java数字签名（签名生成，用证书验证签名）

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();
}
}