// Copyright (C) 2012 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;
import static javax.servlet.http.HttpServletResponse.SC_UNAUTHORIZED;
import com.google.common.base.Objects;
import com.google.common.base.Strings;
import com.google.gerrit.server.account.AccountCache;
import com.google.gerrit.server.account.AccountException;
import com.google.gerrit.server.account.AccountManager;
import com.google.gerrit.server.account.AccountState;
import com.google.gerrit.server.account.AuthMethod;
import com.google.gerrit.server.account.AuthRequest;
import com.google.gerrit.server.account.AuthResult;
import com.google.gerrit.server.config.AuthConfig;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.Locale;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
/**
* Authenticates the current user by HTTP basic authentication.
* <p>
* The current HTTP request is authenticated by looking up the username and
* password from the Base64 encoded Authorization header and validating them
* against any username/password configured authentication system in Gerrit.
* This filter is intended only to protect the {@link ProjectServlet} and its
* handled URLs, which provide remote repository access over HTTP.
*
* @see <a href="http://www.ietf.org/rfc/rfc2617.txt">RFC 2617</a>
*/
@Singleton
class ProjectBasicAuthFilter implements Filter {
private static final Logger log = LoggerFactory
.getLogger(ProjectBasicAuthFilter.class);
public static final String REALM_NAME = "Gerrit Code Review";
private static final String AUTHORIZATION = "Authorization";
private static final String LIT_BASIC = "Basic ";
private final Provider<WebSession> session;
private final AccountCache accountCache;
private final AccountManager accountManager;
private final AuthConfig authConfig;
@Inject
ProjectBasicAuthFilter(Provider<WebSession> session,
AccountCache accountCache, AccountManager accountManager,
AuthConfig authConfig) {
this.session = session;
this.accountCache = accountCache;
this.accountManager = accountManager;
this.authConfig = authConfig;
}
@Override
public void init(FilterConfig config) {
}
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
Response rsp = new Response((HttpServletResponse) response);
if (verify(req, rsp)) {
chain.doFilter(req, rsp);
}
}
private boolean verify(HttpServletRequest req, Response rsp)
throws IOException {
final String hdr = req.getHeader(AUTHORIZATION);
if (hdr == null) {
// Allow an anonymous connection through, or it might be using a
// session cookie instead of basic authentication.
//
return true;
}
final byte[] decoded =
Base64.decodeBase64(hdr.substring(LIT_BASIC.length()));
String usernamePassword = new String(decoded, encoding(req));
int splitPos = usernamePassword.indexOf(':');
if (splitPos < 1) {
rsp.sendError(SC_UNAUTHORIZED);
return false;
}
String username = usernamePassword.substring(0, splitPos);
String password = usernamePassword.substring(splitPos + 1);
if (Strings.isNullOrEmpty(password)) {
rsp.sendError(SC_UNAUTHORIZED);
return false;
}
if (authConfig.isUserNameToLowerCase()) {
username = username.toLowerCase(Locale.US);
}
final AccountState who = accountCache.getByUsername(username);
if (who == null || !who.getAccount().isActive()) {
log.warn("Authentication failed for " + username
+ ": account inactive or not provisioned in Gerrit");
rsp.sendError(SC_UNAUTHORIZED);
return false;
}
AuthRequest whoAuth = AuthRequest.forUser(username);
whoAuth.setPassword(password);
try {
AuthResult whoAuthResult = accountManager.authenticate(whoAuth);
session.get().setUserAccountId(whoAuthResult.getAccountId(),
AuthMethod.PASSWORD);
return true;
} catch (AccountException e) {
log.warn("Authentication failed for " + username, e);
rsp.sendError(SC_UNAUTHORIZED);
return false;
}
}
private String encoding(HttpServletRequest req) {
return Objects.firstNonNull(req.getCharacterEncoding(), "UTF-8");
}
class Response extends HttpServletResponseWrapper {
private static final String WWW_AUTHENTICATE = "WWW-Authenticate";
Response(HttpServletResponse rsp) {
super(rsp);
}
private void status(int sc) {
if (sc == SC_UNAUTHORIZED) {
StringBuilder v = new StringBuilder();
v.append(LIT_BASIC);
v.append("realm=\"" + REALM_NAME + "\"");
setHeader(WWW_AUTHENTICATE, v.toString());
} else if (containsHeader(WWW_AUTHENTICATE)) {
setHeader(WWW_AUTHENTICATE, null);
}
}
@Override
public void sendError(int sc, String msg) throws IOException {
status(sc);
super.sendError(sc, msg);
}
@Override
public void sendError(int sc) throws IOException {
status(sc);
super.sendError(sc);
}
@Override
public void setStatus(int sc, String sm) {
status(sc);
super.setStatus(sc, sm);
}
@Override
public void setStatus(int sc) {
status(sc);
super.setStatus(sc);
}
}
}