Terraform Fails SSH Authentication with Amazon Linux 2023 (OpenSSH 8.7+/8.9+) in v0.14.x

Terraform
1

Terraform version 0.14.x fails to authenticate over SSH when using remote-exec or null_resource with EC2 instances running Amazon Linux 2023 (AL2023). The same code works fine with Amazon Linux 2 and CentOS-based images.

Error: timeout - last error: SSH authentication failed (ec2-user@<IP>:22): 
ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain

Even though the correct private key is specified and verified with

"ssh -i ~/.ssh/my_key.pem ec2-user@<IP>
# Login successful
"

Here is my code sample

resource "null_resource" "print_hostname" {
  provisioner "remote-exec" {
    inline = [
      "echo 'Hostname is: $(hostname)'"
    ]

    connection {
      type        = "ssh"
      user        = "ec2-user"
      private_key = file("~/.ssh/my_key.pem")
      host        = "<IP_ADDRESS>"
      timeout     = "2m"
    }
  }

  triggers = {
    always_run = timestamp()
  }
}

Note: Key format and permission are good.

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