Requirements

• Requires System.Formats.Cbor unzipped to the current directory: https://www.nuget.org/packages/System.Formats.Cbor
• Only tested with powershell core (7.2)
• Only works with sk-ssh-ed25519 keys
• requires attestation.bin and challengefile in the current directory.
• the ssh-keygen command will create ed25519-sk and ed25519-sk.pub - neither of these files are necessary to evaluate the attestation.
• the attestation script will generate sk.pub
• Only supports the default application "ssh:"

Running

1. Create a Challenge File - can be anything that isn't null, save it as challengefile get-date | Set-Content challengefile
2. Create a new ed25519 key with provided challenge: ssh-keygen -t ed25519-sk -f ed25519-sk -O challenge=challengefile -O write-attestation=attestation.bin
3. Run the script ./ssh-sk-attestation-tools.ps1