keystool export private key

keystore to openssl .

java -jar ExportPrivateKey.zip {keystore_path} JKS {keystore_password} {alias} {target_file}

This would export the key to PKCS #8 PEM format. Now run openssl to convert it to the format apache modssl expects the file in
openssl pkcs8 -inform PEM -nocrypt -in exported-pkcs8.key -out exported.key

The java code for exporting the private key in PKCS #8 format

   1.
      import java.io.File;
   2.
      import java.io.FileInputStream;
   3.
      import java.io.FileWriter;
   4.
      import java.security.Key;
   5.
      import java.security.KeyPair;
   6.
      import java.security.KeyStore;
   7.
      import java.security.KeyStoreException;
   8.
      import java.security.NoSuchAlgorithmException;
   9.
      import java.security.PrivateKey;
  10.
      import java.security.PublicKey;
  11.
      import java.security.UnrecoverableKeyException;
  12.
      import java.security.cert.Certificate;
  13.
      
  14.
      import sun.misc.BASE64Encoder;
  15.
      
  16.
      public class ExportPrivateKey {
  17.
              private File keystoreFile;
  18.
              private String keyStoreType;
  19.
              private char[] password;
  20.
              private String alias;
  21.
              private File exportedFile;
  22.
      
  23.
              public static KeyPair getPrivateKey(KeyStore keystore, String alias, char[] password) {
  24.
                      try {
  25.
                              Key key=keystore.getKey(alias,password);
  26.
                              if(key instanceof PrivateKey) {
  27.
                                      Certificate cert=keystore.getCertificate(alias);
  28.
                                      PublicKey publicKey=cert.getPublicKey();
  29.
                                      return new KeyPair(publicKey,(PrivateKey)key);
  30.
                              }
  31.
                      } catch (UnrecoverableKeyException e) {
  32.
              } catch (NoSuchAlgorithmException e) {
  33.
              } catch (KeyStoreException e) {
  34.
              }
  35.
              return null;
  36.
              }
  37.
      
  38.
              public void export() throws Exception{
  39.
                      KeyStore keystore=KeyStore.getInstance(keyStoreType);
  40.
                      BASE64Encoder encoder=new BASE64Encoder();
  41.
                      keystore.load(new FileInputStream(keystoreFile),password);
  42.
                      KeyPair keyPair=getPrivateKey(keystore,alias,password);
  43.
                      PrivateKey privateKey=keyPair.getPrivate();
  44.
                      String encoded=encoder.encode(privateKey.getEncoded());
  45.
                      FileWriter fw=new FileWriter(exportedFile);
  46.
                      fw.write(“—–BEGIN PRIVATE KEY—–\n“);
  47.
                      fw.write(encoded);
  48.
                      fw.write(“\n“);
  49.
                      fw.write(“—–END PRIVATE KEY—–”);
  50.
                      fw.close();
  51.
              }
  52.
      
  53.
      
  54.
              public static void main(String args[]) throws Exception{
  55.
                      ExportPrivateKey export=new ExportPrivateKey();
  56.
                      export.keystoreFile=new File(args[0]);
  57.
                      export.keyStoreType=args[1];
  58.
                      export.password=args[2].toCharArray();
  59.
                      export.alias=args[3];
  60.
                      export.exportedFile=new File(args[4]);
  61.
                      export.export();
  62.
              }
  63.
      }

虽然有错 ，， 还是记录下~！
，，  居然 搞出来是 空指针错误，，

                      KeyPair keyPair=getPrivateKey(keystore,alias,password);
                      PrivateKey privateKey=keyPair.getPrivate();
             
这里读取不到，，   

还有Keystore Explorer 这个工具 是可以出私钥的。

大家可以试试。  找到你的 keystore 文件就可以了。