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-rw-r--r--src/eap_server/eap_server_pax.c569
1 files changed, 569 insertions, 0 deletions
diff --git a/src/eap_server/eap_server_pax.c b/src/eap_server/eap_server_pax.c
new file mode 100644
index 0000000..1dc023b
--- /dev/null
+++ b/src/eap_server/eap_server_pax.c
@@ -0,0 +1,569 @@
+/*
+ * hostapd / EAP-PAX (RFC 4746) server
+ * Copyright (c) 2005-2007, Jouni Malinen <j@w1.fi>
+ *
+ * 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 "includes.h"
+
+#include "common.h"
+#include "eap_server/eap_i.h"
+#include "eap_common/eap_pax_common.h"
+
+/*
+ * Note: only PAX_STD subprotocol is currently supported
+ *
+ * TODO: Add support with PAX_SEC with the mandatory to implement ciphersuite
+ * (HMAC_SHA1_128, IANA DH Group 14 (2048 bits), RSA-PKCS1-V1_5) and
+ * recommended ciphersuite (HMAC_SHA256_128, IANA DH Group 15 (3072 bits),
+ * RSAES-OAEP).
+ */
+
+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 = os_zalloc(sizeof(*data));
+ if (data == NULL)
+ return NULL;
+ data->state = PAX_STD_1;
+ /*
+ * TODO: make this configurable once EAP_PAX_HMAC_SHA256_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;
+ os_free(data->cid);
+ os_free(data);
+}
+
+
+static struct wpabuf * eap_pax_build_std_1(struct eap_sm *sm,
+ struct eap_pax_data *data, u8 id)
+{
+ struct wpabuf *req;
+ struct eap_pax_hdr *pax;
+ u8 *pos;
+
+ wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (sending)");
+
+ if (os_get_random(data->rand.r.x, EAP_PAX_RAND_LEN)) {
+ wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
+ sizeof(*pax) + 2 + EAP_PAX_RAND_LEN +
+ EAP_PAX_ICV_LEN, EAP_CODE_REQUEST, id);
+ if (req == NULL) {
+ wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
+ "request");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ pax = wpabuf_put(req, sizeof(*pax));
+ pax->op_code = EAP_PAX_OP_STD_1;
+ pax->flags = 0;
+ pax->mac_id = data->mac_id;
+ pax->dh_group_id = EAP_PAX_DH_GROUP_NONE;
+ pax->public_key_id = EAP_PAX_PUBLIC_KEY_NONE;
+
+ wpabuf_put_be16(req, EAP_PAX_RAND_LEN);
+ wpabuf_put_data(req, data->rand.r.x, EAP_PAX_RAND_LEN);
+ wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: A = X (server rand)",
+ data->rand.r.x, EAP_PAX_RAND_LEN);
+
+ pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
+ eap_pax_mac(data->mac_id, (u8 *) "", 0,
+ wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
+ NULL, 0, NULL, 0, pos);
+ wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
+
+ return req;
+}
+
+
+static struct wpabuf * eap_pax_build_std_3(struct eap_sm *sm,
+ struct eap_pax_data *data, u8 id)
+{
+ struct wpabuf *req;
+ struct eap_pax_hdr *pax;
+ u8 *pos;
+
+ wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (sending)");
+
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
+ sizeof(*pax) + 2 + EAP_PAX_MAC_LEN +
+ EAP_PAX_ICV_LEN, EAP_CODE_REQUEST, id);
+ if (req == NULL) {
+ wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
+ "request");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ pax = wpabuf_put(req, sizeof(*pax));
+ pax->op_code = EAP_PAX_OP_STD_3;
+ pax->flags = 0;
+ pax->mac_id = data->mac_id;
+ pax->dh_group_id = EAP_PAX_DH_GROUP_NONE;
+ pax->public_key_id = EAP_PAX_PUBLIC_KEY_NONE;
+
+ wpabuf_put_be16(req, EAP_PAX_MAC_LEN);
+ pos = wpabuf_put(req, 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;
+
+ /* Optional ADE could be added here, if needed */
+
+ pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
+ eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
+ wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
+ NULL, 0, NULL, 0, pos);
+ wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
+
+ return req;
+}
+
+
+static struct wpabuf * eap_pax_buildReq(struct eap_sm *sm, void *priv, u8 id)
+{
+ struct eap_pax_data *data = priv;
+
+ switch (data->state) {
+ case PAX_STD_1:
+ return eap_pax_build_std_1(sm, data, id);
+ case PAX_STD_3:
+ return eap_pax_build_std_3(sm, data, id);
+ 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,
+ struct wpabuf *respData)
+{
+ struct eap_pax_data *data = priv;
+ struct eap_pax_hdr *resp;
+ const u8 *pos;
+ size_t len, mlen;
+ u8 icvbuf[EAP_PAX_ICV_LEN], *icv;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
+ if (pos == NULL || len < sizeof(*resp)) {
+ wpa_printf(MSG_INFO, "EAP-PAX: Invalid frame");
+ return TRUE;
+ }
+
+ mlen = sizeof(struct eap_hdr) + 1 + len;
+ resp = (struct eap_pax_hdr *) pos;
+
+ 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 = wpabuf_mhead_u8(respData) + mlen - 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,
+ wpabuf_mhead(respData),
+ wpabuf_len(respData) - EAP_PAX_ICV_LEN,
+ NULL, 0, NULL, 0, icvbuf);
+ if (os_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,
+ struct wpabuf *respData)
+{
+ struct eap_pax_hdr *resp;
+ u8 mac[EAP_PAX_MAC_LEN], icvbuf[EAP_PAX_ICV_LEN];
+ const u8 *pos;
+ size_t len, left;
+ int i;
+
+ if (data->state != PAX_STD_1)
+ return;
+
+ wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX_STD-2");
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
+ if (pos == NULL || len < sizeof(*resp) + EAP_PAX_ICV_LEN)
+ return;
+
+ resp = (struct eap_pax_hdr *) pos;
+ pos = (u8 *) (resp + 1);
+ left = len - sizeof(*resp);
+
+ if (left < 2 + EAP_PAX_RAND_LEN ||
+ WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
+ wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (B)");
+ return;
+ }
+ pos += 2;
+ left -= 2;
+ os_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 || (size_t) 2 + WPA_GET_BE16(pos) > left) {
+ wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (CID)");
+ return;
+ }
+ data->cid_len = WPA_GET_BE16(pos);
+ os_free(data->cid);
+ data->cid = os_malloc(data->cid_len);
+ if (data->cid == NULL) {
+ wpa_printf(MSG_INFO, "EAP-PAX: Failed to allocate memory for "
+ "CID");
+ return;
+ }
+ os_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 ||
+ WPA_GET_BE16(pos) != 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].vendor != EAP_VENDOR_IETF ||
+ sm->user->methods[i].method != EAP_TYPE_NONE);
+ i++) {
+ if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
+ sm->user->methods[i].method == EAP_TYPE_PAX)
+ break;
+ }
+
+ if (i >= EAP_MAX_METHODS ||
+ sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
+ sm->user->methods[i].method != 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;
+ }
+ os_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 (os_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,
+ wpabuf_head(respData),
+ wpabuf_len(respData) - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0,
+ icvbuf);
+ if (os_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,
+ struct wpabuf *respData)
+{
+ 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,
+ struct wpabuf *respData)
+{
+ struct eap_pax_data *data = priv;
+ struct eap_pax_hdr *resp;
+ const u8 *pos;
+ size_t len;
+
+ if (sm->user == NULL || sm->user->password == NULL) {
+ wpa_printf(MSG_INFO, "EAP-PAX: Plaintext password not "
+ "configured");
+ data->state = FAILURE;
+ return;
+ }
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
+ if (pos == NULL || len < sizeof(*resp))
+ return;
+
+ resp = (struct eap_pax_hdr *) pos;
+
+ switch (resp->op_code) {
+ case EAP_PAX_OP_STD_2:
+ eap_pax_process_std_2(sm, data, respData);
+ break;
+ case EAP_PAX_OP_ACK:
+ eap_pax_process_ack(sm, data, respData);
+ 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 = 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 != SUCCESS)
+ 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;
+}
+
+
+static Boolean eap_pax_isSuccess(struct eap_sm *sm, void *priv)
+{
+ struct eap_pax_data *data = priv;
+ return data->state == SUCCESS;
+}
+
+
+int eap_server_pax_register(void)
+{
+ struct eap_method *eap;
+ int ret;
+
+ eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
+ EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
+ if (eap == NULL)
+ return -1;
+
+ eap->init = eap_pax_init;
+ eap->reset = eap_pax_reset;
+ eap->buildReq = eap_pax_buildReq;
+ eap->check = eap_pax_check;
+ eap->process = eap_pax_process;
+ eap->isDone = eap_pax_isDone;
+ eap->getKey = eap_pax_getKey;
+ eap->isSuccess = eap_pax_isSuccess;
+ eap->get_emsk = eap_pax_get_emsk;
+
+ ret = eap_server_method_register(eap);
+ if (ret)
+ eap_server_method_free(eap);
+ return ret;
+}