Duo SAML Implementation
This article contains Duo-specific help for configuring login with SSO via SAML 2.0 For help configuring login with SSO for another IdP, refer to SAML 2.0 Configuration.
Configuration involves working simultaneously between the Bitwarden web vault and the Duo Admin Portal. As you proceed, we recommend having both readily available and completing steps in the order they are documented.
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Already an SSO expert? Skip the instructions in this article and download screenshots of sample configurations to compare against your own.
Open SSO in the web vault
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This article assumes that you have already set up Duo with an Identity Provider. If you haven't, see Duo's documentation for details.
If you are coming straight from SAML 2.0 Configuration, you should already have an organization ID created. If you do not, refer to that article to create an organization ID for SSO.
Navigate to your organization's Manage → Single Sign-On screen:
You don't need to edit anything on this screen yet, but keep it open for easy reference.
tip
If you are self-hosting Bitwarden, you can use alternative Member Decryption Options. This feature is disabled by default, so continue with Master Password decryption for now and learn how to get started using Key Connector once your configuration is complete and successfully working.
Protect an application
In the Duo Admin Portal, navigate to the Applications screen and select the Protect an Application button:
In the search bar, type generic service provider and select Generic Service Provider (Single Sign-On):
Complete the following steps and configurations on the Application configuration screen, some of which you will need to retrieve from the Bitwarden Single Sign-On screen:
Metadata
You don't need to edit anything in the Metadata section, but you will need to use these values later:
Downloads
Select the Download certificate button to download your X.509 Certificate, as you will need to use it later in the configuration.
Service provider
| Field | Description |
|---|---|
| Entity ID | Set this field to the pre-generated SP Entity ID retrieved from the Bitwarden SSO configuration screen. For cloud-hosted customers, this is always https://sso.bitwarden.com/saml2. For self-hosted instances, this is determined by your configured server URL, for example https://your.domain.com/sso.saml2. |
| Assertion Consumer Service (ACS) URL | Set this field to the pre-generated Assertion Consumer Service (ACS) URL retrieved from the Bitwarden SSO Configuration screen. For cloud-hosted customers, this is always https://sso.bitwarden.com/saml2/your-org-id/Acs. For self-hosted instances, this is determined by your configured server URL, for example https://your.domain.com/sso/saml2/your-org-id/Acs. |
| Service Provider Login URL | Set this field to the login URL from which users will access Bitwarden. For cloud-hosted customers, this is always https://vault.bitwarden.com/#/sso. For self-hosted instances, this is determined by your configured server URL, for example https://your.domain.com/#/sso. |
SAML response
| Field | Description |
|---|---|
| NameID format | Set this field to the SAML NameID format for Duo to send in SAML responses. |
| NameID attribute | Set this field to the Duo attribute that will populate the NameID in responses. |
| Signature algorithm | Set this field to the encryption algorithm to use for SAML assertions and responses. |
| Signing options | Select whether to Sign response, Sign assertion, or both. |
| Map attributes | Use these fields to map IdP attributes to SAML response attributes. Regardless of which NameID attribute you configured, map the IdP Email Address attribute to Email, as in the following screenshot: |
Once you have finished configuring these fields, Save your changes.
Back to the web vault
At this point, you have configured everything you need within the context of the Duo Portal. return to the Bitwarden web vault to complete configuration.
The Single Sign-On screen separates configuration into two sections:
SAML Service Provider Configuration will determine the format of SAML requests.
SAML Identity Provider Configuration will determine the format to expect for SAML responses.
Service provider configuration
Configure the following fields according to the choices selected in the Duo Admin Portal during application setup:
| Field | Description |
|---|---|
| Name ID Format | NameID Format to use in the SAML request (NameIDPolicy). Set this field to the selected NameID format. |
| Outbound Signing Algorithm | Algorithm used to sign SAML requests, by default rsa-sha256. |
| Signing Behavior | Whether/when SAML requests will be signed. By default, Duo will not require requests to be signed. |
| Minimum Incoming Signing Algorithm | The minimum signing algorithm Bitwarden will accept in SAML responses. By default, Duo will sign with rsa-sha256, so choose that option from the dropdown unless you have selected a different option. |
| Want Assertions Signed | Whether Bitwarden wants SAML assertions signed. Check this box if you selected the Sign assertion signing option. |
| Validate Certificates | Check this box when using trusted and valid certificates from your IdP through a trusted CA. Self-signed certificates may fail unless proper trust chains are configured within the Bitwarden Login with SSO docker image. |
When you are done with the service provider configuration, Save your work.
Identity provider configuration
Identity provider configuration will often require you to refer back to the Duo Admin Portal to retrieve application values:
| Field | Description |
|---|---|
| Entity ID | Enter the Entity ID value of your Duo application, which can be retrieved from the Duo app Metadata section. |
| Binding Type | Set this field to HTTP Post. |
| Single Sign On Service URL | Enter the Single Sign-On URL value of your Duo application, which can be retrieved from the Duo app Metadata section. |
| Single Log Out Service URL | Login with SSO currently does not support SLO. This option is planned for future development, however you may pre-configure with the Single Log-Out URL value of your Duo application. |
| X509 Public Certificate | Paste the downloaded certificate, removing -----BEGIN CERTIFICATE----- and -----END CERTIFICATE-----.Extra spaces, carriage returns, and other extraneous characters will cause certifiation validation to fail. |
| Outbound Signing Algorithm | Set this field to the selected SAML Response signature algorithm. |
| Disable Outbound Logout Requests | Login with SSO currently does not support SLO. This option is planned for future development. |
| Want Authentication Requests Signed | Whether Duo expects SAML requests to be signed. |
When you are done with the identity provider configuration, Save your work.
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You can require users to log in with SSO by activating the single sign-on authentication policy. Please note, this will require activating the single organization policy as well. Learn more.
Test the Configuration
Once your configuration is complete, test it by navigating to https://vault.bitwarden.com and selecting the Enterprise Single Sign-On button:
Enter the configured organiztion identifier and select Log In. If your implementation is successfully configured, you will be redirected to your source IdP's login screen.
After you authenticate with your IdP login and Duo Two-factor, enter your Bitwarden master password to decrypt your vault!