LSB-Audio-Steganography

LSB.py

import wave
import struct
import utils.logger as logger

logger = logger.setup(__name__)

def encode(inputFile, outputFile, secret):
	try:
		logger.info("Encoding starts...")
		audio = wave.open(inputFile, mode="rb")
		frame_bytes = bytearray(list(audio.readframes(audio.getnframes())))
		logger.info(f"Secret: {secret}")
		secretBit = ''.join([bin(byte).lstrip('0b').rjust(8, '0') for byte in bytes(secret, "ASCII")])
		secretLenBit = ''.join([bin(byte).lstrip('0b').rjust(8, '0') for byte in struct.pack('>I', len(secretBit))])
		fullBits = secretLenBit + secretBit
		if len(fullBits) > len(frame_bytes):
			raise ValueError("The secret message is too large to fit in the audio file.")
		for i, bit in enumerate(fullBits):
			frame_bytes[i] = (frame_bytes[i] & 254) | int(bit)
		frame_modified = bytes(frame_bytes)
		with wave.open(outputFile, 'wb') as new_audio:
			new_audio.setparams(audio.getparams())
			new_audio.writeframes(frame_modified)
		audio.close()
		logger.info(f"Successfully encoded into {outputFile}")
	except Exception as e:
		logger.error(f"Error during encoding: {e}")

def decode(inputFile):
	try:
		logger.info("Decoding starts...")
		audio = wave.open(inputFile, mode='rb')
		frame_bytes = bytearray(list(audio.readframes(audio.getnframes())))
		length_bits = ''.join([str((frame_bytes[i] & 1)) for i in range(32)])
		message_length = struct.unpack('>I', int(length_bits, 2).to_bytes(4, byteorder='big'))[0]
		logger.info(f"Extracted message length: {message_length} bits")
		if message_length > len(frame_bytes) * 8:
			raise ValueError("The extracted message length is larger than the available audio data.")
		message_bits = ''.join([str((frame_bytes[i + 32] & 1)) for i in range(message_length)])
		decoded_message = ''.join(chr(int(message_bits[i:i + 8], 2)) for i in range(0, len(message_bits), 8))
		logger.info(f"Successfully decoded: {decoded_message}")
		audio.close()
		return decoded_message
	except Exception as e:
		logger.error(f"Error during decoding: {e}")
		return None