Implement role-based SSO from AD FS

Process

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

After an AD administrator completes the configurations of role-based SSO, the user Alice can log on to the Alibaba Cloud Management Console based on the process shown in the figure. For more information, see Overview of role-based SSO.

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

Step 1: Configure AD FS as a trusted SAML IdP in Alibaba Cloud

1. Log on to the Alibaba Cloud RAM console. Create an IdP named ADFS and upload a metadata file. You can obtain the metadata file of AD FS from https://<ADFS-server>/federationmetadata/2007-06/federationmetadata.xml.
   Note <ADFS-server> indicates 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 for Account 1. When you create the RAM roles, select IdP as the type of trusted entity and ADFS as the trusted IdP. Then, attach the AdministratorAccess policy to the ADFS-Admin role and 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 the same IdP and two RAM roles for Account 2. Then, attach policies to the RAM roles.

Step 2: Configure Alibaba Cloud as a trusted SAML SP in AD FS

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

1. In the top navigation bar of Server Manager, choose Tools > AD FS Management.
2. Select Add Relying Party Trust.
   
3. Configure the SAML SP metadata file of Alibaba Cloud for the relying party. You can obtain the metadata file from the following URL: https://signin.alibabacloud.com/saml-role/sp-metadata.xml.
   
4. Complete the wizard as prompted.

Step 3: Configure SAML assertion attributes for the Alibaba Cloud SP

The SAML assertion that is issued by AD FS must contain the NameID, Role, and RoleSessionName attributes. AD FS provides these attributes by using issuance transform rules.

• NameID

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

  1. Right-click the display name of the relying party and select Edit Claim Issuance Policy.
  2. Add an issuance transform rule.
     Note An issuance transform rule indicates how to transform a known user attribute and issue it as an attribute in the SAML assertion. If you want to issue the Windows account name of a user in AD as NameID, you must create an issuance transform rule.
  3. Set Claim rule template to Transform an Incoming Claim.
  4. Configure the following parameters and click Finish.
     • Set Claim rule name to NameID.
     • Set Incoming claim type to Windows account name.
     • Set Outgoing claim type to Name ID.
     • Set Outgoing name ID format to Persistent Identifier.
     • Select Pass through all claim values.
     

     After you complete the configurations, AD FS sends the NameID attribute in the format required by 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 RoleSessionName attribute in the SAML assertion to the User Principal Name (UPN) of a user in AD:

  1. In the Issuance Transform Rules dialog box, click Add Rule.
  2. Set Claim rule template to Send LDAP Attributes as Claims.
  3. Configure the following parameters and click Finish.
     • Set Claim rule name to RoleSessionName.
     • Set Attribute store to Active Directory.
     • Select User-Principal-Name in the LDAP Attribute column. You can also use a different option, such as Email, based on your business requirements.
     • Enter https://www.aliyun.com/SAML-Role/Attributes/RoleSessionName in the Outgoing Claim Type column.
     

  After you complete the configurations, AD FS sends the RoleSessionName attribute in the format required by 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 and set its value to the name of an Alibaba Cloud RAM role that is associated with the AD group of a user:

  1. In the Issuance Transform Rules dialog box, click Add Rule.
  2. Set Claim rule template to Send Claims Using a Custom Rule and click Next.
  3. Configure the following parameters and click Finish.
     • Set Claim rule name to Get AD Groups.
     • In the Custom rule field, enter the required information. Set this parameter based on the following 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. In the Issuance Transform Rules dialog box, click Add Rule.
  5. Repeat the preceding steps and click Finish.
     • Set Claim rule name to Role.
     • In the Custom rule field, enter the required information. Set this parameter based on the following 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 If the user belongs to the Aliyun-<account-id>-ADFS-Admin or Aliyun-<account-id>-ADFS-Reader group, a SAML attribute is generated and mapped to the ADFS-Admin or ADFS-Reader role in Alibaba Cloud based on this rule.

  After you complete the configurations, your IdP returns the required part of 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>

Verify the configuration results

1. Log on to the AD FS portal for SSO at https://<ADFS-server>/adfs/ls/IdpInitiatedSignOn.aspx. Select the Alibaba Cloud application and enter the username and password of your user.
   Note <ADFS-server> indicates 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 RAM role that you want to use and click Sign In.
   Note If your user belongs to only one AD group, the user corresponds to only one RAM role in Alibaba Cloud. In this case, you can log on to the Alibaba Cloud Management Console without the need to select a RAM role.