def test_generate_header():
"""The header is generated as expected"""
stegs = Steganographer()
header = bytes(stegs._header._HEADER_TITLE, 'utf-8') + \
bytes(stegs._header.data_len.to_bytes(stegs._header._HEADER_DATA_SIZE, "little")) + \
bytes(stegs._header.bits_used.to_bytes(stegs._header._HEADER_BITS_SIZE, "little")) + \
bytes(stegs._header.file_name_len.to_bytes(stegs._header._HEADER_FILE_LENGTH_SIZE, "little"))
assert header == stegs._generate_header(stegs._header.data_len,
stegs._header.bits_used, "")
def test_retrieve_header():
"""The header is retrieved as expected"""
stegs = Steganographer()
test_message = "12345".encode('utf-8')
test_data_len = len(test_message)
test_bits_used = 1
test_file_name = "test_retrieve_header.txt"
test_file_name_len = len(test_file_name)
test_data = bytes(b'\x01' * 1000)
test_header = stegs._generate_header(test_data_len, test_bits_used,
test_file_name)
hidden_data = stegs._hide_data(
test_data[:stegs._header.header_length * stegs._BYTELEN], test_header)
hidden_data += stegs._hide_data(
test_data[stegs._header.header_length * stegs._BYTELEN:], test_message)
header_retrieved = stegs._retrieve_header(hidden_data)
assert header_retrieved is True
assert stegs._header.data_len == test_data_len
assert stegs._header.bits_used == test_bits_used
assert stegs._header.file_name_len == test_file_name_len
assert stegs._header.file_name.decode('utf-8') == test_file_name
