Duo Kerberos Integration
A duo kerberos integration adds a two-factor check to standard ticket logins. Teams set this up by linking the login flow to Duo cloud services. Most teams use this setup to protect servers, databases, and internal apps. Still, Kerberos tickets often map to broad shared roles on the target host. Once a user passes the check, they gain full access to that role. How a duo kerberos integration works Kerberos uses a central key server to hand out tickets to users. First, a user logs in to the dom
Kerberos Integration: the complete guide
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A duo kerberos integration adds a two-factor check to standard ticket logins. Teams set this up by linking the login flow to Duo cloud services. Most teams use this setup to protect servers, databases, and internal apps. Still, Kerberos tickets often map to broad shared roles on the target host. Once a user passes the check, they gain full access to that role.
How a duo kerberos integration works
Kerberos uses a central key server to hand out tickets to users. First, a user logs in to the domain and gets a ticket. Next, the user presents that ticket to a target server or database. Standard Kerberos trusts the ticket on its own without a second check. It does not ask for a phone push or hardware token by default.
To add a second factor, admins install a Duo module on the host. On Linux systems, this module hooks into the local login check stack. On Windows systems, an agent intercepts the login event on the machine. When the host receives a valid ticket, the Duo module pauses the login. It sends a request to the Duo cloud service over the network.
The Duo service then sends a push prompt to the user's phone. The user taps approve on the phone to finish the login check. Only then does the host open the shell or database session. Admins can also set up a Duo RADIUS server for legacy apps. In that case, the target system talks to the RADIUS server during login.
What native ticket checks solve and what they miss
This setup stops attackers who steal passwords or forge local tickets. Even with a valid ticket, an attacker cannot pass the phone prompt. It also helps teams meet basic compliance rules for two-factor logins. Admins can enforce rules based on user groups or network locations. If a phone is offline, the user can enter a passcode instead.
Yet this integration only acts at the start of a session. Once the login succeeds, Kerberos and Duo step out of the way. They do not watch what the user runs inside the active session. A database admin with a valid ticket can still run a drop table command. A developer on a server can still read raw customer data files.
Kerberos Integration: architecture patterns and best practices
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Kerberos also relies on cached tickets that stay valid for hours. If a team skips re-checks on every host, stolen tickets still work. Managing host agents across hundreds of servers also takes steady upkeep. Each server needs network rules to reach the Duo cloud service. If a server loses internet access, the fail-open setting might skip the check.
Managing permissions after the login check
Relying only on login checks leaves live sessions wide open to mistakes. Teams often map Kerberos principals to high-level admin roles for convenience. That means every person in the group gets the same broad rights. You can see who logged in, but not what queries they ran. System logs rarely tie a specific SQL statement back to one person.
To lower this risk, teams must look beyond the initial login step. Good security checks every command or query while the session runs. It also rewrites sensitive fields like emails, phone numbers, and card numbers in results. Separating the login check from runtime command control closes this operational gap.
Govern statements and responses across databases and APIs
Good config and scoped roles are needed setup. They do not check single queries in flight or mask sensitive fields in returned rows. Across Postgres, MySQL, SQL Server, MongoDB, ClickHouse, Kubernetes APIs, SSH, and internal HTTP endpoints, hoop.dev sits inline in the protocol beside each supported service as an open-source proxy, a sidecar for your database or API. For every query or command an AI agent or engineer runs against production, hoop.dev decides to pass, mask, block, or hold it for human approval.
First, hoop.dev guardrails block banned queries before they run or hold risky ones for review, and hoop.dev data masking rewrites matched sensitive values in responses in memory. Furthermore, hoop.dev holds SOC 2 Type II and is open source on GitHub.
Frequently asked questions
Does Kerberos support two-factor checks on its own?
Standard Kerberos relies on shared secret keys and tickets, not phone prompts. You must add a host plugin or external service to trigger Duo checks.
What happens when the target host cannot reach Duo?
Admins choose a fail-open or fail-closed rule during the agent setup. Fail-open lets the user log in with just the ticket during an outage.
Does a duo kerberos integration log database queries?
No, the integration only logs whether the user passed the login prompt. It does not record or filter SQL queries or shell commands after login.