通过JSCH使用sftp连接时的安全异常

Question

java.lang.ExceptionInInitializerError
at javax.crypto.Cipher.getInstance(DashoA13*..)
at com.jcraft.jsch.jce.AES256CTR.init(AES256CTR.java:56)
at com.jcraft.jsch.Session.checkCipher(Session.java:2072)
at com.jcraft.jsch.Session.checkCiphers(Session.java:2049)
at com.jcraft.jsch.Session.send_kexinit(Session.java:592)
at com.jcraft.jsch.Session.connect(Session.java:286)
at com.jcraft.jsch.Session.connect(Session.java:162)
at scb.frame.runner.ServerSetup.contactServer(ServerSetup.java:56)

Caused by: java.lang.SecurityException: Cannot set up certs for trusted CAs
at javax.crypto.SunJCE_b.<clinit>(DashoA13*..)
... 34 more
Caused by: java.lang.SecurityException: Cannot locate policy or framework files!
at javax.crypto.SunJCE_b.i(DashoA13*..)
at javax.crypto.SunJCE_b.g(DashoA13*..)
at javax.crypto.SunJCE_b$1.run(DashoA13*..)
at java.security.AccessController.doPrivileged(Native Method)
... 35 more

我要连接的代码：

    String host = serverProperties.getProperty("Host");
    String username = serverProperties.getProperty("Username");
    String password = serverProperties.getProperty("Password");
        JSch jsch = new JSch();
        Security.addProvider(new com.sun.crypto.provider.SunJCE());
        Session session;
        try {
            session = jsch.getSession(username, host, 22);

        session.setPassword(password);

        Properties config = new Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
        ChannelSftp sftpChannel = (ChannelSftp) session.openChannel("sftp");
        sftpChannel.connect();
        sftpChannel.get(sourceFile,destFile);

命令行版本的相同的程序，我可以运行没有任何例外！另一个来自JCraft[link]http://www.jcraft.com/jsch/examples/SFTP.java.html网站的SFTP示例运行良好。

Answer 1

这与Java的安全限制有关。默认情况下，限制密钥大小为128位。从您的stacktrace中，我看到您试图使用AES 256位加密。

要解决您的问题，请访问Java的网站并下载Java加密扩展(JCE)无限强度权限策略文件：

http://www.oracle.com/technetwork/java/javase/downloads/index.html