SSH Keys and migrating to a new device
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Here is how you do it assuming Fedora/Korora 25
We are assuming that the username is the same on both machines because this is a migration.
- On the new machine, start the SSH server. Since this is a laptop/desktop, it should not be running normally.
systemctl start sshd- On the new machine, make sure you have no private key yet. There should not be anything here. If there is, you have to figure out what you are already using a private key for.
[12:53 jbusch ~]$ ls -la ~/.ssh/ drwx------. 2 jbusch jbusch 4096 May 28 23:50 . drwxrwxr-x+ 32 jbusch jbusch 4096 Jun 28 21:38 ..- On the old machine use rsync to transfer everything.
rsync /home/jbusch/.ssh/* [email protected]:/home/jbusch/.ssh/ [email protected]'s password:- On your new machine turn the SSH server back off
systemctl stop sshd- Test a login from your new machine to some server
ssh 10.254.0.108 Last login: Fri Jun 30 12:53:31 2017 from 24.14.15.238 [jbusch@relay ~]$ -
@JaredBusch Thanks. This is great. I'm going to spin some VM's up on my home server and do this
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@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
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@JaredBusch said in SSH Keys and migrating to a new device:
@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
I agree. And you want your keys labelled with their origination device, easier to track.
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@JaredBusch said in SSH Keys and migrating to a new device:
@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
Understood. That would make administrating those devices unnecessarily difficult
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@scottalanmiller said in SSH Keys and migrating to a new device:
@JaredBusch said in SSH Keys and migrating to a new device:
@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
I agree. And you want your keys labelled with their origination device, easier to track.
If you're nuking the profile after you migrate it what benefit would that give you?
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@wirestyle22 said in SSH Keys and migrating to a new device:
@scottalanmiller said in SSH Keys and migrating to a new device:
@JaredBusch said in SSH Keys and migrating to a new device:
@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
I agree. And you want your keys labelled with their origination device, easier to track.
If you're nuking the profile after you migrate it what benefit would that give you?
He means on the server side.
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@wirestyle22 said in SSH Keys and migrating to a new device:
@scottalanmiller said in SSH Keys and migrating to a new device:
@JaredBusch said in SSH Keys and migrating to a new device:
@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
I agree. And you want your keys labelled with their origination device, easier to track.
If you're nuking the profile after you migrate it what benefit would that give you?
That you know that that one key still represents just one device.
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@JaredBusch @scottalanmiller OH, got it. Thanks.
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@JaredBusch said in SSH Keys and migrating to a new device:
@wirestyle22 said in SSH Keys and migrating to a new device:
@JaredBusch Thanks. This is great
Again, you want a unique private key on every device, in order to lock things out discretely. Otherwise if you simply had the same private key everywhere, you would lose all access form every device just because your laptop was compromised and you had to lock out the public key.
So this process is really only something that should ever happen on a profile migration.
Ya it's a big advantage to having automounted home directories or having LDAP store the keys. You can easily revoke and add another key and have it work everywhere.
Or using Kerberos instead of pub/priv keys.
I realize @JaredBusch knows this, but for others who may not.
