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-rw-r--r--src/eap_server/eap_server_sake.c542
1 files changed, 542 insertions, 0 deletions
diff --git a/src/eap_server/eap_server_sake.c b/src/eap_server/eap_server_sake.c
new file mode 100644
index 0000000..ce4848f
--- /dev/null
+++ b/src/eap_server/eap_server_sake.c
@@ -0,0 +1,542 @@
+/*
+ * hostapd / EAP-SAKE (RFC 4763) server
+ * Copyright (c) 2006-2007, 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_sake_common.h"
+
+
+struct eap_sake_data {
+ enum { IDENTITY, CHALLENGE, CONFIRM, SUCCESS, FAILURE } state;
+ u8 rand_s[EAP_SAKE_RAND_LEN];
+ u8 rand_p[EAP_SAKE_RAND_LEN];
+ struct {
+ u8 auth[EAP_SAKE_TEK_AUTH_LEN];
+ u8 cipher[EAP_SAKE_TEK_CIPHER_LEN];
+ } tek;
+ u8 msk[EAP_MSK_LEN];
+ u8 emsk[EAP_EMSK_LEN];
+ u8 session_id;
+ u8 *peerid;
+ size_t peerid_len;
+ u8 *serverid;
+ size_t serverid_len;
+};
+
+
+static const char * eap_sake_state_txt(int state)
+{
+ switch (state) {
+ case IDENTITY:
+ return "IDENTITY";
+ case CHALLENGE:
+ return "CHALLENGE";
+ case CONFIRM:
+ return "CONFIRM";
+ case SUCCESS:
+ return "SUCCESS";
+ case FAILURE:
+ return "FAILURE";
+ default:
+ return "?";
+ }
+}
+
+
+static void eap_sake_state(struct eap_sake_data *data, int state)
+{
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
+ eap_sake_state_txt(data->state),
+ eap_sake_state_txt(state));
+ data->state = state;
+}
+
+
+static void * eap_sake_init(struct eap_sm *sm)
+{
+ struct eap_sake_data *data;
+
+ data = os_zalloc(sizeof(*data));
+ if (data == NULL)
+ return NULL;
+ data->state = CHALLENGE;
+
+ if (os_get_random(&data->session_id, 1)) {
+ wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
+ os_free(data);
+ return NULL;
+ }
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Initialized Session ID %d",
+ data->session_id);
+
+ /* TODO: add support for configuring SERVERID */
+ data->serverid = (u8 *) os_strdup("hostapd");
+ if (data->serverid)
+ data->serverid_len = os_strlen((char *) data->serverid);
+
+ return data;
+}
+
+
+static void eap_sake_reset(struct eap_sm *sm, void *priv)
+{
+ struct eap_sake_data *data = priv;
+ os_free(data->serverid);
+ os_free(data->peerid);
+ os_free(data);
+}
+
+
+static struct wpabuf * eap_sake_build_msg(struct eap_sake_data *data,
+ u8 id, size_t length, u8 subtype)
+{
+ struct eap_sake_hdr *sake;
+ struct wpabuf *msg;
+ size_t plen;
+
+ plen = sizeof(struct eap_sake_hdr) + length;
+
+ msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
+ EAP_CODE_REQUEST, id);
+ if (msg == NULL) {
+ wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
+ "request");
+ return NULL;
+ }
+
+ sake = wpabuf_put(msg, sizeof(*sake));
+ sake->version = EAP_SAKE_VERSION;
+ sake->session_id = data->session_id;
+ sake->subtype = subtype;
+
+ return msg;
+}
+
+
+static struct wpabuf * eap_sake_build_identity(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ u8 id)
+{
+ struct wpabuf *msg;
+ size_t plen;
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Identity");
+
+ plen = 4;
+ if (data->serverid)
+ plen += 2 + data->serverid_len;
+ msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_IDENTITY);
+ if (msg == NULL) {
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PERM_ID_REQ");
+ eap_sake_add_attr(msg, EAP_SAKE_AT_PERM_ID_REQ, NULL, 2);
+
+ if (data->serverid) {
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
+ eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
+ data->serverid, data->serverid_len);
+ }
+
+ return msg;
+}
+
+
+static struct wpabuf * eap_sake_build_challenge(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ u8 id)
+{
+ struct wpabuf *msg;
+ size_t plen;
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge");
+
+ if (os_get_random(data->rand_s, EAP_SAKE_RAND_LEN)) {
+ wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
+ data->state = FAILURE;
+ return NULL;
+ }
+ wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
+ data->rand_s, EAP_SAKE_RAND_LEN);
+
+ plen = 2 + EAP_SAKE_RAND_LEN;
+ if (data->serverid)
+ plen += 2 + data->serverid_len;
+ msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_CHALLENGE);
+ if (msg == NULL) {
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_S");
+ eap_sake_add_attr(msg, EAP_SAKE_AT_RAND_S,
+ data->rand_s, EAP_SAKE_RAND_LEN);
+
+ if (data->serverid) {
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
+ eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
+ data->serverid, data->serverid_len);
+ }
+
+ return msg;
+}
+
+
+static struct wpabuf * eap_sake_build_confirm(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ u8 id)
+{
+ struct wpabuf *msg;
+ u8 *mic;
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Confirm");
+
+ msg = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
+ EAP_SAKE_SUBTYPE_CONFIRM);
+ if (msg == NULL) {
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_S");
+ wpabuf_put_u8(msg, EAP_SAKE_AT_MIC_S);
+ wpabuf_put_u8(msg, 2 + EAP_SAKE_MIC_LEN);
+ mic = wpabuf_put(msg, EAP_SAKE_MIC_LEN);
+ if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
+ data->serverid, data->serverid_len,
+ data->peerid, data->peerid_len, 0,
+ wpabuf_head(msg), wpabuf_len(msg), mic, mic))
+ {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
+ data->state = FAILURE;
+ os_free(msg);
+ return NULL;
+ }
+
+ return msg;
+}
+
+
+static struct wpabuf * eap_sake_buildReq(struct eap_sm *sm, void *priv, u8 id)
+{
+ struct eap_sake_data *data = priv;
+
+ switch (data->state) {
+ case IDENTITY:
+ return eap_sake_build_identity(sm, data, id);
+ case CHALLENGE:
+ return eap_sake_build_challenge(sm, data, id);
+ case CONFIRM:
+ return eap_sake_build_confirm(sm, data, id);
+ default:
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Unknown state %d in buildReq",
+ data->state);
+ break;
+ }
+ return NULL;
+}
+
+
+static Boolean eap_sake_check(struct eap_sm *sm, void *priv,
+ struct wpabuf *respData)
+{
+ struct eap_sake_data *data = priv;
+ struct eap_sake_hdr *resp;
+ size_t len;
+ u8 version, session_id, subtype;
+ const u8 *pos;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
+ if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Invalid frame");
+ return TRUE;
+ }
+
+ resp = (struct eap_sake_hdr *) pos;
+ version = resp->version;
+ session_id = resp->session_id;
+ subtype = resp->subtype;
+
+ if (version != EAP_SAKE_VERSION) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Unknown version %d", version);
+ return TRUE;
+ }
+
+ if (session_id != data->session_id) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
+ session_id, data->session_id);
+ return TRUE;
+ }
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype=%d", subtype);
+
+ if (data->state == IDENTITY && subtype == EAP_SAKE_SUBTYPE_IDENTITY)
+ return FALSE;
+
+ if (data->state == CHALLENGE && subtype == EAP_SAKE_SUBTYPE_CHALLENGE)
+ return FALSE;
+
+ if (data->state == CONFIRM && subtype == EAP_SAKE_SUBTYPE_CONFIRM)
+ return FALSE;
+
+ if (subtype == EAP_SAKE_SUBTYPE_AUTH_REJECT)
+ return FALSE;
+
+ wpa_printf(MSG_INFO, "EAP-SAKE: Unexpected subtype=%d in state=%d",
+ subtype, data->state);
+
+ return TRUE;
+}
+
+
+static void eap_sake_process_identity(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ const struct wpabuf *respData,
+ const u8 *payload, size_t payloadlen)
+{
+ if (data->state != IDENTITY)
+ return;
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Identity");
+ /* TODO: update identity and select new user data */
+ eap_sake_state(data, CHALLENGE);
+}
+
+
+static void eap_sake_process_challenge(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ const struct wpabuf *respData,
+ const u8 *payload, size_t payloadlen)
+{
+ struct eap_sake_parse_attr attr;
+ u8 mic_p[EAP_SAKE_MIC_LEN];
+
+ if (data->state != CHALLENGE)
+ return;
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Challenge");
+
+ if (eap_sake_parse_attributes(payload, payloadlen, &attr))
+ return;
+
+ if (!attr.rand_p || !attr.mic_p) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Response/Challenge did not "
+ "include AT_RAND_P or AT_MIC_P");
+ return;
+ }
+
+ os_memcpy(data->rand_p, attr.rand_p, EAP_SAKE_RAND_LEN);
+
+ os_free(data->peerid);
+ data->peerid = NULL;
+ data->peerid_len = 0;
+ if (attr.peerid) {
+ data->peerid = os_malloc(attr.peerid_len);
+ if (data->peerid == NULL)
+ return;
+ os_memcpy(data->peerid, attr.peerid, attr.peerid_len);
+ data->peerid_len = attr.peerid_len;
+ }
+
+ if (sm->user == NULL || sm->user->password == NULL ||
+ sm->user->password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Plaintext password with "
+ "%d-byte key not configured",
+ 2 * EAP_SAKE_ROOT_SECRET_LEN);
+ data->state = FAILURE;
+ return;
+ }
+ eap_sake_derive_keys(sm->user->password,
+ sm->user->password + EAP_SAKE_ROOT_SECRET_LEN,
+ data->rand_s, data->rand_p,
+ (u8 *) &data->tek, data->msk, data->emsk);
+
+ eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
+ data->serverid, data->serverid_len,
+ data->peerid, data->peerid_len, 1,
+ wpabuf_head(respData), wpabuf_len(respData),
+ attr.mic_p, mic_p);
+ if (os_memcmp(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
+ eap_sake_state(data, FAILURE);
+ return;
+ }
+
+ eap_sake_state(data, CONFIRM);
+}
+
+
+static void eap_sake_process_confirm(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ const struct wpabuf *respData,
+ const u8 *payload, size_t payloadlen)
+{
+ struct eap_sake_parse_attr attr;
+ u8 mic_p[EAP_SAKE_MIC_LEN];
+
+ if (data->state != CONFIRM)
+ return;
+
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Confirm");
+
+ if (eap_sake_parse_attributes(payload, payloadlen, &attr))
+ return;
+
+ if (!attr.mic_p) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Response/Confirm did not "
+ "include AT_MIC_P");
+ return;
+ }
+
+ eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
+ data->serverid, data->serverid_len,
+ data->peerid, data->peerid_len, 1,
+ wpabuf_head(respData), wpabuf_len(respData),
+ attr.mic_p, mic_p);
+ if (os_memcmp(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
+ wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
+ eap_sake_state(data, FAILURE);
+ } else
+ eap_sake_state(data, SUCCESS);
+}
+
+
+static void eap_sake_process_auth_reject(struct eap_sm *sm,
+ struct eap_sake_data *data,
+ const struct wpabuf *respData,
+ const u8 *payload, size_t payloadlen)
+{
+ wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Auth-Reject");
+ eap_sake_state(data, FAILURE);
+}
+
+
+static void eap_sake_process(struct eap_sm *sm, void *priv,
+ struct wpabuf *respData)
+{
+ struct eap_sake_data *data = priv;
+ struct eap_sake_hdr *resp;
+ u8 subtype;
+ size_t len;
+ const u8 *pos, *end;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
+ if (pos == NULL || len < sizeof(struct eap_sake_hdr))
+ return;
+
+ resp = (struct eap_sake_hdr *) pos;
+ end = pos + len;
+ subtype = resp->subtype;
+ pos = (u8 *) (resp + 1);
+
+ wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
+ pos, end - pos);
+
+ switch (subtype) {
+ case EAP_SAKE_SUBTYPE_IDENTITY:
+ eap_sake_process_identity(sm, data, respData, pos, end - pos);
+ break;
+ case EAP_SAKE_SUBTYPE_CHALLENGE:
+ eap_sake_process_challenge(sm, data, respData, pos, end - pos);
+ break;
+ case EAP_SAKE_SUBTYPE_CONFIRM:
+ eap_sake_process_confirm(sm, data, respData, pos, end - pos);
+ break;
+ case EAP_SAKE_SUBTYPE_AUTH_REJECT:
+ eap_sake_process_auth_reject(sm, data, respData, pos,
+ end - pos);
+ break;
+ }
+}
+
+
+static Boolean eap_sake_isDone(struct eap_sm *sm, void *priv)
+{
+ struct eap_sake_data *data = priv;
+ return data->state == SUCCESS || data->state == FAILURE;
+}
+
+
+static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
+{
+ struct eap_sake_data *data = priv;
+ u8 *key;
+
+ if (data->state != SUCCESS)
+ return NULL;
+
+ key = os_malloc(EAP_MSK_LEN);
+ if (key == NULL)
+ return NULL;
+ os_memcpy(key, data->msk, EAP_MSK_LEN);
+ *len = EAP_MSK_LEN;
+
+ return key;
+}
+
+
+static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
+{
+ struct eap_sake_data *data = priv;
+ u8 *key;
+
+ if (data->state != SUCCESS)
+ return NULL;
+
+ key = os_malloc(EAP_EMSK_LEN);
+ if (key == NULL)
+ return NULL;
+ os_memcpy(key, data->emsk, EAP_EMSK_LEN);
+ *len = EAP_EMSK_LEN;
+
+ return key;
+}
+
+
+static Boolean eap_sake_isSuccess(struct eap_sm *sm, void *priv)
+{
+ struct eap_sake_data *data = priv;
+ return data->state == SUCCESS;
+}
+
+
+int eap_server_sake_register(void)
+{
+ struct eap_method *eap;
+ int ret;
+
+ eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
+ EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
+ if (eap == NULL)
+ return -1;
+
+ eap->init = eap_sake_init;
+ eap->reset = eap_sake_reset;
+ eap->buildReq = eap_sake_buildReq;
+ eap->check = eap_sake_check;
+ eap->process = eap_sake_process;
+ eap->isDone = eap_sake_isDone;
+ eap->getKey = eap_sake_getKey;
+ eap->isSuccess = eap_sake_isSuccess;
+ eap->get_emsk = eap_sake_get_emsk;
+
+ ret = eap_server_method_register(eap);
+ if (ret)
+ eap_server_method_free(eap);
+ return ret;
+}