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Re: Can't connect with some clients


On 1/12/21 4:09 PM, Emiliano Gonzalez wrote:
I have a ssh server.

When I connect with the client on Fedora 32 ssh there are no problems.

With PuTTY: Release 0.74 I can't connect with error: Couldn't agree a host key algorithm (available: rsa-sha2-512, rsa-sha2-256)

That sounds like an issue of PuTTY, that it can not use the RSA SHA2 hostkey algorithms from RFC8332.

As a workaround, you can configure your server with different hostkeys (ed25519) so incompatible clients can connect too.

 From Centos 7 ssh server crash. In packet.c (line 1862):

|/* For smaller blocks use limit of 1 GB as recommended in RFC4253 */ cipher->max_blocks = ((uint64_t)1 << 30) / cipher->blocksize; |

cipher->blocksize is 0;

What cipher is used for this connection? There is no cipher that would have blocksize == 0.

Can you get a debug log?

Regards,
--
Jakub Jelen
Senior Software Engineer
Crypto Team, Security Engineering
Red Hat, Inc.


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Re: Can't connect with some clientsEmiliano Gonzalez <egonzalez.hiperion@xxxxxxxxx>
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Can't connect with some clientsEmiliano Gonzalez <egonzalez.hiperion@xxxxxxxxx>
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