private static void generatePrivateKey()

in modules/jdktools/src/main/java/org/apache/harmony/tools/keytool/KeyCertGenerator.java [99:256]
122 lines of code
23 McCabe index (conditional complexity)

    private static void generatePrivateKey(KeytoolParameters param)
            throws NoSuchAlgorithmException, KeyStoreException,
            NoSuchProviderException, InvalidKeyException, SignatureException,
            IOException, KeytoolException, UnrecoverableKeyException,
            CertificateException {

        KeyStore keyStore = param.getKeyStore();

        PrivateKey issuerPrivateKey = null;
        Certificate[] issuerCertChain = null;
        String issuerDN = null;
        // if the generated certificate shouldn't be self-signed
        // but should be signed with a chain.
        boolean selfSigned = (param.getIssuerAlias() == null);
        if (!selfSigned) {
            String issuerAlias = param.getIssuerAlias();
            if (!keyStore.containsAlias(issuerAlias)) {
                throw new KeytoolException("Certificate issuer alias <"
                        + issuerAlias + "> does not exist.");
            }

            if (!keyStore.entryInstanceOf(issuerAlias,
                    KeyStore.PrivateKeyEntry.class)) {
                throw new KeytoolException("Issuer alias <" + issuerAlias
                        + "> is not a private key entry. ");
            }
            issuerCertChain = keyStore.getCertificateChain(issuerAlias);
            issuerPrivateKey = (PrivateKey) keyStore.getKey(issuerAlias, param
                    .getIssuerPass());
            issuerDN = ((X509Certificate) issuerCertChain[0])
                    .getSubjectX500Principal().getName();
        }

        KeyPairGenerator kpg = null;
        String keyAlg = param.getKeyAlg();
        // key algorithm is DSA by default
        if (keyAlg == null) {
            keyAlg = "DSA";
        }

        String sigAlgName = null;

        // if signature algorithm is not set, use a default
        if (param.getSigAlg() != null) {
            sigAlgName = param.getSigAlg();
        } else if (selfSigned) {
            if (keyAlg.equalsIgnoreCase("DSA")) {
                sigAlgName = "SHA1withDSA";
            } else if (keyAlg.equalsIgnoreCase("RSA")) {
                sigAlgName = "MD5withRSA";
            }else {
                sigAlgName = keyAlg;
            }
        } else {
            String issuerKeyAlg = issuerPrivateKey.getAlgorithm();
            if (issuerKeyAlg.equalsIgnoreCase("DSA")) {
                sigAlgName = "SHA1withDSA";
            } else if (issuerKeyAlg.equalsIgnoreCase("RSA")) {
                sigAlgName = "MD5withRSA";
            } else {
                sigAlgName = issuerKeyAlg;
            }
        }
        // set the certificate validity period
        // 90 days by default
        long validity = (param.getValidity() != 0) ? param.getValidity() : 90;

        // set the X.509 version to use with the certificate
        int version = (param.getX509version() != 0) ?
        // TBSCertificate needs 0, 1 or 2 as version in constructor (not 1,2,3);
                // X.509 v.3 certificates by default
                param.getX509version() - 1 : 2;

        // set certificate serial number
        BigInteger serialNr;
        if (param.getCertSerialNr() != 0) {
            serialNr = BigInteger.valueOf(param.getCertSerialNr());
        } else {
            int randomInt = new Random().nextInt();
            if (randomInt < 0) {
                randomInt = -randomInt;
            }
            serialNr = BigInteger.valueOf(randomInt);
        }

        int keySize = param.getKeySize();
        if (param.isVerbose()) {
            StringBuffer strBuf = new StringBuffer("Generating a " + keyAlg
                    + " key pair, key length " + keySize + " bit \nand a ");
            if (selfSigned) {
                strBuf.append("self-signed ");
            }
            strBuf.append("certificate (signature algorithm is " + sigAlgName
                    + ")\n for " + param.getDName());
            System.out.println(strBuf);
        }

        // generate a pair of keys
        String provider = param.getProvider();
        String keyProvider = (param.getKeyProvider() != null) ? param
                .getKeyProvider() : provider;
        try {
            if (keyProvider == null) {
                kpg = KeyPairGenerator.getInstance(keyAlg);
            } else {
                kpg = KeyPairGenerator.getInstance(keyAlg, keyProvider);
            }
        } catch (NoSuchAlgorithmException e) {
            throw new NoSuchAlgorithmException("The algorithm " + keyAlg
                    + " is not available in current environment.");
        } catch (NoSuchProviderException e) {
            throw (NoSuchProviderException) new NoSuchProviderException(
                    "The provider " + keyProvider
                            + " is not found in the environment.").initCause(e);
        }
        // initialize the KeyPairGenerator with the key size
        kpg.initialize(keySize);

        KeyPair keyPair = kpg.genKeyPair();
        PrivateKey privateKey = keyPair.getPrivate();

        String subjectDN = param.getDName();
        String sigProvider = (param.getSigProvider() != null) ? param
                .getSigProvider() : provider;

        if (selfSigned) {
            // generate the certificate
            X509CertImpl x509cert = genX509CertImpl(sigAlgName, version,
                    serialNr, subjectDN, subjectDN, validity, keyPair
                            .getPublic(), privateKey, sigProvider,
                    param.isCA());

            // put the key pair with the newly created cert into the keystore
            keyStore.setKeyEntry(param.getAlias(), privateKey, param
                    .getKeyPass(), new X509Certificate[] { x509cert });

        } else {
            // generate the certificate
            X509CertImpl x509cert = genX509CertImpl(sigAlgName, version,
                    serialNr, subjectDN, issuerDN, validity, keyPair
                            .getPublic(), issuerPrivateKey,
                    sigProvider, param.isCA());

            // construct the certificate chain
            int issuerChainLength = issuerCertChain.length;
            X509Certificate[] certChain = new X509Certificate[issuerChainLength + 1];
            certChain[0] = x509cert;
            System.arraycopy(issuerCertChain, 0, certChain, 1,
                    issuerChainLength);

            // put the key pair with the newly created cert into the keystore
            keyStore.setKeyEntry(param.getAlias(), privateKey, param
                    .getKeyPass(), certChain);

        }

        param.setNeedSaveKS(true);
    }