package org.jscep.util;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.security.spec.RSAPublicKeySpec;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.params.RSAKeyParameters;
import org.bouncycastle.crypto.util.PublicKeyFactory;
import org.bouncycastle.pkcs.PKCS10CertificationRequest;
/**
* This class is used for performing utility operations on
* <tt>CertificationRequest</tt> instances.
*/
public class CertificationRequestUtils {
private CertificationRequestUtils() {
}
/**
* Extracts the <tt>PublicKey</tt> from the provided CSR.
* <p>
* This method will throw a {@link RuntimeException} if the JRE is missing
* the RSA algorithm, which is a required algorithm as defined by the JCA.
*
* @param csr
* the CSR to extract from.
* @return the extracted <tt>PublicKey</tt>
* @throws InvalidKeySpecException
* if the CSR is not using an RSA key.
* @throws IOException
* if there is an error extracting the <tt>PublicKey</tt>
* parameters.
*/
public static PublicKey getPublicKey(PKCS10CertificationRequest csr)
throws InvalidKeySpecException, IOException {
SubjectPublicKeyInfo pubKeyInfo = csr.getSubjectPublicKeyInfo();
RSAKeyParameters keyParams = (RSAKeyParameters) PublicKeyFactory
.createKey(pubKeyInfo);
KeySpec keySpec = new RSAPublicKeySpec(keyParams.getModulus(),
keyParams.getExponent());
KeyFactory kf;
try {
kf = KeyFactory.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
}
return kf.generatePublic(keySpec);
}
}