* EAP server/peer: EAP-GPSK shared routines
* 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.
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
*/
#include "includes.h"
u8 *pk, size_t *pk_len)
{
u8 *seed, *pos;
- size_t seed_len;
int ret;
wpa_printf(MSG_DEBUG, "EAP-GPSK: Deriving keys (%d:%d)",
wpa_hexdump_key(MSG_DEBUG, "EAP-GPSK: PSK", psk, psk_len);
/* Seed = RAND_Peer || ID_Peer || RAND_Server || ID_Server */
- seed_len = 2 * EAP_GPSK_RAND_LEN + id_server_len + id_peer_len;
- seed = os_malloc(seed_len);
+ seed = os_malloc(2 * EAP_GPSK_RAND_LEN + id_server_len + id_peer_len);
if (seed == NULL) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to allocate memory "
"for key derivation");
pos += EAP_GPSK_RAND_LEN;
os_memcpy(pos, id_server, id_server_len);
pos += id_server_len;
- wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Seed", seed, seed_len);
+ wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Seed", seed, pos - seed);
switch (specifier) {
case EAP_GPSK_CIPHER_AES:
- ret = eap_gpsk_derive_keys_aes(psk, psk_len, seed, seed_len,
+ ret = eap_gpsk_derive_keys_aes(psk, psk_len, seed, pos - seed,
msk, emsk, sk, sk_len,
pk, pk_len);
break;
#ifdef EAP_GPSK_SHA256
case EAP_GPSK_CIPHER_SHA256:
- ret = eap_gpsk_derive_keys_sha256(psk, psk_len, seed, seed_len,
+ ret = eap_gpsk_derive_keys_sha256(psk, psk_len, seed,
+ pos - seed,
msk, emsk, sk, sk_len);
break;
#endif /* EAP_GPSK_SHA256 */
}
+static int eap_gpsk_derive_mid_helper(u32 csuite_specifier,
+ u8 *kdf_out, size_t kdf_out_len,
+ const u8 *psk, const u8 *seed,
+ size_t seed_len, u8 method_type)
+{
+ u8 *pos, *data;
+ size_t data_len;
+ int (*gkdf)(const u8 *_psk, const u8 *_data, size_t _data_len,
+ u8 *buf, size_t len);
+
+ gkdf = NULL;
+ switch (csuite_specifier) {
+ case EAP_GPSK_CIPHER_AES:
+ gkdf = eap_gpsk_gkdf_cmac;
+ break;
+#ifdef EAP_GPSK_SHA256
+ case EAP_GPSK_CIPHER_SHA256:
+ gkdf = eap_gpsk_gkdf_sha256;
+ break;
+#endif /* EAP_GPSK_SHA256 */
+ default:
+ wpa_printf(MSG_DEBUG, "EAP-GPSK: Unknown cipher %d used in "
+ "Session-Id derivation", csuite_specifier);
+ return -1;
+ }
+
+#define SID_LABEL "Method ID"
+ /* "Method ID" || EAP_Method_Type || CSuite_Sel || inputString */
+ data_len = strlen(SID_LABEL) + 1 + 6 + seed_len;
+ data = os_malloc(data_len);
+ if (data == NULL)
+ return -1;
+ pos = data;
+ os_memcpy(pos, SID_LABEL, strlen(SID_LABEL));
+ pos += strlen(SID_LABEL);
+#undef SID_LABEL
+ os_memcpy(pos, &method_type, 1);
+ pos += 1;
+ WPA_PUT_BE32(pos, EAP_GPSK_VENDOR_IETF); /* CSuite/Vendor = IETF */
+ pos += 4;
+ WPA_PUT_BE16(pos, csuite_specifier); /* CSuite/Specifier */
+ pos += 2;
+ os_memcpy(pos, seed, seed_len); /* inputString */
+ wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Data to Method ID derivation",
+ data, data_len);
+
+ if (gkdf(psk, data, data_len, kdf_out, kdf_out_len) < 0) {
+ os_free(data);
+ return -1;
+ }
+ os_free(data);
+ wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Method ID", kdf_out, kdf_out_len);
+
+ return 0;
+}
+
+
+/**
+ * eap_gpsk_session_id - Derive EAP-GPSK Session ID
+ * @psk: Pre-shared key
+ * @psk_len: Length of psk in bytes
+ * @vendor: CSuite/Vendor
+ * @specifier: CSuite/Specifier
+ * @rand_peer: 32-byte RAND_Peer
+ * @rand_server: 32-byte RAND_Server
+ * @id_peer: ID_Peer
+ * @id_peer_len: Length of ID_Peer
+ * @id_server: ID_Server
+ * @id_server_len: Length of ID_Server
+ * @method_type: EAP Authentication Method Type
+ * @sid: Buffer for 17-byte Session ID
+ * @sid_len: Buffer for returning length of Session ID
+ * Returns: 0 on success, -1 on failure
+ */
+int eap_gpsk_derive_session_id(const u8 *psk, size_t psk_len, int vendor,
+ int specifier,
+ const u8 *rand_peer, const u8 *rand_server,
+ const u8 *id_peer, size_t id_peer_len,
+ const u8 *id_server, size_t id_server_len,
+ u8 method_type, u8 *sid, size_t *sid_len)
+{
+ u8 *seed, *pos;
+ u8 kdf_out[16];
+ int ret;
+
+ wpa_printf(MSG_DEBUG, "EAP-GPSK: Deriving Session ID(%d:%d)",
+ vendor, specifier);
+
+ if (vendor != EAP_GPSK_VENDOR_IETF)
+ return -1;
+
+ wpa_hexdump_key(MSG_DEBUG, "EAP-GPSK: PSK", psk, psk_len);
+
+ /*
+ * inputString = RAND_Peer || ID_Peer || RAND_Server || ID_Server
+ * (= seed)
+ * KS = 16, CSuite_Sel = 0x00000000 0x0001
+ * Method-ID = GKDF-16 (zero, "Method ID" || EAP_Method_Type ||
+ * CSuite_Sel || inputString)
+ */
+ seed = os_malloc(2 * EAP_GPSK_RAND_LEN + id_server_len + id_peer_len);
+ if (seed == NULL) {
+ wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to allocate memory "
+ "for Session-Id derivation");
+ return -1;
+ }
+
+ pos = seed;
+ os_memcpy(pos, rand_peer, EAP_GPSK_RAND_LEN);
+ pos += EAP_GPSK_RAND_LEN;
+ os_memcpy(pos, id_peer, id_peer_len);
+ pos += id_peer_len;
+ os_memcpy(pos, rand_server, EAP_GPSK_RAND_LEN);
+ pos += EAP_GPSK_RAND_LEN;
+ os_memcpy(pos, id_server, id_server_len);
+ pos += id_server_len;
+ wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Seed", seed, pos - seed);
+
+ ret = eap_gpsk_derive_mid_helper(specifier,
+ kdf_out, sizeof(kdf_out),
+ psk, seed, pos - seed,
+ method_type);
+
+ sid[0] = method_type;
+ os_memcpy(sid + 1, kdf_out, sizeof(kdf_out));
+ *sid_len = 1 + sizeof(kdf_out);
+
+ os_free(seed);
+
+ return ret;
+}
+
+
/**
* eap_gpsk_mic_len - Get the length of the MIC
* @vendor: CSuite/Vendor
projects / mech_eap.git / blobdiff