我使用apache.commons.net-framework在java中实现了FTPS客户端(FTP over SSL / TLS).
它被配置为在默认端口21上执行显式安全性.

ftpsClient = new FTPSClient(false);
ftpsClient.setTrustManager(getConfiguration().getCertificatesManager());
ftpsClient.connect(getConfiguration().getHostName(), getConfiguration().getPort());

只要我不在服务器上强制执行客户端身份验证,一切正常.
但我需要启用客户端身份验证,因此我在服务器上强制执行它并配置客户端系统属性：

-Djavax.net.ssl.keyStore="D:/.../ftps-client-auth.keystore"
-Djavax.net.ssl.keyStorePassword="*****"
-Djavax.net.ssl.keyStoreType=JKS

我得到的就像我没有设置系统属性一样：

javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
    at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:174)
    at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:136)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:1806)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:986)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1170)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1197)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1181)
    at org.apache.commons.net.ftp.FTPSClient.sslNegotiation(FTPSClient.java:265)
    at org.apache.commons.net.ftp.FTPSClient._connectAction_(FTPSClient.java:207)
    at org.apache.commons.net.SocketClient.connect(SocketClient.java:172)
    at org.apache.commons.net.SocketClient.connect(SocketClient.java:192)

服务器日志说：

DEBUG: Client "<my ip address>", "SSL_accept failed: error:140890C7:SSL routines:SSL3_GET_CLIENT_CERTIFICATE:peer did not return a certificate"

似乎没错 – 我启用了-Djavax.net.debug = all,这表明服务器发送了它接受的CN列表,但是客户端发送了一个空的证书链.

>我做错了什么？
>我是否需要以编程方式进行一些配置？
>证书或私钥是否需要支持SSL / TLS的特殊功能？

解决方法:

弄清楚：你需要以编程方式设置KeyManager.
设置系统属性(-Djavax.net.ssl.keyStore,…)是不够的,因为框架不使用Suns SSLSocketFactory.

例：

ftpsClient = new FTPSClient(false);
ftpsClient.setTrustManager(TrustManagerUtils.getAcceptAllTrustManager());
KeyManager keyManager = org.apache.commons.net.util.KeyManagerUtils.createClientKeyManager(new File(keystorePath), keystorePass);
ftpsClient.setKeyManager(keyManager);
ftpsClient.connect(getConfiguration().getHostName(), getConfiguration().getPort());

您可能想要选择其他信任管理器,例如一个基于Java密钥库的. utils也提供了一种方法：TrustManagerUtils.getDefaultTrustManager(keystore)