Skip to content

Update GitHub SSH known host keys #1982

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
safeengineauto wants to merge 2 commits into
base: dev
Choose a base branch
from
+27 −5
Open

Update GitHub SSH known host keys #1982

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
0ff5ff2
Update SSH known hosts configuration
safeengineauto Apr 28, 2026
9072c66
Add tests for SSH known hosts handling
safeengineauto Apr 28, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions __tests__/ssh.test.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,9 @@ import {execute} from '../src/execute.js'
import {configureSSH} from '../src/ssh.js'

const originalAction = JSON.stringify(action)
const expectedGitHubKnownHostRsa = `\ngithub.com ssh-rsa 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\n`
const expectedGitHubKnownHostEcdsa = `\ngithub.com ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEmKSENjQEezOmxkZMy7opKgwFB9nkt5YRrYMjNuG5N87uRgg6CLrbo5wAdT/y6v0mKV0U2w0WZ2YB/++Tpockg=\n`
const expectedGitHubKnownHostEd25519 = `\ngithub.com ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl\n`

jest.mock('fs', () => ({
appendFileSync: jest.fn(),
Expand Down Expand Up @@ -75,6 +78,23 @@ describe('configureSSH', () => {
expect(execFileSync).toHaveBeenCalledTimes(1)
expect(exportVariable).toHaveBeenCalledTimes(2)
expect(execSync).toHaveBeenCalledTimes(3)
expect(appendFileSync).toHaveBeenCalledTimes(3)
expect(appendFileSync).toHaveBeenCalledWith(
`${process.env['HOME']}/.ssh/known_hosts`,
expectedGitHubKnownHostRsa
)
expect(appendFileSync).toHaveBeenCalledWith(
`${process.env['HOME']}/.ssh/known_hosts`,
expectedGitHubKnownHostEcdsa
)
expect(appendFileSync).toHaveBeenCalledWith(
`${process.env['HOME']}/.ssh/known_hosts`,
expectedGitHubKnownHostEd25519
)
expect(appendFileSync).not.toHaveBeenCalledWith(
expect.any(String),
expect.stringContaining('ssh-dss')
)
})

it('should not export variables if the return from ssh-agent is skewed', async () => {
Expand Down
12 changes: 7 additions & 5 deletions src/ssh.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,16 +14,18 @@ export async function configureSSH(action: ActionInterface): Promise<void> {
const sshDirectory = `${process.env['HOME']}/.ssh`
const sshKnownHostsDirectory = `${sshDirectory}/known_hosts`

// SSH fingerprints provided by GitHub: https://docs.github.com/en/free-pro-team@latest/github/authenticating-to-github/githubs-ssh-key-fingerprints
const sshGitHubKnownHostRsa = `\n${action.hostname} ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==\n`
const sshGitHubKnownHostDss = `\n${action.hostname} ssh-dss AAAAB3NzaC1kc3MAAACBANGFW2P9xlGU3zWrymJgI/lKo//ZW2WfVtmbsUZJ5uyKArtlQOT2+WRhcg4979aFxgKdcsqAYW3/LS1T2km3jYW/vr4Uzn+dXWODVk5VlUiZ1HFOHf6s6ITcZvjvdbp6ZbpM+DuJT7Bw+h5Fx8Qt8I16oCZYmAPJRtu46o9C2zk1AAAAFQC4gdFGcSbp5Gr0Wd5Ay/jtcldMewAAAIATTgn4sY4Nem/FQE+XJlyUQptPWMem5fwOcWtSXiTKaaN0lkk2p2snz+EJvAGXGq9dTSWHyLJSM2W6ZdQDqWJ1k+cL8CARAqL+UMwF84CR0m3hj+wtVGD/J4G5kW2DBAf4/bqzP4469lT+dF2FRQ2L9JKXrCWcnhMtJUvua8dvnwAAAIB6C4nQfAA7x8oLta6tT+oCk2WQcydNsyugE8vLrHlogoWEicla6cWPk7oXSspbzUcfkjN3Qa6e74PhRkc7JdSdAlFzU3m7LMkXo1MHgkqNX8glxWNVqBSc0YRdbFdTkL0C6gtpklilhvuHQCdbgB3LBAikcRkDp+FCVkUgPC/7Rw==\n`

// GitHub.com SSH host keys:
// https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/githubs-ssh-key-fingerprints
const sshGitHubKnownHostRsa = `\n${action.hostname} ssh-rsa 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\n`
const sshGitHubKnownHostEcdsa = `\n${action.hostname} ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEmKSENjQEezOmxkZMy7opKgwFB9nkt5YRrYMjNuG5N87uRgg6CLrbo5wAdT/y6v0mKV0U2w0WZ2YB/++Tpockg=\n`
const sshGitHubKnownHostEd25519 = `\n${action.hostname} ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl\n`
info(`Configuring SSH client… 🔑`)

await mkdirP(sshDirectory)

appendFileSync(sshKnownHostsDirectory, sshGitHubKnownHostRsa)
appendFileSync(sshKnownHostsDirectory, sshGitHubKnownHostDss)
appendFileSync(sshKnownHostsDirectory, sshGitHubKnownHostEcdsa)
appendFileSync(sshKnownHostsDirectory, sshGitHubKnownHostEd25519)

// Initializes SSH agent.
const agentOutput = execFileSync('ssh-agent').toString().split('\n')
Expand Down