com.google.appengine.repackaged.com.google.datastore.v1.client.EndToEndChecksumHandler Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of appengine-api-1.0-sdk
Show all versions of appengine-api-1.0-sdk
API for Google App Engine standard environment with some of the dependencies shaded (repackaged)
/*
* Copyright 2021 Google LLC
*
* 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.datastore.v1.client;
import com.google.api.client.http.HttpResponse;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/** This class provides End-to-End Checksum API for http protocol. */
class EndToEndChecksumHandler {
/** The checksum http header on http requests */
static final String HTTP_REQUEST_CHECKSUM_HEADER = "x-request-checksum-348659783";
/** The checksum http header on http responses */
static final String HTTP_RESPONSE_CHECKSUM_HEADER = "x-response-checksum-348659783";
/** Algorithm used for checksum */
private static final String MD5 = "MD5";
/**
* Create and return checksum as a string value for the input 'bytes'.
*
* @param bytes raw message for which the checksum is being computed
* @return computed checksum as a hex string
* @throws RuntimeException if MD5 Algorithm is not found in the VM
*/
static String computeChecksum(byte[] bytes) {
if (bytes == null || (bytes.length == 0)) {
return null;
}
return com.google.common.io.BaseEncoding.base16()
.encode(getMessageDigestInstance().digest(bytes));
}
/**
* Validates the checksum for the given input 'bytes' and returns true if valid, false otherwise.
*
* @param checksum the checksum as a hex string
* @param bytes the raw message for which the checksum was sent
* @return {@code true} if input checksum is valid for the input bytes; {@code false} otherwise
*/
static boolean validateChecksum(String checksum, byte[] bytes) {
return checksum != null
&& !checksum.isEmpty()
&& bytes != null
&& bytes.length > 0
&& checksum.equalsIgnoreCase(computeChecksum(bytes));
}
static MessageDigest getMessageDigestInstance() {
try {
return MessageDigest.getInstance(MD5);
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException("MD5 algorithm is not found when computing checksum!");
}
}
static boolean hasChecksumHeader(HttpResponse response) {
String checksum = getChecksumHeader(response);
return checksum != null && !checksum.isEmpty();
}
static String getChecksumHeader(HttpResponse response) {
return response.getHeaders().getFirstHeaderStringValue(HTTP_RESPONSE_CHECKSUM_HEADER);
}
}