java代码获取私钥 java私钥签名

java des 加密 解密 密钥随机取得方法java DES 加密 解密 生成随机密钥
举例说明:
//保存生成的key
public static void saveDesKey() {
try {
SecureRandom sr = new SecureRandom();
// 选择的DES算法生成一个KeyGenerator对象
KeyGenerator kg = KeyGenerator.getInstance("DES");
kg.init(sr);
// 相对路径 需要新建 conf 文件夹
// String fileName = "conf/DesKey.xml";
// 绝对路径
String fileName = "d:/DesKey.xml";
FileOutputStream fos = new FileOutputStream(fileName);
ObjectOutputStream oos = new ObjectOutputStream(fos);
// 生成密钥
Key key = kg.generateKey();
oos.writeObject(key);
oos.close();
} catch (Exception e) {
e.printStackTrace();
}
}
//获取生成的key
public static Key getKey() {
Key kp = null;
try {
// 相对路径 需要新建 conf 文件夹
// String fileName = "conf/DesKey.xml";
// InputStream is = Encrypt.class.getClassLoader().getResourceAsStream(fileName);
// 绝对路径
String fileName = "d:/DesKey.xml";
FileInputStream is = new FileInputStream(fileName);
ObjectInputStream oos = new ObjectInputStream(is);
kp = (Key) oos.readObject();
oos.close();
} catch (Exception e) {
e.printStackTrace();
}
return kp;
}
//加密开始
public static void encrypt(String file, String dest) throws Exception {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, getKey());
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(dest);
CipherInputStream cis = new CipherInputStream(is, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = cis.read(buffer))0) {
out.write(buffer, 0, r);
}
cis.close();
is.close();
out.close();
}
//解密开始
public static void decrypt(String file, String dest) throws Exception {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, getKey());
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(dest);
CipherOutputStream cos = new CipherOutputStream(out, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = is.read(buffer)) = 0) {
cos.write(buffer, 0, r);
}
cos.close();
out.close();
is.close();
}
}
//des加密主方法
public class DES {
public static void main(String[] args) throws Exception {
Encrypt.saveDesKey();
System.out.println("生成key");
Encrypt.getKey();
System.out.println("获取key");
Encrypt.encrypt("d:\\hello.txt", "d:\\encrypt.txt");
System.out.println("加密");
Encrypt.decrypt("d:\\encrypt.txt", "d:\\decrypt.txt");
System.out.println("解密");
}
以上方法亲测可用 。
用Java编写一个程序,生成公钥和私钥对一:需要包含的包
import java.security.*;
import java.io.*;
import java.util.*;
import java.security.*;
import java.security.cert.*;
import sun.security.x509.*
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
CertificateFactory cf=CertificateFactory.getInstance("X.509");
FileInputStream in=new FileInputStream("out.csr");
Certificate c=cf.generateCertificate(in);
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");
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());
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());
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());
byte [] sig=t.getSignature();//签名值
PublicKey pk=t.getPublicKey();
byte [] pkenc=pk.getEncoded();
System.out.println("公钥");
for(int i=0;ipkenc.length;i)System.out.print(pkenc[i] ",");
五:JAVA程序列出密钥库所有条目
String pass="123456";
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,pass.toCharArray());
Enumeration e=ks.aliases();
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";
String newpass="654321";
FileInputStream in=new FileInputStream(".keystore");
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,oldpass.toCharArray());
in.close();
FileOutputStream output=new FileOutputStream(".keystore");
ks.store(output,newpass.toCharArray());
output.close();
七:JAVA程序修改密钥库条目的口令及添加条目
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
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
第一个参数指定所添加条目的别名,假如使用已存在别名将覆盖已存在条目,使用新别名将增加一个新条目,第二个参数为条目的私钥,第三个为设置的新口令,第四个为该私钥的公钥的证书链
FileOutputStream output=new FileOutputStream("another");
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");
ks.load(in,storepass.toCharArray());
ks.containsAlias("sage");检验条目是否在密钥库中,存在返回true
ks.deleteEntry("sage");删除别名对应的条目
FileOutputStream output=new FileOutputStream(".keystore");
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");
KeyStore ks=KeyStore.getInstance("JKS");
ks.load(in,storepass.toCharArray());
java.security.cert.Certificate c1=ks.getCertificate("caroot");
(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
X509CertImpl cimp1=new X509CertImpl(encod1);用该编码创建X509CertImpl类型对象
X509CertInfo cinfo1=(X509CertInfo)cimp1.get(X509CertImpl.NAME "." X509CertImpl.INFO);获取X509CertInfo对象
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");
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();
X509CertImpl cimp2=new X509CertImpl(encod2);用该编码创建X509CertImpl类型对象
X509CertInfo cinfo2=(X509CertInfo)cimp2.get(X509CertImpl.NAME "." X509CertImpl.INFO);获取X509CertInfo对象
(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
cinfo2.set(X509CertInfo.VALIDITY,cv);设置有效期
(7)设置新证书序列号
int sn=(int)(begindate.getTime()/1000);以当前时间为序列号
CertificateSerialNumber csn=new CertificateSerialNumber(sn);
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
AlgorithmId algorithm=new AlgorithmId(AlgorithmId.md5WithRSAEncryption_oid);
cinfo2.set(CertificateAlgorithmId.NAME "." CertificateAlgorithmId.ALGORITHM,algorithm);
(10)创建证书并使用CA的私钥对其签名
X509CertImpl newcert=new X509CertImpl(cinfo2);
newcert.sign(caprk,"MD5WithRSA"); 使用CA私钥对其签名
(11)将新证书写入密钥库
ks.setCertificateEntry("lf_signed",newcert);
FileOutputStream out=new FileOutputStream("newstore");
ks.store(out,"newpass".toCharArray());这里是写入了新的密钥库 , 也可以使用第七条来增加条目
十:数字证书的检验
(1)验证证书的有效期
(a)获取X509Certificate类型对象
CertificateFactory cf=CertificateFactory.getInstance("X.509");
FileInputStream in1=new FileInputStream("aa.crt");
java.security.cert.Certificatec1=cf.generateCertificate(in1);
X509Certificate t=(X509Certificate)c1;
in2.close();
(b)获取日期
Date TimeNow=new Date();
(c)检验有效性
try{
t.checkValidity(TimeNow);
System.out.println("OK");
}catch(CertificateExpiredException e){//过期
System.out.println("Expired");
System.out.println(e.getMessage());
}catch((CertificateNotYetValidException e){ //尚未生效
System.out.println("Too early");
System.out.println(e.getMessage());}
(2)验证证书签名的有效性
(a)获取CA证书
CertificateFactory cf=CertificateFactory.getInstance("X.509");
FileInputStream in2=new FileInputStream("caroot.crt");
java.security.cert.Certificatecac=cf.generateCertificate(in2);
in2.close();
(c)获取CA的公钥
PublicKey pbk=cac.getPublicKey();
(b)获取待检验的证书(上步已经获取了,就是C1)
(c)检验证书
boolean pass=false;
try{
c1.verify(pbk);
pass=true;
}catch(Exception e){
pass=false;
System.out.println(e);
}
openssl 生成的.pem文件 java怎么从这个文件中得到私钥信息您好java代码获取私钥,这样的java代码获取私钥:
java.security.cert.CertificateFactory;
java.security.cert.X509Certificate;
下载API文档java代码获取私钥,好好看看这两个类的说明 。
如果PEM是BASE64格式的文件,则先转换成二进制 。
可以尝试调用openssl的api函数PEM_read_bio_PrivateKey()来读取密钥 。
Java通过RSA算法获取公私钥对 将公钥提供出去 如何获取字符串的公钥直接将公匙BYTE数组转换为16进制java代码获取私钥的串啊
private static char hexTable[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
public static String toHexString(byte bytes[])
{
StringBuilder sb = new StringBuilder();
for (int i = 0; ibytes.length; i)
{
char chars[] = new char[2];
int d = (bytes[i]240)4;
int m = bytes[i]15;
chars[0] = hexTable[d];
chars[1] = hexTable[m];
sb.append(chars);
}
return sb.toString();
}
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