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SSH fingerprint changes unexpectedly [not relevant]

asked 2014-07-24 22:43:52 +0200

aclex gravatar image

updated 2014-12-01 20:31:58 +0200

simo gravatar image

I noticed that SSH fingerprint changes unexpectedly in some moment during the phone is working. It seems that something scary happens to sshd as even when I remove fingerprint from my host's known_hosts I can't login to Jolla neither with password nor with public key. After reboot everything works flawlessly with the previous fingerprint.

Sailfish OS version is Host's OpenSSH version is 6.4.

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The question has been closed for the following reason "question is not relevant or outdated" by chemist
close date 2014-07-28 20:51:39.468708



Usually when that happens it's a sign that something weird is going on your network. I'm quite certain that the device you trying to login (the changed fingerprint) is not anymore Jolla.

tigeli ( 2014-07-24 22:49:23 +0200 )edit

That has happened to me in the past (first days of playing around quite a lot with my Jolla), but I also think it had something to do with me messin' around too much with all my settings on the computer and IP-adresses in my homenetwork. I'm quite confident it isn't ssh-keys changing or something like that and I'm sure someone here can explain it.

darvari ( 2014-07-24 23:25:08 +0200 )edit

Thanks for the advice, guys! Just changed my DHCP server settings to reserve an IP for Jolla, will see if the problem goes away.

aclex ( 2014-07-25 00:04:17 +0200 )edit

Can you verify whether the fingerprint REALLY changed or if the problem was caused by a changed IP address? See my comment below with this link. The warning is different depending on whether the fingerprint (and pub/priv keys) have changed or if the IP changed.

jzrz ( 2014-07-25 12:26:16 +0200 )edit

@jzrz it really was that I knocked to another ssh server (my router) and from the client it looked like the fingerprint was changed. Indeed it was just a subtle problem in my network configuration.

aclex ( 2014-07-26 23:17:21 +0200 )edit

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answered 2014-07-26 23:14:30 +0200

aclex gravatar image

Thank you all for your help, guys! I changed settings of my DHCP server and tried to connect to Jolla for a couple of days. It works fine, so it was really a problem of my network configuration, sorry for disturbing.

If anyone interested in the real problem: I have DHCP server up on my ADSL router with network bridge on one of its LAN ports. The problem was that bridge network interface inside the router obtained the same IP as Jolla did. Ironically, the router seemed to have sshd running as well, so I actually connected to it instead of my Jolla phone, and it answered me as if fingerprint of Jolla was changed. I just reserved another IP specially for Jolla and now everything works just fine.

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answered 2014-07-25 00:43:30 +0200

Leinad gravatar image

updated 2014-07-25 11:25:04 +0200

new IP, new fingerprint...

edit: no new fingerprint, see below

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Nope, nope, nope. The fingerprint does not change. However since the IP has changed, SSH can no longer trust the server, since the cached IP address does not match the presented public key. See here.

jzrz ( 2014-07-25 10:29:27 +0200 )edit

ok, just noticed, the warning comes up, everytime the IP changes

Leinad ( 2014-07-25 11:23:57 +0200 )edit

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Asked: 2014-07-24 22:43:52 +0200

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Last updated: Jul 26 '14