Arch Linux

mr.MikyMaus

Member

From: disabled

Registered: 2006-03-31

Posts: 285

[solved] ssh: no matching key exchange method with dropbear

Hi, I have a dropbear v 0.52 on my android device running (with no real prospect of ever being able to upgrade it) and when I try to connect to it from my Arch box I get:

Unable to negotiate with example.com: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1

What I do not understand is this:

[me@archbox ~]$ ssh -Q kex
diffie-hellman-group1-sha1
...
...
...

Either the first error message from ssh is wrong or there is some funny business going on. From what I can tell "their offer" means that the server (Android dropbear) offers only a certain diffie-hellman kex while the client doesn't support it. However, the client, when asked, says it DOES support it. I'm confused. So far I only found tips on how to make the server work but for me the server is a black box. I need to make the client more cooperative.

thanks for any tips,

-m.

Last edited by mr.MikyMaus (2015-09-16 07:06:14)

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What happened to Arch's KISS? systemd sure is stupid but I must have missed the simple part ...

... and who is general Failure and why is he reading my harddisk?

byte

Member

From: Düsseldorf (DE)

Registered: 2006-05-01

Posts: 2,046

Re: [solved] ssh: no matching key exchange method with dropbear

Potentially-incompatible Changes
--------------------------------
[...]
* Support for the 1024-bit diffie-hellman-group1-sha1 key exchange
   is disabled by default at run-time. It may be re-enabled using
   the instructions at http://www.openssh.com/legacy.html

Did you try with 'ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 user@android'?
No idea otherwise, but a full 'ssh -v' log might be useful nonetheless.

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1000

mr.MikyMaus

Member

From: disabled

Registered: 2006-03-31

Posts: 285

Re: [solved] ssh: no matching key exchange method with dropbear

I wonder why that page didn't come up in my web searches, I used all the keywords there.

Nevertheless, it works. Thanks a lot!

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What happened to Arch's KISS? systemd sure is stupid but I must have missed the simple part ...

... and who is general Failure and why is he reading my harddisk?

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: [solved] ssh: no matching key exchange method with dropbear

Please remember to mark the thread as solved https://bbs.archlinux.org/viewtopic.php?id=130309

ayr-ton

Member

From: Brazil

Registered: 2015-09-14

Posts: 29

Website

Re: [solved] ssh: no matching key exchange method with dropbear

I have added these instructions at:

https://wiki.archlinux.org/index.php/Se … mentations

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