Download M3u8 from VOD Movistar.es

[Bryan_122]

Hi,

anyone can I help me to download a streaming video from vod movistar.es?

links:

http://b38545.1.vod.cdn.telefonica.com/38545/prod/hls/cplus-1422250_cplus-1422250-hls_...ex-02-spa.m3u8
http://b38545-p67-h29.1.vod.cdn.telefonica.com/_38545/prod/hls/cplus-1422250_cplus-142...083550/05.m3u8

I tried to download with youtube-dl but it's not working...

Thank you

[peerflyian]

This video not playing when i add to my player online

[geronimo007]

Hi Bryan_122!

Lately I've been trying to download VoD from Movistar without luck. Both URLs you post are perfectly valid, but they're encrypted in a way I struggle to understand.
In this post I'll to explain what I've found so far, so anyone interested could solve this once and for all


1. Getting stream data

Ok, let's take your first link as an starting point for this example: http://XXXXX.vod.cdn.telefonica.com/.../index-02-spa.m3u8

This M3U8 file contains all SD qualities available for that digital content. But, and here's the trick, if we request index-01-spa.m3u8 instead, we get all available streams (both SD and HD):

#EXTM3U
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=5895680,RESOLUTION=1280x720,CODECS="avc1.4d4020,mp4a.40.2"
01.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=4355584,RESOLUTION=1280x720,CODECS="avc1.4d4020,mp4a.40.2"
03.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2815488,RESOLUTION=1024x576,CODECS="avc1.4d401f,mp4a.40.2"
05.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2200352,RESOLUTION=1024x576,CODECS="avc1.4d401e,mp4a.40.2"
07.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2200352,RESOLUTION=640x360,CODECS="avc1.4d4015,mp4a.40.2"
09.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1481440,RESOLUTION=640x360,CODECS="avc1.4d401f,mp4a.40.2"
11.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1173120,RESOLUTION=480x270,CODECS="avc1.4d401f,mp4a.40.2"
13.m3u8

Next, we target the first stream (http://XXXXX.vod.cdn.telefonica.com/.../01.m3u8) as is the one with the better quality:

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-KEY:METHOD=AES-128,URI="http://www.nagra.com/key=268327&prm=eyJjb250ZW50SWQiOiIyNjgzMjciLCJrZXlJZCI6ImFhZTk5NzhjLWJkZGUtNDMyZi1hMDg3LTYxNTI4MjVkZjVlZCJ9",IV=0x00000000000000000000000000000000
#EXTINF:10,
01-0.ts
#EXTINF:10,
01-1.ts
[...]
#EXTINF:5.6,
01-326.ts
#EXT-X-ENDLIST

2. Extracting the key

Now, this is when this gets tricky. Due to the stream being encrypted we need a way to decrypt it before merging all TS files. This is usually achieved by using FFMPEG:

ffmpeg -protocol_whitelist "file,http,https,tcp,tls,crypto"
-allowed_extensions ALL
-i "http://XXXXX.vod.cdn.telefonica.com/.../01.m3u8"
-c copy "output.ts"

But, unfortunately, this results in a "Unable to open key" error. So, what's hapenning?

FFMPEG is trying to download the key specified in the M3U8, which is supposed to be located at http://www.nagra.com/key=268327&prm=a_really_long_base64_string. But that URL doesn't exists, and the Movistar player has to be taking the decryption key from somewhere.

After doing some traffic captures, I came to the conclusion that the key has to be hidden inside the M3U8 file.


3. Understanding the key

Let's take that long string from the fake key URL: eyJjb250ZW50SWQiOiIyNjgzMjciLCJrZXlJZCI6ImFhZTk5Nz hjLWJkZGUtNDMyZi1hMDg3LTYxNTI4MjVkZjVlZCJ9.

If we Base64-decode it, we get this JSON object:

{"contentId":"268327","keyId":"aae9978c-bdde-432f-a087-6152825df5ed"}

The keyId field seems to be a hexadecimal representation of binary data. Removing the hyphens we get a 16 bytes chuck of data, which equals to 128 bits, the length that an AES-128 cypher key should have.

We seem to have found the decryption key: 0xaae9978cbdde432fa0876152825df5ed. But... that doesn't work either, as FFMPEG returns this error message:

Error when loading first segment 'http://b38545.1.vod.cdn.telefonica.com/38545/prod/hls/cplus-1422250_cplus-1422250-hls_20170921_083550/01-0.ts'
D:\ConsoleProjects\tmp\stream.m3u8: Invalid data found when processing input

Conclusion

This is what I've got so far. I've have no idea why this doesn't work, so any help will be appreciated. I attach three files if you want to test this for yourself:

• stream.m3u8: contains the parsed stream file with the key path fixed
• stream.key: the 16 bytes decryption key
• command.bat: the FFMPEG command

[ponens]

FFMPEG is trying to download the key specified in the M3U8, which is supposed to be located at http://www.nagra.com/key=268327&prm=a_really_long_base64_string. But that URL doesn't exists, ...

The URL exists, but is does not return the key value - probably because of missing cookie(s) or other header data.

After doing some traffic captures, I came to the conclusion that the key has to be hidden inside the M3U8 file.

Let's take that long string from the fake key URL: eyJjb250ZW50SWQiOiIyNjgzMjciLCJrZXlJZCI6ImFhZTk5Nz hjLWJkZGUtNDMyZi1hMDg3LTYxNTI4MjVkZjVlZCJ9.

If we Base64-decode it, we get this JSON object:

{"contentId":"268327","keyId":"aae9978c-bdde-432f-a087-6152825df5ed"}

The keyId field seems to be a hexadecimal representation of binary data. Removing the hyphens we get a 16 bytes chuck of data, which equals to 128 bits, the length that an AES-128 cypher key should have.

We seem to have found the decryption key: 0xaae9978cbdde432fa0876152825df5ed.

That's not the (decryption) key. It's a key value parameter passed to nagra.