Decrypting an HLS Stream

gistfile1.txt

import os
import Crypto
from hashlib import md5
from Crypto.Cipher import AES
from Crypto import Random
import hexdump
from chardet import detect

source_directory = ''
target_directory = ''

### Inspiration: https://gist.github.com/delimitry/053db410f7fdd4e1d6034a0a7fd45d9b

def decrypt(data, key, iv):
    """Decrypt using AES CBC"""
    decryptor = AES.new(key, AES.MODE_CBC, IV=iv)
    return decryptor.decrypt(data)


# iterate through a specific stream, e.g. "hd", "sd", "low"
def decryptStream(directory, key):
    print("decrypting " + directory)
    for filename in os.listdir(directory):
        if filename.endswith(".ts"):
            out_file = os.path.join(target_directory, os.path.basename(directory), filename)
            # 'rb' is read-as-binary: https://stackoverflow.com/questions/8710456/reading-a-binary-file-with-python
            enc_data = open(os.path.join(directory, filename), 'rb').read()
            iv = os.urandom(16)
            with open(out_file, 'wb') as f:
                dec_data = decrypt(enc_data, key, iv)
                f.write(dec_data)
        elif filename.endswith(".m3u8"):
            out_file = os.path.join(target_directory, os.path.basename(directory), filename)
            m3u8 = open(os.path.join(directory, filename), 'rb').read()
            with open(out_file, 'wb') as f:
                f.write(m3u8)
        else:
            continue


# get file encoding type
# https://stackoverflow.com/questions/12468179/unicodedecodeerror-utf8-codec-cant-decode-byte-0x9c
def get_encoding_type(file):
    with open(file, 'rb') as f:
        rawdata = f.read()
    return detect(rawdata)['encoding']


# get key
def getKey(source_directory):
    for filename in os.listdir(source_directory):
        if filename.endswith(".key"):
            # 'rb' is read-as-binary: https://stackoverflow.com/questions/8710456/reading-a-binary-file-with-python
            key = open(os.path.join(source_directory, filename), 'rb').read()
            return key

# iterate through parent source directory
key = getKey(source_directory)
for filename in os.listdir(source_directory):
    if os.path.isdir(os.path.join(source_directory, filename)):
        # if (stream) directory (e.g. "hd", "sd", "low")
        # first create the stream directory in the target folder
        os.mkdir(os.path.join(target_directory, filename))
        # now decrypt the stream
        decryptStream(os.path.join(source_directory, filename), key)
    elif filename.endswith(".m3u8"):
        out_file = os.path.join(target_directory, filename)
        encoding_type = get_encoding_type(os.path.join(source_directory, filename))
        m3u8 = open(os.path.join(source_directory, filename), 'rb').read()
        with open(out_file, 'wb') as f:
            f.write(m3u8)