java上环签名的代码 java签名实现方式

阿里云OSS的java实现生成url签名的代码示例吗

生成签名以后的URL的示例代码如下：

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// Generate a presigned URL

Date expires = new Date (new Date().getTime() 1000 * 60); // 1 minute to expire

GeneratePresignedUrlRequest generatePresignedUrlRequest =

new GeneratePresignedUrlRequest(bucketName, key);

generatePresignedUrlRequest.setExpiration(expires);

URL url = client.generatePresignedUrl(generatePresignedUrlRequest);

System.out.println(url.toString());

这段代码假定指定bucketName和key的Object已经上传到OSS，用户可以根据修改设定expires，即过期时间。更详细的操作可以参考OSSClient#generatePresignedUrl方法和GeneratePresignedUrlRequest类的帮助。

求ECDSA的Java代码

【方案1】

package ECDSA;

import com.sun.org.apache.xerces.internal.impl.dv.util.HexBin;

import java.security.*;

import java.security.interfaces.ECPrivateKey;

import java.security.interfaces.ECPublicKey;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.spec.X509EncodedKeySpec;

public class Ecdsa {

private static String src = "hello berber" ;

public static void main(String []args){

  jdkECDSA();

}

public static void jdkECDSA(){

  // 1.初始化密钥

  try{

      KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");

      keyPairGenerator.initialize(256);

      KeyPair keyPair = keyPairGenerator.generateKeyPair() ;

      ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic() ;

      ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate() ;

      // 执行签名

      PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded());

      KeyFactory keyFactory = KeyFactory.getInstance("EC") ;

      PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec) ;

      Signature signature = Signature.getInstance("SHA1withECDSA");

      signature.initSign(privateKey);

      signature.update(src.getBytes());

      byte []arr = signature.sign();

      System.out.println("jdk ecdsa sign :"+ HexBin.encode(arr));

      // 验证签名

      X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ecPublicKey.getEncoded());

      keyFactory = KeyFactory.getInstance("EC");

      PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);

      signature = Signature.getInstance("SHA1withECDSA");

      signature.initVerify(publicKey);

      signature.update(src.getBytes());

      boolean bool = signature.verify(arr);

      System.out.println("jdk ecdsa verify:"+bool);

  }catch(Exception e){

  }

}

}

Java数字签名——ECDSA算法

【方案2】

public class MyTest {

/**

* @param args

*/

public static void main(String[] args) {

new MyTest().getSign();

}

void getSign() {

// Get the instance of the Key Generator with "EC" algorithm

try {

KeyPairGenerator g = KeyPairGenerator.getInstance("EC");

ECGenParameterSpec kpgparams = new ECGenParameterSpec("secp256r1");

g.initialize(kpgparams);

KeyPair pair = g.generateKeyPair();

// Instance of signature class with SHA256withECDSA algorithm

Signature ecdsaSign = Signature.getInstance("SHA256withECDSA");

ecdsaSign.initSign(pair.getPrivate());

System.out.println("Private Keys is::" + pair.getPrivate());

System.out.println("Public Keys is::" + pair.getPublic());

String msg = "text ecdsa with sha256";//getSHA256(msg)

ecdsaSign.update((msg + pair.getPrivate().toString())

.getBytes("UTF-8"));

byte[] signature = ecdsaSign.sign();

System.out.println("Signature is::"

+ new BigInteger(1, signature).toString(16));

// Validation

ecdsaSign.initVerify(pair.getPublic());

ecdsaSign.update(signature);

if (ecdsaSign.verify(signature))

System.out.println("valid");

else

System.out.println("invalid!!!!");

} catch (Exception e) {

// TODO: handle exception

e.printStackTrace();

}

}}

java – 使用secp256r1曲线和SHA256算法生

怎么验证生成的Ecdsa签名是正确的呢，可以看下这篇文章:RSA,ECC,Ecdsa,国密SM2的签名，验签，加密

java如何对pdf文件实现数字签名

用Spire.Doc  for Java 可以添加及验证数字签名，参考代码：

import com.spire.pdf.*;

import com.spire.pdf.graphics.PdfImage;

import com.spire.pdf.graphics.PdfTrueTypeFont;

import com.spire.pdf.security.GraphicMode;

import com.spire.pdf.security.PdfCertificate;

import com.spire.pdf.security.PdfCertificationFlags;

import com.spire.pdf.security.PdfSignature;

import java.awt.*;

import java.awt.geom.Point2D;

import java.awt.geom.Rectangle2D;

public class AddCertificate {

public static void main(String[]args){

//加载PDF文档

PdfDocument doc = new PdfDocument();

doc.loadFromFile("test.pdf");

//加载pfx证书，及证书秘钥

PdfCertificate cert = new PdfCertificate("Cermia.pfx","123654yes!");

//添加数字签名到指定页面，并设置其位置和大小

PdfSignature signature = new PdfSignature(doc, doc.getPages().get(2), cert, "MySignature");

Rectangle2D rect = new Rectangle2D.Float();

rect.setFrame(new Point2D.Float((float) doc.getPages().get(0).getActualSize().getWidth() - 340, (float) doc.getPages().get(0).getActualSize().getHeight() - 230), new Dimension(280, 150));

signature.setBounds(rect);

//设置签名为图片加文本模式

signature.setGraphicMode(GraphicMode.Sign_Image_And_Sign_Detail);

//设置签名的内容

signature.setNameLabel("签字者：");

signature.setName("Mia");

signature.setContactInfoLabel("联系电话：");

signature.setContactInfo("02881705109");

signature.setDateLabel("日期：");

signature.setDate(new java.util.Date());

signature.setLocationInfoLabel("地点：");

signature.setLocationInfo("成都");

signature.setReasonLabel("原因：");

signature.setReason("文档所有者");

signature.setDistinguishedNameLabel("DN: ");

signature.setDistinguishedName(signature.getCertificate().get_IssuerName().getName());

signature.setSignImageSource(PdfImage.fromFile("sign.png"));

//设置签名的字体

signature.setSignDetailsFont(new PdfTrueTypeFont(new Font("Arial Unicode MS", Font.PLAIN, 9)));

//设置文档权限为禁止更改

signature.setDocumentPermissions(PdfCertificationFlags.Forbid_Changes);

signature.setCertificated(true);

//保存文档

doc.saveToFile("AddSignature.pdf");

doc.close();

}

}

数字签名添加效果：

数字签名效果

参考原文