eap-wsc: Generate M5 messages

This commit is contained in:
Denis Kenzior 2016-08-30 23:20:24 -05:00
parent c0de9d1790
commit ba55afa3f4
1 changed files with 81 additions and 0 deletions

View File

@ -56,6 +56,7 @@ enum state {
STATE_EXPECT_START = 0,
STATE_EXPECT_M2,
STATE_EXPECT_M4,
STATE_EXPECT_M6,
};
static struct l_key *dh5_generator;
@ -140,6 +141,13 @@ static inline bool keywrap_authenticator_check(struct eap_wsc_state *wsc,
return true;
}
static inline void keywrap_authenticator_put(struct eap_wsc_state *wsc,
uint8_t *pdu, size_t len)
{
l_checksum_update(wsc->hmac_auth_key, pdu, len - 12);
l_checksum_get_digest(wsc->hmac_auth_key, pdu + len - 8, 8);
}
static uint8_t *encrypted_settings_decrypt(struct eap_wsc_state *wsc,
const uint8_t *pdu,
size_t len,
@ -193,6 +201,36 @@ fail:
return NULL;
}
static bool encrypted_settings_encrypt(struct eap_wsc_state *wsc,
const uint8_t *iv,
const uint8_t *in,
size_t in_len,
uint8_t *out,
size_t *out_len)
{
size_t len = 0;
unsigned int i;
uint8_t pad;
l_cipher_set_iv(wsc->aes_cbc_128, iv, 16);
memcpy(out, iv, 16);
len += 16;
memcpy(out + len, in, in_len);
len += in_len;
pad = 16 - in_len % 16;
for (i = 0; i < pad; i++)
out[len++] = pad;
if (!l_cipher_encrypt(wsc->aes_cbc_128, out + 16, out + 16, len - 16))
return false;
*out_len = len;
return true;
}
static int eap_wsc_probe(struct eap_state *eap, const char *name)
{
struct eap_wsc_state *wsc;
@ -270,6 +308,45 @@ static void eap_wsc_send_nack(struct eap_state *eap,
return;
}
static void eap_wsc_send_m5(struct eap_state *eap,
const uint8_t *m4_pdu, size_t m4_len)
{
struct eap_wsc_state *wsc = eap_get_data(eap);
struct wsc_m5_encrypted_settings m5es;
struct wsc_m5 m5;
uint8_t *pdu;
size_t pdu_len;
/* 20 for SNonce, 12 for Authenticator, 16 for IV + up to 16 pad */
uint8_t encrypted[64];
size_t encrypted_len;
bool r;
memcpy(m5es.e_snonce1, wsc->e_snonce1, sizeof(wsc->e_snonce1));
pdu = wsc_build_m5_encrypted_settings(&m5es, &pdu_len);
if (!pdu)
return;
keywrap_authenticator_put(wsc, pdu, pdu_len);
r = encrypted_settings_encrypt(wsc, wsc->iv1, pdu, pdu_len,
encrypted, &encrypted_len);
l_free(pdu);
if (!r)
return;
m5.version2 = true;
memcpy(m5.registrar_nonce, wsc->m2->registrar_nonce,
sizeof(m5.registrar_nonce));
pdu = wsc_build_m5(&m5, encrypted, encrypted_len, &pdu_len);
if (!pdu)
return;
authenticator_put(wsc, m4_pdu, m4_len, pdu, pdu_len);
eap_wsc_send_response(eap, pdu, pdu_len);
wsc->state = STATE_EXPECT_M6;
}
static void eap_wsc_handle_m4(struct eap_state *eap,
const uint8_t *pdu, size_t len)
{
@ -334,6 +411,8 @@ static void eap_wsc_handle_m4(struct eap_state *eap,
/* Now store R_Hash2 so we can verify it when we receive M6 */
memcpy(wsc->r_hash2, m4.r_hash2, sizeof(m4.r_hash2));
eap_wsc_send_m5(eap, pdu, len);
return;
invalid_settings:
@ -565,6 +644,8 @@ static void eap_wsc_handle_request(struct eap_state *eap,
case STATE_EXPECT_M4:
eap_wsc_handle_m4(eap, pkt + 2, len - 2);
break;
case STATE_EXPECT_M6:
break;
}
}