java.security.NoSuchAlgorithmException:找不到带有RSA实现的签名MD5

我在WebSphereServer8.5上遇到问题 具有 Java版本=1.6.0，Java运行时版本=pap6460_26sr8fp7ifx-20151008_01（SR8 FP7）

失败的代码是：

   Security.addProvider(new BouncyCastleProvider());
   Signature sign = Signature.getInstance("MD5withRSA", "BC");

我得到的错误是：

java.security.NoSuchAlgorithmException: Signature MD5WITHRSA implementation not found: java.lang.ClassNotFoundException: org.bouncycastle.jcajce.provider.asymmetric.rsa.DigestSignatureSpi$MD5

相同的代码适用于java版本稍有不同的开发环境（java版本=1.6.0，java运行时版本=pap6460_26sr8fp20-20160111_01（SR8 FP20））

我尝试用以下代码列出所有签名算法：

addProvider（新的BouncyCastleProvider（））

所以，MD5withRSA就在那里

类org.bouncycastle.jcajce.provider.asymetric.rsa.DigestSignatureSpi$MD5位于应用程序内部，并且

 System.out.println("--->DigestSignatureSpi" + MD5.class.getResource("DigestSignatureSpi$MD5.class"));

正确返回类的位置

---

那么可能是什么问题呢？

请用以下代码片段验证您的输出

AlgoCheck.java

import java.net.URL;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Security;
import java.security.Signature;
import org.bouncycastle.jcajce.provider.asymmetric.rsa.DigestSignatureSpi;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

public class AlgoCheck {

public static void main(String[] args) throws NoSuchAlgorithmException,
    NoSuchProviderException, ClassNotFoundException {

Security.addProvider(new BouncyCastleProvider());
URL bcClassUrl = AlgoCheck.class.getClassLoader()
        .getResource("org/bouncycastle/jce/provider/BouncyCastleProvider.class");
System.out.println("BouncyCastleProvider class URL   = " + bcClassUrl);

ClassLoader loader = DigestSignatureSpi.MD5.class.getClassLoader();
URL md5ClassUrl = loader.getResource(
 "org/bouncycastle/jcajce/provider/asymmetric/rsa/DigestSignatureSpi$MD5.class");
System.out.println("DigestSignatureSpi.MD5 class URL = " + md5ClassUrl);

Signature sign = Signature.getInstance("MD5withRSA", "BC");
System.out.println("algorithm = " + sign.getAlgorithm());
    }
}

加载类

BouncyCastleProvider

和

DigestSignatureSpi.MD5

的库应该相同

示例输出

BouncyCastleProvider class URL   = jar:file:/home/suboptimal/.m2/repository/org/bouncycastle/bcprov-jdk15on/1.49/bcprov-jdk15on-1.49.jar!/org/bouncycastle/jce/provider/BouncyCastleProvider.class
DigestSignatureSpi.MD5 class URL = jar:file:/home/suboptimal/.m2/repository/org/bouncycastle/bcprov-jdk15on/1.49/bcprov-jdk15on-1.49.jar!/org/bouncycastle/jcajce/provider/asymmetric/rsa/DigestSignatureSpi$MD5.class
algorithm = MD5withRSA

---

这是一个众所周知的和谐问题。将Bouncy JAR放入appserver lib/ext目录。

基于

java.lang.ClassNotFoundException

我相信

org.bouncycastle.jcajce.provider.asymmetric.rsa.DigestSignatureSpi$MD5

在执行

Signature=Signature.getInstance（“MD5withRSA”，“BC”）

时，类路径中不存在。在这两种情况下，您都检查过Bouncy Castle的版本了吗？版本与web应用程序中的jar版本相同。文件必须位于类路径中。否则System.out.println（“-->DigestSignatureSpi”+MD5.class.getResource（“DigestSignatureSpi$MD5.class”））不会告诉我它在哪里。

import java.net.URL;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Security;
import java.security.Signature;
import org.bouncycastle.jcajce.provider.asymmetric.rsa.DigestSignatureSpi;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

public class AlgoCheck {

public static void main(String[] args) throws NoSuchAlgorithmException,
    NoSuchProviderException, ClassNotFoundException {

Security.addProvider(new BouncyCastleProvider());
URL bcClassUrl = AlgoCheck.class.getClassLoader()
        .getResource("org/bouncycastle/jce/provider/BouncyCastleProvider.class");
System.out.println("BouncyCastleProvider class URL   = " + bcClassUrl);

ClassLoader loader = DigestSignatureSpi.MD5.class.getClassLoader();
URL md5ClassUrl = loader.getResource(
 "org/bouncycastle/jcajce/provider/asymmetric/rsa/DigestSignatureSpi$MD5.class");
System.out.println("DigestSignatureSpi.MD5 class URL = " + md5ClassUrl);

Signature sign = Signature.getInstance("MD5withRSA", "BC");
System.out.println("algorithm = " + sign.getAlgorithm());
    }
}

BouncyCastleProvider class URL   = jar:file:/home/suboptimal/.m2/repository/org/bouncycastle/bcprov-jdk15on/1.49/bcprov-jdk15on-1.49.jar!/org/bouncycastle/jce/provider/BouncyCastleProvider.class
DigestSignatureSpi.MD5 class URL = jar:file:/home/suboptimal/.m2/repository/org/bouncycastle/bcprov-jdk15on/1.49/bcprov-jdk15on-1.49.jar!/org/bouncycastle/jcajce/provider/asymmetric/rsa/DigestSignatureSpi$MD5.class
algorithm = MD5withRSA