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pax->op_code = op_code;
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pax->flags = 0;
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pax->mac_id = req->mac_id;
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pax->dh_group_id = req->dh_group_id;
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pax->public_key_id = req->public_key_id;
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return resp;
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}
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static struct wpabuf * eap_pax_process_std_1(struct eap_pax_data *data,
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struct eap_method_ret *ret, u8 id,
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const struct eap_pax_hdr *req,
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size_t req_plen)
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{
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struct wpabuf *resp;
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const u8 *pos;
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u8 *rpos;
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size_t left, plen;
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wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (received)");
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if (data->state != PAX_INIT) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 received in "
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"unexpected state (%d) - ignored", data->state);
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ret->ignore = TRUE;
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return NULL;
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}
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if (req->flags & EAP_PAX_FLAGS_CE) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with CE flag set - "
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"ignored");
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ret->ignore = TRUE;
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return NULL;
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}
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left = req_plen - sizeof(*req);
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if (left < 2 + EAP_PAX_RAND_LEN) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with too short "
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"payload");
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ret->ignore = TRUE;
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return NULL;
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}
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pos = (const u8 *) (req + 1);
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if (WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with incorrect A "
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"length %d (expected %d)",
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WPA_GET_BE16(pos), EAP_PAX_RAND_LEN);
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ret->ignore = TRUE;
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return NULL;
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}
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pos += 2;
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left -= 2;
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os_memcpy(data->rand.r.x, pos, EAP_PAX_RAND_LEN);
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: X (server rand)",
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data->rand.r.x, EAP_PAX_RAND_LEN);
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pos += EAP_PAX_RAND_LEN;
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left -= EAP_PAX_RAND_LEN;
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if (left > 0) {
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
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pos, left);
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}
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if (random_get_bytes(data->rand.r.y, EAP_PAX_RAND_LEN)) {
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wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
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ret->ignore = TRUE;
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return NULL;
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}
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)",
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data->rand.r.y, EAP_PAX_RAND_LEN);
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if (eap_pax_initial_key_derivation(req->mac_id, data->ak, data->rand.e,
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data->mk, data->ck, data->ick) < 0)
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{
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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-PAX: PAX_STD-2 (sending)");
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plen = 2 + EAP_PAX_RAND_LEN + 2 + data->cid_len + 2 + EAP_PAX_MAC_LEN +
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EAP_PAX_ICV_LEN;
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resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_STD_2, plen);
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if (resp == NULL)
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return NULL;
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wpabuf_put_be16(resp, EAP_PAX_RAND_LEN);
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wpabuf_put_data(resp, data->rand.r.y, EAP_PAX_RAND_LEN);
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: B = Y (client rand)",
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data->rand.r.y, EAP_PAX_RAND_LEN);
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wpabuf_put_be16(resp, data->cid_len);
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wpabuf_put_data(resp, data->cid, data->cid_len);
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wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
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(u8 *) data->cid, data->cid_len);
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wpabuf_put_be16(resp, EAP_PAX_MAC_LEN);
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rpos = wpabuf_put(resp, EAP_PAX_MAC_LEN);
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eap_pax_mac(req->mac_id, data->ck, EAP_PAX_CK_LEN,
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data->rand.r.x, EAP_PAX_RAND_LEN,
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data->rand.r.y, EAP_PAX_RAND_LEN,
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(u8 *) data->cid, data->cid_len, rpos);
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
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rpos, EAP_PAX_MAC_LEN);
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/* Optional ADE could be added here, if needed */
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rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
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eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
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wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
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NULL, 0, NULL, 0, rpos);
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
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data->state = PAX_STD_2_SENT;
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data->mac_id = req->mac_id;
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data->dh_group_id = req->dh_group_id;
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data->public_key_id = req->public_key_id;
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return resp;
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}
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static struct wpabuf * eap_pax_process_std_3(struct eap_pax_data *data,
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struct eap_method_ret *ret, u8 id,
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const struct eap_pax_hdr *req,
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size_t req_plen)
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{
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struct wpabuf *resp;
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u8 *rpos, mac[EAP_PAX_MAC_LEN];
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const u8 *pos;
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size_t left;
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wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (received)");
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if (data->state != PAX_STD_2_SENT) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 received in "
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"unexpected state (%d) - ignored", data->state);
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ret->ignore = TRUE;
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return NULL;
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}
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if (req->flags & EAP_PAX_FLAGS_CE) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with CE flag set - "
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"ignored");
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ret->ignore = TRUE;
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return NULL;
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}
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left = req_plen - sizeof(*req);
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if (left < 2 + EAP_PAX_MAC_LEN) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with too short "
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"payload");
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ret->ignore = TRUE;
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return NULL;
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}
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pos = (const u8 *) (req + 1);
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if (WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
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wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with incorrect "
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"MAC_CK length %d (expected %d)",
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WPA_GET_BE16(pos), EAP_PAX_MAC_LEN);
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ret->ignore = TRUE;
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return NULL;
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}
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pos += 2;
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left -= 2;
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
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pos, EAP_PAX_MAC_LEN);
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eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
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data->rand.r.y, EAP_PAX_RAND_LEN,
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(u8 *) data->cid, data->cid_len, NULL, 0, mac);
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if (os_memcmp(pos, mac, EAP_PAX_MAC_LEN) != 0) {
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wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(B, CID) "
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"received");
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected MAC_CK(B, CID)",
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mac, EAP_PAX_MAC_LEN);
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ret->methodState = METHOD_DONE;
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ret->decision = DECISION_FAIL;
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return NULL;
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}
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pos += EAP_PAX_MAC_LEN;
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left -= EAP_PAX_MAC_LEN;
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if (left > 0) {
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
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pos, left);
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}
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wpa_printf(MSG_DEBUG, "EAP-PAX: PAX-ACK (sending)");
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resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_ACK, EAP_PAX_ICV_LEN);
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if (resp == NULL)
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return NULL;
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/* Optional ADE could be added here, if needed */
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rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
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eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
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wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
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NULL, 0, NULL, 0, rpos);
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
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data->state = PAX_DONE;
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ret->methodState = METHOD_DONE;
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ret->decision = DECISION_UNCOND_SUCC;
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ret->allowNotifications = FALSE;
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return resp;
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}
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static struct wpabuf * eap_pax_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_pax_data *data = priv;
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const struct eap_pax_hdr *req;
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struct wpabuf *resp;
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u8 icvbuf[EAP_PAX_ICV_LEN], id;
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const u8 *icv, *pos;
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size_t len;
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u16 flen, mlen;
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pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, reqData, &len);
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if (pos == NULL || len < EAP_PAX_ICV_LEN) {
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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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req = (const struct eap_pax_hdr *) pos;
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flen = len - EAP_PAX_ICV_LEN;
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mlen = wpabuf_len(reqData) - EAP_PAX_ICV_LEN;
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wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x "
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"flags 0x%x mac_id 0x%x dh_group_id 0x%x "
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"public_key_id 0x%x",
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req->op_code, req->flags, req->mac_id, req->dh_group_id,
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req->public_key_id);
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload",
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pos, len - EAP_PAX_ICV_LEN);
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if (data->state != PAX_INIT && data->mac_id != req->mac_id) {
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wpa_printf(MSG_INFO, "EAP-PAX: MAC ID changed during "
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"authentication (was 0x%d, is 0x%d)",
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data->mac_id, req->mac_id);
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ret->ignore = TRUE;
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return NULL;
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}
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if (data->state != PAX_INIT && data->dh_group_id != req->dh_group_id) {
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wpa_printf(MSG_INFO, "EAP-PAX: DH Group ID changed during "
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"authentication (was 0x%d, is 0x%d)",
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data->dh_group_id, req->dh_group_id);
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ret->ignore = TRUE;
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return NULL;
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}
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if (data->state != PAX_INIT &&
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data->public_key_id != req->public_key_id) {
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wpa_printf(MSG_INFO, "EAP-PAX: Public Key ID changed during "
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"authentication (was 0x%d, is 0x%d)",
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data->public_key_id, req->public_key_id);
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ret->ignore = TRUE;
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return NULL;
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}
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/* TODO: add support EAP_PAX_HMAC_SHA256_128 */
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if (req->mac_id != EAP_PAX_MAC_HMAC_SHA1_128) {
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wpa_printf(MSG_INFO, "EAP-PAX: Unsupported MAC ID 0x%x",
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req->mac_id);
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ret->ignore = TRUE;
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return NULL;
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}
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if (req->dh_group_id != EAP_PAX_DH_GROUP_NONE) {
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wpa_printf(MSG_INFO, "EAP-PAX: Unsupported DH Group ID 0x%x",
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req->dh_group_id);
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ret->ignore = TRUE;
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return NULL;
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}
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if (req->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) {
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wpa_printf(MSG_INFO, "EAP-PAX: Unsupported Public Key ID 0x%x",
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req->public_key_id);
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ret->ignore = TRUE;
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return NULL;
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}
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if (req->flags & EAP_PAX_FLAGS_MF) {
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/* TODO: add support for reassembling fragments */
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wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported - "
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"ignored packet");
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ret->ignore = TRUE;
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return NULL;
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}
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icv = pos + len - EAP_PAX_ICV_LEN;
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
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if (req->op_code == EAP_PAX_OP_STD_1) {
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eap_pax_mac(req->mac_id, (u8 *) "", 0,
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wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
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icvbuf);
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} else {
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eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
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wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
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icvbuf);
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}
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if (os_memcmp(icv, icvbuf, EAP_PAX_ICV_LEN) != 0) {
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wpa_printf(MSG_DEBUG, "EAP-PAX: invalid ICV - ignoring the "
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"message");
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wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected ICV",
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icvbuf, EAP_PAX_ICV_LEN);
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ret->ignore = TRUE;
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return NULL;
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}
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ret->ignore = FALSE;
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ret->methodState = METHOD_MAY_CONT;
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ret->decision = DECISION_FAIL;
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ret->allowNotifications = TRUE;
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switch (req->op_code) {
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case EAP_PAX_OP_STD_1:
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resp = eap_pax_process_std_1(data, ret, id, req, flen);
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break;
|
|
case EAP_PAX_OP_STD_3:
|
|
resp = eap_pax_process_std_3(data, ret, id, req, flen);
|
|
break;
|
|
default:
|
|
wpa_printf(MSG_DEBUG, "EAP-PAX: ignoring message with unknown "
|
|
"op_code %d", req->op_code);
|
|
ret->ignore = TRUE;
|
|
return NULL;
|
|
}
|
|
|
|
if (ret->methodState == METHOD_DONE) {
|
|
ret->allowNotifications = FALSE;
|
|
}
|
|
|
|
return resp;
|
|
}
|
|
|
|
|
|
static Boolean eap_pax_isKeyAvailable(struct eap_sm *sm, void *priv)
|
|
{
|
|
struct eap_pax_data *data = priv;
|
|
return data->state == PAX_DONE;
|
|
}
|
|
|
|
|
|
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 != PAX_DONE)
|
|
return NULL;
|
|
|
|
key = os_malloc(EAP_MSK_LEN);
|
|
if (key == NULL)
|
|
return NULL;
|
|
|
|
*len = EAP_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_MSK_LEN, key);
|
|
|
|
return key;
|
|
}
|
|
|
|
|
|
static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
|
|
{
|
|
struct eap_pax_data *data = priv;
|
|
u8 *key;
|
|
|
|
if (data->state != PAX_DONE)
|
|
return NULL;
|
|
|
|
key = os_malloc(EAP_EMSK_LEN);
|
|
if (key == NULL)
|
|
return NULL;
|
|
|
|
*len = EAP_EMSK_LEN;
|
|
eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
|
|
"Extended Master Session Key",
|
|
data->rand.e, 2 * EAP_PAX_RAND_LEN,
|
|
EAP_EMSK_LEN, key);
|
|
|
|
return key;
|
|
}
|
|
|
|
|
|
int eap_peer_pax_register(void)
|
|
{
|
|
struct eap_method *eap;
|
|
int ret;
|
|
|
|
eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
|
|
EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
|
|
if (eap == NULL)
|
|
return -1;
|
|
|
|
eap->init = eap_pax_init;
|
|
eap->deinit = eap_pax_deinit;
|
|
eap->process = eap_pax_process;
|
|
eap->isKeyAvailable = eap_pax_isKeyAvailable;
|
|
eap->getKey = eap_pax_getKey;
|
|
eap->get_emsk = eap_pax_get_emsk;
|
|
|
|
ret = eap_peer_method_register(eap);
|
|
if (ret)
|
|
eap_peer_method_free(eap);
|
|
return ret;
|
|
}
|