download videos protected with widevine DRM

widevine-decryption.md

Downloading Widevine content

Specifically from Rakuten TV (live.tv.rakuten.co.jp)

FMI: https://cdm-project.com/How-To/ & https://old.reddit.com/r/Piracy/comments/y30ffr/

Setup

1. Install Tampermonkey: https://www.tampermonkey.net/
2. Install yt-dlp: https://github.com/yt-dlp/yt-dlp#installation
3. Install ffmpeg: https://ffmpeg.org/download.html
4. Download Bento4: https://www.bento4.com/downloads/
5. Have a proxy/VPN if you're not in Japan since stuff is geolocked

Getting your decryption key

Get PSSH

1. Install this userscript: https://greasyfork.org/en/scripts/373903-eme-logger
2. Search browser JS Console for MediaKeySession::generateRequest, then press play on the video and look under "Init Data"
3. Get something like AAAAMnBzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAXXXXXXXXFtoyTEzFOZDD4T9lmTiI=

Get License URL

1. After doing the above, go to your browser developer tools' Network tab and search for Widevine
2. Right click > Copy > Copy link address
3. Get something like https://azcp001.keydelivery.japaneast.media.azure.net/Widevine/?kid=e0c5b68c-9313-314e-6430-f8XXXXXXXX22

Get headers

1. Left click on the Widevine entry from the above steps, under the "Headers tab" scroll down to "Request Headers"
2. Copy the following lines & do some manual formatting, get something like:

Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9,ja-JP;q=0.8,ja;q=0.7
Authorization: blahblah
Cache-Control: no-cache
Content-Length: "blahblah"
Origin: https://live.tv.rakuten.co.jp
Pragma: no-cache
Referer: https://live.tv.rakuten.co.jp/
User-Agent: blahblah

Getting the key

1. Open https://cdrm-project.com/
2. Input the results from the previous steps and press "Send"
3. Hopefully see the "SUCCESS" message along with a key that looks like e0c5b68c93133XXXXXXXX84fd9664e22:499047f36b770957XXXXXXXX9dfc4033

Downloading the encrypted files

2. In the developer console Network tab, search for mpd
3. Find something that starts with Manifest, right click and copy the URL, e.g. https://azclwds01.akamaized.net/9dc3547a-ede5-4aed-841f-5cXXXXXXXX0f/tXyKyP_tab_hd.ism/Manifest(format=mpd-time-csf,encryption=cenc,filter=pc_hd_001)
4. Run the Terminal command: yt-dlp --allow-unplayable [url]
5. Get two files, an .mp4 and an .m4a

Decrypting & merging the files

1. In Bento4's bin/ folder, find the mp4decrypt command line utility
2. Navigate to this folder in your Terminal and run mp4decrypt --key [yourkey] /path/to/corrupted.file /path/to/fixed.file on both files
3. Run ffmpeg -i fixedvideo.mp4 -i fixedaudio.m4a -c:v copy -c:a copy output.mp4
4. The end