Authenticate a user with a social provider, Database/AD/LDAP (Passive), SAML/Windows Azure AD (Passive), Authorization Code Flow, Authorization Code Grant (PKCE) Flow, or Implicit Flow

Use this endpoint to authenticate a user. The following flows are supported: - Social Provider Authentication - Database/AD/LDAP (Passive) Authentication - SAML/Windows Azure AD (Passive) Authentication - Authorization Code Flow - Authorization Code Grant (PKCE) Flow - Implicit Flow