# Database Access with Amazon RDS for Microsoft SQL Server with Active Directory Authentication Teleport can provide secure access to Microsoft SQL Server via the [Teleport Database Service](https://goteleport.com/docs/enroll-resources/database-access.md). This allows for fine-grained access control through [Teleport's RBAC](https://goteleport.com/docs/enroll-resources/database-access/rbac.md). In this guide, you will: 1. Configure your Microsoft SQL Server database with Active Directory authentication. 2. Add the database to your Teleport cluster. 3. Connect to the database via Teleport. This guide will focus on Amazon RDS for SQL Server using AWS-managed Active Directory authentication. ## How it works The Teleport Database Service joins the same Active Directory domain as the SQL Server database and uses the Kerberos protocol to authenticate with SQL Server. When a user connects to SQL Server via Teleport, the Database Service obtains a service ticket from Active Directory, then uses a long-term key for the database user to decrypt the ticket and connect to SQL Server. At that point, the Database Service forwards user traffic to the database. **Self-Hosted** ![Database access with SQL Server and AD authentication](/docs/assets/images/sql-server-ad-1-920860423ae711c4ea381c8a75bc034f.png) **Teleport Enterprise Cloud** ![Database access with SQL Server and AD authentication](/docs/assets/images/sql-server-ad-2-d3065fd7a3ab79e7caa2028d1e4ad03e.png) ## Prerequisites - A running Teleport cluster. If you want to get started with Teleport, [sign up](https://goteleport.com/signup) for a free trial or [set up a demo environment](https://goteleport.com/docs/get-started/deploy-community.md). - The `tctl` and `tsh` clients. Installing `tctl` and `tsh` clients 1. Determine the version of your Teleport cluster. The `tctl` and `tsh` clients must be at most one major version behind your Teleport cluster version. Send a GET request to the Proxy Service at `/v1/webapi/find` and use a JSON query tool to obtain your cluster version. Replace teleport.example.com:443 with the web address of your Teleport Proxy Service: ``` $ TELEPORT_DOMAIN=teleport.example.com:443 $ TELEPORT_VERSION="$(curl -s https://$TELEPORT_DOMAIN/v1/webapi/find | jq -r '.server_version')" ``` 2. Follow the instructions for your platform to install `tctl` and `tsh` clients: **Mac** Download the signed macOS .pkg installer for Teleport, which includes the `tctl` and `tsh` clients: ``` $ curl -O https://cdn.teleport.dev/teleport-${TELEPORT_VERSION?}.pkg ``` In Finder double-click the `pkg` file to begin installation. --- DANGER Using Homebrew to install Teleport is not supported. The Teleport package in Homebrew is not maintained by Teleport and we can't guarantee its reliability or security. --- **Windows - Powershell** ``` $ curl.exe -O https://cdn.teleport.dev/teleport-v${TELEPORT_VERSION?}-windows-amd64-bin.zip Unzip the archive and move the `tctl` and `tsh` clients to your %PATH% NOTE: Do not place the `tctl` and `tsh` clients in the System32 directory, as this can cause issues when using WinSCP. Use %SystemRoot% (C:\Windows) or %USERPROFILE% (C:\Users\) instead. ``` **Linux** All of the Teleport binaries in Linux installations include the `tctl` and `tsh` clients. For more options (including RPM/DEB packages and downloads for i386/ARM/ARM64) see our [installation page](https://goteleport.com/docs/installation.md). ``` $ curl -O https://cdn.teleport.dev/teleport-v${TELEPORT_VERSION?}-linux-amd64-bin.tar.gz $ tar -xzf teleport-v${TELEPORT_VERSION?}-linux-amd64-bin.tar.gz $ cd teleport $ sudo ./install Teleport binaries have been copied to /usr/local/bin ``` * A SQL Server database with Active Directory authentication enabled. * A SQL Server network listener configured with a Certificate using Subject Alternative Names * A Windows machine joined to the same Active Directory domain as the database. * A Linux node joined to the same Active Directory domain as the database. This guide will walk you through the joining steps if you don't have one. * To check that you can connect to your Teleport cluster, sign in with `tsh login`, then verify that you can run `tctl` commands using your current credentials. For example, run the following command, assigning teleport.example.com to the domain name of the Teleport Proxy Service in your cluster and email\@example.com to your Teleport username: ``` $ tsh login --proxy=teleport.example.com --user=email@example.com $ tctl status Cluster teleport.example.com Version 18.7.3 CA pin sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678 ``` If you can connect to the cluster and run the `tctl status` command, you can use your current credentials to run subsequent `tctl` commands from your workstation. If you host your own Teleport cluster, you can also run `tctl` commands on the computer that hosts the Teleport Auth Service for full permissions. ## Step 1/7. Create a Teleport user --- TIP To modify an existing user to provide access to the Database Service, see [Database Access Controls](https://goteleport.com/docs/enroll-resources/database-access/rbac.md) --- **Teleport Community Edition** Create a local Teleport user with the built-in `access` role: ``` $ tctl users add \ --roles=access \ --db-users="*" \ --db-names="*" \ alice ``` **Teleport Enterprise/Enterprise Cloud** Create a local Teleport user with the built-in `access` and `requester` roles: ``` $ tctl users add \ --roles=access,requester \ --db-users="*" \ --db-names="*" \ alice ``` | Flag | Description | | ------------ | ---------------------------------------------------------------------------------------------------------------------------------------- | | `--roles` | List of roles to assign to the user. The builtin `access` role allows them to connect to any database server registered with Teleport. | | `--db-users` | List of database usernames the user will be allowed to use when connecting to the databases. A wildcard allows any user. | | `--db-names` | List of logical databases (aka schemas) the user will be allowed to connect to within a database server. A wildcard allows any database. | --- WARNING Database names are only enforced for PostgreSQL, MongoDB, and Cloud Spanner databases. --- For more detailed information about database access controls and how to restrict access see [RBAC](https://goteleport.com/docs/enroll-resources/database-access/rbac.md) documentation. ## Step 2/7. Join the Linux node to Active Directory --- NOTE You can skip this step if you already have a Linux node joined to the same Active Directory domain as your SQL Server instance. --- The Linux node where the Database Service will run must be joined to the same Active Directory domain as the SQL Server database. Note that in order to be able to join, the Linux node must be able to resolve your Active Directory fully-qualified domain name. For example, for AWS-managed AD, use nameservers provided under "Networking details" on the directory's overview page. Install necessary packages: **Ubuntu** ``` $ sudo apt-get update $ sudo apt-get -y install sssd realmd krb5-user samba-common packagekit adcli ``` **RHEL / CentOS 7** ``` $ sudo yum -y update $ sudo yum -y install sssd realmd krb5-workstation samba-common-tools ``` Edit `/etc/krb5.conf` to disable reverse DNS resolution and set the default realm. Make sure that the `[realms]` section contains your domain definition and has `admin_server` and `kdc` fields set pointing to the domain controllers: ``` [libdefaults] default_realm = EXAMPLE.COM rdns = false [realms] EXAMPLE.COM = { kdc = example.com admin_server = example.com } ``` Join the realm: ``` $ sudo realm join -v -U admin@EXAMPLE.COM example.com ... * Successfully enrolled machine in realm ``` --- WARNING Note that the realm name in `admin@EXAMPLE.COM` **must** be capital case, otherwise the node might not be able to join. --- To confirm the node has joined the realm, use the `realm list` command: ``` $ sudo realm list example.com type: kerberos realm-name: EXAMPLE.COM domain-name: example.com configured: kerberos-member server-software: active-directory client-software: sssd ... ``` ## Step 3/7. Create keytab file Teleport requires a keytab file to obtain Kerberos service tickets from your Active Directory for authentication with SQL Server. The easiest way to generate it is to use the `adutil` Linux CLI utility. Install `adutil` on the Linux node you have joined to your Active Directory domain: **Ubuntu 18.04** ``` $ curl https://packages.microsoft.com/keys/microsoft.asc | sudo tee /etc/apt/trusted.gpg.d/microsoft.asc $ curl https://packages.microsoft.com/config/ubuntu/18.04/prod.list | sudo tee /etc/apt/sources.list.d/msprod.list $ sudo apt-get update $ sudo ACCEPT_EULA=Y apt-get install -y adutil ``` **Ubuntu 20.04** ``` $ curl https://packages.microsoft.com/keys/microsoft.asc | sudo tee /etc/apt/trusted.gpg.d/microsoft.asc $ curl https://packages.microsoft.com/config/ubuntu/20.04/prod.list | sudo tee /etc/apt/sources.list.d/msprod.list $ sudo apt-get update $ sudo ACCEPT_EULA=Y apt-get install -y adutil ``` **Ubuntu 22.04** ``` $ curl https://packages.microsoft.com/keys/microsoft.asc | sudo tee /etc/apt/trusted.gpg.d/microsoft.asc $ curl https://packages.microsoft.com/config/ubuntu/22.04/prod.list | sudo tee /etc/apt/sources.list.d/msprod.list $ sudo apt-get update $ sudo ACCEPT_EULA=Y apt-get install -y adutil ``` **RHEL 8** ``` $ sudo curl -o /etc/yum.repos.d/msprod.repo https://packages.microsoft.com/config/rhel/8/prod.repo $ sudo ACCEPT_EULA=Y yum install -y adutil ``` **RHEL 9** ``` $ sudo curl -o /etc/yum.repos.d/msprod.repo https://packages.microsoft.com/config/rhel/9/prod.repo $ sudo ACCEPT_EULA=Y yum install -y adutil ``` Log in to Active Directory using the `kinit` command: ``` $ kinit admin@EXAMPLE.COM ``` Use the `adutil keytab create` command to generate keytab entries for each Active Directory user that will be connecting to the SQL Server database: ``` $ adutil keytab create teleport.keytab alice $ adutil keytab create teleport.keytab bob ``` You will be prompted to enter each user's password. All keytab entries will be merged into the same `teleport.keytab` file. --- ASSIGN SERVICE PRINCIPAL NAMES For the `adutil keytab create` command to work, each user account must be assigned a Service Principal Name, otherwise the command will not be able to determine its `kvno` (key version number). To check if the user has any SPNs assigned, run the following command on the Windows machine joined to your Active Directory domain: ``` $ setspn -L alice ``` To assign an SPN to a user account, use the following command: ``` $ setspn -s user/alice alice ``` --- You can verify entries in the keytab file using `klist` command: ``` $ klist -ke teleport.keytab Keytab name: FILE:teleport.keytab KVNO Principal ---- -------------------------------------------------------------------------- 5 alice@EXAMPLE.COM (aes256-cts-hmac-sha1-96) 2 bob@EXAMPLE.COM (aes256-cts-hmac-sha1-96) ``` --- WARNING You must update the keytab file after updating a user's password to avoid authentication failures. --- ## Step 4/7. Set up the Teleport Database Service The Database Service requires a valid join token to join your Teleport cluster. Run the following `tctl` command and save the token output in `/tmp/token` on the server that will run the Database Service: ``` $ tctl tokens add --type=db --format=text abcd123-insecure-do-not-use-this ``` To install a Teleport Agent on your Linux server: The recommended installation method is the cluster install script. It will select the correct version, edition, and installation mode for your cluster. 1. Assign teleport.example.com:443 to your Teleport cluster hostname and port, but not the scheme (https\://). 2. Run your cluster's install script: ``` $ curl "https://teleport.example.com:443/scripts/install.sh" | sudo bash ``` --- NOTE Teleport Database Service must run on a Linux server joined to the same Active Directory domain as the SQL Server. --- **Self-Hosted** Configure the Teleport Database Service. Make sure to update `--proxy` to point to your Teleport Proxy Service address and `--uri` to the SQL Server endpoint. ``` $ sudo teleport db configure create \ -o file \ --token=/tmp/token \ --proxy=teleport.example.com:443 \ --name=sqlserver \ --protocol=sqlserver \ --uri=sqlserver.example.com:1433 \ --ad-keytab-file=/path/to/teleport.keytab \ --ad-domain=EXAMPLE.COM \ --ad-spn=MSSQLSvc/sqlserver.example.com:1433 \ --labels=env=dev ``` **Teleport Enterprise Cloud** Configure the Teleport Database Service. Make sure to update `--proxy` to point to your Teleport Cloud tenant address and `--uri` to the SQL Server endpoint. ``` $ sudo teleport db configure create \ -o file \ --token=/tmp/token \ --proxy=mytenant.teleport.sh:443 \ --name=sqlserver \ --protocol=sqlserver \ --uri=sqlserver.example.com:1433 \ --ad-keytab-file=/path/to/teleport.keytab \ --ad-domain=EXAMPLE.COM \ --ad-spn=MSSQLSvc/sqlserver.example.com:1433 \ --labels=env=dev ``` Provide Active Directory parameters: | Flag | Description | | ------------------ | -------------------------------------------------------------------- | | `--ad-keytab-file` | Path to Kerberos keytab file generated above. | | `--ad-domain` | Active Directory domain (Kerberos realm) that SQL Server is joined. | | `--ad-spn` | Service Principal Name for SQL Server to fetch Kerberos tickets for. | ### Service Principal Name You can use `ldapsearch` command to see the SPNs registered for your SQL Server. Typically, they take a form of `MSSQLSvc/.:`. For example, an Amazon RDS SQL Server named `sqlserver` and joined to an AWS managed Active Directory domain `EXAMPLE.COM` will have the following SPNs registered: ``` $ ldapsearch -x -h example.com -D admin -W -b DC=example,DC=com servicePrincipalName ... EC2AMAZ-4KN05DU, RDS, AWS Reserved, example.com dn: CN=EC2AMAZ-4KN05DU,OU=RDS,OU=AWS Reserved,DC=example,DC=com servicePrincipalName: MSSQLSvc/sqlserver-rds.example.com:1433 servicePrincipalName: MSSQLSvc/EC2AMAZ-4KN05DU.example.com:1433 servicePrincipalName: MSSQLSvc/EC2AMAZ-4KN05DU.example.com ... ``` Alternatively, you can look SPNs up in the Attribute Editor of the Active Directory Users and Computers dialog on your AD-joined Windows machine. The RDS SQL Server object typically resides under the AWS Reserved / RDS path: ![SPN](/docs/assets/images/spn@2x-cc5d90561cbd74a79f7e92ef751fa6d1.png) --- TIP If you don't see Attribute Editor tab, make sure that "View > Advanced Features" toggle is enabled. --- ## Step 5/7. Start the Database Service Configure the Teleport Database Service to start automatically when the host boots up by creating a systemd service for it. The instructions depend on how you installed the Teleport Database Service. **Package Manager** On the host where you will run the Teleport Database Service, enable and start Teleport: ``` $ sudo systemctl enable teleport $ sudo systemctl start teleport ``` **TAR Archive** On the host where you will run the Teleport Database Service, create a systemd service configuration for Teleport, enable the Teleport service, and start Teleport: ``` $ sudo teleport install systemd -o /etc/systemd/system/teleport.service $ sudo systemctl enable teleport $ sudo systemctl start teleport ``` You can check the status of the Teleport Database Service with `systemctl status teleport` and view its logs with `journalctl -fu teleport`. ## Step 6/7. Create SQL Server AD users --- NOTE You can skip this step if you already have Active Directory logins in your SQL Server. --- Connect to your SQL Server as an administrative account (e.g. `sa`) and create logins that will use Active Directory authentication: ``` master> CREATE LOGIN [EXAMPLE\alice] FROM WINDOWS WITH DEFAULT_DATABASE = [master], DEFAULT_LANGUAGE = [us_english]; ``` ## Step 7/7. Connect Log in to your Teleport cluster. Your SQL Server database should appear in the list of available databases: **Self-Hosted** ``` $ tsh login --proxy=teleport.example.com --user=alice $ tsh db ls Name Description Labels --------- ------------------- ------- sqlserver env=dev ``` **Teleport Enterprise Cloud** ``` $ tsh login --proxy=mytenant.teleport.sh --user=alice $ tsh db ls Name Description Labels --------- ------------------- ------- sqlserver env=dev ``` To retrieve credentials for a database and connect to it: ``` $ tsh db connect --db-user=teleport sqlserver ``` --- NOTE Either the `sqlcmd` or `mssql-cli` command-line clients should be available in `PATH` in order to be able to connect. `tsh` attempts to run `sqlcmd` first and, if it's not present on the `PATH`, runs `mssql-cli`. If you have neither command-line clients available on your system, you can run the following command to start a local proxy server that you can connect to with your SQL Server client: ``` $ tsh proxy db --db-user=teleport --tunnel sqlserver ``` Read the [Database GUI Clients](https://goteleport.com/docs/connect-your-client/third-party/gui-clients.md#sql-server-with-azure-data-studio) guide for how to connect your DB GUI client to the local proxy. --- To log out of the database and remove credentials: ``` $ tsh db logout sqlserver ``` ## Troubleshooting ### Certificate error If your `tsh db connect` error includes the following text, the certificate used by SQL Server is not a known Certificate Authority. ``` Error message: TLS Handshake failed: x509: certificate signed by unknown authority ``` To solve this, you can add the CA configuration to the database like the following: ``` databases: - name: sqlserver protocol: sqlserver uri: sqlserver.example.com:1433 ad: keytab_file: /path/to/teleport.keytab domain: EXAMPLE.COM spn: MSSQLSvc/sqlserver.example.com:1433 static_labels: "env": "dev" + tls: + # Point it to your Database CA PEM certificate. + ca_cert_file: "rdsca.pem" + # If your database certificate has an empty CN field, you must change + # the TLS mode to only verify the CA. + mode: verify-ca ``` If you’re unable to acquire the database CA, you can skip TLS verification by providing the configuration `tls.mode: "insecure"`. However, we do not recommend skipping TLS verification in production environments. ## Next steps - Learn how to [restrict access](https://goteleport.com/docs/enroll-resources/database-access/rbac.md) to certain users and databases. * View the [High Availability (HA)](https://goteleport.com/docs/enroll-resources/agents/high-availability.md) guide. - Take a look at the YAML configuration [reference](https://goteleport.com/docs/enroll-resources/database-access/reference/configuration.md). * See the full CLI [reference](https://goteleport.com/docs/enroll-resources/database-access/reference/cli.md). ## Further reading - [Manually join a Linux instance](https://docs.aws.amazon.com/directoryservice/latest/admin-guide/join_linux_instance.html) in the AWS documentation. - [Introduction to `adutil`](https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-ad-auth-adutil-introduction) in the Microsoft documentation.