// Copyright (C) 2009 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.httpd.auth.container;
import com.google.gerrit.common.PageLinks;
import com.google.gerrit.httpd.HtmlDomUtil;
import com.google.gerrit.httpd.WebSession;
import com.google.gerrit.server.account.AccountException;
import com.google.gerrit.server.account.AccountManager;
import com.google.gerrit.server.account.AuthRequest;
import com.google.gerrit.server.account.AuthResult;
import com.google.gerrit.server.config.AuthConfig;
import com.google.gerrit.server.config.CanonicalWebUrl;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import org.eclipse.jgit.util.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import java.io.IOException;
import javax.annotation.Nullable;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Initializes the user session if HTTP authentication is enabled.
* <p>
* If HTTP authentication has been enabled this servlet binds to {@code /login/}
* and initializes the user session based on user information contained in the
* HTTP request.
*/
@Singleton
class HttpLoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final Logger log =
LoggerFactory.getLogger(HttpLoginServlet.class);
private static final String AUTHORIZATION = "Authorization";
private final Provider<WebSession> webSession;
private final Provider<String> urlProvider;
private final AccountManager accountManager;
private final String loginHeader;
@Inject
HttpLoginServlet(final AuthConfig authConfig,
final Provider<WebSession> webSession,
@CanonicalWebUrl @Nullable final Provider<String> urlProvider,
final AccountManager accountManager) {
this.webSession = webSession;
this.urlProvider = urlProvider;
this.accountManager = accountManager;
final String hdr = authConfig.getLoginHttpHeader();
this.loginHeader = hdr != null && !hdr.equals("") ? hdr : AUTHORIZATION;
}
@Override
protected void doGet(final HttpServletRequest req,
final HttpServletResponse rsp) throws ServletException, IOException {
final String token = getToken(req);
if ("logout".equals(token) || "signout".equals(token)) {
req.getRequestDispatcher("/logout").forward(req, rsp);
return;
}
rsp.setHeader("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
rsp.setHeader("Pragma", "no-cache");
rsp.setHeader("Cache-Control", "no-cache, must-revalidate");
final String user = getRemoteUser(req);
if (user == null || "".equals(user)) {
log.error("Unable to authenticate user by " + loginHeader
+ " request header. Check container or server configuration.");
final Document doc = HtmlDomUtil.parseFile( //
HttpLoginServlet.class, "ConfigurationError.html");
replace(doc, "loginHeader", loginHeader);
replace(doc, "ServerName", req.getServerName());
replace(doc, "ServerPort", ":" + req.getServerPort());
replace(doc, "ContextPath", req.getContextPath());
final byte[] bin = HtmlDomUtil.toUTF8(doc);
rsp.setStatus(HttpServletResponse.SC_FORBIDDEN);
rsp.setContentType("text/html");
rsp.setCharacterEncoding("UTF-8");
rsp.setContentLength(bin.length);
final ServletOutputStream out = rsp.getOutputStream();
try {
out.write(bin);
} finally {
out.flush();
out.close();
}
return;
}
final AuthRequest areq = AuthRequest.forUser(user);
final AuthResult arsp;
try {
arsp = accountManager.authenticate(areq);
} catch (AccountException e) {
log.error("Unable to authenticate user \"" + user + "\"", e);
rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
return;
}
final StringBuilder rdr = new StringBuilder();
rdr.append(urlProvider.get());
rdr.append('#');
if (arsp.isNew() && !token.startsWith(PageLinks.REGISTER + ",")) {
rdr.append(PageLinks.REGISTER);
rdr.append(',');
}
rdr.append(token);
webSession.get().login(arsp, true /* persistent cookie */);
rsp.sendRedirect(rdr.toString());
}
private void replace(Document doc, String name, String value) {
Element e = HtmlDomUtil.find(doc, name);
if (e != null) {
e.setTextContent(value);
} else {
replaceByClass(doc, name, value);
}
}
private void replaceByClass(Node parent, String name, String value) {
final NodeList list = parent.getChildNodes();
for (int i = 0; i < list.getLength(); i++) {
final Node n = list.item(i);
if (n instanceof Element) {
final Element e = (Element) n;
if (name.equals(e.getAttribute("class"))) {
e.setTextContent(value);
}
}
replaceByClass(n, name, value);
}
}
private String getToken(final HttpServletRequest req) {
String token = req.getPathInfo();
if (token != null && token.startsWith("/")) {
token = token.substring(1);
}
if (token == null || token.isEmpty()) {
token = PageLinks.MINE;
}
return token;
}
private String getRemoteUser(final HttpServletRequest req) {
if (AUTHORIZATION.equals(loginHeader)) {
final String user = req.getRemoteUser();
if (user != null && !"".equals(user)) {
// The container performed the authentication, and has the user
// identity already decoded for us. Honor that as we have been
// configured to honor HTTP authentication.
//
return user;
}
// If the container didn't do the authentication we might
// have done it in the front-end web server. Try to split
// the identity out of the Authorization header and honor it.
//
String auth = req.getHeader(AUTHORIZATION);
if (auth == null || "".equals(auth)) {
return null;
} else if (auth.startsWith("Basic ")) {
auth = auth.substring("Basic ".length());
auth = new String(Base64.decode(auth));
final int c = auth.indexOf(':');
return c > 0 ? auth.substring(0, c) : null;
} else if (auth.startsWith("Digest ")) {
final int u = auth.indexOf("username=\"");
if (u <= 0) {
return null;
}
auth = auth.substring(u + 10);
final int e = auth.indexOf('"');
return e > 0 ? auth.substring(0, auth.indexOf('"')) : null;
} else {
return null;
}
} else {
// Nonstandard HTTP header. We have been told to trust this
// header blindly as-is.
//
final String user = req.getHeader(loginHeader);
return user != null && !"".equals(user) ? user : null;
}
}
}