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I'm working in a cloud hosting environment, where a lot of new server instances appear: as a result, I keep getting the "unknown host key" dialogue box in FileZilla. How can a configure to trust any key so as to avoid the "unknown host key" dialogue box?

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(note that it seems impossible to do in PuTTY)

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You can't configure it to trust any key (that would be a breathtakingly huge security vulnerability), but you can get SSL certificates for your servers, either self-signed (import/trust the root CA) or buy them from a trusted CA.

You can definitely set up an automated process without too much effort that generates new SSL keys for each server based on your own self-generated Root CA, and deploys them whenever a cloud server spins up. Then you just have to trust the Root CA on your FileZilla client and you won't get the popup.

You might ask "well how do I do that?" -- that'd have to be another question, and it would depend entirely on:

  • Which operating system/version/distribution you're using on the cloud server(s)
  • Which operating system you're using on the box that generates the keys (the "Root CA" box)
  • Which FTP software you're using
  • Which SSL suite you're using
  • What sort of deployment/scripting/automation environment you have set up, and the mechanism for customizing it


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