Unable to execute command: InternalError: Algorithm negotiation fail

Products

• VMware Aria Suite

Issue/Introduction

• When using Aria Orchestrator 8.18.0 (Embedded or External) and using the "Run SSH command" workflow or similar, you get an error such as:

• Unable to execute command: InternalError: Algorithm negotiation fail: algorithmName="server_host_key" jschProposal="ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-512,rsa-sha2-256" serverProposal="ssh-rsa,ssh-dss" (Workflow:Run SSH command / Execute SSH Command (item#)###) (Workflow:Run SSH command / Execute SSH Command (item#)###)

• This occurs when you try to connect using weak ciphers.

Environment

• Aria Automation 8.17+
• Aria Orchestrator 8.17+

Cause

•  Changed from SHA1 supported algorithms and ciphers as per: Steps for removing weak SHA1 algorithms and ciphers from VMware Aria Products.

Resolution

• The ciphers are controlled by the Plugin version which should be updated and compatible in line with the version of Aria Orchestrator you are using, and hence, we can not modify which ciphers and algorithms are in use.
• A potential available workaround is to change the SSHd configuration file on the Virtual Machines which you are trying to connect to via SSH from the Aria Orchestrator or workflows.
• The following algorithms are currently supported on the listed versions for the Aria Orchestrator SSH Plugin:
  

  jschProposal="ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-512,rsa-sha2-256"