Merge "Merge branch 'stable-3.1' into stable-3.2" into stable-3.2
diff --git a/Documentation/concept-patch-sets.txt b/Documentation/concept-patch-sets.txt
index 8609afd..274fbb0 100644
--- a/Documentation/concept-patch-sets.txt
+++ b/Documentation/concept-patch-sets.txt
@@ -89,7 +89,7 @@
 set description does not become a part of the project's history.
 
 To add a patch set description, click *Add a patch set description*, located in
-the file list.
+the file list, or provide it link:user-upload.html#patch_set_description[on upload].
 
 GERRIT
 ------
diff --git a/Documentation/user-upload.txt b/Documentation/user-upload.txt
index 926aa71..cdaf155 100644
--- a/Documentation/user-upload.txt
+++ b/Documentation/user-upload.txt
@@ -315,11 +315,11 @@
 preference is set so the default behavior is to create `work-in-progress`
 changes, this can be overridden with the `ready` option.
 
-[[message]]
-==== Message
+[[patch_set_description]]
+==== Patch Set Description
 
-A comment message can be applied to the change by using the `message` (or `m`)
-option:
+A link:concept-patch-sets.html#_description[patch set description] can be
+applied by using the `message` (or `m`) option:
 
 ----
   git push ssh://john.doe@git.example.com:29418/kernel/common HEAD:refs/for/experimental%m=This_is_a_rebase_on_master%21
diff --git a/java/com/google/gerrit/server/mail/send/SmtpEmailSender.java b/java/com/google/gerrit/server/mail/send/SmtpEmailSender.java
index 8e53558..cd342f7 100644
--- a/java/com/google/gerrit/server/mail/send/SmtpEmailSender.java
+++ b/java/com/google/gerrit/server/mail/send/SmtpEmailSender.java
@@ -391,11 +391,7 @@
   }
 
   private SMTPClient open() throws EmailException {
-    final AuthSMTPClient client = new AuthSMTPClient(UTF_8.name());
-
-    if (smtpEncryption == Encryption.SSL) {
-      client.enableSSL(sslVerify);
-    }
+    final AuthSMTPClient client = new AuthSMTPClient(smtpEncryption == Encryption.SSL, sslVerify);
 
     client.setConnectTimeout(connectTimeout);
     try {
@@ -411,7 +407,7 @@
       }
 
       if (smtpEncryption == Encryption.TLS) {
-        if (!client.startTLS(smtpHost, smtpPort, sslVerify)) {
+        if (!client.execTLS()) {
           throw new EmailException("SMTP server does not support TLS");
         }
         if (!client.login()) {
diff --git a/java/com/google/gerrit/util/ssl/BlindSSLSocketFactory.java b/java/com/google/gerrit/util/ssl/BlindSSLSocketFactory.java
index 6dc1006..88845ef 100644
--- a/java/com/google/gerrit/util/ssl/BlindSSLSocketFactory.java
+++ b/java/com/google/gerrit/util/ssl/BlindSSLSocketFactory.java
@@ -20,7 +20,6 @@
 import java.net.UnknownHostException;
 import java.security.GeneralSecurityException;
 import java.security.SecureRandom;
-import java.security.cert.X509Certificate;
 import javax.net.SocketFactory;
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.SSLSocketFactory;
@@ -32,19 +31,7 @@
   private static final BlindSSLSocketFactory INSTANCE;
 
   static {
-    final X509TrustManager dummyTrustManager =
-        new X509TrustManager() {
-          @Override
-          public X509Certificate[] getAcceptedIssuers() {
-            return null;
-          }
-
-          @Override
-          public void checkClientTrusted(X509Certificate[] chain, String authType) {}
-
-          @Override
-          public void checkServerTrusted(X509Certificate[] chain, String authType) {}
-        };
+    final X509TrustManager dummyTrustManager = new BlindTrustManager();
 
     try {
       final SSLContext context = SSLContext.getInstance("SSL");
diff --git a/java/com/google/gerrit/util/ssl/BlindTrustManager.java b/java/com/google/gerrit/util/ssl/BlindTrustManager.java
new file mode 100644
index 0000000..2db091a
--- /dev/null
+++ b/java/com/google/gerrit/util/ssl/BlindTrustManager.java
@@ -0,0 +1,33 @@
+// Copyright (C) 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.util.ssl;
+
+import java.security.cert.X509Certificate;
+import javax.net.ssl.X509TrustManager;
+
+/** TrustManager implementation that accepts all certificates without validation. */
+public class BlindTrustManager implements X509TrustManager {
+
+  @Override
+  public X509Certificate[] getAcceptedIssuers() {
+    return null;
+  }
+
+  @Override
+  public void checkClientTrusted(X509Certificate[] chain, String authType) {}
+
+  @Override
+  public void checkServerTrusted(X509Certificate[] chain, String authType) {}
+}
diff --git a/java/org/apache/commons/net/smtp/AuthSMTPClient.java b/java/org/apache/commons/net/smtp/AuthSMTPClient.java
index 85e4dbf..0f8c1f4 100644
--- a/java/org/apache/commons/net/smtp/AuthSMTPClient.java
+++ b/java/org/apache/commons/net/smtp/AuthSMTPClient.java
@@ -17,68 +17,66 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.common.io.BaseEncoding;
-import com.google.gerrit.util.ssl.BlindSSLSocketFactory;
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
+import com.google.gerrit.util.ssl.BlindTrustManager;
 import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.OutputStreamWriter;
 import java.io.UnsupportedEncodingException;
-import java.net.SocketException;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
 import java.util.List;
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
-import javax.net.ssl.SSLParameters;
-import javax.net.ssl.SSLSocket;
-import javax.net.ssl.SSLSocketFactory;
 
-public class AuthSMTPClient extends SMTPClient {
+/**
+ * SMTP Client with authentication support and optional SSL processing and verification. {@link
+ * org.apache.commons.net.smtp.SMTPSClient} is used for the SSL handshake and hostname verification.
+ *
+ * <p>If shouldHandshakeOnConnect mode is selected, SSL/TLS negotiation starts right after the
+ * connection has been established. Otherwise SSL/TLS negotiation will only occur if {@link
+ * AuthSMTPClient#execTLS} is explicitly called and the server accepts the command.
+ *
+ * <p>Examples:
+ *
+ * <ul>
+ *   <li>For SSL connection:
+ *       <pre>
+ *       AuthSMTPClient c = new AuthSMTPClient(true, sslVerify);
+ *       c.connect("127.0.0.1", 465);
+ *     </pre>
+ *   <li>For TLS connection:
+ *       <pre>
+ *       AuthSMTPClient c = new AuthSMTPClient(false, sslVerify);
+ *       c.connect("127.0.0.1", 25);
+ *       if (c.execTLS()) { /rest of the commands here/ }
+ *     </pre>
+ *   <li>If SSL encryption is not required:
+ *       <pre>
+ *       AuthSMTPClient c = new AuthSMTPClient(false, false);
+ *       c.connect("127.0.0.1", port);
+ *     </pre>
+ */
+public class AuthSMTPClient extends SMTPSClient {
+
   private String authTypes;
 
-  public AuthSMTPClient(String charset) {
-    super(charset);
-  }
-
-  public void enableSSL(boolean verify) {
-    _socketFactory_ = sslFactory(verify);
-  }
-
-  public boolean startTLS(String hostname, int port, boolean verify)
-      throws SocketException, IOException {
-    if (sendCommand("STARTTLS") != 220) {
-      return false;
+  /**
+   * Constructs AuthSMTPClient.
+   *
+   * @param shouldHandshakeOnConnect the SSL processing mode, {@code true} if SSL negotiation should
+   *     start right after connect, {@code false} if it will be started by the user explicitly or
+   *     SSL negotiation is not required.
+   * @param sslVerificationEnabled {@code true} if the SMTP server's SSL certificate and hostname
+   *     should be verified, {@code false} otherwise.
+   */
+  public AuthSMTPClient(boolean shouldHandshakeOnConnect, boolean sslVerificationEnabled) {
+    // If SSL Encryption is required, SMTPSClient is used for the handshake.
+    // Otherwise, use  SMTPSClient in 'explicit' mode without calling execTLS().
+    // See SMTPSClient._connectAction_ in commons-net-3.6.
+    super("TLS", shouldHandshakeOnConnect, UTF_8.name());
+    this.setEndpointCheckingEnabled(sslVerificationEnabled);
+    if (!sslVerificationEnabled) {
+      this.setTrustManager(new BlindTrustManager());
     }
-
-    _socket_ = sslFactory(verify).createSocket(_socket_, hostname, port, true);
-
-    if (verify) {
-      SSLParameters sslParams = new SSLParameters();
-      sslParams.setEndpointIdentificationAlgorithm("HTTPS");
-      ((SSLSocket) _socket_).setSSLParameters(sslParams);
-    }
-
-    // XXX: Can't call _connectAction_() because SMTP server doesn't
-    // give banner information again after STARTTLS, thus SMTP._connectAction_()
-    // will wait on __getReply() forever, see source code of commons-net-2.2.
-    //
-    // The lines below are copied from SocketClient._connectAction_() and
-    // SMTP._connectAction_() in commons-net-2.2.
-    _socket_.setSoTimeout(_timeout_);
-    _input_ = _socket_.getInputStream();
-    _output_ = _socket_.getOutputStream();
-    _reader = new BufferedReader(new InputStreamReader(_input_, UTF_8));
-    _writer = new BufferedWriter(new OutputStreamWriter(_output_, UTF_8));
-    return true;
-  }
-
-  private static SSLSocketFactory sslFactory(boolean verify) {
-    if (verify) {
-      return (SSLSocketFactory) SSLSocketFactory.getDefault();
-    }
-    return (SSLSocketFactory) BlindSSLSocketFactory.getDefault();
   }
 
   @Override