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Boundary
HCP administration

Manage SSH keys with HCP Boundary and Vault

  • 20min
  • |
  • HCP
  • Vault
  • Boundary

Boundary includes support for credential management of SSH keys though its credential brokering feature. HCP Boundary and Boundary Enterprise introduce credential injection: the ability to inject SSH credentials into sessions, particularly using Vault.

This tutorial will demonstrate SSH credential injection for an SSH target previously configured in this tutorial series.

Warning

This tutorial requires you to have completed all previous tutorials in this series. For a complete example of SSH credential injection, refer to the HCP credential injection with private Vault tutorial.

A self-managed HCP worker is required for integrating private Vault clusters with HCP Boundary. To learn more about setting up self-managed workers, refer back to the Self-Managed Worker Registration with HCP Boundary tutorial.

Tutorial overview

  1. Prerequisites
  2. Background
  3. Set up Vault
  4. Set up Boundary
  5. Configure an SSH target
  6. Inject credentials into sessions

Prerequisites

  • This tutorial assumes the learner has completed all previous tutorials in the HCP Boundary Getting Administration collection. The learner should have a working HCP Boundary cluster, a preconfigured Ubuntu target, and a self-managed worker deployed in the same network as the target.

  • A Boundary binary greater than 0.12.0 in your PATH

  • A Vault binary greater than 1.7.0 in your PATH

  • Installing the Boundary Desktop App provides an optional workflow at the end of this tutorial. The 1.2.0 version or above is required for Vault support.

This tutorial assumes basic knowledge of using Vault, including running a development server and managing policies, roles, and tokens. If you are new to using Vault, complete the Getting Started with Vault quick start tutorials before integrating Vault with Boundary.

Credential injection background

Boundary is a distributed system for managing identity-based access to computing resources. Core to Boundary are controllers and workers which, from a resource point of view, are referred to as servers. Controllers are responsible for authenticating and authorizing users, as well as serving user API requests for processes like session initiation. They also assign jobs to workers, such as session handling, session recording, and parsing. Workers are responsible for session proxying, as well as other jobs that involve storage.

SSH, also known as Secure Shell, is arguably the de facto tool for remote administration, enabling end users and administrators with a simple, powerful and secure access method. SSH offers a variety of benefits and configurations, such as:

  • Encryption
  • Support for multiple keys types and sizes
  • Built in key exchange
  • Ability to create a tunnel and spawn multiple channels

Boundary seamlessly provides authenticated users access to remote machines via their SSH client, regardless of the authentication mechanisms implemented by their administrators.

Previously Boundary supported credential brokering, where Boundary controllers check out credentials from Vault and return them back to users and clients. In this workflow, Boundary acts as a broker of the credential.

Brokering lacks the ability to hide credentials from clients. For credential injection, controllers instead return credentials to Boundary workers and create a session to a target where the user/client never has access to the credential. This workflow is called credential injection because the credential is injected into a worker’s session, instead of being passed back to the client.

Set up Vault

Note

This tutorial uses a Vault dev server to test credential injection. To access Vault, HCP Boundary requires a self-managed worker deployed in the same network.

Open a new terminal session and run Vault in development mode.

$ vault server -dev -dev-root-token-id=groot
==> Vault server configuration:

             Api Address: http://127.0.0.1:8200
                     Cgo: disabled
         Cluster Address: https://127.0.0.1:8201
              Go Version: go1.16.7
              Listener 1: tcp (addr: "127.0.0.1:8200", cluster address: "127.0.0.1:8201", max_request_duration: "1m30s", max_request_size: "33554432", tls: "disabled")
               Log Level: info
                   Mlock: supported: false, enabled: false
           Recovery Mode: false
                 Storage: inmem
                 Version: Vault v1.8.2
             Version Sha: aca76f63357041a43b49f3e8c11d67358496959f

==> Vault server started! Log data will stream in below:

2022-05-05T14:01:31.647-0500 [INFO]  proxy environment: http_proxy="" https_proxy="" no_proxy=""
2022-05-05T14:01:31.648-0500 [WARN]  no `api_addr` value specified in config or in VAULT_API_ADDR; falling back to detection if possible, but this value should be manually set
2022-05-05T14:01:31.649-0500 [INFO]  core: security barrier not initialized
2022-05-05T14:01:31.650-0500 [INFO]  core: security barrier initialized: stored=1 shares=1 threshold=1
2022-05-05T14:01:31.650-0500 [INFO]  core: post-unseal setup starting
2022-05-05T14:01:31.657-0500 [INFO]  core: loaded wrapping token key
2022-05-05T14:01:31.657-0500 [INFO]  core: successfully setup plugin catalog: plugin-directory=""
2022-05-05T14:01:31.657-0500 [INFO]  core: no mounts; adding default mount table
2022-05-05T14:01:31.658-0500 [INFO]  core: successfully mounted backend: type=cubbyhole path=cubbyhole/
2022-05-05T14:01:31.659-0500 [INFO]  core: successfully mounted backend: type=system path=sys/
2022-05-05T14:01:31.659-0500 [INFO]  core: successfully mounted backend: type=identity path=identity/
2022-05-05T14:01:31.663-0500 [INFO]  core: successfully enabled credential backend: type=token path=token/
2022-05-05T14:01:31.663-0500 [INFO]  rollback: starting rollback manager
2022-05-05T14:01:31.663-0500 [INFO]  core: restoring leases
2022-05-05T14:01:31.664-0500 [INFO]  identity: entities restored
2022-05-05T14:01:31.664-0500 [INFO]  identity: groups restored
2022-05-05T14:01:31.666-0500 [INFO]  core: post-unseal setup complete
2022-05-05T14:01:31.667-0500 [INFO]  expiration: lease restore complete
2022-05-05T14:01:31.667-0500 [INFO]  core: root token generated
2022-05-05T14:01:31.667-0500 [INFO]  core: pre-seal teardown starting
2022-05-05T14:01:31.667-0500 [INFO]  rollback: stopping rollback manager
2022-05-05T14:01:31.667-0500 [INFO]  core: pre-seal teardown complete
2022-05-05T14:01:31.668-0500 [INFO]  core.cluster-listener.tcp: starting listener: listener_address=127.0.0.1:8201
2022-05-05T14:01:31.668-0500 [INFO]  core.cluster-listener: serving cluster requests: cluster_listen_address=127.0.0.1:8201
2022-05-05T14:01:31.668-0500 [INFO]  core: post-unseal setup starting
2022-05-05T14:01:31.668-0500 [INFO]  core: loaded wrapping token key
2022-05-05T14:01:31.668-0500 [INFO]  core: successfully setup plugin catalog: plugin-directory=""
2022-05-05T14:01:31.668-0500 [INFO]  core: successfully mounted backend: type=system path=sys/
2022-05-05T14:01:31.668-0500 [INFO]  core: successfully mounted backend: type=identity path=identity/
2022-05-05T14:01:31.668-0500 [INFO]  core: successfully mounted backend: type=cubbyhole path=cubbyhole/
2022-05-05T14:01:31.669-0500 [INFO]  core: successfully enabled credential backend: type=token path=token/
2022-05-05T14:01:31.669-0500 [INFO]  rollback: starting rollback manager
2022-05-05T14:01:31.669-0500 [INFO]  core: restoring leases
2022-05-05T14:01:31.670-0500 [INFO]  identity: entities restored
2022-05-05T14:01:31.670-0500 [INFO]  identity: groups restored
2022-05-05T14:01:31.670-0500 [INFO]  expiration: lease restore complete
2022-05-05T14:01:31.670-0500 [INFO]  core: post-unseal setup complete
2022-05-05T14:01:31.670-0500 [INFO]  core: vault is unsealed
2022-05-05T14:01:31.672-0500 [INFO]  expiration: revoked lease: lease_id=auth/token/root/h49a4c4a4eef16a18370b98f2883fff349e0917dd5913d74c02bd97d04d8edcbb
2022-05-05T14:01:31.675-0500 [INFO]  core: successful mount: namespace="" path=secret/ type=kv
2022-05-05T14:01:31.686-0500 [INFO]  secrets.kv.kv_c1ca00f3: collecting keys to upgrade
2022-05-05T14:01:31.686-0500 [INFO]  secrets.kv.kv_c1ca00f3: done collecting keys: num_keys=1
2022-05-05T14:01:31.686-0500 [INFO]  secrets.kv.kv_c1ca00f3: upgrading keys finished
WARNING! dev mode is enabled! In this mode, Vault runs entirely in-memory
and starts unsealed with a single unseal key. The root token is already
authenticated to the CLI, so you can immediately begin using Vault.

You may need to set the following environment variable:

    $ export VAULT_ADDR='http://127.0.0.1:8200'

The unseal key and root token are displayed below in case you want to
seal/unseal the Vault or re-authenticate.

Unseal Key: Yc27V3wm7l9axQaYQTxeZUlsn4AVOtqOPPUvvQuVOng=
Root Token: groot

Development mode should NOT be used in production installations!

Leave Vault running in dev mode and open a new terminal window.

Next, export the required Vault environment variables for the address and token.

$ export VAULT_ADDR="http://127.0.0.1:8200"; export VAULT_TOKEN="groot"

Deploy a self-managed worker

An HCP worker deployed on the same network as Vault is required for integrating private Vault clusters with HCP Boundary. To learn more about setting up self-managed workers, refer to the Self-Managed Worker Registration with HCP Boundary tutorial.

Download the Boundary Enterprise binary

Download the Boundary Enterprise binary to the ~/boundary/ directory. If you already have the Boundary Enterprise binary locally available from a previous tutorial, skip to the Write the worker config section.

Note

If you already deployed a self-managed worker locally in the Self-managed worker registration tutorial, verify it is still running, then skip to the Define the controller policy section.

You can manually download the latest binary for your operating system by navigating to the Boundary releases page. The example below demonstrates downloading the binary using the command line.

Note

The binary version should match the version of the HCP control plane. Check the version of the control plane in the HCP Boundary portal, and download the appropriate version using wget. The example below downloads the 0.13.2 version of the Boundary Enterprise binary.

Below is an example of downloading and unzipping the Boundary Enterprise binary on Ubuntu, MacOS, and Windows.

The following command downloads the Boundary Enterprise binary and unzips it to the current directory.

$ wget -q https://releases.hashicorp.com/boundary/0.13.2+ent/boundary_0.13.2+ent_linux_amd64.zip ;\
sudo apt-get update && sudo apt-get install unzip ;\
unzip *.zip

Once downloaded, verify the version of the boundary binary.

$ ./boundary version

Version information:
  Build Date:          2023-06-07T16:41:10Z
  Git Revision:        b1f75f5c731c843f5c987feae310d86e635806c7
  Metadata:            ent
  Version Number:      0.13.2+ent

Ensure the Version Number matches the version of the HCP Boundary control plane. They should match in order to get the latest HCP Boundary features.

Write the worker config

Next, create a new file named vault-worker.hcl in the ~/boundary/ directory.

$ touch ~/boundary/vault-worker.hcl

Open the file with a text editor, such as Vi.

Paste the following configuration into the worker config file:

~/boundary/vault-worker.hcl

disable_mlock = true

hcp_boundary_cluster_id = "<cluster-id>"

listener "tcp" {
  address = "127.0.0.1:9202"
  purpose = "proxy"
}

worker {
  auth_storage_path = "/home/myusername/boundary/vault-worker"
  tags {
    type = ["worker", "vault"]
  }
}

Update the cluster id in the vault-worker.hcl file:

The <cluster-id> on line 3 can be determined from the UUID in the HCP Boundary Cluster URL. For example, if your Cluster URL is:

https://c3a7a20a-f663-40f3-a8e3-1b2f69b36254.boundary.hashicorp.cloud, then the cluster id is c3a7a20a-f663-40f3-a8e3-1b2f69b36254

The auth_storage_path should match the full path to the ~/boundary/vault-worker directory, such as /home/myusername/boundary/vault-worker.

Save this file.

Start the worker

With the worker config defined, start the worker server. Provide the full path to the worker config file (such as /home/myusername/boundary/vault-worker.hcl).

$ ./boundary server -config="/home/myusername/boundary/vault-worker.hcl"

==> Boundary server configuration:

                               Cgo: disabled
                        Listener 1: tcp (addr: "0.0.0.0:9202", max_request_duration: "1m30s", purpose: "proxy")
                         Log Level: info
                             Mlock: supported: true, enabled: false
                           Version: Boundary v0.13.2+ent
                       Version Sha: b1f75f5c731c843f5c987feae310d86e635806c7
        Worker Auth Current Key Id: preaching-favored-verbalize-widen-duchess-relish-jurist-sly
  Worker Auth Registration Request: GzusqckarbczHoLGQ4UA25uSRmUHY1BGSRA6cePp8RWHQFUYSrf3hnDw4ETPswFnMrcxx6tq7BUWD5azGULzPecPicuYGD6qg3qYvaGRgHgKwvh9FLY9Gu891KSj8hAef19JjHog8d7qpo9f9KoiwrhfcV2YxGyVu1P943656iNGCFHWiBR3ofsyTatQ7fzcMV2ciKtuYYGfx4FfiRStnkAzoE98RdR2LeCk2huRkFt7ayeeWVfD7Awm8xaZfFJn4pYRJwu2LRBeNs915warEBaS8XHXSKoi3cRUYif8Qu
          Worker Auth Storage Path: /home/ubuntu/boundary/vault-worker
          Worker Public Proxy Addr: 127.0.0.1:9202

==> Boundary server started! Log data will stream in below:

{"id":"Rb7PMMBdZa","source":"https://hashicorp.com/boundary/ip-172-31-84-100/worker","specversion":"1.0","type":"system","data":{"version":"v0.1","op":"worker.(Worker).StartControllerConnections","data":{"msg":"Setting HCP Boundary cluster address e58fe114-7624-431c-994d-b6670e90b09f.proxy.boundary.hashicorp.cloud:9202 as upstream address"}},"datacontentype":"application/cloudevents","time":"2022-09-19T22:16:38.770232603Z"}

The worker will start and begin attempting to connect to the upstream Controller.

The worker also outputs its authorization request as the Worker Auth Registration Request token. This will also be saved to a file, auth_request_token, defined by the auth_storage_path in the worker config.

Note the Worker Auth Registration Request: value. This value can also be located in the ~/boundary/vault-worker/auth_request_token directory. Copy this value.

Register the worker with HCP

HCP workers can be registered using the Boundary CLI or Admin Console Web UI.

Authenticate to HCP Boundary as the admin user.

  1. Log in to the HCP portal.

  2. From the HCP Portal's Boundary page, click Open Admin UI - a new page will open.

  3. Enter the admin username and password you created when you deployed the new instance and click Authenticate.

Once logged in, navigate to the Workers page.

Notice that only HCP workers are listed.

Click New.

Scroll down to the bottom of the New Worker page and paste the Worker Auth Registration Request key you copied earlier.

Click Register Worker.

Register worker with auth token Register worker with auth token

Click Done and notice the new worker on the Workers page.

Workers page with local worker Workers page with local worker

Define the controller policy

The following Vault policy must be defined for the Boundary controller to support credential brokering. To learn more about these policies, refer to the HCP Boundary Vault credential brokering quickstart tutorial.

Export the required Vault environment variables to store the Vault address and token.

$ export VAULT_ADDR="http://127.0.0.1:8200"; export VAULT_TOKEN="groot"

Now write the controller policy to Vault.

$ vault policy write boundary-controller -<<EOF
path "auth/token/lookup-self" {
  capabilities = ["read"]
}
path "auth/token/renew-self" {
  capabilities = ["update"]
}
path "auth/token/revoke-self" {
  capabilities = ["update"]
}
path "sys/leases/renew" {
  capabilities = ["update"]
}
path "sys/leases/revoke" {
  capabilities = ["update"]
}
path "sys/capabilities-self" {
  capabilities = ["update"]
}
EOF

Define the KV policy

A policy must also be defined for the key-value secrets that will be brokered via Vault.

Create a new kv-read policy in Vault.

$ vault policy write kv-read -<<EOF
path "secret/data/ubuntu-secret" {
  capabilities = ["read"]
}
EOF

Lastly, create a new Vault KV credential at the secret/my-secret path and provide the username and private key for the ubuntu target machine you are connecting to. If using a cloud provider like AWS, the private key was provided or created when the instance was set up at the beginning of the HCP administration tutorials.

Ensure the path to the private key is entered after the @ symbol (for example, private_key=@/Users/myuser/.ssh/ubuntu-private-key.pem)

$ vault kv put secret/ubuntu-secret username=ubuntu private_key=@/path/to/private-key

====== Secret Path ======
secret/data/ubuntu-secret

======= Metadata =======
Key                Value
---                -----
created_time       2023-08-24T23:45:06.923374Z
custom_metadata    <nil>
deletion_time      n/a
destroyed          false
version            1

Create a Vault token

Now create a Vault token.

$  vault token create \
  -no-default-policy=true \
  -policy="boundary-controller" \
  -policy="kv-read" \
  -orphan=true \
  -period=20m \
  -renewable=true \
  -field=token

Example:

$ vault token create \
  -no-default-policy=true \
  -policy="boundary-controller" \
  -policy="kv-read" \
  -orphan=true \
  -period=20m \
  -renewable=true \
  -field=token

hvs.CAESIIGB4m5Z0ZkimEXi0GKZ5k0twCBkJPI5mcHyPq1rSs_wGh4KHGh2cy5Rb1F4NDVabTVIb1lwVUMzY3ZMdThsVTE

Copy the token value and export it as the $CRED_STORE_TOKEN variable.

Note

If you plan on using the Admin Console UI to connect, save this value for creating a credential store later on.

$ export CRED_STORE_TOKEN=hvs.CAESIIGB4m5Z0ZkimEXi0GKZ5k0twCBkJPI5mcHyPq1rSs_wGh4KHGh2cy5Rb1F4NDVabTVIb1lwVUMzY3ZMdThsVTE

Set up Boundary

Start by logging in to HCP Boundary within the terminal.

Export the BOUNDARY_ADDR and BOUNDARY_AUTH_METHOD_ID environment variables. These values are gathered from the HCP Boundary Admin Console, as demonstrated in the Get Started with HCP Boundary tutorials.

$ export BOUNDARY_AUTH_METHOD_ID=copied-value-from-boundary-ui; export BOUNDARY_ADDR=copied-value-from-hcp-portal

Log in to the CLI as an admin user, or a user with privileges to manage resources in the global scope. Enter your admin username for login-name.

Enter password at the Please enter the password (it will be hidden): prompt.

$ boundary authenticate password \
  -auth-method-id=$BOUNDARY_AUTH_METHOD_ID \
  -login-name=awesome-admin

You will also need an ORG_ID to create the SSH test project within. You may create a new global scope for this, or utilize an existing scope used for testing.

If creating a new org for testing, execute the following:

$ boundary scopes create -scope-id=global -name=testing-org -description="SSH testing org"

Scope information:
  Created Time:        Mon, 09 May 2022 12:33:12 CDT
  Description:         SSH testing org
  ID:                  o_YcngFcjRcP
  Name:                testing-org
  Updated Time:        Mon, 09 May 2022 12:33:12 CDT
  Version:             1

  Scope (parent):
    ID:                global
    Name:              global
    Type:              global

  Authorized Actions:
    no-op
    read
    update
    delete

Whether you create a new org or not, be sure to export the org ID.

$ export ORG_ID=global-testing-org-id

Set up a new project

Create a new project scope within Boundary. You will need an org ID to create the new project within. To view your existing orgs, execute boundary scopes list -recursive.

Note

You may use an existing org scope, or create a new org scope for the ssh-project. Refer to the Manage Scopes tutorial to learn more about creating and managing scopes.

$ boundary scopes create -scope-id=$ORG_ID -name=ssh-project -description="SSH test machines"

Scope information:
  Created Time:        Fri, 06 May 2022 14:13:39 CDT
  Description:         SSH test machines
  ID:                  p_TRfAEMzkAP
  Name:                ssh-project
  Updated Time:        Fri, 06 May 2022 14:13:39 CDT
  Version:             1

  Scope (parent):
    ID:                o_26VOj9vJjN
    Name:              ssh-org
    Parent Scope ID:   global
    Type:              org

  Authorized Actions:
    no-op
    read
    update
    delete

Copy the ID from the output and export it as the $PROJECT_ID variable.

$ export PROJECT_ID=p_TRfAEMzkAP

Create a credential store

Next, create a new credential store within Boundary using the new token. The vault credential store type is used to integrate with Vault, but static credential stores can also be used with credential injection.

When setting up an HCP worker, it's important to create a worker filter for the credential store. A worker filter will identify workers that should be used as proxies for the new credential store, and ensure these credentials are brokered from the private Vault.

Recall the filters defined in the vault-worker.hcl file earlier:

worker {
  auth_storage_path = "/home/myusername/boundary/vault-worker"
  tags {
    type = ["worker", "vault"]
  }
}

The Tags or Name of the worker (vault-worker) can be used to create a worker filter for the target.

The example below adds a worker tag filter that searches for workers with the vault tag. Boundary will consider any worker with this tag assigned to it an acceptable proxy for the new credential store.

Create a new vault credential store with a worker-filter.

$ boundary credential-stores create vault \
  -scope-id $PROJECT_ID \
  -vault-address $VAULT_ADDR \
  -vault-token $CRED_STORE_TOKEN \
  -worker-filter='"vault" in "/tags/type"'

Example output:

$ boundary credential-stores create vault \
  -scope-id $PROJECT_ID \
  -vault-address $VAULT_ADDR \
  -vault-token $CRED_STORE_TOKEN \
  -worker-filter='"vault" in "/tags/type"'

Credential Store information:
  Created Time:        Thu, 24 Aug 2023 17:57:27 MDT
  ID:                  csvlt_ItzbO5ULBF
  Type:                vault
  Updated Time:        Thu, 24 Aug 2023 17:57:27 MDT
  Version:             1

  Scope:
    ID:                p_1PgXI0HPSR
    Name:              ssh-project
    Parent Scope ID:   o_pwVF9V4hK6
    Type:              project

  Authorized Actions:
    no-op
    read
    update
    delete

  Authorized Actions on Credential Store's Collections:
    credential-libraries:
      create
      list

  Attributes:
    Address:           http://127.0.0.1:8200
    Token HMAC:
    8xy1fErkPOtQ36OZbyKg4TPOp2XQtQRZXE7V9WZJPk0
    Token Status:      current
    Worker Filter:     "vault" in "/tags/type"

Store the returned ID value in the $CRED_STORE_ID variable.

$ export CRED_STORE_ID=csvlt_ItzbO5ULBF

Create credential library

Create a new credential library of type ssh_private_key within Boundary using the credential store ID and passing the vault-path of ubuntu-secret.

$ boundary credential-libraries create vault-generic \
  -credential-store-id $CRED_STORE_ID \
  -vault-path "secret/data/ubuntu-secret" \
  -name "vault-cred-library" \
  -credential-type ssh_private_key

Example output:

$ boundary credential-libraries create vault-generic \
  -credential-store-id $CRED_STORE_ID \
  -vault-path "secret/data/ubuntu-secret" \
  -name "vault-cred-library" \
  -credential-type ssh_private_key

Credential Library information:
  Created Time:          Thu, 24 Aug 2023 18:00:37 MDT
  Credential Store ID:   csvlt_ItzbO5ULBF
  ID:                    clvlt_xzJeddzCw6
  Name:                  vault-cred-library
  Type:                  vault-generic
  Updated Time:          Thu, 24 Aug 2023 18:00:37 MDT
  Version:               1

  Scope:
    ID:                  p_1PgXI0HPSR
    Name:                ssh-project
    Parent Scope ID:     o_pwVF9V4hK6
    Type:                project

  Authorized Actions:
    no-op
    read
    update
    delete

  Attributes:
    HTTP Method:         GET
    Path:                secret/data/ubuntu-secret

  Credential Type:
    ssh_private_key

Copy the ID from the output and export it as the $CRED_LIB_SSH_ID variable.

$ export CRED_LIB_ID=clvlt_xzJeddzCw6

Create an SSH target

Earlier in this series, you created a target of type tcp. To inject SSH credentials, a target of type ssh is required instead.

In the previous tutorials on worker management, you set up a multi-hop session to the target by configuring egress and ingress workers.

Ensure that you have the correct worker filter defined when setting up your target. If you have modified how Boundary accesses the target, select from the following examples to define the target worker config. For example, if you are testing injection using a public ip address, you can omit the -egress-worker-filter entirely.

Select the appropriate tab for your worker setup.

Create a new ssh target, and set the address directly. Replace "ubuntu-public-ip-address" with the actual address of your Ubuntu host.

$ boundary targets create ssh -scope-id $PROJECT_ID \
  -name "ubuntu ssh target" \
  -address "ubuntu-public-ip-address" \
  -session-connection-limit -1 \
  -default-port 22

Example output:

$ boundary targets create ssh -scope-id $PROJECT_ID \
  -name "ubuntu ssh target" \
  -address 50.16.114.201 \
  -session-connection-limit -1 \
  -default-port 22

Target information:
  Address:                    50.16.114.201
  Created Time:               Thu, 24 Aug 2023
  18:17:33 MDT
  ID:                         tssh_4lKEOzTdi6
  Name:                       ubuntu ssh target
  Session Connection Limit:   -1
  Session Max Seconds:        28800
  Type:                       ssh
  Updated Time:               Thu, 24 Aug 2023
  18:17:33 MDT
  Version:                    1

  Scope:
    ID:                       p_1PgXI0HPSR
    Name:                     ssh-project
    Parent Scope ID:          o_pwVF9V4hK6
    Type:                     project

  Authorized Actions:
    no-op
    read
    update
    delete
    add-host-sources
    set-host-sources
    remove-host-sources
    add-credential-sources
    set-credential-sources
    remove-credential-sources
    authorize-session

  Attributes:
    Default Port:             22
    Enable Session Recording: false

Copy the ID from the output and export it as the $SSH_TARGET_ID variable.

$ export SSH_TARGET_ID=tssh_4lKEOzTdi6

Associate the SSH target with the SSH credential library for credential injection.

$ boundary targets add-credential-sources -id $SSH_TARGET_ID -injected-application-credential-source $CRED_LIB_ID

Target information:
  Address:                    50.16.114.201
  Created Time:               Thu, 24 Aug 2023
  18:17:33 MDT
  ID:                         tssh_4lKEOzTdi6
  Name:                       ubuntu ssh target
  Session Connection Limit:   -1
  Session Max Seconds:        28800
  Type:                       ssh
  Updated Time:               Thu, 24 Aug 2023
  18:18:53 MDT
  Version:                    2

  Scope:
    ID:                       p_1PgXI0HPSR
    Name:                     ssh-project
    Parent Scope ID:          o_pwVF9V4hK6
    Type:                     project

  Authorized Actions:
    no-op
    read
    update
    delete
    add-host-sources
    set-host-sources
    remove-host-sources
    add-credential-sources
    set-credential-sources
    remove-credential-sources
    authorize-session

  Host Sources:
    Host Catalog ID:          hcst_51IX0mMocD
    ID:                       hsst_xhgJzsoEO8

  Injected Application Credential Sources:
    Credential Store ID:      csvlt_EsUGNcboLT
    ID:                       clvlt_i5ZCg7LH4Q

  Attributes:
    Default Port:             2222
    Enable Session Recording: false

Inject credentials into sessions

Now you are ready to inject credentials directly into the shell session. You can accomplish this using the boundary connect command, which has a helper called ssh.

Enter yes when prompted to establish the connection.

$ boundary connect ssh -target-id $SSH_TARGET_ID
The authenticity of host '[127.0.0.1]:58677 ([127.0.0.1]:58677)' can't be established.
ED25519 key fingerprint is SHA256:WDPtMwr4whbVp5VUJwvzee7x9O25XhqMyApnz1mmNfg.
This host key is known by the following other names/addresses:
    ~/.ssh/known_hosts:9: hst_7jeh2z1mkk
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[127.0.0.1]:58677' (ED25519) to the list of known hosts.

Welcome to Ubuntu 22.04.2 LTS (GNU/Linux 5.19.0-1025-aws x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

ubuntu@ip-172-32-88-177:~

Notice that you do not have to pass the target credentials to the boundary connect command. The credentials are injected by Boundary directly from Vault, and never returned to the client.

Troubleshooting

If the boundary connect ssh command fails with the following error message, then the Vault credential store token may have expired.

Expand the accordion below to continue troubleshooting.

$ Error from controller when performing authorize-session action against given target

Error information:
  Kind:                FailedPrecondition
  Message:             No egress workers can handle this session, as they have all been filtered
  out.
  Status:              400
  context:             Error from controller when performing authorize-session action against
  given target

The error information states that No egress workers can handle this session, as they have all been filtered.

This implies that Boundary does not understand which worker should handle the session, and cannot route traffic through the worker it selected.

In this example the error could be due to either of the following errors:

  1. Boundary is unable to log into Vault using the provided credential store token.
  2. The ubuntu target's worker filters are unset, or incorrect.

First, troubleshoot the Vault credential store by generating a new Vault token.

$ export CRED_STORE_TOKEN=$(vault token create \
  -no-default-policy=true \
  -policy="boundary-controller" \
  -policy="kv-read" \
  -orphan=true \
  -period=20m \
  -renewable=true \
  -field=token) && echo $CRED_STORE_TOKEN

Copy this token (such as hvs.CAESIAbmG5WIi0qILYm87ucbJSGa0rv879aJAchvFR6wG0pbGh4KHGh2cy5xY1BzTGpHUW91ZEx4ZGFTcFVDTkdPMTY), and then update Boundary's Vault cred store with the new token value.

  1. Log in to the Boundary Admin UI and select the testing-org scope. Select the ssh-project, then click Credential Stores.

  2. Select the Vault credential store (such as csvlt_EsUGNcboLT). Scroll down to the bottom of the credential store's Details page, and click Edit Form.

  3. Paste the newly generated vault token into the Token field, then click Save at the bottom of the page.

With the updated token in place, attempt to connect to the SSH target again.

$ boundary connect ssh -target-id $SSH_TARGET_ID

If you are still unable to establish a connection, check that the filter has been defined correctly on the SSH target.

  1. Navigate to Targets using the sidebar and select the ubuntu ssh target.

  2. Select the Workers tab.

    Ensure that the Egress worker filter is not set, because any worker can be used to connect to the public instance.

  3. If this is enabled, click Edit worker filters and delete the filter expression. When finished, click Save.

After verifying the correct filter value, attempt to establish a session.

$ boundary connect ssh -target-id $SSH_TARGET_ID

When finished, the user can close the connection to the server using exit, or the session can be canceled directly from Boundary in a new authenticated terminal window.

Inject credentials with the Desktop App

To log into Boundary using the Desktop App, the BOUNDARY_ADDR (Boundary cluster address) and BOUNDARY_AUTH_METHOD_ID (user Auth Method ID) values must be gathered from the HCP Boundary Admin Console, as demonstrated in the HCP Boundary Getting Started tutorial.

Open the Boundary desktop app.

Enter the Boundary cluster URL (for example, https://ffee961b-5fd8-4e68-ba1d-2bbb487b576e.boundary.hashicorp.cloud) and click Submit.

Authenticate using your HCP Boundary user credentials.

Boundary Desktop cluster URL Boundary Desktop cluster URL

Under the Targets page, notice the target details for the ubuntu ssh target.

Click Connect to initiate a session.

The Successfully Connected page will display the target ID (Target Connection details) and Proxy URL. Copy the Proxy URL and port.

To start a session, open your terminal or SSH client. A session can be started using SSH and the Proxy URL from the Boundary Desktop app.

Start an SSH connection on 127.0.0.1 and provide the proxy port using the -p option. Enter yes when prompted to establish a connection.

$ ssh 127.0.0.1 -p 51968

The authenticity of host '[127.0.0.1]:53639 ([127.0.0.1]:53639)' can't be established.
ED25519 key fingerprint is SHA256:FkCPEt0izeFdyNkD1iRDa8IygT0UoHMxC2+NmneAyT8.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[127.0.0.1]:53639' (ED25519) to the list of known hosts.

Welcome to Ubuntu 22.04.2 LTS (GNU/Linux 5.19.0-1025-aws x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

ubuntu@ip-172-32-88-177:~

When finished, the user can close the connection to the server by entering exit, or the session can be canceled directly from the Boundary desktop app under the Sessions view.

Cleanup and teardown

  1. Locate the terminal session used to execute the vault dev server command, and execute ctrl+c to stop Vault.

  2. Locate the terminal session used to deploy the HCP worker server command, and execute ctrl+c to stop the Boundary worker.

  3. Unset the environment variables used in any active terminal windows for this tutorial.

    $ unset VAULT_ADDR; unset VAULT_TOKEN

  4. Clean up the Ubuntu target in Amazon EC2. Refer to the instructions for terminating your Ubuntu instance.

Next steps

This tutorial demonstrated the steps to set up credential injection using HCP Boundary and an SSH target previously configured in this tutorial collection. You set up Vault, configured a self-managed worker to access Vault, and configured an SSH target within Boundary. Then you associated a vault credential store with the SSH target, and tested credential injection.

To learn more about credential injection, check out the SSH credential injection with private Vault tutorial.

Help and reference

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Manage multi-hop sessions with HCP

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Self-managed administration