InvalidKeyException : Illegal Key Size - Java code throwing exception for encryption class - how to fix?

java security exception encryption paypal
katura picture katura · Jun 15, 2011 · Viewed 112.1k times · Source

I've been trying to get some working Java code to use for encrypting Paypal buttons. This is no easy task! Even when I get some code, from Paypal, I'm faced with errors..ugh..

So here is what I have so far, that I think will work eventually.

I downloaded the Java.zip file from Paypal's website. Within it are two classes - ClientSide.java and ButtonEncryption.java

The Problem - I'm getting an InvalidKeyException : Illegal key size error.

Questions
1) How do I resolve this issue? 2) What line of code is throwing the error?

C:\jakarta-tomcat\webapps\PlanB\WEB-INF\classes>java palmb.servlets.paypal.ButtonEncryption
java.io.IOException: exception decrypting data - java.security.InvalidKeyException: Illegal key size
        at org.bouncycastle.jce.provider.JDKPKCS12KeyStore.cryptData(Unknown Source)
        at org.bouncycastle.jce.provider.JDKPKCS12KeyStore.engineLoad(Unknown Source)
        at java.security.KeyStore.load(Unknown Source)
        at palmb.servlets.paypal.ClientSide.getButtonEncryptionValue(ClientSide.java:63)
        at palmb.servlets.paypal.ButtonEncryption.main(ButtonEncryption.java:81)


ClientSide class

package palmb.servlets.paypal;

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.security.InvalidAlgorithmParameterException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PrivateKey;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertStore;
import java.security.cert.CertStoreException;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.CollectionCertStoreParameters;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Enumeration;

import org.bouncycastle.cms.CMSEnvelopedData;
import org.bouncycastle.cms.CMSEnvelopedDataGenerator;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.CMSSignedDataGenerator;
import org.bouncycastle.openssl.PEMReader;
import org.bouncycastle.util.encoders.Base64;

/**
 */
public class ClientSide 
{
    private String  keyPath;
    private String  certPath;
    private String  paypalCertPath;
    private String  keyPass;

    public ClientSide( String keyPath, String certPath, String paypalCertPath, String keyPass )
    {
        this.keyPath = keyPath;
        this.certPath = certPath;
        this.paypalCertPath = paypalCertPath;
        this.keyPass = keyPass;
    }   

    public String getButtonEncryptionValue(String _data, String _privateKeyPath, String _certPath, String _payPalCertPath,
                                            String _keyPass) throws IOException,CertificateException,KeyStoreException,
                                            UnrecoverableKeyException,InvalidAlgorithmParameterException,NoSuchAlgorithmException,
                                            NoSuchProviderException,CertStoreException,CMSException {
        _data = _data.replace(',', '\n');
        CertificateFactory cf = CertificateFactory.getInstance("X509", "BC");

        // Read the Private Key
        KeyStore ks = KeyStore.getInstance("PKCS12", "BC");
        ks.load( new FileInputStream(_privateKeyPath), _keyPass.toCharArray() );

        String keyAlias = null;
        Enumeration aliases = ks.aliases();
        while (aliases.hasMoreElements()) {
            keyAlias = (String) aliases.nextElement();
        }

        PrivateKey privateKey = (PrivateKey) ks.getKey( keyAlias, _keyPass.toCharArray() );

        // Read the Certificate
        X509Certificate certificate = (X509Certificate) cf.generateCertificate( new FileInputStream(_certPath) );

        // Read the PayPal Cert
        X509Certificate payPalCert = (X509Certificate) cf.generateCertificate( new FileInputStream(_payPalCertPath) );

        // Create the Data
        byte[] data = _data.getBytes();

        // Sign the Data with my signing only key pair
        CMSSignedDataGenerator signedGenerator = new CMSSignedDataGenerator();

        signedGenerator.addSigner( privateKey, certificate, CMSSignedDataGenerator.DIGEST_SHA1 );

        ArrayList certList = new ArrayList();
        certList.add(certificate);
        CertStore certStore = CertStore.getInstance( "Collection", new CollectionCertStoreParameters(certList) );
        signedGenerator.addCertificatesAndCRLs(certStore);

        CMSProcessableByteArray cmsByteArray = new CMSProcessableByteArray(data);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        cmsByteArray.write(baos);
        System.out.println( "CMSProcessableByteArray contains [" + baos.toString() + "]" );

        CMSSignedData signedData = signedGenerator.generate(cmsByteArray, true, "BC");

        byte[] signed = signedData.getEncoded();

        CMSEnvelopedDataGenerator envGenerator = new CMSEnvelopedDataGenerator();
        envGenerator.addKeyTransRecipient(payPalCert);
        CMSEnvelopedData envData = envGenerator.generate( new CMSProcessableByteArray(signed),
                CMSEnvelopedDataGenerator.DES_EDE3_CBC, "BC" );

        byte[] pkcs7Bytes = envData.getEncoded();


        return new String( DERtoPEM(pkcs7Bytes, "PKCS7") );

    }

    public static byte[] DERtoPEM(byte[] bytes, String headfoot) 
    {
        ByteArrayOutputStream pemStream = new ByteArrayOutputStream();
        PrintWriter writer = new PrintWriter(pemStream);

        byte[] stringBytes = Base64.encode(bytes);

        System.out.println("Converting " + stringBytes.length + " bytes");

        String encoded = new String(stringBytes);

        if (headfoot != null) {
            writer.print("-----BEGIN " + headfoot + "-----\n");
        }

        // write 64 chars per line till done
        int i = 0;
        while ((i + 1) * 64 < encoded.length()) {
            writer.print(encoded.substring(i * 64, (i + 1) * 64));
            writer.print("\n");
            i++;
        }
        if (encoded.length() % 64 != 0) {
            writer.print(encoded.substring(i * 64)); // write remainder
            writer.print("\n");
        }
        if (headfoot != null) {
            writer.print("-----END " + headfoot + "-----\n");
        }
        writer.flush();
        return pemStream.toByteArray();
    }

}


ButtonEncryption class

package palmb.servlets.paypal;

//import com.paypal.crypto.sample.*;

import palmb.servlets.paypal.ClientSide;

import java.io.*;
import java.security.InvalidAlgorithmParameterException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Security;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertStoreException;
import java.security.cert.CertificateException;
import org.bouncycastle.cms.CMSException;

/**
 */
public class ButtonEncryption {


    //path to public cert
    private static String certPath = "C:/jakarta-tomcat/webapps/PlanB/Certs/public-cert.pem";

    //path to private key in PKCS12 format
    private static String keyPath = "C:/jakarta-tomcat/webapps/PlanB/Certs/my_pkcs12.p12";

    //path to Paypal's public cert
    private static String paypalCertPath = "C:/jakarta-tomcat/webapps/PlanB/Certs/paypal_cert_pem.txt";

    //private key password
    private static String keyPass = "password"; //will be replaced with actual password when compiled and executed

    //the button command, properties/parameters
    private static String cmdText = "cmd=_xclick\[email protected]\nitem_name=vase\nitemprice=25.00";  //cmd=_xclick,[email protected],amount=1.00,currency_code=USD

    //output file for form code
    private static String output = "test.html";


    public static void main(String[] args) 
    {
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider()); 


        String stage = "sandbox";

        try 
        {
            ClientSide client_side = new ClientSide( keyPath, certPath, paypalCertPath, keyPass );

            String result = client_side.getButtonEncryptionValue( cmdText, keyPath, certPath, paypalCertPath, keyPass );

            File outputFile = new File( output );
            if ( outputFile.exists() )
                outputFile.delete();

            if ( result != null && result != "")
            {
                try {        
                    OutputStream fout= new FileOutputStream( output );
                    OutputStream bout= new BufferedOutputStream(fout);
                    OutputStreamWriter out = new OutputStreamWriter(bout, "US-ASCII");

                    out.write( "<form action=\"https://www." );
                    out.write( stage );
                    out.write( "paypal.com/cgi-bin/webscr\" method=\"post\">" );  
                    out.write( "<input type=\"hidden\" name=\"cmd\" value=\"_s-xclick\">" );  ;
                    out.write( "<input type=\"image\" src=\"https://www." );
                    out.write( stage );
                    out.write( "paypal.com/en_US/i/btn/x-click-but23.gif\" border=\"0\" name=\"submit\" " );
                    out.write( "alt=\"Make payments with PayPal - it's fast, free and secure!\">" );
                    out.write( "<input type=\"hidden\" name=\"encrypted\" value=\"" );
                    out.write( result );
                    out.write( "\">" );
                    out.write( "</form>");

                    out.flush();  // Don't forget to flush!
                    out.close();
                  }
                  catch (UnsupportedEncodingException e) {
                    System.out.println(
                     "This VM does not support the ASCII character set."
                    );
                  }
                  catch (IOException e) {
                    System.out.println(e.getMessage());        
                  }
            }
        } 
        catch (NoSuchAlgorithmException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (NoSuchProviderException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (IOException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (CMSException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (CertificateException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (KeyStoreException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (UnrecoverableKeyException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (InvalidAlgorithmParameterException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        catch (CertStoreException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}


Edited : info about keys/certificates

I generated the Private Key and Public Certificate with OpenSSL via the following commands.
Private Key
openssl genrsa -out private-key.pem 1024
Public Certificate
openssl req -new -key private-key.pem -x509 -days 1095 -out public-cert.pem
Created PKCS12 File
openssl pkcs12 -export -in public-cert.pem -inkey private-key.pem -out my_pkcs12.p12


Additionally, I had to download the Paypal Public Certificate from the Paypal website.


Edited - adding compilation warnings - BouncyCastle

C:\jakarta-tomcat\webapps\PlanB\WEB-INF\classes>javac .\palmb\servlets\paypal\ClientSide.java -Xlint
.\palmb\servlets\paypal\ClientSide.java:85: warning: [deprecation] addSigner(java.security.PrivateKey,java.security.cert.X509Certificate,java.lang.String) in org.bouncycastle.cms.CMSSignedDataGenerator has been deprecated
                signedGenerator.addSigner( privateKey, certificate, CMSSignedDat
aGenerator.DIGEST_SHA1 );
                               ^
.\palmb\servlets\paypal\ClientSide.java:88: warning: [unchecked] unchecked call
to add(E) as a member of the raw type java.util.ArrayList
                certList.add(certificate);
                            ^
.\palmb\servlets\paypal\ClientSide.java:90: warning: [deprecation] addCertificatesAndCRLs(java.security.cert.CertStore) in org.bouncycastle.cms.CMSSignedGenerat
or has been deprecated
                signedGenerator.addCertificatesAndCRLs(certStore);
                               ^
.\palmb\servlets\paypal\ClientSide.java:97: warning: [deprecation] generate(org.
bouncycastle.cms.CMSProcessable,boolean,java.lang.String) in org.bouncycastle.cm
s.CMSSignedDataGenerator has been deprecated
                CMSSignedData signedData = signedGenerator.generate(cmsByteArray, true, "BC");
                                                          ^
.\palmb\servlets\paypal\ClientSide.java:102: warning: [deprecation] addKeyTransR
ecipient(java.security.cert.X509Certificate) in org.bouncycastle.cms.CMSEnvelope
dGenerator has been deprecated
                envGenerator.addKeyTransRecipient(payPalCert);
                            ^
.\palmb\servlets\paypal\ClientSide.java:103: warning: [deprecation] generate(org.bouncycastle.cms.CMSProcessable,java.lang.String,java.lang.String) in org.bouncycastle.cms.CMSEnvelopedDataGenerator has been deprecated
                CMSEnvelopedData envData = envGenerator.generate( new CMSProcess
ableByteArray(signed),
                                                       ^
6 warnings


JCE policy file installation steps

These are the steps I took to installing the JCE Unlimited Strength Policy files:
1) Went to Java JCE Download Page on Oracle.
2) Extracted files from zip.
3) Placed local_policy.jar and US_export_policy.jar files in C:\Java\jdk1.6.0_22\jre\lib\security folder.
Note: C:\Java\jdk1.6.0_22 is set as %JAVA_HOME%
4) Updated system classpath to include location of jars.
Note: There are other files, that came with the JDK 1.6 within the security folder, including : java.policy, java.security, javaws.policy, trusted.libraries - but those probably have nothing to do with the JCE files, right?

Edit 6/23/2011 - results after further configuration

I went to Bouncy Castle page at http://www.bouncycastle.org/specifications.html#install
Scroll down to 5.0 Bouncy Castle Provider then read info under 5.1 Example. It makes mention of adding a parameter for the Bouncy Castle Provider to the java.security file. My file is under C:\Java\jdk1.6.0_22\jre\lib\security.

I added the following line to my file - security.provider.10=org.bouncycastle.jce.provider.BouncyCastleProvider

In addition, I discovered that I hadn't added the Bouncy Castle jars to the classpath, so I went ahead and did so.

Now after making these changes, recompiling and attempting to execute ClientSide.java I'm given the same exception : but maybe the focus should be on the part of the exception where it says this about bouncycastle provider -

at org.bouncycastle.jce.provider.JDKPKCS12KeyStore.cryptData(Unknown Source)
at org.bouncycastle.jce.provider.JDKPKCS12KeyStore.engineLoad(Unknown Source)

@PeteyB - I'm certain that I installed the policy files correctly. Based on what I've stated here, is there anything else you can suggest I try? Can you look at the Bouncy Castle site @ http://www.bouncycastle.org/specifications.html#install and see if there is something I'm missing?

Answer

Petey B picture Petey B · Jun 17, 2011

So the problem must be with your JCE Unlimited Strength installation.

Be sure you overwrite the local_policy.jar and US_export_policy.jar in both your JDK's jdk1.6.0_25\jre\lib\security\ and in your JRE's lib\security\ folder.

In my case I would place the new .jars in:

C:\Program Files\Java\jdk1.6.0_25\jre\lib\security

and

C:\Program Files\Java\jre6\lib\security

If you are running Java 8 and you encounter this issue. Below steps should help!

Go to your JRE installation (e.g - jre1.8.0_181\lib\security\policy\unlimited) copy local_policy.jar and replace it with 'local_policy.jar' in your JDK installation directory (e.g - jdk1.8.0_141\jre\lib\security).

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