Pragma Systems Technical Forum

No matching DH grp found

https://forums.pragmasys.com/Topic510.aspx

By stephencky - 10/18/2019 3:51:57 AM

Dears,

We are using Pragma FortressSSH 5.0.9.2696 as a server role.

Recently we encounter a problem related to "Protocol error: no matching DH grp found" after the client upgrade the OPENSSH from v6.9 to v8.0. With reference to the information from the link below, seems diffie-hellman-group-exchange-sha256 changed to support the minimal modulus length from 1024 to 2048, which doesn't compatible with current Pragma version. We would like to know which Pragma version could compatible with OPENSSH 8.0?

https://tools.ietf.org/html/draft-ietf-curdle-ssh-dh-group-exchange-05

Stephen
By Technical Support Group (TSG) - 10/24/2019 7:49:27 AM

 
stephencky - 10/18/2019 9:51:57 AM
Dears,

We are using Pragma FortressSSH 5.0.9.2696 as a server role.

Recently we encounter a problem related to "Protocol error: no matching DH grp found" after the client upgrade the OPENSSH from v6.9 to v8.0. With reference to the information from the link below, seems diffie-hellman-group-exchange-sha256 changed to support the minimal modulus length from 1024 to 2048, which doesn't compatible with current Pragma version. We would like to know which Pragma version could compatible with OPENSSH 8.0?

https://tools.ietf.org/html/draft-ietf-curdle-ssh-dh-group-exchange-05

Stephen

I recommend you update to the latest build at www.pragmasys.com/ssh-server/download.