com.googlesource.gerrit.plugins.oauth.GoogleOAuthService.java Source code

Java tutorial

Introduction

Here is the source code for com.googlesource.gerrit.plugins.oauth.GoogleOAuthService.java

Source

// 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.googlesource.gerrit.plugins.oauth;

import static com.google.gerrit.json.OutputFormat.JSON;

import com.google.common.base.CharMatcher;
import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.gerrit.extensions.annotations.PluginName;
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.server.config.CanonicalWebUrl;
import com.google.gerrit.server.config.PluginConfig;
import com.google.gerrit.server.config.PluginConfigFactory;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.codec.binary.Base64;
import org.scribe.builder.ServiceBuilder;
import org.scribe.model.OAuthRequest;
import org.scribe.model.Response;
import org.scribe.model.Token;
import org.scribe.model.Verb;
import org.scribe.model.Verifier;
import org.scribe.oauth.OAuthService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
class GoogleOAuthService implements OAuthServiceProvider {
    private static final Logger log = LoggerFactory.getLogger(GoogleOAuthService.class);
    static final String CONFIG_SUFFIX = "-google-oauth";
    private static final String GOOGLE_PROVIDER_PREFIX = "google-oauth:";
    private static final String PROTECTED_RESOURCE_URL = "https://www.googleapis.com/oauth2/v2/userinfo";
    private static final String SCOPE = "email profile";
    private final OAuthService service;
    private final String canonicalWebUrl;
    private final List<String> domains;
    private final boolean useEmailAsUsername;
    private final boolean fixLegacyUserId;

    @Inject
    GoogleOAuthService(PluginConfigFactory cfgFactory, @PluginName String pluginName,
            @CanonicalWebUrl Provider<String> urlProvider) {
        PluginConfig cfg = cfgFactory.getFromGerritConfig(pluginName + CONFIG_SUFFIX);
        this.canonicalWebUrl = CharMatcher.is('/').trimTrailingFrom(urlProvider.get()) + "/";
        if (cfg.getBoolean(InitOAuth.LINK_TO_EXISTING_OPENID_ACCOUNT, false)) {
            log.warn(
                    String.format("The support for: %s is disconinued", InitOAuth.LINK_TO_EXISTING_OPENID_ACCOUNT));
        }
        fixLegacyUserId = cfg.getBoolean(InitOAuth.FIX_LEGACY_USER_ID, false);
        this.domains = Arrays.asList(cfg.getStringList(InitOAuth.DOMAIN));
        this.useEmailAsUsername = cfg.getBoolean(InitOAuth.USE_EMAIL_AS_USERNAME, false);
        this.service = new ServiceBuilder().provider(Google2Api.class).apiKey(cfg.getString(InitOAuth.CLIENT_ID))
                .apiSecret(cfg.getString(InitOAuth.CLIENT_SECRET)).callback(canonicalWebUrl + "oauth").scope(SCOPE)
                .build();
        if (log.isDebugEnabled()) {
            log.debug("OAuth2: canonicalWebUrl={}", canonicalWebUrl);
            log.debug("OAuth2: scope={}", SCOPE);
            log.debug("OAuth2: domains={}", domains);
            log.debug("OAuth2: useEmailAsUsername={}", useEmailAsUsername);
        }
    }

    @Override
    public OAuthUserInfo getUserInfo(OAuthToken token) throws IOException {
        OAuthRequest request = new OAuthRequest(Verb.GET, PROTECTED_RESOURCE_URL);
        Token t = new Token(token.getToken(), token.getSecret(), token.getRaw());
        service.signRequest(t, request);
        Response response = request.send();
        if (response.getCode() != HttpServletResponse.SC_OK) {
            throw new IOException(String.format("Status %s (%s) for request %s", response.getCode(),
                    response.getBody(), request.getUrl()));
        }
        JsonElement userJson = JSON.newGson().fromJson(response.getBody(), JsonElement.class);
        if (log.isDebugEnabled()) {
            log.debug("User info response: {}", response.getBody());
        }
        if (userJson.isJsonObject()) {
            JsonObject jsonObject = userJson.getAsJsonObject();
            JsonElement id = jsonObject.get("id");
            if (id == null || id.isJsonNull()) {
                throw new IOException("Response doesn't contain id field");
            }
            JsonElement email = jsonObject.get("email");
            JsonElement name = jsonObject.get("name");
            String login = null;

            if (domains.size() > 0) {
                boolean domainMatched = false;
                JsonObject jwtToken = retrieveJWTToken(token);
                String hdClaim = retrieveHostedDomain(jwtToken);
                for (String domain : domains) {
                    if (domain.equalsIgnoreCase(hdClaim)) {
                        domainMatched = true;
                        break;
                    }
                }
                if (!domainMatched) {
                    // TODO(davido): improve error reporting in OAuth extension point
                    log.error("Error: hosted domain validation failed: {}", Strings.nullToEmpty(hdClaim));
                    return null;
                }
            }
            if (useEmailAsUsername && !email.isJsonNull()) {
                login = email.getAsString().split("@")[0];
            }
            return new OAuthUserInfo(GOOGLE_PROVIDER_PREFIX + id.getAsString() /*externalId*/, login /*username*/,
                    email == null || email.isJsonNull() ? null : email.getAsString() /*email*/,
                    name == null || name.isJsonNull() ? null : name.getAsString() /*displayName*/,
                    fixLegacyUserId ? id.getAsString() : null /*claimedIdentity*/);
        }

        throw new IOException(String.format("Invalid JSON '%s': not a JSON Object", userJson));
    }

    private JsonObject retrieveJWTToken(OAuthToken token) {
        JsonElement idToken = JSON.newGson().fromJson(token.getRaw(), JsonElement.class);
        if (idToken != null && idToken.isJsonObject()) {
            JsonObject idTokenObj = idToken.getAsJsonObject();
            JsonElement idTokenElement = idTokenObj.get("id_token");
            if (idTokenElement != null && !idTokenElement.isJsonNull()) {
                String payload = decodePayload(idTokenElement.getAsString());
                if (!Strings.isNullOrEmpty(payload)) {
                    JsonElement tokenJsonElement = JSON.newGson().fromJson(payload, JsonElement.class);
                    if (tokenJsonElement.isJsonObject()) {
                        return tokenJsonElement.getAsJsonObject();
                    }
                }
            }
        }
        return null;
    }

    private static String retrieveHostedDomain(JsonObject jwtToken) {
        JsonElement hdClaim = jwtToken.get("hd");
        if (hdClaim != null && !hdClaim.isJsonNull()) {
            String hd = hdClaim.getAsString();
            log.debug("OAuth2: hd={}", hd);
            return hd;
        }
        log.debug("OAuth2: JWT doesn't contain hd element");
        return null;
    }

    /**
     * Decode payload from JWT according to spec: "header.payload.signature"
     *
     * @param idToken Base64 encoded tripple, separated with dot
     * @return openid_id part of payload, when contained, null otherwise
     */
    private static String decodePayload(String idToken) {
        Preconditions.checkNotNull(idToken);
        String[] jwtParts = idToken.split("\\.");
        Preconditions.checkState(jwtParts.length == 3);
        String payloadStr = jwtParts[1];
        Preconditions.checkNotNull(payloadStr);
        return new String(Base64.decodeBase64(payloadStr));
    }

    @Override
    public OAuthToken getAccessToken(OAuthVerifier rv) {
        Verifier vi = new Verifier(rv.getValue());
        Token to = service.getAccessToken(null, vi);
        OAuthToken result = new OAuthToken(to.getToken(), to.getSecret(), to.getRawResponse());
        return result;
    }

    @Override
    public String getAuthorizationUrl() {
        String url = service.getAuthorizationUrl(null);
        try {
            if (domains.size() == 1) {
                url += "&hd=" + URLEncoder.encode(domains.get(0), StandardCharsets.UTF_8.name());
            } else if (domains.size() > 1) {
                url += "&hd=*";
            }
        } catch (UnsupportedEncodingException e) {
            throw new IllegalArgumentException(e);
        }
        if (log.isDebugEnabled()) {
            log.debug("OAuth2: authorization URL={}", url);
        }
        return url;
    }

    @Override
    public String getVersion() {
        return service.getVersion();
    }

    @Override
    public String getName() {
        return "Google OAuth2";
    }
}