Zero trust SSH

Passwordless, keyless SSH at any scale

Octelium is a free and open source, self-hosted zero trust access platform. Its SSH mode authenticates to the upstream server on the User's behalf, so nobody receives a password or a private key, there is no SSH certificate authority to operate, and every session is authorized per connection and recorded.

  • Free and open source
  • No keys to distribute
  • No PKI to operate

Every request from a human, a browser, a CLI, a workload or an AI agent is authenticated against your identity providers, authorized per request at the application layer by the Octelium Service in front of the resource, exported to your SIEM and observability stack whether it is allowed or denied, and only then routed to the upstream HTTP API, database, SSH server, Kubernetes cluster, LLM or MCP server.

Signing in once, then reaching Services with and without a client

  • A browser opens grafana.acme.com and is redirected to the Cluster sign-in page at acme.com/login.
  • jane signs in with a passkey verified by a biometric on the device, and the browser returns to the Grafana dashboard at grafana.acme.com with no client installed.
  • In a terminal, octelium connect -d opens the browser at acme.com/callback/success/approval, where the same browser session approves the login with one click.
  • ~ ❯ octelium connect -d
  • Please authenticate yourself using Octelium web Portal
  • Waiting for you to approve the login in your browser. Press Ctrl-C to cancel.
  • You are now authenticated as jane
  • Octelium has started running in detached mode.
  • ~ ❯ curl -s my-api/v1/users/42 | jq
  • {
  • "id": 42,
  • "name": "Jane Doe",
  • "email": "jane@acme.com"
  • }
  • ~ ❯ psql -h pg-prod -d shop
  • psql (17.4)
  • Type "help" for help.
  • shop=> SELECT * FROM orders LIMIT 3;
  • id | status | total
  • -----+---------+--------
  • 981 | paid | 129.00
  • 982 | shipped | 48.50
  • 983 | paid | 310.25
  • (3 rows)
  • shop=> \q
  • ~ ❯ ssh bastion
  • Welcome to Ubuntu 24.04.1 LTS (GNU/Linux 6.8.0-1021-aws x86_64)

Requests authorized one by one against CEL rules in the HTTP, LLM and Kubernetes modes

  • HTTP: the HTTP Service billing is configured as follows.
  • kind: Service
  • metadata:
  • name: billing
  • spec:
  • mode: HTTP
  • config:
  • authorization:
  • inlinePolicies:
  • - spec:
  • rules:
  • - effect: ALLOW
  • condition:
  • all:
  • of:
  • - match: '"finance" in ctx.user.spec.groups'
  • - match: ctx.request.http.method == "GET"
  • - match: ctx.request.http.path.startsWith("/invoices")
  • jane, a member of the finance Group, runs curl -i billing/invoices/42 and gets HTTP/1.1 200 OK Content-Type: application/json {"id":42,"status":"paid","total":1290}. The access log records ALLOWED GET /invoices/42 with POLICY_MATCH.
  • jane, a member of the finance Group, runs curl -i -X DELETE billing/invoices/42 and gets HTTP/1.1 403 Forbidden X-Octelium-Unauthorized: true Content-Length: 0. The access log records DENIED DELETE /invoices/42 with NO_POLICY_MATCH.
  • LLM: the LLM Service openai is configured as follows.
  • kind: Service
  • metadata:
  • name: openai
  • spec:
  • mode: LLM
  • config:
  • authorization:
  • inlinePolicies:
  • - spec:
  • rules:
  • - effect: ALLOW
  • condition:
  • any:
  • of:
  • - match: '"ai-admins" in ctx.user.spec.groups'
  • - all:
  • of:
  • - match: '"ai-agents" in ctx.user.spec.groups'
  • - match: ctx.request.llm.operation == "GENERATE"
  • - match: ctx.request.llm.model == "gpt-5-mini"
  • support-bot, a member of the ai-agents Group, runs curl openai/v1/responses --json '{"model":"gpt-5-mini","input":"Hello"}' and gets { "id": "resp_68e8e1f0c4d0", "object": "response", "created_at": 1791628935, "status": "completed", "model": "gpt-5-mini-2025-08-07",. The access log records ALLOWED RESPONSES gpt-5-mini with POLICY_MATCH.
  • support-bot, a member of the ai-agents Group, runs curl openai/v1/responses --json '{"model":"gpt-5","input":"Hello"}' and gets {"error":{"message":"Octelium: unauthorized request","type":"permission_error","param":null,"code":"octelium_unauthorized"}}. The access log records DENIED RESPONSES gpt-5 with NO_POLICY_MATCH.
  • Kubernetes: the KUBERNETES Service k8s-prod is configured as follows.
  • kind: Service
  • metadata:
  • name: k8s-prod
  • spec:
  • mode: KUBERNETES
  • config:
  • authorization:
  • inlinePolicies:
  • - spec:
  • rules:
  • - effect: ALLOW
  • condition:
  • all:
  • of:
  • - match: '"sre-agents" in ctx.user.spec.groups'
  • - match: ctx.request.kubernetes.verb in ["get", "list"]
  • - match: ctx.request.kubernetes.namespace == "production"
  • - not: ctx.request.kubernetes.resource == "secrets"
  • ops-agent, a member of the sre-agents Group, runs kubectl get configmaps -n production and gets NAME DATA AGE app-config 4 12d feature-flags 2 3d kube-root-ca.crt 1 12d. The access log records ALLOWED list configmaps · production with POLICY_MATCH.
  • ops-agent, a member of the sre-agents Group, runs kubectl get secrets -n production and gets Error from server (Forbidden): Octelium: Unauthorized request. The access log records DENIED list secrets · production with NO_POLICY_MATCH.
Secretless access

Keys and passwords that are never distributed

The upstream password or private key is stored in the Cluster as a Secret and used by the proxy to authenticate to the SSH server once a connection has been authorized. Nobody receives it, so there is nothing to rotate across laptops when someone leaves.

Read about secretless access

Upstream credentials injected per request by identity in the HTTP, SSH and PostgreSQL modes

  • HTTP: the HTTP Service stripe proxies https://api.stripe.com and picks the upstream credential of every request with dynamic configuration rules.
  • elena, a member of the finance-eu Group, runs curl -s stripe/v1/account | jq '{id, country}' without holding any credential. The rule "finance-eu" in ctx.user.spec.groups selects the eu config, so Octelium injects the Secret stripe-eu and the upstream authenticates the request as acct_1Pq8EuGmbH2bXvK3. The terminal shows { "id": "acct_1Pq8EuGmbH2bXvK3", "country": "DE" }
  • pay-agent, a member of the finance-us Group, runs curl -s stripe/v1/account | jq '{id, country}' without holding any credential. The rule "finance-us" in ctx.user.spec.groups selects the us config, so Octelium injects the Secret stripe-us and the upstream authenticates the request as acct_1Nf2UsQ7cLm4RtW9. The terminal shows { "id": "acct_1Nf2UsQ7cLm4RtW9", "country": "US" }
  • SSH: the SSH Service web-01 proxies ssh://10.0.4.21 and picks the upstream credential of every request with dynamic configuration rules.
  • sam, a member of the sre Group, runs ssh web-01 without holding any credential. The rule "sre" in ctx.user.spec.groups selects the root config, so Octelium injects the Secret root-key and the upstream authenticates the request as root. The terminal shows Welcome to Ubuntu 24.04.3 LTS (GNU/Linux 6.14.0-1015-aws x86_64) root@web-01:~# id uid=0(root) gid=0(root) groups=0(root)
  • noah, a member of the developers Group, runs ssh web-01 without holding any credential. The rule "developers" in ctx.user.spec.groups selects the deploy config, so Octelium injects the Secret deploy-key and the upstream authenticates the request as deploy. The terminal shows Welcome to Ubuntu 24.04.3 LTS (GNU/Linux 6.14.0-1015-aws x86_64) deploy@web-01:~$ id uid=1001(deploy) gid=1001(deploy) groups=1001(deploy)
  • PostgreSQL: the POSTGRES Service orders-db proxies postgres://10.0.2.8:5432 and picks the upstream credential of every request with dynamic configuration rules.
  • priya, a member of the backend Group, runs psql -h orders-db orders without holding any credential. The rule "backend" in ctx.user.spec.groups selects the rw config, so Octelium injects the Secret pg-rw and the upstream authenticates the request as app_rw. The terminal shows psql (17.2) Type "help" for help. orders=> UPDATE orders SET status = 'shipped' WHERE id = 42; UPDATE 1
  • bi-agent, a member of the analytics Group, runs psql -h orders-db orders without holding any credential. The rule "analytics" in ctx.user.spec.groups selects the ro config, so Octelium injects the Secret pg-ro and the upstream authenticates the request as app_ro. The terminal shows psql (17.2) Type "help" for help. orders=> UPDATE orders SET status = 'shipped' WHERE id = 42; ERROR: permission denied for table orders

Signing in with a passkey and opening the Portal

  • The sign-in page of the Cluster at acme.com/login offers login with Okta, with GitHub, or with a passkey.
  • jane@acme.com chooses Login with a Passkey and verifies it with a biometric on the device through native WebAuthn.
  • The browser is redirected to the Portal at portal.acme.com/services, which lists the Services the User can access:
  • grafana.monitoring: Grafana dashboards, Web App, Namespace monitoring.
  • aws-postgres.production: Amazon RDS for PostgreSQL, PostgreSQL, Namespace production.
  • k8s-prod: Production EKS cluster, Kubernetes, Namespace default.
  • bastion.production: SSH bastion host, SSH, Namespace production.
  • github-mcp: GitHub MCP server, MCP, Namespace default.
  • openai: OpenAI API, AI / LLM, Namespace default.
Visibility and auditing

Session recordings, streamed as they happen

Every SSH session produces AccessLogs identifying the User, Session and Device alongside the SSH detail of the session itself, emitted in real time to your OpenTelemetry OTLP receivers.

Read about visibility and auditing
AccessLogOTLP
ALLOWlinus@acme.compg-prod.dbPOSTGRESquery: select id, email from users limit 50
ALLOWci-runnerprod-k8sKUBERNETESverb=list resource=pods namespace=production
DENYagent-07tools-mcpMCPtools/call name=transfer policy=mcp-tools
ALLOWjane@acme.combastionSSHsession recorded, upstream user=deploy
ALLOWagent-07openaiLLMCHAT_COMPLETIONS model=gpt-5-mini tokens=1284

Cluster resources applied declaratively from YAML with octeliumctl and managed programmatically with the Go, TypeScript, Python and Rust SDKs

  • GitOps: cluster.yaml in the main branch of the ~/octelium repository describes the desired state of the Cluster. Its diff reads as follows, with + for added, ~ for changed and - for removed lines.
  • + kind: Group
  • + metadata:
  • + name: payments
  • + spec: {}
  • + ---
  • + kind: User
  • + metadata:
  • + name: alice
  • + spec:
  • + type: HUMAN
  • + email: alice@acme.com
  • + groups: ["payments"]
  • ---
  • kind: User
  • metadata:
  • name: bob
  • spec:
  • type: HUMAN
  • ~ groups: ["payments"]
  • ---
  • kind: Service
  • metadata:
  • name: billing
  • spec:
  • mode: HTTP
  • config:
  • upstream:
  • ~ url: http://10.0.3.24:8080
  • - ---
  • - kind: Service
  • - metadata:
  • - name: billing-legacy
  • - spec: ⋯
  • - ---
  • - kind: User
  • - metadata:
  • - name: john
  • - spec: ⋯
  • ~/octelium ❯ octeliumctl apply --prune .
  • Group: payments Created
  • User: alice Created
  • User: bob Updated
  • Service: billing.default Updated
  • Service: billing-legacy.default Deleted
  • User: john Deleted
  • Cluster Core resources successfully applied
  • 2 resources created
  • 2 resources updated
  • 2 resources deleted
  • Go: main.go uses the octelium-go SDK to list the Users of the Cluster and update the email and Policies of linus.
  • client, err := octelium.New(ctx)
  • if err != nil {⋯}
  • conn, err := client.Conn(ctx)
  • if err != nil {⋯}
  • api := corev1.NewMainServiceClient(conn)
  • users, err := api.ListUser(ctx, &corev1.ListUserOptions{})
  • if err != nil {⋯}
  • for _, u := range users.Items {
  • fmt.Println(u.Metadata.Name)
  • }
  • user, err := api.GetUser(ctx, &metav1.GetOptions{Name: "linus"})
  • if err != nil {⋯}
  • user.Spec.Email = "linus@acme.com"
  • user.Spec.Authorization = &corev1.User_Spec_Authorization{
  • Policies: []string{"db-readonly"},
  • }
  • if _, err := api.UpdateUser(ctx, user); err != nil {⋯}
  • fmt.Println("updated", user.Metadata.Name)
  • ~/app ❯ go run .
  • alice
  • bob
  • linus
  • updated linus
  • TypeScript: main.ts uses the @octelium/sdk SDK to list the Users of the Cluster and update the email and Policies of linus.
  • const client = await OcteliumClient.create({
  • domain: "acme.com",
  • auth: {⋯},
  • });
  • const users = await client.coreV1.listUser(ListUserOptions.create());
  • for (const u of users.response.items) {
  • console.log(u.metadata?.name);
  • }
  • const { response: user } = await client.coreV1.getUser(
  • GetOptions.create({ name: "linus" }),
  • );
  • user.spec!.email = "linus@acme.com";
  • user.spec!.authorization = User_Spec_Authorization.create({
  • policies: ["db-readonly"],
  • });
  • await client.coreV1.updateUser(user);
  • console.log("updated", user.metadata?.name);
  • await client.close();
  • ~/app ❯ npx tsx main.ts
  • alice
  • bob
  • linus
  • updated linus
  • Python: main.py uses the octelium-sdk SDK to list the Users of the Cluster and update the email and Policies of linus.
  • async with await OcteliumClient.create() as client:
  • users = await client.core_v1.list_user(ListUserOptions())
  • for u in users.items:
  • print(u.metadata.name)
  • user = await client.core_v1.get_user(GetOptions(name="linus"))
  • user.spec.email = "linus@acme.com"
  • user.spec.authorization.policies = ["db-readonly"]
  • await client.core_v1.update_user(user)
  • print("updated", user.metadata.name)
  • ~/app ❯ python main.py
  • alice
  • bob
  • linus
  • updated linus
  • Rust: main.rs uses the octelium SDK to list the Users of the Cluster and update the email and Policies of linus.
  • let client = Client::from_env().await?;
  • let mut api = client.core_v1();
  • let users = api.list_user(ListUserOptions::default()).await?;
  • for u in users.into_inner().items {
  • println!("{}", u.metadata.unwrap_or_default().name);
  • }
  • let options = GetOptions {
  • name: "linus".into(),
  • ..Default::default()
  • };
  • let mut user = api.get_user(options).await?.into_inner();
  • let spec = user.spec.get_or_insert_default();
  • spec.email = "linus@acme.com".into();
  • spec.authorization.get_or_insert_default().policies = vec!["db-readonly".into()];
  • let user = api.update_user(user).await?.into_inner();
  • println!("updated {}", user.metadata.unwrap_or_default().name);
  • ~/app ❯ cargo run -q
  • alice
  • bob
  • linus
  • updated linus
SSH at scale

What SSH access has to solve, and what solves each part

SSH itself is not the difficult part. These are the problems that appear once more than a handful of people reach more than a handful of hosts, next to the mechanism in an Octelium Cluster that handles each one.

  1. 01

    Getting a key onto the right machines

    Nothing is distributed. The upstream password or private key is stored in the Cluster as a Secret and used by the identity-aware proxy to authenticate to the upstream, so no authorized_keys file has to be maintained across a fleet.

    Read more
  2. 02

    Taking it away again

    Revoking access is a Policy change or a Session revocation rather than a key removal on every host someone could reach, which is what makes offboarding reliable rather than a checklist.

    Read more
  3. 03

    Avoiding a certificate authority to run

    There is no SSH PKI to operate, no signing service to keep available and no certificate lifetime to tune. Authentication to the Cluster is your existing identity provider, and authentication to the upstream is the Cluster's own credential.

    Read more
  4. 04

    Deciding which account someone lands in

    The Service can force the upstream SSH user regardless of what the client asks for, and dynamic configuration can map different groups to different accounts and credentials on the same host.

    Read more
  5. 05

    Verifying the host being connected to

    The upstream's public key is pinned in the Service in OpenSSH format and verified by the proxy on connect, so host key checking is configuration rather than something each person confirms on first use.

    Read more
  6. 06

    Reaching hosts that cannot run a server

    The embedded SSH mode serves SSH from inside the octelium client itself, without a standalone SSH server on the host and without root privileges, which suits fleets of containers, IoT devices and confined environments.

    Read more
  7. 07

    Limiting what a session can do

    SSH subsystem requests such as SFTP and local port forwarding are both disabled by default and enabled explicitly per Service, so file transfer and tunnelling are decisions rather than side effects of shell access.

    Read more
  8. 08

    Being able to show what happened

    Sessions are recorded and streamed in real time over OpenTelemetry, alongside exec requests, subsystem requests and port forwarding events, each identified by the User, Session and Device behind it.

    Read more

Certificates shorten the life of a credential, which helps. They do not remove the credential from the person's machine, and they add a certificate authority to operate. Injecting the credential at the proxy removes both.

Questions

Frequently asked

How do people connect?
With their ordinary SSH client. The Service is reachable at a stable private name over the client-based tunnel, and the identity-aware proxy authenticates to the upstream on the User's behalf. Nothing about the local SSH workflow changes, and no key or password is entered.
Do I have to run a certificate authority?
No. There is no SSH PKI to operate. People authenticate to the Cluster through your existing OpenID Connect or SAML 2.0 identity provider, and the Cluster authenticates to the upstream with a password or private key held as a Secret. Which credential is used, and which upstream account it maps to, can be selected per request from identity and context.
Can it SSH into hosts that do not run an SSH server?
Yes. The embedded SSH mode lets a connected client serve SSH from inside the octelium client itself, without a standalone SSH server on the host and without root privileges. Authorized Users then SSH into a host by using that Session's name as the SSH user. A Cluster ships with a built-in Service for this, so nothing has to be defined to use it.
Are sessions recorded?
Yes. SSH Services emit full session recordings alongside exec requests, subsystem requests and port forwarding session events, streamed in real time over OpenTelemetry to your own log management and SIEM providers. Recording can be disabled per Service, and stdin recording can be enabled explicitly, which is useful for non-interactive sessions where stdin is not echoed.
Can SFTP and port forwarding be used?
Both are disabled by default and enabled explicitly per Service, with enableSubsystem for subsystem requests such as SFTP and enableLocalPortForwarding for local forwarding. Port forwarding sessions are recorded as their own event types in the access logs.
Is Octelium free and open source?
Yes. Octelium is designed for self-hosting and does not require a proprietary hosted control plane. The core platform is free and open source. An optional enterprise package adds capabilities for organizations with additional operational, identity-management and security requirements, including the web console, SCIM provisioning and Secret encryption at rest.
Get started

Run Octelium on your own infrastructure

Install a self-hosted Cluster and start applying identity-aware access control to your Services.