JAVA对于数字证书的常用操作方法

System.out.println("签发者:"+t.getIssuerDN());
System.out.println("有效期:"+t.getNotBefore());
System.out.println("签名算法:"+t.getSigAlgName());
byt/签名值
cinfo2.set(X509CertInfo.SERIAL_NUMBER,csn);
(8)设置新证书签发者
cinfo2.set(X509CertInfo.ISSUER+"."+CertificateIssuerName.DN_NAME,issuer);应用第三步的结果
(9)设置新证书签名算法信息
ks.store(output,storepass.toCharArray())将keystore对象内容写入新文件
八:JAVA程序检验别名和删除条目
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
PublicKey pk=t.getPublicKey();
byte [] pkenc=pk.getEncoded();
System.out.println("公钥");
for(int i=0;i
五:JAVA程序列出密钥库所有条目
String pass="123456";
CertificateFactory cf=CertificateFactory.getInstance("X.509");
FileInputStream in=new FileInputStream("out.csr");
Certificate c=cf.generateCertificate(in);
import java.security.*;
import java.io.*;
import java.util.*;
import java.security.*;
import java.security.cert.*;
import sun.security.x509.*
PrivateKey pk=(PrivateKey)ks.getKey(alias,oldkeypass.toCharArray());获取别名对应条目的私钥
ks.setKeyEntry(alias,pk,newkeypass.toCharArray(),cchain);向密钥库中添加条目
(6)设置新证书有效期
Date begindate=new Date(); 获取当前时间
Date enddate=new Date(begindate.getTime()+3000*24*60*60*1000L); 有效期为3000天
CertificateValidity cv=new CertificateValidity(begindate,enddate); 创建对象
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
二:从文件中读取证书
用keytool将.keystore中的证书写入文件中，然后从该文件中读取证书信息
AlgorithmId algorithm=new AlgorithmId(AlgorithmId.md5WithRSAEncryption_oid);
cinfo2.set(+"."+CertificateAlgorithmId.ALGORITHM,algorithm);
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,storepass.toCharArray());
java.security.cert.Certificate c1=ks.getCertificate("caroot");
ks.store(output,storepass.toCharArray())将keystore对象内容写入文件,条目删除成功
九:JAVA程序签发数字证书
(1)从密钥库中读取CA的证书
FileInputStream in=new FileInputStream(".keystore");
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,storepass.toCharArray());
Certificate [] cchain=ks.getCertificate(alias);获取别名对应条目的证书链
X509CertImpl cimp1=new X509CertImpl(encod1); 用该编码创建X509CertImpl类型对象
X509CertInfo cinfo1=(X509CertInfo)cimp1.get(+"."+); 获取X509CertInfo对象
FileInputStream in2=new FileInputStream("user.csr");
java.security.cert.Certificate c2=cf.generateCertificate(in);
(5)从待签发的证书中提取证书信息
byte [] encod2=c2.getEncoded();
X500Name issuer=(X500Name)cinfo1.get(X509CertInfo.SUBJECT+"."+CertificateIssuerName.DN_NAME); 获取X509Name类型的签发者信息
(4)获取待签发的证书
CertificateFactory cf=CertificateFactory.getInstance("X.509");
ks.load(in,pass.toCharArray());
java.security.cert.Certificate c=ks.getCertificate(alias);//alias为条目的别名
四:JAVA程序中显示证书指定信息
System.out.println("输出证书信息:\n"+c.toString());
(2)从密钥库中读取CA的私钥
PrivateKey caprk=(PrivateKey)ks.getKey(alias,cakeypass.toCharArray());
(3)从CA的证书中提取签发者的信息
byte[] encod1=c1.getEncoded(); 提取CA证书的编码
String newpass="654321";
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,oldpass.toCharArray());
String s=c.toString();
三:从密钥库中直接读取证书
String pass="123456";
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
System.out.println("版本号:"+t.getVersion());
System.out.println("序列号:"+t.getSerialNumber().toString(16));
System.out.println("主体名:"+t.getSubjectDN());
while(e.hasMoreElements())
java.security.cert.Certificate c=ks.getCertificate((String)e.nextElement());
六:JAVA程序修改密钥库口令
String oldpass="123456";
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,pass.toCharArray());
Enumeration e=ks.aliases();
in.close();
FileOutputStream output=new FileOutputStream(".keystore");
ks.store(output,newpass.toCharArray());