我正在成为中级java程序员。我一直在努力寻找如何在java中为我正在研究的网络程序签名和读取数字签名。我已经能够使用http://docs.oracle.com/javase/tutorial/security/apisign/index.html上的教程生成私钥和公钥，但无法对它们执行任何操作。虽然我知道如何生成密钥但我没有把它放进去，因为我不确定我是否已经正确地完成了它们。 这是我的代码的简化版本： 主要课程：
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Scanner;
public class Main {
public static void main(String[] args) throws IOException {
Main main = new Main();
Scanner s = new Scanner(System.in);
while (true) {
//This is where i added a command detector so that the program can be in one class
System.out.println("Choose a command from the following:\nGenerate keys\nSign message\nRead message");
String command = s.nextLine();
if (command.equalsIgnoreCase("Generate key")
|| command.equalsIgnoreCase("Generate")) {
/* The code for generating the keys is here */
File f = new File("C:\\Users\\spencer\\Documents\\Stack ex\\src\\app","public.key");
File fi = new File("C:\\Users\\spencer\\Documents\\Stack ex\\src\\app","private.key");
if(!f.isFile()||!fi.isFile()) {
Make make =new Make();
Make.main(args);
}
else{
try {
String path = "C:\\Users\\spencer\\Documents\\ds test 3\\src\\app";
KeyPair loadedKeyPair = main.LoadKeyPair(path, "DSA");
System.out.println("Key pair already exists!");
System.out.println("Loaded Key Pair:");
main.dumpKeyPair(loadedKeyPair);
} catch (Exception e) {
e.printStackTrace();
return;
}
}
}
if (command.equalsIgnoreCase("Sign message")
|| command.equalsIgnoreCase("Sign")) {
long signature = 0;
System.out.println("What is your private key");
String pkey = s.nextLine();
long prkey = Long.parseLong(pkey);
System.out.println("What is you message");
String message = s.nextLine();
/* The code for signing the message goes here */
System.out.println("Signature:"+signature);
} else if (command.equalsIgnoreCase("Read message")
|| command.equalsIgnoreCase("Read")) {
String message = null;
System.out.println("What is the signature");
String sign = s.nextLine();
long signature = Long.parseLong(sign);
/* The code for reading the message goes here */
System.out.println(message);
}
}
}
private void dumpKeyPair(KeyPair keyPair) {
PublicKey pub = keyPair.getPublic();
System.out.println("Public Key: " + getHexString(pub.getEncoded()));
PrivateKey priv = keyPair.getPrivate();
System.out.println("Private Key: " + getHexString(priv.getEncoded()));
}
private String getHexString(byte[] b) {
String result = "";
for (int i = 0; i < b.length; i++) {
result += Integer.toString((b[i] & 0xff) + 0x100, 16).substring(1);
}
return result;
}
public KeyPair LoadKeyPair(String path, String algorithm)
throws IOException, NoSuchAlgorithmException,
InvalidKeySpecException {
// Read Public Key.
File filePublicKey = new File(path + "/public.key");
FileInputStream fis = new FileInputStream(path + "/public.key");
byte[] encodedPublicKey = new byte[(int) filePublicKey.length()];
fis.read(encodedPublicKey);
fis.close();
// Read Private Key.
File filePrivateKey = new File(path + "/private.key");
fis = new FileInputStream(path + "/private.key");
byte[] encodedPrivateKey = new byte[(int) filePrivateKey.length()];
fis.read(encodedPrivateKey);
fis.close();
// Generate KeyPair.
KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(
encodedPublicKey);
PublicKey publicKey = keyFactory.generatePublic(publicKeySpec);
PKCS8EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(
encodedPrivateKey);
PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
return new KeyPair(publicKey, privateKey);
}
}
上课：
import java.io.*;
import java.security.*;
import java.security.spec.*;
public class Make {
public static void main(String args[]) {
Make adam = new Make();
try {
String path = "C:\\Users\\spencer\\Documents\\Stack ex\\src\\app";
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
keyGen.initialize(512);
KeyPair generatedKeyPair = keyGen.genKeyPair();
System.out.println("Generated Key Pair");
adam.dumpKeyPair(generatedKeyPair);
adam.SaveKeyPair(path, generatedKeyPair);
} catch (Exception e) {
e.printStackTrace();
return;
}
}
private void dumpKeyPair(KeyPair keyPair) {
PublicKey pub = keyPair.getPublic();
System.out.println("Public Key: " + getHexString(pub.getEncoded()));
PrivateKey priv = keyPair.getPrivate();
System.out.println("Private Key: " + getHexString(priv.getEncoded()));
}
private String getHexString(byte[] b) {
String result = "";
for (int i = 0; i < b.length; i++) {
result += Integer.toString((b[i] & 0xff) + 0x100, 16).substring(1);
}
return result;
}
public void SaveKeyPair(String path, KeyPair keyPair) throws IOException {
PrivateKey privateKey = keyPair.getPrivate();
PublicKey publicKey = keyPair.getPublic();
// Store Public Key.
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(
publicKey.getEncoded());
FileOutputStream fos = new FileOutputStream(path + "/public.key");
fos.write(x509EncodedKeySpec.getEncoded());
fos.close();
// Store Private Key.
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(
privateKey.getEncoded());
fos = new FileOutputStream(path + "/private.key");
fos.write(pkcs8EncodedKeySpec.getEncoded());
fos.close();
}
}
我需要帮助签名和阅读签名。