KeystoreException : Cannot overwrite own certificate

Question

Hi,
I am trying to import reply for request certification, but i have the following exception:
"Cannot overwrite own certificate"
The code to create the keystore is as follow :
keyStore = KeyStore.getInstance(keyStoreType, provider);
keyStore.load(null, null);
gen = KeyPairGenerator.getInstance("DSA", provider);
algo = "SHA1withDSA";
gen.initialize(512, new SecureRandom());               
pair = gen.generateKeyPair();
privKey = (PrivateKey)pair.getPrivate();
pubKey = (PublicKey)pair.getPublic();
X509V3CertificateGenerator certGen = new X509V3CertificateGenerator();
certGen.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
certGen.setIssuerDN(new X509Principal(attrs));     
certGen.setNotBefore(new Date(System.currentTimeMillis() - 50000));
certGen.setNotAfter(date);
certGen.setSubjectDN(new X509Principal(attrs));
certGen.setPublicKey(pubKey);
certGen.setSignatureAlgorithm( algo);
Certificate[] chain = new Certificate[1];
try
X509Certificate cert = certGen.generateX509Certificate(privKey);
cert.checkValidity(new Date());
cert.verify(pubKey);
chain[0] = cert;
catch (Exception e)
{return false;
keyStore.setKeyEntry(alias, privKey, passwd.toCharArray(), chain);
FileOutputStream out = new FileOutputStream(keyStorePath);
keyStore.store(out, passwd.toCharArray());
out.close();
The code to import the reply to the certification request is as follow :
InputStream fis = new FileInputStream(keyStorePath);
keyStore.load(fis, passwd.toCharArray());
fis.close();
fisP = new FileInputStream(pathcsr);
CertificateFactory factory = CertificateFactory.getInstance("X.509");
java.security.cert.Certificate cert = factory.generateCertificate(fisP);
this.keyStore.setCertificateEntry(alias, cert);
fisP.close();
//Save the new keystore content
FileOutputStream out = new FileOutputStream(keyStorePath);
keyStore.store(out, passwd.toCharArray());
out.close();
At the flooowing line :
this.keyStore.setCertificateEntry(alias, cert);
I have a KeyStoreException at the line in bold with the message "Cannot overwrite own certificate"
Please, can anyone help me?
Many thanks.

Answer 1

The exception is correct. You can't overwrite a key alias with a certificate alias. What
you need to do is call KeyStore.setKeyEntry again, and overwrite the previous entry.
Use the same key as before, but now specify the new certificate chain received in the certificate reply.