从安全指南https://developer.android.com/training/articles/security-ssl.html#CommonHostnameProbs中,当 SSLSocket 与 HttpsUrlConnection 分开使用时,需要通过调用 hostnameverifier.verify() 方法手动验证主机名:
// Open SSLSocket directly to gmail.com
SocketFactory sf = SSLSocketFactory.getDefault();
SSLSocket socket = (SSLSocket) sf.createSocket("gmail.com", 443);
HostnameVerifier hv = HttpsURLConnection.getDefaultHostnameVerifier();
SSLSession s = socket.getSession();
// Verify that the certicate hostname is for mail.google.com
// This is due to lack of SNI support in the current SSLSocket.
if (!hv.verify("mail.google.com", s)) {
throw new SSLHandshakeException("Expected mail.google.com, "
"found " + s.getPeerPrincipal());
}
// At this point SSLSocket performed certificate verification and
// we have performed hostname verification, so it is safe to proceed.
// ... use socket ...
socket.close();
但我也看到安全代码示例说:
/*
* This example demostrates how to use a SSLSocket as client to
* send a HTTP request and get response from an HTTPS server.
* It assumes that the client is not behind a firewall
*/
public class SSLSocketClient {
public static void main(String[] args) throws Exception {
try {
SSLSocketFactory factory =
(SSLSocketFactory)SSLSocketFactory.getDefault();
SSLSocket socket =
(SSLSocket)factory.createSocket("www.verisign.com", 443);
/*
* send http request
*
* Before any application data is sent or received, the
* SSL socket will do SSL handshaking first to set up
* the security attributes.
*
* SSL handshaking can be initiated by either flushing data
* down the pipe, or by starting the handshaking by hand.
*
* Handshaking is started manually in this example because
* PrintWriter catches all IOExceptions (including
* SSLExceptions), sets an internal error flag, and then
* returns without rethrowing the exception.
*
* Unfortunately, this means any error messages are lost,
* which caused lots of confusion for others using this
* code. The only way to tell there was an error is to call
* PrintWriter.checkError().
*/
socket.startHandshake();
PrintWriter out = new PrintWriter(
new BufferedWriter(
new OutputStreamWriter(
socket.getOutputStream())));
out.println("GET / HTTP/1.0");
out.println();
out.flush();
/*
* Make sure there were no surprises
*/
if (out.checkError())
System.out.println(
"SSLSocketClient: java.io.PrintWriter error");
/* read response */
BufferedReader in = new BufferedReader(
new InputStreamReader(
socket.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);
in.close();
out.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
是否安全?在此套接字的读/写行为之前,我没有看到任何主机名验证方法被调用。socket.startHandShake() 是否包含它?