Question

我们必须通过配置用户名，密码和公共密钥，使用代理服务器internet.ford.com从我们的应用程序连接到外部SFTP服务器。

我们正在面对带有JSch库的Java代码以连接到SFTP服务器。尝试从服务器环境（Dev，QA）中托管的应用程序连接SFTP服务器时，我们遇到了一个问题

我收到UnknownHostKey异常，如下面的日志所示。

4463 [8/19/19 12:05:06:301 EDT] 0001fadf TransCommunic I   JSchException @  TransCommunicationMgr:- connect Result Code: UnknownHostKey: 74.126.93.138. RSA key fingerprint is e8:90:a9:f3:3d:8f:83:26:e3:24:2b:2f:a1:71:e3:7c

我在下面的代码块中将公共密钥设置为字节数组值。

// knownHostPublicKey is a String variable 
knownHostPublicKey=config.getKnownHostPublicKey();

jsch.setKnownHosts(new 
ByteArrayInputStream(knownHostPublicKey.getBytes()));

在显示一些代码部分中添加了涉及SFTP连接过程的完整代码。

我尝试使用Java JSch库和代理服务器internet.ford.com进行SFTP服务器连接

public Session connectSFTP(final FtpCredentials config)
throws OfBusinessRuntimeException{
final String METHOD_NAME = "connect";
log.entering(CLASS_NAME, METHOD_NAME, config);

    /*Local attributes declaration */
    String host = null;
    String user = null;
    String password = null;
    int elapsedTime = 0;
    int sftpPort = 0;
    String knownHostPublicKey = null;
    String sftpProxy = null;
    int sftpProxyPort=0;
    Session sftpSession = null;
    JSch jsch = new JSch();
    /* Beginning of try catch block */
    try {

        // Getting FTP connection details.
        if (config != null) {
            host = config.getHost();
            user = config.getUserId();
            sftpPort = config.getSftpPort();
            password = config.getPassword();
            elapsedTime = config.getElapsedTime();
            knownHostPublicKey=config.getKnownHostPublicKey();
            /*byte[] hostPublicKey=Base64.getDecoder().decode(knownHostPublicKey);
            HostKey hostKey=new HostKey(host,hostPublicKey);
            jsch.getHostKeyRepository().add(hostKey,null);
            */                

            jsch.

            jsch.setKnownHosts(new ByteArrayInputStream(knownHostPublicKey.getBytes()));

            sftpProxy=config.getSftpProxy();
            sftpProxyPort=config.getSftpProxyPort();
            sftpSession = jsch.getSession(user, host, sftpPort);
        }
        log.info("Before Connect " + host + " User :- " + user);
        if (host == null || user == null || password == null) {
            throw new OfBusinessRuntimeException(
                    "SFTP Host Information not found.");
        }
        sftpSession.setHost(host);
        sftpSession.setPassword(password);
        sftpSession.setPort(sftpPort);

        //java.util.Properties config = new java.util.Properties();
        // // force aes256-ctr encryption
        //config.put("cipher.s2c", "aes256-ctr");
        //config.put("cipher.c2s", "aes256-ctr");
        //config.put("CheckCiphers", "aes256-ctr");
        //session.setConfig(config);

        sftpSession.setProxy(new ProxyHTTP(sftpProxy,sftpProxyPort));
        /*
         * Setting the timeout to 30 seconds to ensure connection is made
         * for testing setting the port to 22 as this should be the one
         * to accept the connection
         **/

        sftpSession.setTimeout(elapsedTime);
        sftpSession.connect();
        log.info("SFTP Session Connection is successful");

    } catch (final JSchException jschException) {
        jschException.printStackTrace();
        log.info("JSchException @  TransCommunicationMgr:- "
                 + METHOD_NAME + " Result Code: "
                 + jschException.getMessage());
        //throw new OfBusinessRuntimeException(jschException.getMessage(),jschException);
    }
    /* Log existing method. */
    log.exiting(CLASS_NAME, METHOD_NAME, sftpSession);
    return sftpSession;
}

期望与外部SFTP服务器的连接成功。

Answer 1

JSch.setKnownHosts接受OpenSSH authorized_keys文件格式的公钥，例如：

example.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA0hVqZOvZ7yWgie9OHdTORJVI5fJJoH1yEGamAd5G3werH0z7e9ybtq1mGUeRkJtea7bzru0ISR0EZ9HIONoGYrDmI7S+BiwpDBUKjva4mAsvzzvsy6Ogy/apkxm6Kbcml8u4wjxaOw3NKzKqeBvR3pc+nQVA+SJUZq8D2XBRd4EDUFXeLzwqwen9G7gSLGB1hJkSuRtGRfOHbLUuCKNR8RV82i3JvlSnAwb3MwN0m3WGdlJA8J+5YAg4e6JgSKrsCObZK7W1R6iuyuH1zA+dtAHyDyYVHB4FnYZPL0hgz2PSb9c+iDEiFcT/lT4/dQ+kRW6DYn66lS8peS8zCJ9CSQ==

这不是您使用的格式。

我们如何使用公共密钥通过服务器托管的应用程序使用JSch连接到SFTP服务器

1 个答案: