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Vault and Keycloak - The combination for rotation Vault Token

Mar 30, 2025, 16 min read

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Hi @all, It’s me again and It’s been a while after I chill out and enjoy the technologies, so I turn back and today I will talk about Vault, Identity Server like KeyCloak which provide OIDC Authentication methods for accessing Vault, How can we use this combination for rotating vault token. One more time, happy to see you here and now let’s digest what we got today πŸ™Œ

Problem and What things do we have ?

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First of all, as usual we will try to walkthrough a bit concept, technologies and moreover situation of this articles, it will help you why we should order and combine vault and keycloak for your service

Hashicorp Vault - Secrets Management

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Info

What is Vault

Vault is an identity-based secret and encryption management system. It’s a product of Hashicorp, same providers of Terraform, Vagrant, Nomad, …

If you want to find the optional for your secrets management, Vault is great options for your choice, because It provides us what a features, such as

In terms of protection, Vault support us for authorization for multiple ways, such as

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It’s been a while when I use vault but not much for understanding whole of feature of this platform, so we can turn back later in another blog and go detail of incredible tools.

But talk about what I like most about Vault, honestly you should talk about methodology Vault supplies for authenticating with multiple platform and access to Vault for getting secrets. Currently, Vault support authentication via

It makes Vault to become more flexible than multiple tools with various platforms can make connect and compatible with Vault to become consistent. It’s not bad to say β€œVault is a great option for you in currently, as OpenSource (Self-hosted Version)β€œ

Why I told, Vault is great choice because It has huge community, support SDK in multiple languages and have CLI for who want to stick with this platform

  • Vault CLI: A static binary that wraps the Vault API
  • Hvac: πŸ”’ Python 3.X client for HashiCorp Vault

But here is the deal, if you want to work with Vault because this platform has multiple to usage via

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So I promise if we have occasion, I will write a blog to guide you about how to selfhosted vault for your own. But now, make sure you try self-hosted Vault for your own.

But hold on, wait a sec, There are many tools out there can become actual rival of Vault, you can find more of them, like

  • infisical: the open-source secret management platform
  • sops : Simple and flexible tool for managing secrets
  • openbao: An open source, community-driven fork of Vault managed by the Linux Foundation.

KeyCloak - Identity Server for y’all

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I try to refer to Vault with OIDC/JWT as authentication method, right ? It means you need identity servers where help you authentication via callback function to login from this one into Vault, and Keycloak brings back the solution

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What is KeyCloak

Keycloak is an Open Source Identity and Access Management For Modern Applications and Services - a single sign on solution for web apps and RESTful web services. This one is one of popular projects managed by CNCF

Keycloak supports user multiple features, such as

  • Single Sign On (SSO)
  • Identity Brokering and Social Login
  • User Federation
  • Standard Protocol such as OpenID Connect, SAML and OAuth 2.0
  • …

Let’s talk a bit about KeyCloak Architecture, but the documentation It’s quite hard to read and following concept, so you can read add-on articles or read server-admin of KeyCloak πŸ˜ƒ, such as

If you run KeyCloak in Kubernetes, you will usually see that exist two components, including

  • KeyCloak Server: It’s only KeyCloak runtime and core processor for whole tasks you work with KeyCloak via API, UI or SDK
  • KeyCloak Database: If you run KeyCloak as production, It’s actual recommend you run with Database and PostgreSQL is one of databases choice by KeyCloak

With Keycloak, you will approach with couple of concepts, like

  • Realm: A realm manages a set of users, credentials, roles, and groups.
  • roles: Roles identify a type or category of user
  • consent: when you as an admin want a user to give permission to a client before that client can participate in the authentication process

For Installation KeyCloak, you will have multiple ways, and run with database is best practice to keep your data with KeyCloak

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One time again, We don’t have much time to go through detail about KeyCloak, I will keep that for individual blog because KeyCloak is really huge and you should give bunch of time to use and gain experience with KeyCloak

But KeyCloak is not unique things about Identity Server, This category have at least 5 - 10 candidates as actual rival of KeyCloak, like

  • authentik : Β An IdP (Identity Provider) and SSO (single sign on) that is built with security at the forefront of every piece of code, every feature, with an emphasis on flexibility and versatility.
  • spicedb: Open Source, Google Zanzibar-inspired database for scalably storing and querying fine-grained authorization data. Documentation
  • FusionAuth: a modern platform for Customer Identity and Access Management (CIAM).
  • zitadel: Identity infrastructure, simplified forΒ you.
  • authelia: The Single Sign-On Multi-Factor portal for web apps
  • hydra: Fully customizable OpenID Certifiedβ„’ OpenID Connect and OAuth2 Provider in the world.
  • Moreover at OIDC, Authentication, …

The Actual Problem

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So turn back to the real story, It is about how can we solve problem when you need rotation your Token for couple of reasons

  • Renew TTL because Vault lets you borrow the token as lease state, It means after TTL reach to expire, your token will revoke and It can cause corrupt your work progress.
  • Secure your application and your authentication, It grants you specific policies on the right aud and suitable ttl

For practice with vault, you can use multiple ways to authentication and it give a couple of ideas and that why you can see I bring keycloak with vault.

  1. Use OIDC with tools for access by automation test tools, such as selenium or playwright, authorized by keycloak and generate Vault Token
  2. Use jwt token to authentication, authorized by keycloak and generate Vault Token
  3. Use userpass to authentication to Vault and generate Vault Token

You can follow a couple of articles to understand why

Practice Session

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In this practice session, we will try follow the strategy to login vault via oidc/jwt and I will show you how can we setup and configuration for authentication with these method. We can use Python for write a code to try a couple of method idea above

Source: Integrating Keycloak OIDC with HashiCorp Vault HCP: A Terraform Comprehensive Guide πŸ§‘β€πŸ’»

Preparation

First of all, you should install vault-cli in your host, you can follow this code to get stable version

https://releases.hashicorp.com/vault/1.18.5/vault_1.18.5_linux_amd64.zip && unzip vault_1.18.5_linux_amd64.zip && sudo mv vault /usr/local/bin && rm -rf vault_1.18.5_linux_amd64.zip LICENSE.txt

Next you need to configuration KeyCloak with a couple of steps to follow or tutorial

  1. Access into your keycloak, I recommend use master realms for add another realm into your host
  2. After, you create realms, such as vault for example, you can go to client and create new one

  1. In Login Settings, you can put into textbox follow your Vault Host

    • Root URL: Your Vault Host, e.g: http://localhost:8200
    • Valid redirect URIs: http://localhost:8200/ui/vault/auth/oidc/oidc/callback and http://localhost:8250/oidc/callback
    • Admin URL: http://localhost:8200/ui/vault/auth/oidc/oidc/callback

    Explain:

    • If you use UI, your callback URL will return from localhost:8200 so if you map domain, you should exchange into localhost:8200 into vault.test.com for example
    • If you use CLI, your callback URL will return from localhost:8250 so It will return via CLI at localhost:8250, It means you not need map it to any domain because it only work on with vault-cli. Or if you want to use domain, make sure it have path oidc/callback to handle this response

  2. Get your client secrets and we will done with keycloak

Vault with OIDC and JWT

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To enable OIDC/JWT in Vault, you can use with both version UI or CLI, I prefer UI because you can create and configuration directly via this tools than UI (NOTE: some functionality can configure only via CLI, If you want to use UI, you can use at CLI symbol)

To setup and enable, you need to export environment for VAULT configuration

  • VAULT_ADDR=β€œyour-vault-address”
  • VAULT_TOKEN=β€œroot-token-plz”

Now enable oidc and jwt via command

# default
vault auth enable jwt
vault auth enable oidc
 
# if you want to more specific path
vault auth enable oidc -path keycloak # Your OIDC will use /keycloak path

Warning

if you set path in your auth method, you should be exchange your URL in UI configuration to specific to mount directory, e.g: /keycloak

  • UI Path: https://{vault_host}/ui/vault/auth/keycloak/oidc/callback
  • Template: https://{host:port}/ui/vault/auth/{path}/oidc/callback

Next, configuration profile for oidc and jwt

oidc

vault write auth/oidc/config \
oidc_discovery_url="https://{your-keycloak-host}/realms/{your-vault}" \
oidc_client_id="{your-client-name}" \
oidc_client_secret="{your-client-secret}" \
bound_issuer="https://{your-keycloak-host}/realms/{your-vault}" \
default_role="default"

jwt

vault write auth/jwt/config \
oidc_discovery_url="https://{your-keycloak-host}/realms/{your-vault}" \
oidc_client_id="" \
oidc_client_secret="" \
bound_issuer="https://{your-keycloak-host}/realms/{your-vault}" \
default_role="default"

There are two situations for configuration jwt, including

  • To support JWT roles, either local keys, JWKS URL(s), or an OIDC Discovery URL must be present. For OIDC roles, OIDC Discovery URL, OIDC Client ID and OIDC Client Secret are required. For the list of available configuration options, please see theΒ API documentation.
  • If you need to perform JWT verification with JWT token validation, then leave theΒ oidc_client_idΒ andΒ oidc_client_secretΒ blank. (This is my situation)

Next, role profile for oidc and jwt. You should read OIDC Configuration to understand more about role

oidc

vault write auth/oidc/role/default \
allowed_redirect_uris="https://{vault-host}/ui/vault/auth/oidc/oidc/callback" \
allowed_redirect_uris="http://localhost:8250/oidc/callback" \
user_claim="sub" \
ttl="1h" \
role_type="oidc" \
policies="your-policies"

jwt

vault write auth/jwt/role/default \
allowed_redirect_uris="http://localhost:8250/oidc/callback" \
bound_subject="your-bound-subject" \
bound_audiences="your-bound-audience"
user_claim="sub" \
ttl="1h" \
role_type="jwt" \
policies="your-policies"

For understand about claim, you should read about Bound claims

  • bound_subject: must match the providedΒ subΒ claim (In your jwt token)
  • bound_audiencesΒ parameter is required when anΒ audΒ claim is set.
  • bound_audiencesΒ parameter must match at least one of providedΒ audΒ claims.

But how to understand the structure of jwt token generate about KeyCloak, you should read these articles

Now define the policies, and you can kickoff your login with oidc/jwt

vault policy write your-policies <<EOF
path "secret/data/test/*" {
  capabilities = ["read"]
}
EOF

Remember create kv secret engine with name secret and provide PATH /data/test

Alright, now you can login Vault with OIDC/JWT

Login Vault with CLI and UI

If you choose UI for login option, your page will return this

OIDC

JWT

If you choose OIDC, It will pop up and return you a page of keycloak for callback functionality, login with username and password in that realms and you can directly login into Vault

What else if you use CLI for authentication, It’s same as UI but it operate via CLI πŸ˜„

vault login -method=oidc role="default"

This command will return vault-token, you can use for long-term purpose but now your host will authentication into Vault

JWT only supports for validate your JWT Generated, so you need to use API or SDK to help you generate it via KeyCloak. So we will move to authentication via Python and use hvac to tackle this option

Use Python for Authentication

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First of all, I want to talk a bit about my stupid plan, use automation test tools for automatically login as OIDC providers. It’s actually to say I fail but that kinda fun idea to help we can login with used selenium or pypeeteer to run chrome as headless mode to login via browser running in background. But it’s hard to control because you need to programming as asynchronous to sort of task via thread. If you wanna try, go ahead because I curious how can I do it for production πŸ˜„

To make a code run, you should install couple of library

hvac==2.3.0
requests==2.32.3

The success optional is one used to render jwt token and login into vault via this. You can follow this python

keycloak_auth_vault_jwt.py
import requests
import hvac
 
client = hvac.Client("https://vault.example.xyz")
ROLE = 'default'
 
KEYCLOAK_URL="your-keycloak-url"
KEYCLOAK_REALM="your-realm"
KEYCLOAK_CLIENT_ID="your-client-id"
KEYCLOAK_CLIENT_SECRET="your-client-secret"
KEYCLOAK_USERNAME="your-keycloak-username"
KEYCLOAK_PASSWORD="yout-keycloak-password"
 
token_url = f"{KEYCLOAK_URL}/realms/{KEYCLOAK_REALM}/protocol/openid-connect/token"
 
data = {
        "grant_type": "password",
        "client_id": KEYCLOAK_CLIENT_ID,
        "client_secret": KEYCLOAK_CLIENT_SECRET,
        "username": KEYCLOAK_USERNAME,
        "password": KEYCLOAK_PASSWORD,
}
 
response = requests.post(token_url,data=data)
 
# print(response.elapsed.total_seconds())
 
token_data = response.json()
 
# print(token_data['access_token'])
response = client.auth.jwt.jwt_login(
    role=ROLE,
    jwt=token_data['access_token'],
)
print('Client token returned: %s' % response['auth']['client_token'])

The code will split into two progress

  • Request to keycloak to generate JWT token, used requests
  • Sending the jwt from keycloak to Vault with ROLE, and result will return client_token of vault, used hvac to create client_connection

The failure, you can read about example - OIDC Authorization URL Request to understand what they do. I will try to brief this one depend on my knowledge

  • In a head of script, they try to define the callback_url with port, as you can remember that one same as vault-cli required, so default it should be port 8250. One more they define the closing page for help your return into your browser if you login successful
  • In login_oidc_get_token func, they try to define HTTP Server which run and handle request from browser about your login, It will listen in localhost:8250 for your login become success
  • In main func, they will get callback url and open browser to redirect you to that keycloak login page, after you login successful they will use localhost:8250 to turn back HTML definition with parameter attaching. They try to get token for login_oidc_get_token to make authenticate into vault with token, nonce, state retrieve from callback_url
  • At the end they return client_token same as jwt way

But, I want to automatically this functionality so why I make decision for use playwright to login with chrome headless version. So I’m not good to code async because I don’t have much experience with this, but use gemini and I got this

keycloak_auth_vault_playwright.py
import asyncio
import hvac
import urllib.parse
from playwright.async_api import async_playwright
from http.server import BaseHTTPRequestHandler, HTTPServer
import threading
import logging
 
OIDC_CALLBACK_PORT = 8250
OIDC_REDIRECT_URI = f'http://localhost:{OIDC_CALLBACK_PORT}/oidc/callback'
ROLE = 'default'
# SELF_CLOSING_PAGE = '''<!doctype html><html><head><script>// Closes IE, Edge, Chrome, Bravewindow.onload = function load() {  window.open('', '_self', '');  window.close();};</script></head><body>  <p>Authentication successful, you can close the browser now.</p>  <script>    // Needed for Firefox security    setTimeout(function() {          window.close()    }, 5000);  </script></body></html>'''
SELF_CLOSING_PAGE = '''
<!DOCTYPE html>
<html>
<head>
    <title>Authentication Successful</title>
</head>
<body>
    <p>Authentication successful. You can close this tab now.</p>
</body>
</html>
'''
 
logging.basicConfig(level=logging.DEBUG)
 
async def login_oidc_get_token_playwright(auth_url):
    """Uses Playwright to automate the OIDC login process."""
 
    class HttpServ(HTTPServer):
        def __init__(self, *args, **kwargs):
            HTTPServer.__init__(self, *args, **kwargs)
            self.token = None
            self.event = threading.Event()
            self.error = None
 
    class AuthHandler(BaseHTTPRequestHandler):
        def do_GET(self):
            try:
                params = urllib.parse.parse_qs(self.path.split('?')[1])
                self.server.token = params['code'][0]
            except Exception as e:
                logging.error(f"HTTP Server Error: {e}")
                self.server.error = e
            finally:
                self.server.event.set() # Event is always set
 
            self.send_response(200)
            self.end_headers()
            self.wfile.write(str.encode(SELF_CLOSING_PAGE))
 
    server_address = ('', OIDC_CALLBACK_PORT)
    httpd = HttpServ(server_address, AuthHandler)
 
    def run_server():
        try:
            httpd.handle_request()
        except Exception as e:
            logging.error(f"Server Thread error: {e}")
            httpd.error = e
        finally:
            httpd.event.set() #event is always set
        httpd.server_close()
 
    server_thread = threading.Thread(target=run_server)
    server_thread.start()
 
    async with async_playwright() as p:
        browser = await p.chromium.launch(headless=False)
        page = await browser.new_page()
        await page.goto(auth_url)
 
        await page.wait_for_selector('#username')
        await page.fill('#username', 'your-username')
        await page.fill('#password', 'your-password')
 
        await page.click('#kc-login')
        await page.wait_for_url(url=OIDC_REDIRECT_URI, wait_until="load")
 
        # await browser.close()
        logging.debug("Playwright finished, waiting for server...")
        await browser.close()
        logging.debug("Browser closed successfully.")
 
    if not httpd.event.wait(timeout=30):  # Timeout after 30 seconds
        logging.error("Timeout waiting for HTTP server.")
        return None
 
    if httpd.error:
        logging.error(f"HTTP Server error: {httpd.error}")
        return None
 
    logging.debug(f"Token received: {httpd.token}")
    server_thread.join(timeout=5) #added timeout to thread join.
    logging.debug("Server Thread finished")
 
    return httpd.token
 
async def main():
    client = hvac.Client("https://vault.example.xyz")
 
    auth_url_response = client.auth.oidc.oidc_authorization_url_request(
        role=ROLE,
        redirect_uri=OIDC_REDIRECT_URI,
    )
    auth_url = auth_url_response['data']['auth_url']
    if auth_url == '':
        return None
 
    params = urllib.parse.parse_qs(auth_url.split('?')[1])
    auth_url_nonce = params['nonce'][0]
    auth_url_state = params['state'][0]
 
    token = await login_oidc_get_token_playwright(auth_url)
    if token is None:
        return None
 
    auth_result = client.auth.oidc.oidc_callback(
        code=token,
        path='oidc',
        nonce=auth_url_nonce,
        state=auth_url_state,
    )
    new_token = auth_result['auth']['client_token']
    logging.debug(f'Client token returned: {new_token}')
 
    client.token = new_token
    return client
 
if __name__ == '__main__':
    asyncio.get_event_loop().run_until_complete(main())

This code is not completely, if you have any idea, it should be considered for implementing. Cheer 1 hour of mine exhausted with gemini to deal with it

Remember install playwright before playing around with above script

pip install playwright
 
playwright install

Conclusion

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Success

That’s all for this weekend, hope you walkaround to the end of session and find well with your implementation. It’s kinda curious and fun, I have time to learn again who been as dev for implementation, learn and share with you about couple of idea that’s crazy enough. But don’t deal with your production, let’s keep it simple 🍻

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Feel great and enjoyable with mywork, I’am super curious with whole things I learn from my job, that give me more advice and ability to brain storm and deal with crazy idea, like run headless for authentication OIDC, that’s really fun. So stay safe, keep working and learning y’all guy and we will meet together on next weekend. Bye and have happy weekend !!!

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