def decode_aes256_base64_auto(data, encryption_key):
assert isinstance(data, bytes)<EOL>length = len(data)<EOL>if length == <NUM_LIT:0>:<EOL><INDENT>return b'<STR_LIT>'<EOL><DEDENT>elif data[<NUM_LIT:0>] == b'<STR_LIT:!>'[<NUM_LIT:0>]:<EOL><INDENT>return decode_aes256_cbc_base64(data, encryption_key)<EOL><DEDENT>else:<EOL><INDENT>return decode_aes256_ecb_base64(data, encryption_key)<EOL><DEDENT>
Guesses AES cipher (EBC or CBD) from the length of the base64 encoded data.