Java数字签名——RSA算法

 1 package RSA;
 2 
 3 import com.sun.org.apache.xerces.internal.impl.dv.util.HexBin;
 4 
 5 import java.security.*;
 6 import java.security.interfaces.RSAPrivateKey;
 7 import java.security.interfaces.RSAPublicKey;
 8 import java.security.spec.PKCS8EncodedKeySpec;
 9 import java.security.spec.X509EncodedKeySpec;
10 
11 public class Rsa {
12     public static String src = "hello human";
13     public static void main(String[] args) {
14         jdkRSA();
15     }
16     public static void jdkRSA(){
17         try{
18             // 密钥初始化
19             KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
20             keyPairGenerator.initialize(512);
21             KeyPair keyPair = keyPairGenerator.generateKeyPair();
22             RSAPublicKey rsaPublicKey = (RSAPublicKey)keyPair.getPublic() ;
23             RSAPrivateKey rsaPrivateKey = (RSAPrivateKey)keyPair.getPrivate() ;
24             // 签名
25             PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
26             KeyFactory keyFactory = KeyFactory.getInstance("RSA");
27             PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
28             Signature signature = Signature.getInstance("MD5withRSA");
29             signature.initSign(privateKey);
30             signature.update(src.getBytes());
31             byte []arr = signature.sign();
32             System.out.println("jdk rsa sign:"+ HexBin.encode(arr));
33             // 验证签名
34             X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded()) ;
35             keyFactory = KeyFactory.getInstance("RSA");
36             PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
37             signature = Signature.getInstance("MD5withRSA");
38             signature.initVerify(publicKey);
39             signature.update(src.getBytes());
40             boolean bool = signature.verify(arr);
41             System.out.println("jdk rsa verify:"+bool);
42         }catch (Exception e){
43 
44         }
45     }
46 }