Advanced certificate signing options in a SAML token
Today Azure Active Directory (Azure AD) supports thousands of pre-integrated applications in the Azure Active Directory App Gallery. Over 500 of the applications support single sign-on by using the Security Assertion Markup Language (SAML) 2.0 protocol, such as the NetSuite application. When a customer authenticates to an application through Azure AD by using SAML, Azure AD sends a token to the application (via an HTTP POST). The application then validates and uses the token to sign in the customer instead of prompting for a username and password. These SAML tokens are signed with the unique certificate that's generated in Azure AD and by specific standard algorithms.
Azure AD uses some of the default settings for the gallery applications. The default values are set up based on the application's requirements.
In Azure AD, you can set up certificate signing options and the certificate signing algorithm.
Certificate signing options
Azure AD supports three certificate signing options:
Sign SAML assertion. This default option is set for most of the gallery applications. If you select this option, Azure AD as an Identity Provider (IdP) signs the SAML assertion and certificate with the X.509 certificate of the application.
Sign SAML response. If you select this option, Azure AD as an IdP signs the SAML response with the X.509 certificate of the application.
Sign SAML response and assertion. If you select this option, Azure AD as an IdP signs the entire SAML token with the X.509 certificate of the application.
Certificate signing algorithms
Azure AD supports two signing algorithms, or secure hash algorithms (SHAs), to sign the SAML response:
SHA-256. Azure AD uses this default algorithm to sign the SAML response. It's the newest algorithm and is more secure than SHA-1. Most of the applications support the SHA-256 algorithm. If an application supports only SHA-1 as the signing algorithm, you can change it. Otherwise, we recommend that you use the SHA-256 algorithm for signing the SAML response.
SHA-1. This algorithm is older, and it's treated as less secure than SHA-256. If an application supports only this signing algorithm, you can select this option in the Signing Algorithm drop-down list. Azure AD then signs the SAML response with the SHA-1 algorithm.
Change certificate signing options and signing algorithm
To change an application's SAML certificate signing options and the certificate signing algorithm, select the application in question:
In the Azure Active Directory portal, sign in to your account. The Azure Active Directory admin center page appears.
In the left pane, select Enterprise applications. A list of the enterprise applications in your account appears.
Select an application. An overview page for the application appears. In this example, the Salesforce application is used.
Next, change the certificate signing options in the SAML token for that application:
In the left pane of the application overview page, select Single sign-on.
If the Set up Single Sign-On with SAML - Preview page appears, go to step 5.
If the Select a single sign-on method page doesn't appear, select Change single sign-on modes to display that page.
In the Select a single sign-on method page, select SAML if available. (If SAML isn't available, the application doesn't support SAML, and you may ignore the rest of this procedure and article.)
In the Set up Single Sign-On with SAML - Preview page, find the SAML Signing Certificate heading and select the Edit icon (a pencil). The SAML Signing Certificate page appears.
In the Signing Option drop-down list, choose Sign SAML response, Sign SAML assertion, or Sign SAML response and assertion. Descriptions of these options appear earlier in this article in the Certificate signing options.
In the Signing Algorithm drop-down list, choose SHA-1 or SHA-256. Descriptions of these options appear earlier in this article in the Certificate signing algorithms section.
If you're satisfied with your choices, select Save to apply the new SAML signing certificate settings. Otherwise, select the X to discard the changes.