Implement role-based SSO by using Active Directory Federation Services

SSO process

The following figure shows the process of role-based SSO.

After an AD administrator completes the configurations of role-based SSO, Alice can log on to the Alibaba Cloud console based on the process. For more information, see Overview of role-based SSO.

The SSO process shows that users can be authenticated without the need to provide Alibaba Cloud usernames and passwords during logon.

Configure AD FS as a trusted SAML IdP in Alibaba Cloud

1. Log on to the Alibaba Cloud RAM console by using Account1. Create an IdP named ADFS and upload a metadata file. You can obtain the metadata file of AD FS from the URL: https://<ADFS-server>/federationmetadata/2007-06/federationmetadata.xml.
   Note <ADFS-server> in the URL is the domain name or IP address of your AD FS server.

   For more information, see Configure the SAML settings of Alibaba Cloud for role-based SSO.

2. Create two RAM roles named ADFS-Admin and ADFS-Reader. When you create the roles, select IdP for the Trusted entity type parameter and select ADFS from the Select IdP drop-down list. Then, attach the AdministratorAccess policy to the ADFS-Admin role and attach the ReadOnlyAccess policy to the ADFS-Reader role.
   For more information, see Create a RAM role for a trusted IdP.
3. Repeat the preceding steps to create an IdP and two RAM roles for Account2 and attach policies to the RAM roles.

Configure Alibaba Cloud as a trusted SAML SP in AD FS

In AD FS, a SAML service provider (SP) is also known as a relying party. To configure Alibaba Cloud as a trusted SAML SP in AD FS, perform the following steps:

1. On the Server Manager page, choose Tools > AD FS Management.
2. Select Add Relying Party Trust.
   
3. Specify the SAML SP metadata of Alibaba Cloud for the relying party. The metadata URL is https://signin.alibabacloud.com/saml-role/sp-metadata.xml.
   
4. Complete the configurations as instructed.

Configure SAML assertion attributes for the Alibaba Cloud SP

The SAML assertion that is issued by AD FS must contain the attributes, such as NameID, Role, and RoleSessionName. AD FS can provide these attributes by issuing transform rules.

• NameID

  Perform the following steps to set the Windows account name of AD to the value of the NameID attribute in the SAML assertion:

  1. Right-click the display name of the relying party and select Edit Claim Rules.
  2. Click Issuance Transform Rules.
     Note Issuance transform rules indicate how to transform a known user attribute and issue it as an attribute in the SAML assertion. You need to issue the Windows account name of a user in AD as NameID. Therefore, you need to add a new rule.
  3. Select Transform an Incoming Claim from the Claim rule template drop-down list.
  4. Specify the following parameters for the claim rule, and click Finish.
     • Set the Claim rule name parameter to NameID.
     • Set the Incoming claim type parameter to Windows account name.
     • Set the Outgoing claim type parameter to Name ID.
     • Set the Outgoing name ID format parameter to Persistent Identifier.
     • Select the Pass through all claim values option.
     

     After you have configured the required settings, AD FS will send the NameID attribute to Alibaba Cloud. The following code shows an example:

     <NameID Format="urn:oasis:names:tc:SAML:2.0:nameid-format:persistent">
         YourDomain\rolessouser
     </NameID>

• RoleSessionName

  Perform the following steps to set the value of the RoleSessionName attribute in the SAML assertion to be the User Principal Name (UPN) of AD:

  1. Click Add Transform Claim Rule.
  2. Select Send LDAP Attributes as Claims from the Claim rule template drop-down list.
  3. Specify the following parameters for the claim rule, and click Finish.
     • Set the Claim rule name parameter to RoleSessionName.
     • Select Active Directory from the Attribute store drop-down list.
     • Select User-Principal-Name in the LDAP Attribute column. You can select another option as required, for example, Email.
     • Select https://www.aliyun.com/SAML-Role/Attributes/RoleSessionName in the Outgoing Claim Type column.
     

  After you have configured the required settings, AD FS will send the RoleSessionName attribute to Alibaba Cloud. The following code shows an example.

  <Attribute Name="https://www.aliyun.com/SAML-Role/Attributes/RoleSessionName">
      <AttributeValue>rolessouser@example.com<AttributeValue>
  </Attribute>

• Role

  Perform the following steps to configure a custom attribute whose value contains the name of the Alibaba Cloud RAM role that is associated with the AD group of the user:

  1. Click Add Transform Claim Rule.
  2. Select Send Claims Using a Custom Rule from the Claim rule template drop-down list and click Next.
  3. Specify the following parameters for the claim rule, and click Finish.
     • Set the Claim rule name parameter to Get AD Groups.
     • Set the Custom rule parameter. The following code shows an example.

       c:[Type =="http://schemas.microsoft.com/ws/2008/06/identity/claims/windowsaccountname", Issuer == "AD AUTHORITY"] => add(store = "Active Directory",types = ("http://temp/variable"), query = ";tokenGroups;{0}", param =c.Value);

     
     Note This rule is used to obtain the AD group to which the user belongs. The rule is saved in the http://temp/variable intermediate variable.
  4. Click Add Transform Claim Rule.
  5. Repeat the preceding steps to create a custom rule, specify the following parameters for the rule, and then click Finish.
     • Set the Claim rule name parameter to Role.
     • Set the Custom rule parameter. The following code shows an example.

       c:[Type == "http://temp/variable", Value =~ "(?i)^Aliyun-([\d]+)"] => issue(Type = "https://www.aliyun.com/SAML-Role/Attributes/Role",Value = RegExReplace(c.Value, "Aliyun-([\d]+)-(.+)", "acs:ram::$1:role/$2,acs:ram::$1:saml-provider/ADFS"));

     
     Note Based on this rule, if the user belongs to the Aliyun-<account-id>-ADFS-Admin or Aliyun-<account-id>-ADFS-Reader group, a SAML attribute will be generated and sent to Alibaba Cloud to match the RAM role ADFS-Admin or ADFS-Reader.

  After you have configured the required settings, your IdP will return a SAML assertion to Alibaba Cloud. The following code shows an example.

  <Attribute Name="https://www.aliyun.com/SAML-Role/Attributes/Role">
      <AttributeValue>acs:ram::<account-id>:role/ADFS-Admin,acs:ram::<account-id>:saml-provider/ADFS</AttributeValue>
  </Attribute>

Test user-based SSO

1. Log on to the AD FS SSO portal (URL: https://<ADFS-server>/adfs/ls/IdpInitiatedSignOn.aspx). Select the Alibaba Cloud application, and enter the username and password.
   Note <ADFS-server> in the URL is the domain name or IP address of your AD FS server. If the URL is unavailable, run the Set-AdfsProperties -EnableIdpInitiatedSignonPage $True command in PowerShell.

   
2. On the Role-based SSO page of Alibaba Cloud, select the target role and click Sign In.
   Note If your user belongs to only one AD group, the user corresponds to only one role in Alibaba Cloud. In this case, the user can log on to the Alibaba Cloud Management Console without the need to select a role.