WPF Using Certificates for Signed Applications Step by step Implementation and Top 10 Questions and Answers
 Last Update: April 01, 2025      8 mins read      Difficulty-Level: beginner

Certainly! Explaining how to use certificates for signing applications in Windows Presentation Foundation (WPF) can be broken down into a step-by-step guide, making it accessible even to beginners.

Introduction to WPF Application Signing and Certificates

Before delving into the specifics, it's essential to understand the why and what behind signing an application. Code signing is a security measure where software developers sign their applications or libraries using cryptographic hash functions. This step not only ensures the software's authenticity but also verifies that the software hasn't been tampered with since it was signed by its creator.

Certificates are digital credentials that serve as proof of identity for individuals, devices, or software. In the context of WPF applications, developers use Digital Certificates to sign their applications. Certificates are issued by trusted certification authorities (CAs), ensuring the trustworthiness of the software.

Step-by-Step Guide to Signing a WPF Application with a Certificate

Step 1: Generate a Self-Signed Certificate (for Testing)

For demonstration purposes, you can generate a self-signed certificate using the makecert tool or the newer New-SelfSignedCertificate PowerShell cmdlet. For production applications, acquire a certificate from a trusted CA.

Method 1: Using makecert (Deprecated)

  1. Open Command Prompt as Administrator.
  2. Navigate to the Windows SDK 8.0 tools directory, usually located at C:\Program Files (x86)\Windows Kits\8.0\bin\x86.
  3. Run the following command to create a self-signed certificate: 
    makecert -sv mykey.pvk -n "CN=My Company Name" -r mycert.cer
  4. Convert the .cer file to a Personal Information Exchange (PFX) file which is required for signing: 
    pvk2pfx.exe -pvk mykey.pvk -spc mycert.cer -pfx mycert.pfx
  5. Install the .cer file to the Trusted Root Certification Authorities in the local machine’s certificate store to trust your certificate.

Method 2: Using PowerShell (Recommended)

  1. Open PowerShell as Administrator.
  2. Run the following command to create a self-signed certificate and export it with a private key: 
    $password = ConvertTo-SecureString -String "MyStrongPassword" -Force -AsPlainText
$newCert = New-SelfSignedCertificate -Subject "CN=My Company Name" -CertStoreLocationcert:\LocalMachine\My -Type CodeSigningCert
$certPath = "C:\path\to\mycert.pfx"
Export-PfxCertificate -Cert $newCert -FilePath $certPath -Password $password
  3. Install the .pfx file to the Trusted Root Certification Authorities in the local machine’s certificate store to trust your certificate.

Step 2: Import the Certificate into Visual Studio

Once you have your certificate, you need to import it into Visual Studio to use it for signing your application.

  1. Open Visual Studio.
  2. Right-click on your WPF project in the Solution Explorer and select Properties.
  3. Go to the Signing tab.
  4. Check the Sign the ClickOnce manifests or Sign the assembly option depending on your needs.
  5. Click the Select from file button and browse for your .pfx or .cer file.
  6. Enter the password for your certificate.

Step 3: Configure ClickOnce Deployment

For WPF applications deployed via ClickOnce, you need to configure the ClickOnce manifest signing.

  1. In the WPF project properties, go to the Publish tab.
  2. Click on the Trust button.
  3. Select This is a full trust application.
  4. Click OK, then Publish.
  5. In the Publish Wizard, ensure that the signing certificate is selected in the Publishing Options.
  6. Complete the steps in the Publish Wizard to deploy your application.

Step 4: Configure Strong Name Signing

Strong name signing ensures that the assembly is unique and that its identity hasn't changed since it was signed.

  1. In the WPF project properties, go to the Signing tab.
  2. Check the Sign the assembly option.
  3. Select your certificate from the Choose a strong name key file dropdown.
  4. If the certificate is installed correctly, it should appear in the list.
  5. Build the project to ensure it signs successfully.

Step 5: Verify the Signed Application

After signing your application, it’s crucial to verify that the signing was done correctly.

  1. Use SignTool.exe from the Windows SDK to verify the signature of the application manifest. 
    signtool verify /pa path\to\your\publish\setup.exe
  2. If the application is signed correctly, SignTool will display a verification success message.

Benefits of Signing a WPF Application

  • Trustworthiness: Users trust software that is signed by a trusted entity.
  • Integrity: Ensures that the application has not been tampered with since it was signed.
  • Compatibility: Required for some deployment methods like ClickOnce.
  • Security: Adds a layer of security by enabling the application to be authenticated.

Conclusion

Signing WPF applications with a digital certificate is a crucial step to ensure the security, integrity, and trustworthiness of your application. By following the steps outlined above, developers can sign their WPF applications either for development/testing purposes using self-signed certificates or for production by obtaining certificates from trusted CAs. This guide has provided a comprehensive overview, from generating certificates to deploying signed applications, making the process accessible even for beginners.

Additional Resources

By leveraging digital certificates, developers can enhance the security and reliability of their WPF applications, providing a better experience for end-users.