java.security.NoSuchAlgorithmException: RSA 签名不可用
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/35922727/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
java.security.NoSuchAlgorithmException: RSA Signature not available
提问by bearer1024
this is exception
这是例外
Exception in thread "main" java.security.NoSuchAlgorithmException: RSA Signature not available
at java.security.Signature.getInstance(Signature.java:229)
at MailClient.main(MailClient.java:52)
this is my code
这是我的代码
import java.io.*;
import java.net.*;
import java.nio.ByteBuffer;
import java.util.*;
import java.security.*;
public class MailClient {
public String getMessage(Mail m){
return m.message;
}
public static void main(String[] args) throws Exception {
// Initialisation
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String host = args[0];
int port = Integer.parseInt(args[1]);
String userid = args[2];
while(true) {
// connect to server
Socket s = new Socket(host,port);
DataInputStream dis = new DataInputStream(s.getInputStream());
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
oos.flush();
ObjectInputStream ois = new ObjectInputStream(s.getInputStream());
// TO DO: login
// these two lines are here just to make the supplied programs run without crashing.
// You may want to change them, and certainly add things after them
dos.writeUTF(userid);
String userPrivateKeyFileName = userid + ".prv";
// Get the key to create the signature
ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(userPrivateKeyFileName));
PrivateKey privateKey = (PrivateKey)keyIn.readObject();
keyIn.close();
// create timeStamp and random number
long t1 = (new Date()).getTime();
double q1 = Math.random();
// ByteBuffer to convert to bytes later
ByteBuffer bb = ByteBuffer.allocate(16);
bb.putLong(t1);
bb.putDouble(q1);
// create signature, using timeStamp and random number as data
Signature sig = Signature.getInstance("RSA");
sig.initSign(privateKey);
sig.update(bb.array());
byte[] signature = sig.sign();
// send data and signature
DataOutputStream out = new DataOutputStream(s.getOutputStream());
out.writeUTF(userid);
out.writeLong(t1);
out.writeDouble(q1);
out.writeInt(signature.length);
out.write(signature);
out.flush();
boolean answer = dis.readBoolean();
//passed the verifyLogin
if (answer)
{
// receive how many messages
int numMsg = dis.readInt();
System.out.println("You have " + numMsg + " incoming messages.");
// TO DO: read messages
ArrayList<Mail> msg = new ArrayList<>(numMsg);
for(int i=0;i<numMsg;i++){
//@Unchecked
msg = (ArrayList<Mail>) ois.readObject();
}
while(!msg.isEmpty()){
//for each mail, display sender,timestamp,message
System.out.println(msg.get(0).sender);
System.out.println(msg.get(0).timestamp);
System.out.println(msg.get(0).message);
MessageDigest md = MessageDigest.getInstance("SHA-1");
md.update(msg.get(0).hashcash);
byte[] digest = md.digest();
boolean normalMail = msg.get(0).checkHashcash(digest);
if(normalMail){
//check each mail is original that it isn't modified
//receive mail
System.out.println(msg.get(0).message);
}
else{System.out.println("it's a spam message.");
System.out.println(msg.get(0).message);
}
msg.remove(0);
}
// send messages
System.out.println("Do you want to send a message [Y/N]?");
String wantToSend = br.readLine();
if (!wantToSend.equals("Y")) {
dos.writeBoolean(false);
return ;
}
dos.writeBoolean(true);
System.out.println("Enter userid of recipient:");
String recipient = br.readLine();
System.out.println("Type your message:");
String message = br.readLine();
// TO DO: send mail
Mail m = new Mail(userid, recipient, message);
MessageDigest md = MessageDigest.getInstance("SHA-1");
md.update(m.hashcash);
byte[] digest = md.digest();
while(m.checkHashcash(digest)){
m.setHashcash(digest);
}
out.write(digest);
out.flush();
// send timeStamp and digest to server
long mailTimestamp = m.timestamp.getTime();
out.writeLong(mailTimestamp);
oos.writeObject(m);
}
}
}
}
回答by Andreas
If you run the following code, you will get a list of signature algorithms supported by your Java installation.
如果您运行以下代码，您将获得 Java 安装支持的签名算法列表。
TreeSet<String> algorithms = new TreeSet<>();
for (Provider provider : Security.getProviders())
for (Service service : provider.getServices())
if (service.getType().equals("Signature"))
algorithms.add(service.getAlgorithm());
for (String algorithm : algorithms)
System.out.println(algorithm);
When I run it (Windows, Java 1.8.0_65), I get:
当我运行它（Windows，Java 1.8.0_65）时，我得到：
MD2withRSA
MD5andSHA1withRSA
MD5withRSA
NONEwithDSA
NONEwithECDSA
NONEwithRSA
SHA1withDSA
SHA1withECDSA
SHA1withRSA
SHA224withDSA
SHA224withECDSA
SHA224withRSA
SHA256withDSA
SHA256withECDSA
SHA256withRSA
SHA384withECDSA
SHA384withRSA
SHA512withECDSA
SHA512withRSA
As you can see, RSAis not a valid signature algorithm.
Maybe NONEwithRSAis what you're after?
如您所见，RSA不是有效的签名算法。
也许NONEwithRSA这就是你所追求的？
回答by Omer Malik
回答by erickson
Specify a valid algorithm. The hash algorithm needs to be specified. For example, SHA256withRSA.
指定有效的算法。需要指定哈希算法。例如，SHA256withRSA。
回答by whoami
I've checked the algorithms supported by java versions(1.7) & (1.8) in my machine. One of my project runs on jdk 1.7.0_80, which doesn't support SHA224withRSA algorithm, if you're in same situation then upgrade to newer version of java atleast to (Java SE 7 Update 131)as I've read it should have similar algorithms as java 8. If no option to update java then try adding org.bouncycastlebcprov-jdk15onmaven dependency in pom or a jar file to your project & also in java code add where you build SSLContext/HttpClient include below line:
我已经在我的机器上检查了 java 版本（1.7）和（1.8）支持的算法。我的一个项目在 jdk 1.7.0_80 上运行，它不支持 SHA224withRSA 算法，如果您处于相同的情况，那么至少升级到较新版本的 java 到（Java SE 7 Update 131），因为我读过它应该有与 java 8 类似的算法。如果没有更新 java 的选项，则尝试将pom 中的 org.bouncycastle bcprov-jdk15onmaven 依赖项或 jar 文件添加到您的项目中，并在 java 代码中添加您构建 SSLContext/HttpClient 的位置，包括以下行：
Security.addProvider(new BouncyCastleProvider());
Security.addProvider(new BouncyCastleProvider());
Also tried installing Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 7, but it hasn't worked !!
还尝试安装 Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 7，但没有成功！！
