Question

我在Java中实现WebService，其中服务器需要使用RSA算法将3DES密钥发送到客户端。对称性由服务器生成。服务器和客户端都有自己的RSA密钥对，之前已交换过。

在此代码中，服务器将对称密钥发送给客户端。

@WebMethod
public byte[] getSymmetricKey(){
    try{
        Cipher cipher = Cipher.getInstance("RSA");

        // First, encrypts the symmetric key with the client's public key
        cipher.init(Cipher.ENCRYPT_MODE, this.clientKey);
        byte[] partialCipher = cipher.doFinal(this.key.getBytes());

        // Finally, encrypts the previous result with the server's private key
        cipher.init(Cipher.ENCRYPT_MODE, this.privateKey);
        byte[] cipherData = cipher.doFinal(partialCipher);

        return cipherData;
    }catch (Exception ex){
        ex.printStackTrace();
    }

}

当我使用服务器的私钥运行加密时，出现IllegalBlockSizeException错误。如果默认情况下激活填充，为什么会出现此异常？我还尝试使用Cipher.getInstance("RSA/ECB/PKCS1Padding")显式激活填充。最后，这是异常输出：

    SEVERE: javax.crypto.IllegalBlockSizeException: Data must not be longer than 245 bytes
javax.crypto.IllegalBlockSizeException: Data must not be longer than 245 bytes
    at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:346)
    at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:391)
    at javax.crypto.Cipher.doFinal(Cipher.java:2087)
    at server.FileTransfererImpl.getSymmetricKey(FileTransfererImpl.java:112)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.Trampoline.invoke(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.sun.xml.internal.ws.api.server.MethodUtil.invoke(Unknown Source)
    at com.sun.xml.internal.ws.api.server.InstanceResolver$1.invoke(Unknown Source)
    at com.sun.xml.internal.ws.server.InvokerTube$2.invoke(Unknown Source)
    at com.sun.xml.internal.ws.server.sei.EndpointMethodHandler.invoke(Unknown Source)
    at com.sun.xml.internal.ws.server.sei.SEIInvokerTube.processRequest(Unknown Source)
    at com.sun.xml.internal.ws.api.pipe.Fiber.__doRun(Unknown Source)
    at com.sun.xml.internal.ws.api.pipe.Fiber._doRun(Unknown Source)
    at com.sun.xml.internal.ws.api.pipe.Fiber.doRun(Unknown Source)
    at com.sun.xml.internal.ws.api.pipe.Fiber.runSync(Unknown Source)
    at com.sun.xml.internal.ws.server.WSEndpointImpl$2.process(Unknown Source)
    at com.sun.xml.internal.ws.transport.http.HttpAdapter$HttpToolkit.handle(Unknown Source)
    at com.sun.xml.internal.ws.transport.http.HttpAdapter.handle(Unknown Source)
    at com.sun.xml.internal.ws.transport.http.server.WSHttpHandler.handleExchange(Unknown Source)
    at com.sun.xml.internal.ws.transport.http.server.WSHttpHandler.handle(Unknown Source)
    at com.sun.net.httpserver.Filter$Chain.doFilter(Unknown Source)
    at sun.net.httpserver.AuthFilter.doFilter(Unknown Source)
    at com.sun.net.httpserver.Filter$Chain.doFilter(Unknown Source)
    at sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(Unknown Source)
    at com.sun.net.httpserver.Filter$Chain.doFilter(Unknown Source)
    at sun.net.httpserver.ServerImpl$Exchange.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

我今天正在研究soem的东西，并发现了这个问题。由于尚未得到答复，我将此留待此处以供将来参考。

根据PKCS＃1，RSAES-PKCS1-V1_5-ENCRYPT算法可以加密最多k - 11个字节，其中k是＆＃34;大小＆＃34;键的字节数。这11个字节用于＆＃34;标题＆＃34;。

如果您使用的是2048位RSA密钥，则会为您提供k = 256，并且您可以加密最多256 - 11 = 245个字节的数据。

检查this.key的实际尺寸。

3DES与Java中的RSA密钥交换

1 个答案: