4.5 12 Configure Smart Card Authentication

Smart card authentication offers a robust security layer for accessing systems and networks, surpassing traditional username and password methods. By leveraging cryptographic keys stored on a physical smart card, this approach ensures strong authentication and protects sensitive data. Configuring smart card authentication involves a series of steps, from preparing the environment to deploying and testing the solution.

Understanding Smart Card Authentication

Smart card authentication enhances security by utilizing a physical smart card that stores digital certificates and private keys. This method relies on public key infrastructure (PKI), where each user possesses a unique digital certificate issued by a trusted certificate authority (CA). When a user attempts to authenticate, the system verifies the smart card's certificate and challenges the user to prove possession of the corresponding private key. This is typically done by requiring the user to enter a PIN associated with the smart card.

Benefits of Smart Card Authentication

• Enhanced Security: Smart cards provide a higher level of security compared to passwords.
• Two-Factor Authentication (2FA): Smart card authentication inherently provides two-factor authentication (something you have and something you know).
• Non-Repudiation: Smart card authentication enables non-repudiation, ensuring that users cannot deny actions performed with their smart cards.
• Centralized Management: Smart card infrastructure allows for centralized management of user identities and access privileges.
• Compliance: Many regulatory frameworks require strong authentication methods.

Prerequisites for Smart Card Authentication

Before configuring smart card authentication, ensure that your environment meets the necessary prerequisites:

1. Certificate Authority (CA): A trusted CA is essential for issuing digital certificates to users.
2. Smart Cards and Readers: Smart cards and compatible readers are required for each user.
3. Middleware: Install the necessary middleware on user devices to enable communication with smart cards.
4. Domain Infrastructure: An Active Directory domain is typically required for managing users and computers in a centralized manner.
5. Network Connectivity: Ensure that user devices have network connectivity to access the CA and domain controllers.

Step-by-Step Configuration Guide

Configuring smart card authentication involves the following steps:

1. Setting Up the Certificate Authority (CA)

The CA is the foundation of smart card authentication. It is responsible for issuing and managing digital certificates. If you don't have a CA, you'll need to set one up.

Installing Active Directory Certificate Services (AD CS)

1. Open Server Manager: Launch Server Manager on your Windows Server.
2. Add Roles and Features: Click on "Add roles and features."
3. Select Role-Based or Feature-Based Installation: Choose "Role-based or feature-based installation."
4. Select Server: Select the server where you want to install AD CS.
5. Select Server Roles: Check the box for "Active Directory Certificate Services."
6. Add Required Features: Add any required features.
7. Confirmation: Confirm your selections and click "Install."

Configuring AD CS

1. Configure AD CS: After installation, click the "Configure Active Directory Certificate Services on the destination server" link.
2. Select Role Services: Choose "Certification Authority" and "Certification Authority Web Enrollment."
3. Setup Type: Select "Enterprise CA" if integrating with Active Directory or "Standalone CA" for a standalone environment.
4. Specify CA Type: Choose "Root CA" for the top-level CA.
5. Set Up Cryptography: Configure cryptographic settings, such as key length and hash algorithm.
6. CA Name: Specify a name for your CA.
7. Validity Period: Set the validity period for certificates issued by the CA.
8. Certificate Database: Configure the location of the certificate database.
9. Confirmation: Review your settings and click "Configure."

2. Creating a Smart Card Certificate Template

A certificate template defines the settings for certificates issued to smart cards. You need to create a template tailored for smart card authentication.

Opening the Certificate Template Console

1. Open MMC: Press Win + R, type mmc, and press Enter.
2. Add Snap-in: Go to "File" > "Add/Remove Snap-in."
3. Select Certificate Templates: Choose "Certificate Templates" from the list and click "Add."
4. OK: Click "OK" to add the snap-in.

Duplicating the Smart Card Logon Template

1. Locate Smart Card Logon Template: In the Certificate Templates console, find the "Smart Card Logon" template.
2. Duplicate Template: Right-click on the template and select "Duplicate Template."

Configuring the New Template

1. General Tab:
   • Template Name: Specify a descriptive name, like "Smart Card Authentication."
   • Validity Period: Set the desired validity period.
2. Request Handling Tab:
   • Purpose: Select "Signature and encryption."
   • Minimum key size: 2048
3. Cryptography Tab:
   • Provider Category: Select "Key Storage Provider."
   • Algorithm Name: Select "RSA."
   • Minimum key size: 2048
4. Subject Name Tab:
   • Build from this Active Directory information: Ensure that the "User principal name (UPN)" is included.
5. Issuance Requirements Tab:
   • Number of authorized signatures: Set to 1.
   • Application policy: Certificate Request Agent
6. Extensions Tab:
   • Application Policies: Make sure that "Smart Card Logon" is present.
   • Key Usage: Ensure that "Digital Signature" is present.
7. Security Tab:
   • Permissions: Add the appropriate security groups or users who will be enrolling for certificates using this template. Ensure that they have "Enroll" permissions.

Issuing the Certificate Template

1. Open Certification Authority Console: Launch the Certification Authority console from Administrative Tools.
2. Right-Click Certificate Templates: Right-click on "Certificate Templates" and select "New" > "Certificate Template to Issue."
3. Select Your Template: Choose the template you created (e.g., "Smart Card Authentication") and click "OK."

3. Enrolling Smart Cards

After configuring the certificate template, users can enroll for smart card certificates. This process involves generating a key pair on the smart card, submitting a certificate request to the CA, and receiving the signed certificate.

Using the Certificate Enrollment Web Interface

1. Access the Web Interface: Open a web browser and navigate to the CA's web enrollment page (e.g., http://your-ca-server/certsrv).
2. Request a Certificate: Click on "Request a certificate."
3. Advanced Certificate Request: Choose "advanced certificate request."
4. Submit a Certificate Request:
   • Select the smart card certificate template you created.
   • Ensure that the "Use key from Smart Card" option is selected.
   • Click "Submit."
5. Install the Certificate: Once the certificate is issued, install it on the smart card.

Using the certreq Command-Line Tool

1. Create a Request File: Create a text file (e.g., request.inf) with the following content:

   [NewRequest]
   Subject = "CN=User Name"
   KeySpec = 1
   KeyLength = 2048
   Exportable = FALSE
   MachineKeySet = TRUE
   SMIME = FALSE
   PrivateKeyArchive = FALSE
   UserProtected = TRUE
   UseExistingKeySet = TRUE
   ProviderName = "Microsoft Base Smart Card Crypto Provider"
   ProviderType = 1
   RequestType = PKCS10
   KeyAlgorithm = RSA
   
   [EnhancedKeyUsageExtension]
   OID=1.3.6.1.4.1.311.20.2.2
   

2. Generate the Certificate Request: Run the following command:

   certreq -new request.inf request.req
   

3. Submit the Request to the CA: Use the CA's web interface or the certreq command to submit the request.

4. Retrieve the Certificate: Once the certificate is issued, retrieve it and install it on the smart card.

4. Configuring Client Computers

Client computers need to be configured to recognize and use smart cards for authentication. This involves installing the necessary middleware and configuring group policies.

Installing Smart Card Middleware

1. Install Middleware: Install the smart card middleware provided by the smart card vendor on each client computer.
2. Configure Middleware: Configure the middleware to recognize the smart card reader and the smart card.

Configuring Group Policies

1. Open Group Policy Management: Launch Group Policy Management Console (GPMC) from Administrative Tools.
2. Edit Group Policy: Edit the Group Policy Object (GPO) that applies to the users or computers that will use smart card authentication.
3. Computer Configuration: Navigate to "Computer Configuration" > "Policies" > "Windows Settings" > "Security Settings" > "Public Key Policies" > "Certificate Path Validation Settings."
4. Define Trust Anchors: Define the trust anchors for your CA.
5. User Configuration: Navigate to "User Configuration" > "Policies" > "Windows Settings" > "Internet Explorer Maintenance" > "Security" > "Security Zones and Content Ratings."
6. Local Intranet Zone: Add the CA's web enrollment page to the Local Intranet zone and configure it to allow ActiveX controls and scriptlets.

5. Enabling Smart Card Authentication in Active Directory

To enable smart card authentication in Active Directory, you need to configure the "SmartcardLogon" attribute for each user account.

Using Active Directory Users and Computers

1. Open Active Directory Users and Computers: Launch Active Directory Users and Computers from Administrative Tools.
2. Locate User Account: Find the user account for whom you want to enable smart card authentication.
3. Open Properties: Right-click on the user account and select "Properties."
4. Attribute Editor Tab: Navigate to the "Attribute Editor" tab.
5. Locate userCertificate Attribute: Find the userCertificate attribute and click "Edit."
6. Add Certificate: Add the user's smart card certificate to the attribute.
7. Apply Changes: Click "OK" to apply the changes.

Using PowerShell

1. Import Active Directory Module: Import the Active Directory module:

   Import-Module ActiveDirectory
   

2. Get User Account: Get the user account:

   $user = Get-ADUser -Identity "username" -Properties userCertificate
   

3. Get Certificate: Get the smart card certificate:

   $cert = Get-PfxCertificate -FilePath "path\to\certificate.pfx"
   

4. Update userCertificate Attribute: Update the userCertificate attribute:

   Set-ADUser -Identity $user -Replace @{userCertificate=$cert.RawData}
   

6. Testing Smart Card Authentication

After configuring smart card authentication, it is essential to test the setup to ensure that it is working correctly.

Logging in with a Smart Card

1. Insert Smart Card: Insert the smart card into the reader.
2. Log Off: Log off from the computer.
3. Smart Card Login: At the login screen, click on the smart card icon.
4. Enter PIN: Enter the PIN associated with the smart card.
5. Verify Access: Verify that you can successfully log in to the computer.

Testing with Remote Desktop

1. Open Remote Desktop Connection: Launch Remote Desktop Connection.
2. Enter Computer Name: Enter the name of the remote computer.
3. Smart Card Authentication: Select the "Use a smart card" option.
4. Enter PIN: Enter the PIN associated with the smart card.
5. Verify Access: Verify that you can successfully connect to the remote computer.

7. Troubleshooting Common Issues

• Certificate Issues: Verify that the smart card certificate is valid and trusted. Ensure that the certificate has not expired and that the CA is trusted by the client computer.
• Middleware Issues: Ensure that the smart card middleware is installed and configured correctly. Verify that the middleware recognizes the smart card reader and the smart card.
• Group Policy Issues: Check the Group Policy settings to ensure that they are configured correctly. Verify that the trust anchors for the CA are defined correctly.
• Connectivity Issues: Ensure that the client computer has network connectivity to the CA and domain controllers. Verify that the DNS settings are configured correctly.

Best Practices for Smart Card Authentication

• Strong PIN Policies: Implement strong PIN policies to protect smart cards from unauthorized access. Require users to change their PINs regularly.
• Regular Certificate Revocation: Revoke certificates for lost or stolen smart cards to prevent unauthorized access.
• Secure Storage of Smart Cards: Provide secure storage for smart cards when they are not in use.
• User Training: Train users on the proper use and security of smart cards.
• Monitoring and Auditing: Monitor and audit smart card authentication events to detect and respond to security incidents.

Conclusion

Smart card authentication provides a strong security layer for accessing systems and networks. By following the steps outlined in this article, you can successfully configure smart card authentication and enhance the security of your environment. Remember to adhere to best practices and regularly monitor and audit your smart card infrastructure to ensure its ongoing effectiveness.