SAML Signature Hashing Algorithm

Hi all, 

We need to configure SAML as Identity Providers for SSO in Appian. We have been looking into the configuration and we have some doubts about the Signature Hashing Algorithm. As far as we have seen there are only two available algorithms: SHA-1 and SHA-256,but after reviewing this topic with our client and people from Azure AD they told as the algorithm they use is AES.

Does anyone know if it's possible to use different algorithms for this or are those two the only possibilities? Has someone had this same issue before and was able to solve it?

Thanks in advance