static int x25519_keycheck(const EC_KEY *eckey)
{
const char *pubkey;
if (eckey->pub_key == NULL)
return 0;
pubkey = eckey->pub_key->custom_data;
if (pubkey == NULL)
return 0;
if (eckey->custom_data != NULL) {
uint8_t tmp[EC_X25519_KEYLEN];
/* Check eckey->priv_key exists and matches eckey->custom_data */
if (eckey->priv_key == NULL)
return 0;
if (BN_bn2lebinpad(eckey->priv_key, tmp, EC_X25519_KEYLEN)
!= EC_X25519_KEYLEN
|| CRYPTO_memcmp(tmp, eckey->custom_data,
EC_X25519_KEYLEN) != 0) {
OPENSSL_cleanse(tmp, EC_X25519_KEYLEN);
return 0;
}
X25519_public_from_private(tmp, eckey->custom_data);
if (CRYPTO_memcmp(pubkey, tmp, EC_X25519_KEYLEN) == 0)
return 1;
return 0;
} else {
return 1;
}
}
static int x25519_set_private(EC_KEY *eckey, const BIGNUM *priv_key)
{
if (BN_num_bytes(priv_key) > EC_X25519_KEYLEN)
return 0;
if (x25519_init_private(eckey, NULL))
return 0;
/* Convert BIGNUM form private key to internal format */
if (BN_bn2lebinpad(priv_key, eckey->custom_data, EC_X25519_KEYLEN)
!= EC_X25519_KEYLEN)
return 0;
return 1;
}
static void write_lebn(unsigned char **out, const BIGNUM *bn, int len)
{
BN_bn2lebinpad(bn, *out, len);
*out += len;
}
