libeap/src/eap_common/eap_ikev2_common.c

   1 /*
   2  * EAP-IKEv2 common routines
   3  * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "eap_defs.h"
  13 #include "eap_common.h"
  14 #include "ikev2_common.h"
  15 #include "eap_ikev2_common.h"
  16
  17
  18 int eap_ikev2_derive_keymat(int prf, struct ikev2_keys *keys,
  19                             const u8 *i_nonce, size_t i_nonce_len,
  20                             const u8 *r_nonce, size_t r_nonce_len,
  21                             u8 *keymat)
  22 {
  23         u8 *nonces;
  24         size_t nlen;
  25
  26         /* KEYMAT = prf+(SK_d, Ni | Nr) */
  27         if (keys->SK_d == NULL || i_nonce == NULL || r_nonce == NULL)
  28                 return -1;
  29
  30         nlen = i_nonce_len + r_nonce_len;
  31         nonces = os_malloc(nlen);
  32         if (nonces == NULL)
  33                 return -1;
  34         os_memcpy(nonces, i_nonce, i_nonce_len);
  35         os_memcpy(nonces + i_nonce_len, r_nonce, r_nonce_len);
  36
  37         if (ikev2_prf_plus(prf, keys->SK_d, keys->SK_d_len, nonces, nlen,
  38                            keymat, EAP_MSK_LEN + EAP_EMSK_LEN)) {
  39                 os_free(nonces);
  40                 return -1;
  41         }
  42         os_free(nonces);
  43
  44         wpa_hexdump_key(MSG_DEBUG, "EAP-IKEV2: KEYMAT",
  45                         keymat, EAP_MSK_LEN + EAP_EMSK_LEN);
  46
  47         return 0;
  48 }
  49
  50
  51 struct wpabuf * eap_ikev2_build_frag_ack(u8 id, u8 code)
  52 {
  53         struct wpabuf *msg;
  54
  55         msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, 0, code, id);
  56         if (msg == NULL) {
  57                 wpa_printf(MSG_ERROR, "EAP-IKEV2: Failed to allocate memory "
  58                            "for fragment ack");
  59                 return NULL;
  60         }
  61
  62         wpa_printf(MSG_DEBUG, "EAP-IKEV2: Send fragment ack");
  63
  64         return msg;
  65 }
  66
  67
  68 int eap_ikev2_validate_icv(int integ_alg, struct ikev2_keys *keys,
  69                            int initiator, const struct wpabuf *msg,
  70                            const u8 *pos, const u8 *end)
  71 {
  72         const struct ikev2_integ_alg *integ;
  73         size_t icv_len;
  74         u8 icv[IKEV2_MAX_HASH_LEN];
  75         const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
  76
  77         integ = ikev2_get_integ(integ_alg);
  78         if (integ == NULL) {
  79                 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
  80                            "transform / cannot validate ICV");
  81                 return -1;
  82         }
  83         icv_len = integ->hash_len;
  84
  85         if (end - pos < (int) icv_len) {
  86                 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Not enough room in the "
  87                            "message for Integrity Checksum Data");
  88                 return -1;
  89         }
  90
  91         if (SK_a == NULL) {
  92                 wpa_printf(MSG_DEBUG, "EAP-IKEV2: No SK_a for ICV validation");
  93                 return -1;
  94         }
  95
  96         if (ikev2_integ_hash(integ_alg, SK_a, keys->SK_integ_len,
  97                              wpabuf_head(msg),
  98                              wpabuf_len(msg) - icv_len, icv) < 0) {
  99                 wpa_printf(MSG_INFO, "EAP-IKEV2: Could not calculate ICV");
 100                 return -1;
 101         }
 102
 103         if (os_memcmp_const(icv, end - icv_len, icv_len) != 0) {
 104                 wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid ICV");
 105                 wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Calculated ICV",
 106                             icv, icv_len);
 107                 wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Received ICV",
 108                             end - icv_len, icv_len);
 109                 return -1;
 110         }
 111
 112         wpa_printf(MSG_DEBUG, "EAP-IKEV2: Valid Integrity Checksum Data in "
 113                    "the received message");
 114
 115         return icv_len;
 116 }