infisical/docs/documentation/platform/ssh/usage.mdx

---
title: "Overview"
sidebarTitle: "Overview"
description: "Learn how to securely provision user SSH access to your infrastructure using SSH certificates."
---

## Concept

Infisical SSH can be configured to provide users on your team short-lived, secure SSH access to infrastructure. Under the hood, it uses SSH certificates
and improves upon traditional SSH key-based authentication by mitigating private key compromise, static key management,
unauthorized access, and SSH key sprawl.

The following entities are important to understand when configuring and using Infisical SSH:

- Administrator: An individual on your team who is responsible for configuring Infisical SSH.
- Users: Other individuals that gain access to remote hosts through Infisical SSH.
- Host: A remote machine (e.g. EC2 instance, GCP VM, Azure VM, on-prem Linux server, Raspberry Pi, VMware VM, etc.) that users need SSH access to that is registered with Infisical SSH.

## Workflow

The typical workflow for using Infisical SSH consists of the following steps:

1. The administrator registers a remote host with Infisical using the Infisical CLI via the `infisical ssh add-host` command.
2. The administrator configures Infisical SSH to grant users access to the remote host.
3. User(s) access the remote host using the Infisical CLI via the `infisical ssh connect` command.

## Admin Guide for Configuring Infisical SSH

In the following steps, we explore how to configure Infisical SSH to control and streamline your team's SSH access to infrastructure. As part of this guide,
we will register a remote host with Infisical through a [machine identity](/documentation/platform/identities/machine-identities) and configure Infisical to grant user(s) access to the remote host.

<Steps>
  <Step title="Create an Infisical SSH project">
    Start by creating a new Infisical SSH project in Infisical.
    
    ![ssh project create](/images/platform/ssh/v2/ssh-create-project.png)
  </Step>
  <Step title="Create a machine identity for bootstrapping Infisical SSH">
    2.1. Follow the instructions [here](/documentation/platform/identities/universal-auth) to configure a [machine identity](/documentation/platform/identities/machine-identities) in Infisical with Universal Auth.

    By the end of this step, you should have a **Client ID** and **Client Secret** on hand as part of the Universal Auth configuration for the identity to authenticate with Infisical
    as part of registering a remote host in step 3.

    <Note>
        You may use other authentication methods as suitable (e.g. [AWS Auth](/documentation/platform/identities/aws-auth), [Azure Auth](/documentation/platform/identities/azure-auth), [GCP Auth](/documentation/platform/identities/gcp-auth), etc.) as part of the machine identity configuration but, to keep this example simple, we will be using Universal Auth.
    </Note>

    2.2. Add the machine identity to the Infisical SSH project you created in the previous step and assign it the **SSH Host Bootstrapper** role.

      This role grants the ability to **Create** and **Issue Host Certificates** on the **SSH Host** resource; this will enable the linked machine identity to bootstrap a remote host with Infisical
      and establish the necessary configuration on it.

      <Tip>
          If you plan to use a custom role to bootstrap SSH hosts, ensure the role has the **Create** and **Issue Host Certificates** on the **SSH Host** resource.
      </Tip>

    ![ssh add identity to project](/images/platform/ssh/v2/ssh-add-identity-to-project.png)

  </Step>
  <Step title="Configure the remote host">
    3.1. Follow the instructions [here](/cli/overview) to install the Infisical CLI onto the remote host.
    
    3.2. Run the commands below to register the remote host with Infisical.

    Use the **Client ID** and **Client Secret** from the machine identity you created in step 2.1 as part of the `infisical login` command
    to obtain an access token and save it as an environment variable.

    ```bash
    export INFISICAL_TOKEN=$(infisical login --method=universal-auth --client-id=<identity-client-id> --client-secret=<identity-client-secret> --silent --plain)
    ```

    Next, use the `infisical ssh add-host` command to register the remote host with Infisical. As part of this command, input the ID of the Infisical SSH project you created in step 1 for the `--projectId` flag and the hostname of the remote host for the `--hostname` flag.

    ```bash
    sudo infisical ssh add-host --projectId=<project-id> --hostname=<hostname> --token="$INFISICAL_TOKEN" --write-user-ca-to-file --write-host-cert-to-file --configure-sshd
    ```

    <Tip>
        Note that if you're self-hosting Infisical, you can use the `--domain` flag on the `infisical login` command to specify the domain of your Infisical instance.

        For more information on the `infisical ssh add-host` command, please refer to the Infisical CLI [documentation](/cli/overview).
    </Tip>

    If successful, you should see output similar to the following:

    ```bash
    ✅ Successfully registered host: <hostname>
    📁 Wrote User CA public key to: /etc/ssh/infisical_user_ca.pub
    📁 Wrote host certificate to: /etc/ssh/ssh_host_ed25519_key-cert.pub
    📄 Updated sshd_config entries
    ```

    Finally, use the following command to reload the SSH daemon on the remote host to apply the changes:

    ```bash
    sudo systemctl reload sshd
    ```

    <Note>
      The command may differ depending on the host. For older versions of Ubuntu/Debian/CentOS, you may need to use `sudo service ssh reload` instead;
      for Alpine or minimal systems, `/etc/init.d/sshd reload`.
    </Note>

    Back in Infisical, you should now see the remote host you just registered in the Infisical SSH project you created in step 1 under the **Hosts** tab.

    ![ssh hosts](/images/platform/ssh/v2/ssh-added-hosts.png)

  </Step>
  <Step title="Grant users access to the remote host">
    4.1. Add the user(s) you wish to grant access to the remote host to the Infisical SSH project under Access Control > Users.
    
    ![ssh hosts](/images/platform/ssh/v2/ssh-add-user.png)
    
    4.2. On the registered host in the **Hosts** tab, click **Edit SSH Host** and add a login mapping for the user(s) you added in step 4.1.

    The login mapping dictates what user(s) will be allowed access to the remote host and under a specific login user; in the allowed principals,
    you should select user(s) part of the Infisical SSH project that will be allowed to login to the remote host as the login user.

    For instance, if you add a mapping with the login user `ec2-user` to some users John and Alice in Infisical, then they will be allowed to login to the remote host as `ec2-user` which is a system user that
    exists on the remote host.

    ![ssh host mappings](/images/platform/ssh/v2/ssh-host-login-mappings.png)

    <Note>
        Note that you should configure authorized principals files for each login user you add to the remote host.
    </Note>

  </Step>
</Steps>

## User Guide for SSHing to a Host

Once Infisical SSH is configured by an administrator, users can SSH to the remote host using the Infisical CLI.

<Steps>
    <Step title="Install the Infisical CLI">
        Follow the instructions [here](/cli/overview) to install the Infisical CLI onto your local machine.
    </Step>
    <Step title="Connect to the remote host">
        The `infisical ssh connect` command can be used in either interactive or non-interactive mode to connect to a remote host.

        <Tabs>
            <Tab title="Interactive Mode">
                In interactive mode, you'll first need to authenticate with Infisical by running:

                ```bash
                infisical login
                ```

                Then simply run:

                ```bash
                infisical ssh connect
                ```

                You'll be prompted to select an SSH Host from a list of accessible hosts; this is based on project membership and login mappings configured on hosts by
                the administrator.

                ```bash
                Use the arrow keys to navigate: ↓ ↑ → ←
                ? Select an SSH Host:
                ▸ ec2-12-345-678-910.ap-northeast-1.compute.amazonaws.com
                ```

                After selecting a host, you'll be prompted to select a login user from a list of allowed login users:

                ```bash
                ? Select Login User:
                ▸ ec2-user
                ```

                If successful, you should be able to SSH to the remote host.

                ```bash
                ✔ ec2-54-199-104-116.ap-northeast-1.compute.amazonaws.com
                ✔ ec2-user
                ✔ SSH credentials successfully added to agent
                Connecting to ec2-user@ec2-12-345-678-910.ap-northeast-1.compute.amazonaws.com...
                ```
            </Tab>
            <Tab title="Non-Interactive Mode">
                For CI/CD pipelines or automation scenarios, you can use the non-interactive mode with an Infisical token:

                ```bash
                infisical ssh connect \
                  --hostname ec2-12-345-678-910.ap-northeast-1.compute.amazonaws.com \
                  --login-user ec2-user \
                  --out-file-path ~/.ssh/id_rsa-cert.pub \
                  --token <your-infisical-token>
                ```

                This will:
                - Connect to the specified hostname
                - Use the specified login user
                - Write the SSH credentials to the specified path instead of adding them to the SSH agent
                - Authenticate using the provided Infisical token
            </Tab>
        </Tabs>
    </Step>

</Steps>