/* Process an authentication request packet */
static void
licence_process_authreq(STREAM s)
{
uint8 *in_token = NULL, *in_sig;
uint8 out_token[LICENCE_TOKEN_SIZE], decrypt_token[LICENCE_TOKEN_SIZE];
uint8 hwid[LICENCE_HWID_SIZE], crypt_hwid[LICENCE_HWID_SIZE];
uint8 sealed_buffer[LICENCE_TOKEN_SIZE + LICENCE_HWID_SIZE];
uint8 out_sig[LICENCE_SIGNATURE_SIZE];
void * crypt_key;
/* Parse incoming packet and save the encrypted token */
licence_parse_authreq(s, &in_token, &in_sig);
memcpy(out_token, in_token, LICENCE_TOKEN_SIZE);
/* Decrypt the token. It should read TEST in Unicode. */
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
ssl_rc4_crypt(crypt_key, (char *)in_token, (char *)decrypt_token, LICENCE_TOKEN_SIZE);
ssl_rc4_info_delete(crypt_key);
/* Generate a signature for a buffer of token and HWID */
licence_generate_hwid(hwid);
memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE);
memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE);
sec_sign(out_sig, 16, g_licence_sign_key, 16, sealed_buffer, sizeof(sealed_buffer));
/* Now encrypt the HWID */
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
ssl_rc4_crypt(crypt_key, (char *)hwid, (char *)crypt_hwid, LICENCE_HWID_SIZE);
ssl_rc4_info_delete(crypt_key);
licence_send_authresp(out_token, crypt_hwid, out_sig);
}
CryptoRc4
crypto_rc4_init(uint8 * key, uint32 len)
{
CryptoRc4 rc4 = xmalloc(sizeof(*rc4));
ssl_rc4_set_key(&rc4->data, key, len);
return rc4;
}
void
crypto_rc4_set_key(CRYPTO_RC4 * rc4, uint8 * key, uint32 len)
{
#ifdef CRYPTO_OPENSSL
RC4_set_key(rc4, len, key);
#else /* built-in crypto */
ssl_rc4_set_key(rc4, key, len);
#endif
}
/* Process an licence issue packet */
static void
licence_process_issue(STREAM s)
{
void * crypt_key;
uint32 length;
uint16 check;
int i;
in_uint8s(s, 2); /* 3d 45 - unknown */
in_uint16_le(s, length);
if (!s_check_rem(s, length))
return;
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
ssl_rc4_crypt(crypt_key, (char *)s->p, (char *)s->p, length);
ssl_rc4_info_delete(crypt_key);
in_uint16(s, check);
if (check != 0)
return;
g_licence_issued = True;
in_uint8s(s, 2); /* pad */
/* advance to fourth string */
length = 0;
for (i = 0; i < 4; i++)
{
in_uint8s(s, length);
in_uint32_le(s, length);
if (!s_check_rem(s, length))
return;
}
g_licence_issued = True;
save_licence(s->p, length);
}
/* Process a licence demand packet */
static void
licence_process_demand(STREAM s)
{
uint8 null_data[SEC_MODULUS_SIZE];
uint8 *server_random;
uint8 signature[LICENCE_SIGNATURE_SIZE];
uint8 hwid[LICENCE_HWID_SIZE];
uint8 *licence_data;
int licence_size;
void * crypt_key;
/* Retrieve the server random from the incoming packet */
in_uint8p(s, server_random, SEC_RANDOM_SIZE);
/* We currently use null client keys. This is a bit naughty but, hey,
the security of licence negotiation isn't exactly paramount. */
memset(null_data, 0, sizeof(null_data));
licence_generate_keys(null_data, server_random, null_data);
licence_size = load_licence(&licence_data);
if (licence_size > 0)
{
/* Generate a signature for the HWID buffer */
licence_generate_hwid(hwid);
sec_sign(signature, 16, g_licence_sign_key, 16, hwid, sizeof(hwid));
/* Now encrypt the HWID */
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
ssl_rc4_crypt(crypt_key, (char *)hwid, (char *)hwid, sizeof(hwid));
ssl_rc4_info_delete(crypt_key);
licence_present(null_data, null_data, licence_data, licence_size, hwid, signature);
xfree(licence_data);
return;
}
licence_send_request(null_data, null_data, g_username, g_hostname);
}
