EAP server: Add getSessionId

This extends EAP server implementation to derive Session-Id similarly to
the existing EAP peer implementation.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/eap_server/eap.h

@@ -58,6 +58,8 @@ struct eap_eapol_interface {
 	struct wpabuf *eapReqData;
 	u8 *eapKeyData;
 	size_t eapKeyDataLen;
+	u8 *eapSessionId;
+	size_t eapSessionIdLen;
 	Boolean eapKeyAvailable; /* called keyAvailable in IEEE 802.1X-2004 */
 
 	/* AAA interface to full authenticator variables */

src/eap_server/eap_i.h

@@ -88,6 +88,19 @@ struct eap_method {
 	 * private data or this function may derive the key.
 	 */
 	u8 * (*get_emsk)(struct eap_sm *sm, void *priv, size_t *len);
+
+	/**
+	 * getSessionId - Get EAP method specific Session-Id
+	 * @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
+	 * @priv: Pointer to private EAP method data from eap_method::init()
+	 * @len: Pointer to a variable to store Session-Id length
+	 * Returns: Session-Id or %NULL if not available
+	 *
+	 * This function can be used to get the Session-Id from the EAP method.
+	 * The Session-Id may already be stored in the method-specific private
+	 * data or this function may derive the Session-Id.
+	 */
+	u8 * (*getSessionId)(struct eap_sm *sm, void *priv, size_t *len);
 };
 
 /**

src/eap_server/eap_server.c

@@ -171,6 +171,9 @@ SM_STATE(EAP, INITIALIZE)
 	bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
 	sm->eap_if.eapKeyData = NULL;
 	sm->eap_if.eapKeyDataLen = 0;
+	os_free(sm->eap_if.eapSessionId);
+	sm->eap_if.eapSessionId = NULL;
+	sm->eap_if.eapSessionIdLen = 0;
 	sm->eap_if.eapKeyAvailable = FALSE;
 	sm->eap_if.eapRestart = FALSE;
 
@@ -355,6 +358,16 @@ SM_STATE(EAP, METHOD_RESPONSE)
 			sm->eap_if.eapKeyData = NULL;
 			sm->eap_if.eapKeyDataLen = 0;
 		}
+		os_free(sm->eap_if.eapSessionId);
+		sm->eap_if.eapSessionId = NULL;
+		if (sm->m->getSessionId) {
+			sm->eap_if.eapSessionId = sm->m->getSessionId(
+				sm, sm->eap_method_priv,
+				&sm->eap_if.eapSessionIdLen);
+			wpa_hexdump(MSG_DEBUG, "EAP: Session-Id",
+				    sm->eap_if.eapSessionId,
+				    sm->eap_if.eapSessionIdLen);
+		}
 		sm->methodState = METHOD_END;
 	} else {
 		sm->methodState = METHOD_CONTINUE;
@@ -1353,6 +1366,7 @@ void eap_server_sm_deinit(struct eap_sm *sm)
 		sm->m->reset(sm, sm->eap_method_priv);
 	wpabuf_free(sm->eap_if.eapReqData);
 	bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
+	os_free(sm->eap_if.eapSessionId);
 	wpabuf_free(sm->lastReqData);
 	wpabuf_free(sm->eap_if.eapRespData);
 	os_free(sm->identity);

src/eap_server/eap_server_aka.c

@@ -1294,6 +1294,28 @@ static Boolean eap_aka_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_aka_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_aka_data *data = priv;
+	u8 *id;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	*len = 1 + EAP_AKA_RAND_LEN + EAP_AKA_AUTN_LEN;
+	id = os_malloc(*len);
+	if (id == NULL)
+		return NULL;
+
+	id[0] = data->eap_method;
+	os_memcpy(id + 1, data->rand, EAP_AKA_RAND_LEN);
+	os_memcpy(id + 1 + EAP_AKA_RAND_LEN, data->autn, EAP_AKA_AUTN_LEN);
+	wpa_hexdump(MSG_DEBUG, "EAP-AKA: Derived Session-Id", id, *len);
+
+	return id;
+}
+
+
 int eap_server_aka_register(void)
 {
 	struct eap_method *eap;
@@ -1313,6 +1335,7 @@ int eap_server_aka_register(void)
 	eap->getKey = eap_aka_getKey;
 	eap->isSuccess = eap_aka_isSuccess;
 	eap->get_emsk = eap_aka_get_emsk;
+	eap->getSessionId = eap_aka_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)
@@ -1342,6 +1365,7 @@ int eap_server_aka_prime_register(void)
 	eap->getKey = eap_aka_getKey;
 	eap->isSuccess = eap_aka_isSuccess;
 	eap->get_emsk = eap_aka_get_emsk;
+	eap->getSessionId = eap_aka_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_fast.c

@@ -1589,6 +1589,18 @@ static Boolean eap_fast_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_fast_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_fast_data *data = priv;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_FAST,
+						len);
+}
+
+
 int eap_server_fast_register(void)
 {
 	struct eap_method *eap;
@@ -1608,6 +1620,7 @@ int eap_server_fast_register(void)
 	eap->getKey = eap_fast_getKey;
 	eap->get_emsk = eap_fast_get_emsk;
 	eap->isSuccess = eap_fast_isSuccess;
+	eap->getSessionId = eap_fast_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_gpsk.c

@@ -24,6 +24,8 @@ struct eap_gpsk_data {
 	size_t sk_len;
 	u8 pk[EAP_GPSK_MAX_PK_LEN];
 	size_t pk_len;
+	u8 session_id[128];
+	size_t id_len;
 	u8 *id_peer;
 	size_t id_peer_len;
 #define MAX_NUM_CSUITES 2
@@ -417,6 +419,21 @@ static void eap_gpsk_process_gpsk_2(struct eap_sm *sm,
 		return;
 	}
 
+	if (eap_gpsk_derive_session_id(sm->user->password,
+				       sm->user->password_len,
+				       data->vendor, data->specifier,
+				       data->rand_peer, data->rand_server,
+				       data->id_peer, data->id_peer_len,
+				       sm->server_id, sm->server_id_len,
+				       EAP_TYPE_GPSK,
+				       data->session_id, &data->id_len) < 0) {
+		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to derive Session-Id");
+		eap_gpsk_state(data, FAILURE);
+		return;
+	}
+	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Derived Session-Id",
+		    data->session_id, data->id_len);
+
 	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
 	if (end - pos < (int) miclen) {
 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for MIC "
@@ -593,6 +610,24 @@ static Boolean eap_gpsk_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_gpsk_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_gpsk_data *data = priv;
+	u8 *sid;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	sid = os_malloc(data->id_len);
+	if (sid == NULL)
+		return NULL;
+	os_memcpy(sid, data->session_id, data->id_len);
+	*len = data->id_len;
+
+	return sid;
+}
+
+
 int eap_server_gpsk_register(void)
 {
 	struct eap_method *eap;
@@ -612,6 +647,7 @@ int eap_server_gpsk_register(void)
 	eap->getKey = eap_gpsk_getKey;
 	eap->isSuccess = eap_gpsk_isSuccess;
 	eap->get_emsk = eap_gpsk_get_emsk;
+	eap->getSessionId = eap_gpsk_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_ikev2.c

@@ -511,6 +511,36 @@ static u8 * eap_ikev2_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 }
 
 
+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_server_ikev2_register(void)
 {
 	struct eap_method *eap;
@@ -531,6 +561,7 @@ int eap_server_ikev2_register(void)
 	eap->getKey = eap_ikev2_getKey;
 	eap->isSuccess = eap_ikev2_isSuccess;
 	eap->get_emsk = eap_ikev2_get_emsk;
+	eap->getSessionId = eap_ikev2_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_peap.c

@@ -1229,6 +1229,18 @@ static Boolean eap_peap_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_peap_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_peap_data *data = priv;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_PEAP,
+						len);
+}
+
+
 int eap_server_peap_register(void)
 {
 	struct eap_method *eap;
@@ -1247,6 +1259,7 @@ int eap_server_peap_register(void)
 	eap->isDone = eap_peap_isDone;
 	eap->getKey = eap_peap_getKey;
 	eap->isSuccess = eap_peap_isSuccess;
+	eap->getSessionId = eap_peap_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_psk.c

@@ -485,6 +485,28 @@ static Boolean eap_psk_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_psk_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_psk_data *data = priv;
+	u8 *id;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	*len = 1 + 2 * EAP_PSK_RAND_LEN;
+	id = os_malloc(*len);
+	if (id == NULL)
+		return NULL;
+
+	id[0] = EAP_TYPE_PSK;
+	os_memcpy(id + 1, data->rand_p, EAP_PSK_RAND_LEN);
+	os_memcpy(id + 1 + EAP_PSK_RAND_LEN, data->rand_s, EAP_PSK_RAND_LEN);
+	wpa_hexdump(MSG_DEBUG, "EAP-PSK: Derived Session-Id", id, *len);
+
+	return id;
+}
+
+
 int eap_server_psk_register(void)
 {
 	struct eap_method *eap;
@@ -504,6 +526,7 @@ int eap_server_psk_register(void)
 	eap->getKey = eap_psk_getKey;
 	eap->isSuccess = eap_psk_isSuccess;
 	eap->get_emsk = eap_psk_get_emsk;
+	eap->getSessionId = eap_psk_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_pwd.c

@@ -1020,6 +1020,25 @@ static Boolean eap_pwd_is_done(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_pwd_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_pwd_data *data = priv;
+	u8 *id;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	id = os_malloc(1 + SHA256_MAC_LEN);
+	if (id == NULL)
+		return NULL;
+
+	os_memcpy(id, data->session_id, 1 + SHA256_MAC_LEN);
+	*len = 1 + SHA256_MAC_LEN;
+
+	return id;
+}
+
+
 int eap_server_pwd_register(void)
 {
 	struct eap_method *eap;
@@ -1048,6 +1067,7 @@ int eap_server_pwd_register(void)
 	eap->getKey = eap_pwd_getkey;
 	eap->get_emsk = eap_pwd_get_emsk;
 	eap->isSuccess = eap_pwd_is_success;
+	eap->getSessionId = eap_pwd_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_sake.c

@@ -495,6 +495,28 @@ static Boolean eap_sake_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_sake_data *data = priv;
+	u8 *id;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	*len = 1 + 2 * EAP_SAKE_RAND_LEN;
+	id = os_malloc(*len);
+	if (id == NULL)
+		return NULL;
+
+	id[0] = EAP_TYPE_SAKE;
+	os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
+	os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
+	wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
+
+	return id;
+}
+
+
 int eap_server_sake_register(void)
 {
 	struct eap_method *eap;
@@ -514,6 +536,7 @@ int eap_server_sake_register(void)
 	eap->getKey = eap_sake_getKey;
 	eap->isSuccess = eap_sake_isSuccess;
 	eap->get_emsk = eap_sake_get_emsk;
+	eap->getSessionId = eap_sake_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_sim.c

@@ -820,6 +820,29 @@ static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_sim_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_sim_data *data = priv;
+	u8 *id;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	*len = 1 + data->num_chal * GSM_RAND_LEN + EAP_SIM_NONCE_MT_LEN;
+	id = os_malloc(*len);
+	if (id == NULL)
+		return NULL;
+
+	id[0] = EAP_TYPE_SIM;
+	os_memcpy(id + 1, data->rand, data->num_chal * GSM_RAND_LEN);
+	os_memcpy(id + 1 + data->num_chal * GSM_RAND_LEN, data->nonce_mt,
+		  EAP_SIM_NONCE_MT_LEN);
+	wpa_hexdump(MSG_DEBUG, "EAP-SIM: Derived Session-Id", id, *len);
+
+	return id;
+}
+
+
 int eap_server_sim_register(void)
 {
 	struct eap_method *eap;
@@ -839,6 +862,7 @@ int eap_server_sim_register(void)
 	eap->getKey = eap_sim_getKey;
 	eap->isSuccess = eap_sim_isSuccess;
 	eap->get_emsk = eap_sim_get_emsk;
+	eap->getSessionId = eap_sim_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_tls.c

@@ -310,6 +310,18 @@ static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_tls_data *data = priv;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_TLS,
+						len);
+}
+
+
 int eap_server_tls_register(void)
 {
 	struct eap_method *eap;
@@ -329,6 +341,7 @@ int eap_server_tls_register(void)
 	eap->getKey = eap_tls_getKey;
 	eap->isSuccess = eap_tls_isSuccess;
 	eap->get_emsk = eap_tls_get_emsk;
+	eap->getSessionId = eap_tls_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_server_tls_common.c

@@ -140,6 +140,47 @@ fail:
 }
 
 
+/**
+ * eap_server_tls_derive_session_id - Derive a Session-Id based on TLS data
+ * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
+ * @data: Data for TLS processing
+ * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
+ * @len: Pointer to length of the session ID generated
+ * Returns: Pointer to allocated Session-Id on success or %NULL on failure
+ *
+ * This function derive the Session-Id based on the TLS session data
+ * (client/server random and method type).
+ *
+ * The caller is responsible for freeing the returned buffer.
+ */
+u8 * eap_server_tls_derive_session_id(struct eap_sm *sm,
+				      struct eap_ssl_data *data, u8 eap_type,
+				      size_t *len)
+{
+	struct tls_keys keys;
+	u8 *out;
+
+	if (tls_connection_get_keys(sm->ssl_ctx, data->conn, &keys))
+		return NULL;
+
+	if (keys.client_random == NULL || keys.server_random == NULL)
+		return NULL;
+
+	*len = 1 + keys.client_random_len + keys.server_random_len;
+	out = os_malloc(*len);
+	if (out == NULL)
+		return NULL;
+
+	/* Session-Id = EAP type || client.random || server.random */
+	out[0] = eap_type;
+	os_memcpy(out + 1, keys.client_random, keys.client_random_len);
+	os_memcpy(out + 1 + keys.client_random_len, keys.server_random,
+		  keys.server_random_len);
+
+	return out;
+}
+
+
 struct wpabuf * eap_server_tls_build_msg(struct eap_ssl_data *data,
 					 int eap_type, int version, u8 id)
 {

src/eap_server/eap_server_ttls.c

@@ -1181,6 +1181,18 @@ static Boolean eap_ttls_isSuccess(struct eap_sm *sm, void *priv)
 }
 
 
+static u8 * eap_ttls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
+{
+	struct eap_ttls_data *data = priv;
+
+	if (data->state != SUCCESS)
+		return NULL;
+
+	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_TTLS,
+						len);
+}
+
+
 int eap_server_ttls_register(void)
 {
 	struct eap_method *eap;
@@ -1199,6 +1211,7 @@ int eap_server_ttls_register(void)
 	eap->isDone = eap_ttls_isDone;
 	eap->getKey = eap_ttls_getKey;
 	eap->isSuccess = eap_ttls_isSuccess;
+	eap->getSessionId = eap_ttls_get_session_id;
 
 	ret = eap_server_method_register(eap);
 	if (ret)

src/eap_server/eap_tls_common.h

@@ -74,6 +74,9 @@ int eap_server_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
 void eap_server_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data);
 u8 * eap_server_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
 			       char *label, size_t len);
+u8 * eap_server_tls_derive_session_id(struct eap_sm *sm,
+				      struct eap_ssl_data *data, u8 eap_type,
+				      size_t *len);
 struct wpabuf * eap_server_tls_build_msg(struct eap_ssl_data *data,
 					 int eap_type, int version, u8 id);
 struct wpabuf * eap_server_tls_build_ack(u8 id, int eap_type, int version);