输入keystore密码：  abc123
您的名字与姓氏是什么？[Unknown]：  Li
您的组织单位名称是什么？[Unknown]：  InfosecLab
您的组织名称是什么？[Unknown]：  InfosecLab Group
您所在的城市或区域名称是什么？[Unknown]：  Beijing
您所在的州或省份名称是什么？[Unknown]：  Beijing
该单位的两字母国家代码是什么[Unknown]：  CN
CN=Li, OU=InfosecLab, O=InfosecLab Group, L=Beijing, ST=Beijing, C=CN 正确吗？
[否]：  y
输入<testkeypair>的主密码 (如果和 keystore 密码相同，按回车）：

keytool -selfcert -alias testkeypair -dname "CN=Li, OU=InfosecLab, O=InfosecLab
Group, L=Beijing, ST=Beijing, C=CN"
输入keystore密码：  abc123

keytool -export -rfc -alias testkeypair -file mycert.crt
输入keystore密码：  abc123
保存在文件中的认证 <mycert.crt>

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.table.*;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.io.*;
public class CARead extends JPanel {private String CA_Name; private String CA_ItemData[][] = new String[9][2];private String[] columnNames = {"证书字段标记","内容" };public CARead(String CertName) {CA_Name=CertName;/* 三个Panel用来显示证书内容*/JTabbedPane tabbedPane = new JTabbedPane();JPanel panelNormal = new JPanel();tabbedPane.addTab("普通信息", panelNormal);   JPanel panelAll=new JPanel();panelAll.setLayout(new BorderLayout());tabbedPane.addTab("所有信息",panelAll);JPanel panelBase64=new JPanel();panelBase64.setLayout(new BorderLayout());tabbedPane.addTab("Base64编码信息",panelBase64);/* 读取证书常规信息 */Read_Normal(panelNormal);/* 读取证书文件字符串表示内容 */Read_Bin(panelAll);/* 读取证原始Base64编码形式的证书文件 */Read_Raw(panelBase64);tabbedPane.setSelectedIndex(0);setLayout(new GridLayout(1, 1)); add(tabbedPane);}/*以下是定义的Read_Normal()，Read_Bin(),Read_Raw()以及main() 这里省略...   */
}

private int Read_Normal(JPanel panel){String Field;try{CertificateFactory certificate_factory=CertificateFactory.getInstance("X.509");FileInputStream file_inputstream=new FileInputStream(CA_Name);X509Certificate
x509certificate=(X509Certificate)certificate_factory.generateCertificate
(file_inputstream);Field=x509certificate.getType();CA_ItemData[0][0]="类型";CA_ItemData[0][1]=Field;Field=Integer.toString(x509certificate.getVersion());CA_ItemData[1][0]="版本";CA_ItemData[1][1]=Field;    Field=x509certificate.getSubjectDN().getName();CA_ItemData[2][0]="标题";CA_ItemData[2][1]=Field;/* 以下类似，这里省略 Field=x509certificate.getNotBefore().toString();得到开始有效日期Field=x509certificate. getNotAfter().toString();得到截止日期Field=x509certificate.getSerialNumber().toString(16);得到序列号Field=x509certificate.getIssuerDN().getName();得到发行者名Field=x509certificate.getSigAlgName();得到签名算法Field=x509certificate.getPublicKey().getAlgorithm();得到公钥算法 */file_inputstream.close();final JTable table = new JTable(CA_ItemData, columnNames);TableColumn tc=null;tc = table.getColumnModel().getColumn(1);tc.setPreferredWidth(600); panel.add(table);}catch(Exception exception){exception.printStackTrace();return -1;}return 0;
}

private int Read_Bin(JPanel panel){try{FileInputStream file_inputstream=new FileInputStream(CA_Name);DataInputStream data_inputstream=new DataInputStream(file_inputstream);CertificateFactory certificatefactory=CertificateFactory.getInstance("X.509");byte[] bytes=new byte[data_inputstream.available()];data_inputstream.readFully(bytes);ByteArrayInputStream bais=new ByteArrayInputStream(bytes);JEditorPane Cert_EditorPane;Cert_EditorPane=new JEditorPane();while(bais.available()>0){X509Certificate
Cert=(X509Certificate)certificatefactory.generateCertificate(bais);Cert_EditorPane.setText(Cert_EditorPane.getText()+Cert.toString());}Cert_EditorPane.disable();JScrollPane edit_scroll=new JScrollPane(Cert_EditorPane);panel.add(edit_scroll);file_inputstream.close();data_inputstream.close();}catch( Exception exception){exception.printStackTrace();return -1;}return 0;
}

private int Read_Raw(JPanel panel){try{     JEditorPane Cert_EditorPane=new JEditorPane();String CertText=null;File inputFile = new File(CA_Name);FileReader in = new FileReader(inputFile);char[] buf=new char[2000];int len=in.read(buf,0,2000);for(int i=1;i<len;i++) {   CertText=CertText+buf[i];}in.close();Cert_EditorPane.setText(CertText);Cert_EditorPane.disable();JScrollPane edit_scroll=new JScrollPane(Cert_EditorPane);panel.add(edit_scroll);}catch( Exception exception){exception.printStackTrace();return -1;}return 0;
}

public static void main(String[] args) {JFrame frame = new JFrame("证书阅读器");frame.addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {System.exit(0);}});frame.getContentPane().add(new CARead("mycert.crt"),BorderLayout.CENTER);frame.setSize(700, 425);frame.setVisible(true);
}

static byte[] desKeyData = { (byte)0x01, (byte)0x02, (byte)0x03, (byte)0x04,
(byte)0x05, (byte)0x06, (byte)0x07, (byte)0x08 };

public static void crypt(byte[] cipherText,String outFileName){     try{DESKeySpec desKeySpec = new DESKeySpec(desKeyData);SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");SecretKey secretKey = keyFactory.generateSecret(desKeySpec);Cipher cdes = Cipher.getInstance("DES");cdes.init(Cipher.ENCRYPT_MODE, secretKey);byte[] ct = cdes.doFinal(cipherText);try{FileOutputStream out=new FileOutputStream(outFileName);out.write(ct);out.close();}catch(IOException e){e.printStackTrace();}}catch (Exception e){e.printStackTrace();}
}

public static void sig(byte[] sigText, String outFileName,String
KeyPassword,String KeyStorePath){char[] kpass;int i;try{KeyStore ks = KeyStore.getInstance("JKS");FileInputStream ksfis = new FileInputStream(KeyStorePath); BufferedInputStream ksbufin = new BufferedInputStream(ksfis);  kpass=new char[KeyPassword.length()];for(i=0;i<KeyPassword.length();i++)kpass[i]=KeyPassword.charAt(i);ks.load(ksbufin, kpass);PrivateKey priv = (PrivateKey) ks.getKey(KeystoreAlias,kpass );Signature rsa=Signature.getInstance("MD5withRSA");  rsa.initSign(priv);rsa.update(sigText);byte[] sig=rsa.sign();System.out.println("sig is done");try{FileOutputStream out=new FileOutputStream(outFileName);out.write(sig);out.close();}catch(IOException e){e.printStackTrace();}    }catch(Exception e){e.printStackTrace();}
}

public static void veriSig(byte[] updateData, byte[] sigedText){try{  CertificateFactory
certificatefactory=CertificateFactory.getInstance("X.509");FileInputStream fin=new FileInputStream(CertName);X509Certificate
certificate=(X509Certificate)certificatefactory.generateCertificate(fin);PublicKey pub = certificate.getPublicKey();Signature rsa=Signature.getInstance("MD5withRSA");rsa.initVerify(pub);rsa.update(updateData);boolean verifies=rsa.verify(sigedText);System.out.println("verified "+verifies);if(verifies){System.out.println("Verify is done!");}else{System.out.println("verify is not successful");}     }catch(Exception e){    e.printStackTrace();                }
}