[JENKINS-62221] EC2 plugin perpetually loops unable to verify key for host

I've just upgraded our EC2 plugin to the latest (1.50.2) and have found our nodes are not spinning up.

They perpetually loop with the following logs:

May 08, 2020 4:12:23 PM hudson.plugins.ec2.EC2Cloud INFO: The line with the key doesn't have the required format. Found: "ssh-ed25519 AAAAC3Nzarestofkeygoeshere ". Expected a line with this text: "ALGORITHM THEHOSTKEY", example: "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJbvbEIoY3tqKwkeRW/L1FnbCLLp8a1TwSOyZHKJqFFR "

 

Based on this:

https://github.com/jenkinsci/ec2-plugin/blob/master/src/main/java/hudson/plugins/ec2/ssh/verifiers/SshHostKeyVerificationStrategy.java#L139-L146, which says:

String[] parts = line.split(" ");

if (parts.length > 2) {

 

The example will never work:

{{ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJbvbEIoY3tqKwkeRW/L1FnbCLLp8a1TwSOyZHKJqFFR }}

will never split into > 2 pieces as the code says. E.g.: https://repl.it/repls/FoolishCrookedWebsite

Either I'm misunderstanding how this is meant to work, or the error message is unclear.

I've not done anything to change our configuration other than upgrading the plugin.

---
Originally reported by edhgoose, imported from: EC2 plugin perpetually loops unable to verify key for host

• assignee: mramonleon
  
• status: In Review
  
• priority: Major
  
• component(s): ec2-plugin
  
• label(s): ec2-plugin
  
• resolution: Unresolved
  
• votes: 8
  
• watchers: 12
  
• imported: 2025-12-06
  

Raw content of original issue

I've just upgraded our EC2 plugin to the latest (1.50.2) and have found our nodes are not spinning up.


They perpetually loop with the following logs:


May 08, 2020 4:12:23 PM hudson.plugins.ec2.EC2Cloud INFO: The line with the key doesn't have the required format. Found: "ssh-ed25519 AAAAC3Nzarestofkeygoeshere ". Expected a line with this text: "ALGORITHM THEHOSTKEY", example: "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJbvbEIoY3tqKwkeRW/L1FnbCLLp8a1TwSOyZHKJqFFR "

 


Based on this:


https://github.com/jenkinsci/ec2-plugin/blob/master/src/main/java/hudson/plugins/ec2/ssh/verifiers/SshHostKeyVerificationStrategy.java#L139-L146, which says:


        String[] parts = line.split(" ");

        if (parts.length > 2) {

 


The example will never work:


{{ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJbvbEIoY3tqKwkeRW/L1FnbCLLp8a1TwSOyZHKJqFFR }}


will never split into > 2 pieces as the code says. E.g.: https://repl.it/repls/FoolishCrookedWebsite


Either I'm misunderstanding how this is meant to work, or the error message is unclear.


I've not done anything to change our configuration other than upgrading the plugin.

Start in src/main/java/hudson/plugins/ec2/ssh/verifiers/SshHostKeyVerificationStrategy.java at the parsing logic around lines 139-146, then compare it with the logged key format and example message. Reproduce the verification failure and determine whether the parser or its error guidance is inconsistent. Done means the documented key format and verification behavior agree so EC2 nodes no longer loop on this input.

Written by the indexing model from the issue text.