Spotify Audio

[Ranma]

Hello everyone I'm new to this forum

I've recently been looking into audio provided by Spotify (as a personal challenge) but I've hit a snag.

It appears these audio are pre-encrypted before being played.
I've managed to retrieve some information about these, such as the pssh, but I can't figure out how to decrypt them.


Any help would be great, thank in advance !

[Attachment 73315 - Click to enlarge]

[swappyison]

PSSH: AAAAU3Bzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAAADMIARIQrS ycG3HTuLUoX1D64CuinBoHc3BvdGlmeSIUrSycG3HTuLUoX1D6 4CuinC2da3U=
License URL: https://gue1-spclient.spotify.com/widevine-license/v1/audio/license

--key ad2c9c1b71d3b8b5285f50fae02ba29c:debfc7ae603885ffa a9b07eff54a1362

idk how to download though

[Ranma]

Wow, thank you for this quick answer !

Which magic was involved to extract the key and how do I decrypt the file?

[cedric8528]

to download : yt-dlp
To find the link : F12 to open console Developper.
Into Network search the links "audio-ak-spotify"

yt-dlp https://audio-ak-spotify-com.akamaized.net/audio...........

[cedric8528]

some readings for you

https://forum.videohelp.com/threads/404994-Decryption-and-the-Temple-of-Doom

[Ranma]

I'll take a closer look at it later, but it's based on android reverse.
I'm trying to understand decryption process from web version.

[swappyison]

@cedric, I can't find audio-ak url to be exact i found https://audio-fa.scdn.co/audio/ad2c9c1b71d3b8b5285f50fae02ba29c2d9d6b75?1692717475_fj1...946xerazF0G04=

so i used

yt-dlp https://audio-fa.scdn.co/audio/ad2c9c1b71d3b8b5285f50fae02ba29c2d9d6b75?1692717475_fj1Kl0abQxV4wnSTJSF69NeAed-Vqh946xerazF0G04=

which gives me this weird file with .unknown video extension.

the song link is this: https://open.spotify.com/track/0czcoKJbJt08NqKrvSbbz7

[cedric8528]

It's ok you have your file but ...encrypted.... you can rename it ( whatyourwant.mp3)

Now you have to decrypt with mp4decrypt....

[Karoolus]

I'll take a closer look at it later, but it's based on android reverse.
I'm trying to understand decryption process from web version.

it uses an Android CDM to get the keys, so you are able to decrypt the file you download. The platform you use this key on, does not matter.

[swappyison]

the mp3 i downloaded is 128kbps (had a cutoff frequency of 15 kHz as seen on spek), so ig for 320kbps or more you need a premium subscription right?

[cedric8528]

Exactly

[Ranma]

I understand, but I use the tools provided to extrat key. It seems to fail at getting a correct license. I 2 checked the headers which are correct but payload isn't

[Attachment 73320 - Click to enlarge]
[Attachment 73321 - Click to enlarge]

[swappyison]

you need to read the forum, it is the most basic widevine drm, license url is usually a POST request. copy the headers using curlconvertor by pasting the cURL of license url.

[Ranma]

That's what I did bruh but it doesn't parse from curl (F12 -> copy -> copy as cURL) so I extracted them manually.

[Attachment 73323 - Click to enlarge]
Anyways, I parsed them manually but as I said earlier the error more likely occurs because of payload request (protobuf content)
[Attachment 73324 - Click to enlarge]

[T33V33]

Downloading and getting keys from the web site is simple enough... copy headers (same headers can be used if grabbing multiple songs in one session) and use WKS-Keys, PSSH from EME etc.
Quality can be increased with a premium subscription.
I believe files should be m4a not mp3

What I'd like to know is... has anyone worked out how to get keys for the Android app versions? The apps give an even higher quality but it doesn't seem to be as simple to decrypt

[Karoolus]

Downloading and getting keys from the web site is simple enough... copy headers (same headers can be used if grabbing multiple songs in one session) and use WKS-Keys, PSSH from EME etc.
Quality can be increased with a premium subscription.
I believe files should be m4a not mp3

What I'd like to know is... has anyone worked out how to get keys for the Android app versions? The apps give an even higher quality but it doesn't seem to be as simple to decrypt

I haven't tried it yet, but maybe you could try to run the Spotify app on an emulator, intercept the HTTP traffic and see what requests are being made?

[T33V33]

Downloading and getting keys from the web site is simple enough... copy headers (same headers can be used if grabbing multiple songs in one session) and use WKS-Keys, PSSH from EME etc.
Quality can be increased with a premium subscription.
I believe files should be m4a not mp3

What I'd like to know is... has anyone worked out how to get keys for the Android app versions? The apps give an even higher quality but it doesn't seem to be as simple to decrypt

I haven't tried it yet, but maybe you could try to run the Spotify app on an emulator, intercept the HTTP traffic and see what requests are being made?

I've intercepted the traffic from my device.... its not just simple widevine requests

also an update on qualities... web premium is AAC 256kbit/s. Mobile is ~320kbit/s

[lomero]

more easy: try MusicFab or Spotify Music Converter https://www.audkit.com/spotilab-music-converter.html

[lomero]

another python tool for spotify audio

spotify downloader (through yt music)
https://github.com/spotDL/spotify-downloader

open cmd and trype : pip install spotdl
then download ffmpeg : spotdl --download-ffmpeg

to download tracks : spotdl ht*ps://open.spotify.com/track/ ....

[Karoolus]

Thanks ChatGPT

[bamboobali]

The 'best' quality might be a bit more complex than a straightforward bitrate comparison. Some text from Spotify suggests that the 320 kbps and 256 kbps delivery formats use different codecs (Ogg/Vorbis vs. AAC). I wouldn't know how 320 kbps Ogg/Vorbis compares with 256 kbps AAC:

"When we get your audio files, we do the following: Check they aren't corrupt and the format container is known. Transcode the file into different delivery formats for our audio quality options: Ogg/Vorbis (96, 160, 320 kbps) AAC (128, 256 kbps) HE-AACv2 (24kbps)"

[Anonymous84]

--

[Data2006]

Good morning,
I also have something for Spotify.

I have this playlist:
https://open.spotify.com/intl-de/artist/3BmGtnKgCSGYIUhmivXKWX?si=V0aCGPY2TvCeSgw_IubJkw

I can't set the filter to "audio-ak-spotify". Firefox can't find anything.

And the Widevine L3 Decrypter extension shows errors:
No CDM key pair found!

https://github.com/FoxRefire/wvg/wiki/Getting-started#2-put-cdm-key-pair-files

It also works with Widevine L3 Decrypter on Joyn.de.

Best regards
Heiko

[Data2006]

And: https://open.spotify.com/intl-de/album/2SPDnEaqt4IVqtpKmzTNbT?si=8y__X8sRRCOgZk39twpXmw

Best regards
Heiko

[lomero]

easy way:
- deemix: rip plist from spoty and down from deezer
- mediahuman YouTubeToMP3: rip spoty plist down from ytube
- ytsaver: this app download direct from spoty https://ytsaver.net/

direct way: i can't share this info here. PM me if you really need
or ytsaver app

[Data2006]

Hi.

Is ytsaver a trial version? If it's a full version, then I would give it a try.

Best regards
Heiko

[lomero]

from official site, trial only
but you can try this software if work fine for you. if you like, PM me after your tryout

yt-saver have one "bug" only (tested version 9.0, not tested on latest 9.3.0):
to get m4a file need set Original audio. but on final m4a no tag and no cover
if you set as mp3, final mp3 file have also tag and cover art

but no tested 9.3 version, maybe this bug is now solved