deemix-py/deemix/decryption.py

import binascii
from Cryptodome.Cipher import Blowfish, AES
from Cryptodome.Hash import MD5

from deemix import USER_AGENT_HEADER
from deemix.types.DownloadObjects import Single, Collection

from requests import get

from requests.exceptions import ConnectionError, ReadTimeout
from ssl import SSLError
from urllib3.exceptions import SSLError as u3SSLError

import logging
logger = logging.getLogger('deemix')

def _md5(data):
    h = MD5.new()
    h.update(str.encode(data) if isinstance(data, str) else data)
    return h.hexdigest()

def generateBlowfishKey(trackId):
    SECRET = 'g4el58wc0zvf9na1'
    idMd5 = _md5(trackId)
    bfKey = ""
    for i in range(16):
        bfKey += chr(ord(idMd5[i]) ^ ord(idMd5[i + 16]) ^ ord(SECRET[i]))
    return bfKey

def generateStreamPath(sng_id, md5, media_version, format):
    urlPart = b'\xa4'.join(
        [str.encode(md5), str.encode(str(format)), str.encode(str(sng_id)), str.encode(str(media_version))])
    md5val = _md5(urlPart)
    step2 = str.encode(md5val) + b'\xa4' + urlPart + b'\xa4'
    step2 = step2 + (b'.' * (16 - (len(step2) % 16)))
    urlPart = binascii.hexlify(AES.new(b'jo6aey6haid2Teih', AES.MODE_ECB).encrypt(step2))
    return urlPart.decode("utf-8")

def reverseStreamPath(urlPart):
    step2 = AES.new(b'jo6aey6haid2Teih', AES.MODE_ECB).decrypt(binascii.unhexlify(urlPart.encode("utf-8")))
    (md5val, md5, format, sng_id, media_version, _) = step2.split(b'\xa4')
    return (sng_id.decode('utf-8'), md5.decode('utf-8'), media_version.decode('utf-8'), format.decode('utf-8'))

def generateStreamURL(sng_id, md5, media_version, format):
    urlPart = generateStreamPath(sng_id, md5, media_version, format)
    return "https://e-cdns-proxy-" + md5[0] + ".dzcdn.net/mobile/1/" + urlPart

def generateUnencryptedStreamURL(sng_id, md5, media_version, format):
    urlPart = generateStreamPath(sng_id, md5, media_version, format)
    return "https://e-cdns-proxy-" + md5[0] + ".dzcdn.net/api/1/" + urlPart

def reverseStreamURL(url):
    urlPart = url[url.find("/1/")+3:]
    return generateStreamPath(urlPart)

def streamUnencryptedTrack(outputStream, track, start=0, downloadObject=None, interface=None):
    headers= {'User-Agent': USER_AGENT_HEADER}
    chunkLength = start
    percentage = 0

    itemName = f"[{track.mainArtist.name} - {track.title}]"

    try:
        with get(track.downloadUrl, headers=headers, stream=True, timeout=10) as request:
            request.raise_for_status()

            complete = int(request.headers["Content-Length"])
            if complete == 0: raise DownloadEmpty
            if start != 0:
                responseRange = request.headers["Content-Range"]
                logger.info(f'{itemName} downloading range {responseRange}')
            else:
                logger.info(f'{itemName} downloading {complete} bytes')

            for chunk in request.iter_content(2048 * 3):
                outputStream.write(chunk)
                chunkLength += len(chunk)

                if downloadObject:
                    if isinstance(downloadObject, Single):
                        percentage = (chunkLength / (complete + start)) * 100
                        downloadObject.progressNext = percentage
                    else:
                        chunkProgres = (len(chunk) / (complete + start)) / downloadObject.size * 100
                        downloadObject.progressNext += chunkProgres
                    downloadObject.updateProgress(interface)

    except (SSLError, u3SSLError) as e:
        logger.info(f'{itemName} retrying from byte {chunkLength}')
        return streamUnencryptedTrack(outputStream, track, chunkLength, downloadObject, interface)
    except (ConnectionError, ReadTimeout):
        sleep(2)
        return streamUnencryptedTrack(outputStream, track, start, downloadObject, interface)

def streamUnencryptedTrack(outputStream, track, start=0, downloadObject=None, interface=None):
    headers= {'User-Agent': USER_AGENT_HEADER}
    chunkLength = start
    percentage = 0

    itemName = f"[{track.mainArtist.name} - {track.title}]"

    try:
        with get(track.downloadUrl, headers=headers, stream=True, timeout=10) as request:
            request.raise_for_status()

            complete = int(request.headers["Content-Length"])
            if complete == 0: raise DownloadEmpty
            if start != 0:
                responseRange = request.headers["Content-Range"]
                logger.info(f'{itemName} downloading range {responseRange}')
            else:
                logger.info(f'{itemName} downloading {complete} bytes')

            for chunk in request.iter_content(2048 * 3):
                outputStream.write(chunk)
                chunkLength += len(chunk)

                if downloadObject:
                    if isinstance(downloadObject, Single):
                        percentage = (chunkLength / (complete + start)) * 100
                        downloadObject.progressNext = percentage
                    else:
                        chunkProgres = (len(chunk) / (complete + start)) / downloadObject.size * 100
                        downloadObject.progressNext += chunkProgres
                    downloadObject.updateProgress(interface)

    except (SSLError, u3SSLError) as e:
        logger.info(f'{itemName} retrying from byte {chunkLength}')
        return streamUnencryptedTrack(outputStream, track, chunkLength, downloadObject, interface)
    except (ConnectionError, ReadTimeout):
        sleep(2)
        return streamUnencryptedTrack(outputStream, track, start, downloadObject, interface)

def streamTrack(outputStream, track, start=0, downloadObject=None, interface=None):
    headers= {'User-Agent': USER_AGENT_HEADER}
    chunkLength = start
    percentage = 0

    itemName = f"[{track.mainArtist.name} - {track.title}]"

    try:
        with get(track.downloadUrl, headers=headers, stream=True, timeout=10) as request:
            request.raise_for_status()
            blowfish_key = str.encode(generateBlowfishKey(str(track.id)))

            complete = int(request.headers["Content-Length"])
            if complete == 0: raise DownloadEmpty
            if start != 0:
                responseRange = request.headers["Content-Range"]
                logger.info(f'{itemName} downloading range {responseRange}')
            else:
                logger.info(f'{itemName} downloading {complete} bytes')

            for chunk in request.iter_content(2048 * 3):
                if len(chunk) >= 2048:
                    chunk = Blowfish.new(blowfish_key, Blowfish.MODE_CBC, b"\x00\x01\x02\x03\x04\x05\x06\x07").decrypt(chunk[0:2048]) + chunk[2048:]

                outputStream.write(chunk)
                chunkLength += len(chunk)

                if downloadObject:
                    if isinstance(downloadObject, Single):
                        percentage = (chunkLength / (complete + start)) * 100
                        downloadObject.progressNext = percentage
                    else:
                        chunkProgres = (len(chunk) / (complete + start)) / downloadObject.size * 100
                        downloadObject.progressNext += chunkProgres
                    downloadObject.updateProgress(interface)

    except (SSLError, u3SSLError) as e:
        logger.info(f'{itemName} retrying from byte {chunkLength}')
        return streamTrack(outputStream, track, chunkLength, downloadObject, interface)
    except (ConnectionError, ReadTimeout):
        sleep(2)
        return streamTrack(outputStream, track, start, downloadObject, interface)

class DownloadEmpty(Exception):
    pass