temporary_key_pair_type is ignored, RSA is always used #54
Description
Overview of the Issue
Hi,
I noticed that building an image with OpenStack and a non-default (i.e. non-RSA) temporary SSH key type is not possible.
Reproduction Steps
To reproduce, one can simply attempt to build an image with a buildfile containing "temporary_key_pair_type": "ed25519" (the value seems to be entirely ignored, it could be "ecdsa" or even "foobar").
Plugin and Packer version
Packer v1.7.8 (installed via apt from the official repo).
Simplified Packer Buildfile
{
"builders": [
{
"flavor": "xx",
"image_name": "fedora35_test",
"name": "builder",
"networks": "xxx-xxx",
"source_image_name": "Fedora 35",
"ssh_clear_authorized_keys": "true",
"ssh_ip_version": "4",
"ssh_username": "fedora",
"temporary_key_pair_type": "ed25519",
"type": "openstack"
}
]
}Operating system and Environment details
Debian 11.
Log Fragments and crash.log files
From the Packer log:
==> builder: Created temporary keypair: packer_61c5efec-a241-87f9-0f96-ae9c43f3e468
builder: Saving key for debug purposes: os_builder.pem
If I dump the key, it clearly is an RSA key:
$ head -n1 os_builder.pem
-----BEGIN RSA PRIVATE KEY-----
More logs from Packer:
2021/12/24 16:09:09 packer-builder-openstack plugin: [DEBUG] Detected address: w.x.y.z
2021/12/24 16:09:09 packer-builder-openstack plugin: [DEBUG] Using IP address w.x.y.z to connect
2021/12/24 16:09:09 packer-builder-openstack plugin: [INFO] Attempting SSH connection to w.x.y.z:22...
2021/12/24 16:09:09 packer-builder-openstack plugin: [DEBUG] reconnecting to TCP connection for SSH
2021/12/24 16:09:09 packer-builder-openstack plugin: [DEBUG] handshaking with SSH
2021/12/24 16:09:09 packer-builder-openstack plugin: [DEBUG] SSH handshake err: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported met
hods remain
2021/12/24 16:09:09 packer-builder-openstack plugin: [DEBUG] Detected authentication error. Increasing handshake attempts.
Because OpenSSH can use the right key exchange algorithm, I'm able to SSH onto the server and check its logs with ssh -l fedora -i os_builder.pem w.x.y.z journalctl -u sshd.
This shows Dec 24 16:09:23 fedora35-test sshd[897]: userauth_pubkey: key type ssh-rsa not in PubkeyAcceptedAlgorithms [preauth].
I have noticed a similar issue for the Amazon builder: hashicorp/packer-plugin-amazon#144
It would be great to see this fixed because it is really problematic when dealing with modern images such as Fedora 35.