// Copyright (C) 2015 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.oauth;
import static javax.servlet.http.HttpServletResponse.SC_UNAUTHORIZED;
import com.google.common.base.CharMatcher;
import com.google.common.base.Strings;
import com.google.gerrit.extensions.auth.oauth.OAuthServiceProvider;
import com.google.gerrit.extensions.auth.oauth.OAuthToken;
import com.google.gerrit.extensions.auth.oauth.OAuthUserInfo;
import com.google.gerrit.extensions.auth.oauth.OAuthVerifier;
import com.google.gerrit.extensions.registration.DynamicItem;
import com.google.gerrit.extensions.restapi.Url;
import com.google.gerrit.httpd.CanonicalWebUrl;
import com.google.gerrit.httpd.WebSession;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.server.IdentifiedUser;
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.account.externalids.ExternalId;
import com.google.gerrit.server.auth.oauth.OAuthTokenCache;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.servlet.SessionScoped;
import java.io.IOException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Optional;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.codec.binary.Base64;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@SessionScoped
/* OAuth protocol implementation */
class OAuthSession {
private static final Logger log = LoggerFactory.getLogger(OAuthSession.class);
private static final SecureRandom randomState = newRandomGenerator();
private final String state;
private final DynamicItem<WebSession> webSession;
private final Provider<IdentifiedUser> identifiedUser;
private final AccountManager accountManager;
private final CanonicalWebUrl urlProvider;
private final OAuthTokenCache tokenCache;
private OAuthServiceProvider serviceProvider;
private OAuthUserInfo user;
private Account.Id accountId;
private String redirectToken;
private boolean linkMode;
@Inject
OAuthSession(
DynamicItem<WebSession> webSession,
Provider<IdentifiedUser> identifiedUser,
AccountManager accountManager,
CanonicalWebUrl urlProvider,
OAuthTokenCache tokenCache) {
this.state = generateRandomState();
this.identifiedUser = identifiedUser;
this.webSession = webSession;
this.accountManager = accountManager;
this.urlProvider = urlProvider;
this.tokenCache = tokenCache;
}
boolean isLoggedIn() {
return user != null;
}
boolean isOAuthFinal(HttpServletRequest request) {
return Strings.emptyToNull(request.getParameter("code")) != null;
}
boolean login(
HttpServletRequest request, HttpServletResponse response, OAuthServiceProvider oauth)
throws IOException {
log.debug("Login " + this);
if (isOAuthFinal(request)) {
if (!checkState(request)) {
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return false;
}
log.debug("Login-Retrieve-User " + this);
OAuthToken token = oauth.getAccessToken(new OAuthVerifier(request.getParameter("code")));
user = oauth.getUserInfo(token);
if (isLoggedIn()) {
log.debug("Login-SUCCESS " + this);
authenticateAndRedirect(request, response, token);
return true;
}
response.sendError(SC_UNAUTHORIZED);
return false;
}
log.debug("Login-PHASE1 " + this);
redirectToken = request.getRequestURI();
// We are here in content of filter.
// Due to this Jetty limitation:
// https://bz.apache.org/bugzilla/show_bug.cgi?id=28323
// we cannot use LoginUrlToken.getToken() method,
// because it relies on getPathInfo() and it is always null here.
redirectToken = redirectToken.substring(request.getContextPath().length());
response.sendRedirect(oauth.getAuthorizationUrl() + "&state=" + state);
return false;
}
private void authenticateAndRedirect(
HttpServletRequest req, HttpServletResponse rsp, OAuthToken token) throws IOException {
AuthRequest areq = new AuthRequest(ExternalId.Key.parse(user.getExternalId()));
AuthResult arsp;
try {
String claimedIdentifier = user.getClaimedIdentity();
if (!Strings.isNullOrEmpty(claimedIdentifier)) {
if (!authenticateWithIdentityClaimedDuringHandshake(areq, rsp, claimedIdentifier)) {
return;
}
} else if (linkMode) {
if (!authenticateWithLinkedIdentity(areq, rsp)) {
return;
}
}
areq.setUserName(user.getUserName());
areq.setEmailAddress(user.getEmailAddress());
areq.setDisplayName(user.getDisplayName());
arsp = accountManager.authenticate(areq);
accountId = arsp.getAccountId();
tokenCache.put(accountId, token);
} catch (AccountException e) {
log.error("Unable to authenticate user \"" + user + "\"", e);
rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
return;
}
webSession.get().login(arsp, true);
String suffix = redirectToken.substring(OAuthWebFilter.GERRIT_LOGIN.length() + 1);
suffix = CharMatcher.anyOf("/").trimLeadingFrom(Url.decode(suffix));
StringBuilder rdr = new StringBuilder(urlProvider.get(req));
rdr.append(suffix);
rsp.sendRedirect(rdr.toString());
}
private boolean authenticateWithIdentityClaimedDuringHandshake(
AuthRequest req, HttpServletResponse rsp, String claimedIdentifier)
throws AccountException, IOException {
Optional<Account.Id> claimedId = accountManager.lookup(claimedIdentifier);
Optional<Account.Id> actualId = accountManager.lookup(user.getExternalId());
if (claimedId.isPresent() && actualId.isPresent()) {
if (claimedId.get().equals(actualId.get())) {
// Both link to the same account, that's what we expected.
log.debug("OAuth2: claimed identity equals current id");
} else {
// This is (for now) a fatal error. There are two records
// for what might be the same user.
//
log.error(
"OAuth accounts disagree over user identity:\n"
+ " Claimed ID: "
+ claimedId.get()
+ " is "
+ claimedIdentifier
+ "\n"
+ " Delgate ID: "
+ actualId.get()
+ " is "
+ user.getExternalId());
rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
return false;
}
} else if (claimedId.isPresent() && !actualId.isPresent()) {
// Claimed account already exists: link to it.
//
log.info("OAuth2: linking claimed identity to {}", claimedId.get().toString());
try {
accountManager.link(claimedId.get(), req);
} catch (OrmException | ConfigInvalidException e) {
log.error(
"Cannot link: "
+ user.getExternalId()
+ " to user identity:\n"
+ " Claimed ID: "
+ claimedId.get()
+ " is "
+ claimedIdentifier);
rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
return false;
}
}
return true;
}
private boolean authenticateWithLinkedIdentity(AuthRequest areq, HttpServletResponse rsp)
throws AccountException, IOException {
try {
accountManager.link(identifiedUser.get().getAccountId(), areq);
} catch (OrmException | ConfigInvalidException e) {
log.error(
"Cannot link: "
+ user.getExternalId()
+ " to user identity: "
+ identifiedUser.get().getAccountId());
rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
return false;
} finally {
linkMode = false;
}
return true;
}
void logout() {
if (accountId != null) {
tokenCache.remove(accountId);
accountId = null;
}
user = null;
redirectToken = null;
serviceProvider = null;
}
private boolean checkState(ServletRequest request) {
String s = Strings.nullToEmpty(request.getParameter("state"));
if (!s.equals(state)) {
log.error("Illegal request state '" + s + "' on OAuthProtocol " + this);
return false;
}
return true;
}
private static SecureRandom newRandomGenerator() {
try {
return SecureRandom.getInstance("SHA1PRNG");
} catch (NoSuchAlgorithmException e) {
throw new IllegalArgumentException("No SecureRandom available for GitHub authentication", e);
}
}
private static String generateRandomState() {
byte[] state = new byte[32];
randomState.nextBytes(state);
return Base64.encodeBase64URLSafeString(state);
}
@Override
public String toString() {
return "OAuthSession [token=" + tokenCache.get(accountId) + ", user=" + user + "]";
}
public void setServiceProvider(OAuthServiceProvider provider) {
this.serviceProvider = provider;
}
public OAuthServiceProvider getServiceProvider() {
return serviceProvider;
}
public void setLinkMode(boolean linkMode) {
this.linkMode = linkMode;
}
public boolean isLinkMode() {
return linkMode;
}
}