def total_head(self) -> bytes:
"""
`BAIDUPCS_PY_CRYPTO_MAGIC_CODE 32bytes` +
`encrypt algorithm code 1bytes` +
`nonce or iv 16bytes` +
`total_origin_len 64bit`
"""
return (self._encrypted_baidupcs_py_crypto_magic_code +
self.MAGIC_CODE + self._nonce_or_iv +
u64_to_u8x8(self._total_origin_len))
def total_head(self) -> bytes:
"""
Version 1:
aes256cbc_encrypt(`BAIDUPCS_PY_CRYPTO_MAGIC_CODE 32bytes`, encrypt_password, random_bytes(16, encrypt_password)) +
`encrypt algorithm code 1bytes` +
`nonce or iv 16bytes` +
`total_origin_len 8bytes`
Version 2:
aes256cbc_encrypt(
`BAIDUPCS_PY_CRYPTO_MAGIC_CODE 32bytes` +
`encrypt algorithm code 1bytes` +
`nonce_or_iv 16bytes`
`total_origin_len 8bytes`
) +
`salt 8bytes`
Version 3:
aes256cbc_encrypt(
`BAIDUPCS_PY_CRYPTO_MAGIC_CODE 32bytes` +
`encrypt algorithm code 1bytes` +
`salt 8bytes` + `random padding 8bytes`
`total_origin_len 8bytes`
) +
`salt 8bytes`
"""
if self._total_head:
return self._total_head
assert len(self._salt) == 8
ori_head = padding_key(
BAIDUPCS_PY_CRYPTO_MAGIC_CODE + self.MAGIC_CODE + self._salt +
random_sys_bytes(8) + u64_to_u8x8(self._total_origin_len),
PADDED_ENCRYPT_HEAD_LEN,
value=b"",
)
# AES256CBC Encrypt head
self._total_head = (aes256cbc_encrypt(
ori_head, self._encrypt_key_for_head, self._iv_for_head) +
self._salt_for_head)
return self._total_head
def test_u64_u8x8():
i = 2**32
b = u64_to_u8x8(i)
x = u8x8_to_u64(b)
assert i == x