/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* 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 org.apache.shindig.gadgets.oauth2.handler;
import java.io.UnsupportedEncodingException;
import java.security.GeneralSecurityException;
import org.apache.commons.codec.binary.Base64;
import org.apache.shindig.common.crypto.Crypto;
import org.apache.shindig.common.uri.Uri;
import org.apache.shindig.gadgets.http.HttpRequest;
import org.apache.shindig.gadgets.oauth2.OAuth2Accessor;
import org.apache.shindig.gadgets.oauth2.OAuth2Error;
import org.apache.shindig.gadgets.oauth2.OAuth2Message;
import org.apache.shindig.gadgets.oauth2.OAuth2Token;
/**
*
* See {@link ResourceRequestHandler}
*
* Handles the mac token type
*/
public class MacTokenHandler implements ResourceRequestHandler {
public static final String TOKEN_TYPE = OAuth2Message.MAC_TOKEN_TYPE;
private static final OAuth2Error ERROR = OAuth2Error.MAC_TOKEN_PROBLEM;
public MacTokenHandler() {
}
public OAuth2HandlerError addOAuth2Params(final OAuth2Accessor accessor, final HttpRequest request) {
try {
final OAuth2HandlerError handlerError = MacTokenHandler.validateOAuth2Params(accessor, request);
if (handlerError != null) {
return handlerError;
}
final OAuth2Token accessToken = accessor.getAccessToken();
String ext = accessToken.getMacExt();
if ((ext == null) || (ext.length() == 0)) {
ext = "";
}
// REQUIRED. The MAC key identifier.
final String id = new String(accessToken.getSecret(), "UTF-8");
// REQUIRED. A unique string generated by the client to allow the
// server to verify that a request has never been made before and
// helps prevent replay attacks when requests are made over an
// insecure channel. The nonce value MUST be unique across all
// requests with the same MAC key identifier.
// The nonce value MUST consist of the age of the MAC credentials
// expressed as the number of seconds since the credentials were
// issued to the client, a colon character (%x25), and a unique
// string (typically random). The age value MUST be a positive
// integer and MUST NOT include leading zeros (e.g.
// "000137131200"). For example: "273156:di3hvdf8".
// To avoid the need to retain an infinite number of nonce values
// for future checks, the server MAY choose to restrict the time
// period after which a request with an old age is rejected. If
// such a restriction is enforced, the server SHOULD allow for a
// sufficiently large window to accommodate network delays which
// will affect the credentials issue time used by the client to
// calculate the credentials' age.
final long currentTime = System.currentTimeMillis() / 1000;
final String nonce = Long.toString(currentTime - accessToken.getIssuedAt()) + ':'
+ String.valueOf(Math.abs(Crypto.RAND.nextLong()));
// OPTIONAL. The HTTP request payload body hash as described in
// Section 3.2.
String bodyHash = MacTokenHandler.getBodyHash(request, accessToken.getMacSecret(),
accessToken.getMacAlgorithm());
if (bodyHash == null) {
bodyHash = "";
}
// mac
// REQUIRED. The HTTP request MAC as described in Section 3.3.
final Uri uri = request.getUri();
String uriString = uri.getPath();
if (uri.getQuery() != null) {
uriString = uriString + '?' + uri.getQuery();
}
String host = uri.getAuthority();
String port = "80";
final int index = host.indexOf(':');
if (index > 0) {
port = host.substring(index + 1);
host = host.substring(0, index);
} else {
final String scheme = uri.getScheme();
if ("https".equals(scheme)) {
port = "443";
}
}
final String mac = MacTokenHandler.getMac(nonce, request.getMethod(), uriString, host, port,
bodyHash, ext, accessToken.getMacSecret(), accessToken.getMacAlgorithm());
final String headerString = buildHeaderString(id, nonce, bodyHash, ext, mac);
request.setHeader(OAuth2Message.AUTHORIZATION_HEADER, headerString);
return null;
} catch (final Exception e) {
return MacTokenHandler.getError("Exception occurred " + e.getMessage(), e);
}
}
private static String buildHeaderString(String id, String nonce, String bodyHash, String ext, String mac) {
final StringBuilder headerString = new StringBuilder();
headerString.append(OAuth2Message.MAC_HEADER);
headerString.append(" id = \"");
headerString.append(id);
headerString.append("\",");
headerString.append(OAuth2Message.NONCE);
headerString.append("=\"");
headerString.append(nonce);
if (bodyHash.length() > 0) {
headerString.append("\",");
headerString.append(OAuth2Message.BODYHASH);
headerString.append("=\"");
headerString.append(bodyHash);
}
if (ext.length() > 0) {
headerString.append("\",");
headerString.append(OAuth2Message.MAC_EXT);
headerString.append("=\"");
headerString.append(ext);
}
headerString.append("\",");
headerString.append(OAuth2Message.MAC);
headerString.append("=\"");
headerString.append(mac);
headerString.append('\"');
return headerString.toString();
}
private static OAuth2HandlerError validateOAuth2Params(OAuth2Accessor accessor, HttpRequest request) {
if ((accessor == null) || (!accessor.isValid()) || (accessor.isErrorResponse())) {
return MacTokenHandler.getError("accessor is invalid " + accessor);
}
if (request == null) {
return MacTokenHandler.getError("request is null");
}
final OAuth2Token accessToken = accessor.getAccessToken();
if ((accessToken == null) || (accessToken.getTokenType().length() == 0)) {
return MacTokenHandler.getError("accessToken is invalid " + accessToken);
}
if (!MacTokenHandler.TOKEN_TYPE.equalsIgnoreCase(accessToken.getTokenType())) {
return MacTokenHandler.getError("token type mismatch expected " + MacTokenHandler.TOKEN_TYPE
+ " but got " + accessToken.getTokenType());
}
final String algorithm = accessToken.getMacAlgorithm();
if ((algorithm == null) || (algorithm.length() == 0)) {
return MacTokenHandler.getError("invalid mac algorithm " + algorithm);
}
if (!OAuth2Message.HMAC_SHA_1.equalsIgnoreCase(algorithm)) {
return MacTokenHandler.getError("unsupported algorithm " + algorithm);
}
final byte[] macSecret = accessToken.getMacSecret();
if (macSecret == null) {
return MacTokenHandler.getError("mac secret is null");
}
if (macSecret.length == 0) {
return MacTokenHandler.getError("invalid mac secret");
}
return null;
}
public String getTokenType() {
return MacTokenHandler.TOKEN_TYPE;
}
private static String getBodyHash(final HttpRequest request, final byte[] key,
final String algorithm) throws UnsupportedEncodingException, GeneralSecurityException {
if (request.getPostBodyLength() > 0) {
final byte[] text = MacTokenHandler.getBody(request);
final byte[] hashed = MacTokenHandler.hash(text, key, algorithm);
return new String(hashed, "UTF-8");
}
return "";
}
private static byte[] getBody(final HttpRequest request) throws UnsupportedEncodingException {
return request.getPostBodyAsString().getBytes("UTF-8");
}
private static String getMac(final String nonce, final String method, final String uri,
final String host, final String port, final String bodyHash, final String ext,
final byte[] key, final String algorithm) throws UnsupportedEncodingException,
GeneralSecurityException {
final StringBuilder normalizedRequestString = MacTokenHandler.getNormalizedRequestString(nonce,
method, uri, host, port, bodyHash, ext);
final byte[] normalizedRequestBytes = normalizedRequestString.toString().getBytes("UTF-8");
final byte[] mac = MacTokenHandler.hash(normalizedRequestBytes, key, algorithm);
final byte[] encodedBytes = Base64.encodeBase64(mac);
return new String(encodedBytes, "UTF-8");
}
private static byte[] hash(final byte[] text, byte[] key, final String algorithm)
throws GeneralSecurityException {
if (OAuth2Message.HMAC_SHA_1.equalsIgnoreCase(algorithm)) {
return Crypto.hmacSha1(key, text);
}
return new byte[] {};
}
private static StringBuilder getNormalizedRequestString(final String nonce, final String method,
final String uri, final String host, final String port, final String bodyHash,
final String ext) {
final StringBuilder ret = new StringBuilder();
ret.append(nonce);
ret.append('\n');
ret.append(method);
ret.append('\n');
ret.append(uri);
ret.append('\n');
ret.append(host);
ret.append('\n');
ret.append(port);
ret.append('\n');
ret.append(bodyHash);
ret.append('\n');
ret.append(ext);
ret.append('\n');
return ret;
}
private static OAuth2HandlerError getError(final String contextMessage) {
return MacTokenHandler.getError(contextMessage, null);
}
private static OAuth2HandlerError getError(final String contextMessage, final Exception e) {
return new OAuth2HandlerError(MacTokenHandler.ERROR, contextMessage, e);
}
}