Only way to do this would be to do ssl forward proxy and do you own manual AppID signatures to differentiate Whatapp messages or file transfers.
Doing ssl forward-proxy has many complications with importing the SRX's trusted root CA so the firewall can look at the content of the traffic. Secondly there is the massive performance impact. My best guess is that a SRX300 can handle no more than 10 Mbps of SSL/TLS encapsulation before running out of available CPU ressources.
..and then come you have to manually do an AppID signature to block file transfers (meaning you need to analyze the datastream and figure out what you should trigger on). That is a task for itself on top.
So - basically: I don't see any feasible way of doing this on a SRX300, except if you block whatsapp completely via AppID.
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JONAS HAUGE KLINGENBERG
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Original Message:
Sent: 02-04-2021 21:51
From: Leandro Gomes
Subject: Juniper SRX300 - Block file transfer app WhatsApp browser
Hello everyone, everything good ? I have a problem and I need help. I need to allow access to the whatsapp web application or via browser. However, I need to block the file transfer. Users will only exchange messages. Today I have the Juniper SRX300 is it possible?
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Leandro Gomes
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