Sign with .pfx to create .p7s, Verify with .cer

Java example to sign a file using a .pfx and creating a .p7s file as output. It then uses a .cer file to verify the signature.

Download Chilkat Java Library

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[])
  {
    CkCrypt2 crypt = new CkCrypt2();

    //  Any string argument automatically begins the 30-day trial.
    boolean success;
    success = crypt.UnlockComponent("30-day trial");
    if (success != true) {
        System.out.println("Crypt component unlock failed");
        return;
    }

    CkCertStore certStore = new CkCertStore();
    success = certStore.LoadPfxFile("chilkat.pfx","myPfxPassword");
    if (success != true) {
        System.out.println(certStore.lastErrorText());
        return;
    }

    CkCert cert;
    cert = certStore.FindCertBySubjectCN("Chilkat Software, Inc.");
    if (cert == null ) {
        System.out.println("Failed to find certificate");
        return;
    }

    //  We can explicitly choose hash/encryption algorithms using a CSP.
    CkCSP csp = new CkCSP();
    csp.SetProviderMicrosoftEnhanced();
    csp.SetHashAlgorithm("sha-1");

    //  Tell the crypt component to use this cert and this CSP.
    crypt.SetSigningCert(cert);
    crypt.SetCSP(csp);

    //  We can sign any type of file, creating a .p7s as output:
    success = crypt.CreateP7S("hamlet.xml","hamlet.p7s");
    if (success == true) {
        System.out.println("Signature created.");
    }
    else {
        System.out.println(crypt.lastErrorText());
    }

    //  Verify and restore the original file:
    //  Use a cert from a .cer file (which only contains the public key)
    CkCert cert2 = new CkCert();
    success = cert2.LoadFromFile("chilkat.cer");
    if (success != true) {
        System.out.println(cert2.lastErrorText());
        return;
    }

    crypt.SetVerifyCert(cert2);

    success = crypt.VerifyP7S("hamlet.xml","hamlet.p7s");
    if (success == true) {
        System.out.println("Signature verified.");
    }
    else {
        System.out.println(crypt.lastErrorText());
    }


  }
}