GitHub recently began rejecting SSH authentication requests from clients that lack a corresponding public key (.pub) file, forcing users to regenerate it to restore access. The issue stems from a change in GitHub’s SSH server software, which now enforces a specific two-step authentication flow that modern OpenSSH clients only use when the `.pub` file is present. This highlights how subtle protocol variations can disrupt widely used developer workflows.
Background
Secure Shell (SSH) key authentication relies on matching private and public keys, with the public key typically stored on servers like GitHub for access control. OpenSSH clients can handle authentication differently depending on whether the local `.pub` file exists, affecting how keys are negotiated during connection.
- Source
- Lobsters
- Published
- Jul 21, 2026 at 06:11 PM
- Score
- 7.0 / 10