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mirror of https://git.kernel.org/pub/scm/network/wireless/iwd.git synced 2024-11-29 22:19:23 +01:00

eap-wsc: Add utility to decrypt EncryptedSettings

This commit is contained in:
Denis Kenzior 2016-08-30 14:43:49 -05:00
parent b78bef2be8
commit 633389f2f4

View File

@ -134,6 +134,59 @@ static inline bool keywrap_authenticator_check(struct eap_wsc_state *wsc,
return true; return true;
} }
static uint8_t *encrypted_settings_decrypt(struct eap_wsc_state *wsc,
const uint8_t *pdu,
size_t len,
size_t *out_len)
{
size_t encrypted_len;
uint8_t *decrypted;
unsigned int i;
uint8_t pad;
/* WSC 2.0.5, Section 12, Encrypted Settings:
* "The Data field of the Encrypted Settings attribute includes an
* initialization vector (IV) followed by a set of encrypted Wi-Fi
* Simple Configuration TLV attributes."
*
* Account for the IV being in the beginning 16 bytes
*/
if (len < 16 )
return NULL;
encrypted_len = len - 16;
if (encrypted_len < 16 || encrypted_len % 16)
return NULL;
decrypted = l_malloc(encrypted_len);
l_cipher_set_iv(wsc->aes_cbc_128, pdu, 16);
if (!l_cipher_decrypt(wsc->aes_cbc_128, pdu + 16,
decrypted, encrypted_len))
goto fail;
/* Check that the pad value is sane */
pad = decrypted[encrypted_len - 1];
if (pad > encrypted_len)
goto fail;
for (i = 0; i < pad; i++) {
if (decrypted[encrypted_len - pad + i] == pad)
continue;
goto fail;
}
*out_len = encrypted_len - pad;
return decrypted;
fail:
l_free(decrypted);
return NULL;
}
static int eap_wsc_probe(struct eap_state *eap, const char *name) static int eap_wsc_probe(struct eap_state *eap, const char *name)
{ {
struct eap_wsc_state *wsc; struct eap_wsc_state *wsc;