Write PEM encoded certificate in file - java
- by user1349407
Good day.
I recently create X.509 certificate by using bouncy castle API.
I need to save the certificate result rather than display the result.
I tried to use FileOutputStream, but it does not work.
regards
the result is like follows
-----BEGIN CERTIFICATE-----
MIICeTCCAeKgAwIBAgIGATs8OWsXMA0GCSqGSIb3DQEBCwUAMBsxGTAXBgNVBAMT...
-----END CERTIFICATE-----
The code is belows
import java.io.FileOutputStream;
//example of a basic CA
public class PKCS10CertCreateExample
{
public static X509Certificate[] buildChain() throws Exception
{
//create the certification request
KeyPair pair = chapter7.Utils.generateRSAKeyPair();
PKCS10CertificationRequest request =
PKCS10ExtensionExample.generateRequest(pair);
//create a root certificate
KeyPair rootPair=chapter7.Utils.generateRSAKeyPair();
X509Certificate rootCert = X509V1CreateExample.generateV1Certificate
(rootPair);
//validate the certification request
if(!request.verify("BC"))
{
System.out.println("request failed to verify!");
System.exit(1);
}
//create the certificate using the information in the request
X509V3CertificateGenerator certGen = new X509V3CertificateGenerator();
certGen.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
certGen.setIssuerDN(rootCert.getSubjectX500Principal());
certGen.setNotBefore(new Date(System.currentTimeMillis()));
certGen.setNotAfter(new Date(System.currentTimeMillis()+50000));
certGen.setSubjectDN(request.getCertificationRequestInfo().getSubject());
certGen.setPublicKey(request.getPublicKey("BC"));
certGen.setSignatureAlgorithm("SHA256WithRSAEncryption");
certGen.addExtension(X509Extensions.AuthorityKeyIdentifier, false, new AuthorityKeyIdentifierStructure(rootCert));
certGen.addExtension(X509Extensions.SubjectKeyIdentifier, false, new SubjectKeyIdentifierStructure(request.getPublicKey("BC")));
certGen.addExtension(X509Extensions.BasicConstraints, true, new BasicConstraints(false));
//certGen.addExtension(X509Extensions.KeyUsage, true, new BasicConstraints(false));
certGen.addExtension(X509Extensions.KeyUsage, true, new KeyUsage(KeyUsage.digitalSignature | KeyUsage.keyEncipherment));
certGen.addExtension(X509Extensions.ExtendedKeyUsage, true, new ExtendedKeyUsage(KeyPurposeId.id_kp_serverAuth));
//extract the extension request attribute
ASN1Set attributes = request.getCertificationRequestInfo().getAttributes();
for(int i=0;i!=attributes.size();i++)
{
Attribute attr = Attribute.getInstance(attributes.getObjectAt(i));
//process extension request
if(attr.getAttrType().equals(PKCSObjectIdentifiers.pkcs_9_at_extensionRequest))
{
X509Extensions extensions = X509Extensions.getInstance(attr.getAttrValues().getObjectAt(0));
Enumeration<?> e = extensions.oids();
while(e.hasMoreElements())
{
DERObjectIdentifier oid = (DERObjectIdentifier)e.nextElement();
X509Extension ext = extensions.getExtension(oid);
certGen.addExtension(oid, ext.isCritical(), ext.getValue().getOctets());
}
}
}
X509Certificate issuedCert = certGen.generateX509Certificate(rootPair.getPrivate());
return new X509Certificate[]{issuedCert, rootCert};
}
public static void main(String[] args) throws Exception
{
X509Certificate[] chain = buildChain();
PEMWriter pemWrt = new PEMWriter(new OutputStreamWriter(System.out));
pemWrt.writeObject(chain[0]);
//pemWrt.writeObject(chain[1]);
pemWrt.close();
//write it out
//FileOutputStream fOut = new FileOutputStream("pkcs10req.req");
//fOut.write(chain[0].toString());
//fOut.write()
//System.out.println(chain[0].toString());
//fOut.close();
}
}
