OAuth1aTokenExtractor.java

/*
 * Copyright 2016 LINE Corporation
 *
 * LINE Corporation licenses this file to you 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.linecorp.armeria.server.http.auth;

import java.util.function.Function;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Strings;
import com.google.common.collect.ImmutableMap;

import com.linecorp.armeria.common.http.HttpHeaderNames;
import com.linecorp.armeria.common.http.HttpHeaders;

/**
 * Extracts {@link OAuth1aToken} from {@link HttpHeaders}, in order to be used by
 * {@link HttpAuthServiceBuilder}.
 */
final class OAuth1aTokenExtractor implements Function<HttpHeaders, OAuth1aToken> {

    private static final Logger logger = LoggerFactory.getLogger(OAuth1aTokenExtractor.class);
    private static final Pattern AUTHORIZATION_HEADER_PATTERN = Pattern.compile(
            "\\s*(?i)oauth\\s+(?<parameters>\\S+)\\s*");

    @Override
    public OAuth1aToken apply(HttpHeaders headers) {
        String authorization = headers.get(HttpHeaderNames.AUTHORIZATION);
        if (Strings.isNullOrEmpty(authorization)) {
            return null;
        }

        Matcher matcher = AUTHORIZATION_HEADER_PATTERN.matcher(authorization);
        if (!matcher.matches()) {
            logger.warn("Invalid authorization header: " + authorization);
            return null;
        }

        ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
        for (String token : matcher.group("parameters").split(",")) {
            int sep = token.indexOf('=');
            if (sep == -1 || token.charAt(sep + 1) != '"' || token.charAt(token.length() - 1) != '"') {
                logger.warn("Invalid token: " + token);
                return null;
            }
            String key = token.substring(0, sep);
            String value = token.substring(sep + 2, token.length() - 1);
            builder.put(key, value);
        }

        return OAuth1aToken.of(builder.build());
    }
}