(Java) Get PDF Signer Certs

See more PDF Signatures Examples

This example demonstrates how to validate the signatures in a PDF and also shows how to get each signature's signer certificate.

Note: This example requires Chilkat v9.5.0.87 or greater.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkPdf pdf = new CkPdf();

    // Load a PDF that has cryptographic signatures to be validated
    boolean success = pdf.LoadFile("qa_data/pdf/sign_testing_1/helloSigned2.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    // Each time we verify a signature, information about the signature is written into
    // sigInfo (replacing whatever sigInfo previously contained).
    CkJsonObject sigInfo = new CkJsonObject();

    // Iterate over each signature and validate each.
    int numSignatures = pdf.get_NumSignatures();
    boolean validated = false;
    CkCert cert = new CkCert();
    int i = 0;
    while (i < numSignatures) {
        validated = pdf.VerifySignature(i,sigInfo);
        System.out.println("Signature " + i + " validated: " + validated);

        // The GetSignerCert method was added in Chilkat v9.5.0.87
        // After calling VerifySignature, you can get the signer certificate by calling
        // GetSignerCert with the same index. 
        success = pdf.GetSignerCert(i,cert);
        if (success != false) {
            System.out.println("PDF signer certificate: " + cert.subjectDN());
            }

        i = i+1;
        }

    System.out.println("Finished.");
  }
}