This document is in progress!
Summary
Passwords alone are no longer sufficient. To address this RIT has moved to Duo's MFA service for the majority of services. Admins and developers, however, have access to large amounts of information and have privileges on servers that can cause significant damage if their credentials are compromised. Because of those risks, stronger and more efficient MFA is required for certain accounts. To achieve this, ITS has historically used OATH (One Time Passwords) for SSH and sudo access on Linux servers and recently started requiring either certificates + PIN or Duo for Windows logons.
OATH is deprecated and all OATH users are being moved to certificate-based authentication. ITS is issuing YubiKeys that will be used to securely generate and store these certificates.
Requirements
- YubiKey 4 or newer (Blue security keys will not work)
- Latest version of OS
- YubiKey Manager
- Download direct from Yubico: https://www.yubico.com/support/download/yubikey-manager/#h-downloads
- Windows
- Mac
- Linux
Considerations
- These docs are not the only way to accomplish the goal nor are YubiKeys the only way to accomplish password-less authentication however the further you deviate from these docs the less knowledge ITS has to assist you.
- The OS requires a lock on the YubiKey. If using multiple computers, even if a computer is virtual, multiple devices will be needed – one device per instance of the OS.
- A YubiKey can be passed through RDP session(s) (Windows only)
- Each device will have a different certificate. A certificate can, however, be used for access to both Linux and Windows servers.
- Expert mode: While a YubiKey (i.e. a Yubico device) is not required, the docs and process are assuming a YubiKey is being used. Any device that can securely generate and store keys in a way that can be cryptographically verified will work.
Process Overview
- Initialize/Configure YubiKey
- Determine which certificate to use
- Submit certificate for verification
- Configure clients to use certificates
- (OPTIONAL) Next steps
1. Initialize/Configure YubiKey
2. Determine which certificate to use
The following is a suggested determination of which certificate process to follow. If you feel comfortable deviating, feel free to do so.
If you plan on utilizing your YubiKey to login into Windows workstations or Windows servers via RDP you need a Windows CA-issued certificated. Otherwise a self-signed certificate is sufficient.
3. Submit certificate for verification
4. Configure clients to use certificates
Windows: YubiKey Windows SSH Client Configuration
Mac: YubiKey Mac SSH Client Configuration
Linux: YubiKey Linux SSH Client Configuration
5. (OPTIONAL) Next steps
YubiKey Duo Setup
Other uses for certificates
- Sign and encrypt emails
- Main benefit comes from a chained certificate
- Trust follows the chain
- via Windows CA-issued certificate - valid for all RIT Windows domain-bound machines
- via publicly signed certificate - valid for everyone
- Trust follows the chain
- Using Your YubiKey for Email Signing/Encrypting with Outlook on Windows
- Using Your YubiKey for Email Signing/Encrypting with Outlook on Mac
- Main benefit comes from a chained certificate
- Signing Gitlab commits and tags
- Code signing
- Current Windows CA-issued certs are not able to sign code (as of 3/23/2022)
- Code Signing with the YubiKey on Windows
Other uses of YubiKeys
- Register the YubiKey as a security key within Duo by enrolling the device at start.rit.edu/Duo
- Configure the YubiKey as a safe place to store OTP (one time passcodes) for non-RIT services instead of using a phone app
- Register the YubiKey to provide password-less authentication in Azure/M365 services