Stealing unencrypted SSH-agent keys from memory

Re:Stealing unencrypted SSH-agent keys from memory by scott_karana on Monday July 21, 2014 @05:50PM (#8066210)

> I feel like ssh-agent is essential to my life but it's badly designed and I have this nagging feeling it's insecure (and articles like this feed this fear).

If the attacker has root-access, like in this article, they could also recover your decrypted private keys from the memory used in active connections. (SSH and SSL both)

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Re:Stealing unencrypted SSH-agent keys from memory by agwa on Monday July 21, 2014 @05:59PM (#8066258)

I would hope that ssh zeros the memory used for the private key as soon as it's done with it (which would be after the authentication step in the handshake).

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Re:Stealing unencrypted SSH-agent keys from memory by ambrice on Monday July 21, 2014 @06:13PM (#8066332)

But then it would have to either keep the passphrase in memory (just as bad) or ask for the passphrase each time you reconnect later (defeats the purpose of ssh-agent).

Edit: Nevermind, you're talking about ssh, not ssh-agent..

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Re:Stealing unencrypted SSH-agent keys from memory by scott_karana on Wednesday July 23, 2014 @12:52PM (#8075385)

You're right, I forgot that it would switch to asymmetric crypto after the handshake. My bad.

Still, with root it would be trivial to attach a debugger to the daemon, et cetera.

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