org.springframework.boot.ssl.pem.PemCertificateParser Maven / Gradle / Ivy
/*
* Copyright 2012-2023 the original author or authors.
*
* 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
*
* https://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.springframework.boot.ssl.pem;
import java.io.ByteArrayInputStream;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Base64;
import java.util.List;
import java.util.function.Consumer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
/**
* Parser for X.509 certificates in PEM format.
*
* @author Scott Frederick
* @author Phillip Webb
*/
final class PemCertificateParser {
private static final String HEADER = "-+BEGIN\\s+.*CERTIFICATE[^-]*-+(?:\\s|\\r|\\n)+";
private static final String BASE64_TEXT = "([a-z0-9+/=\\r\\n]+)";
private static final String FOOTER = "-+END\\s+.*CERTIFICATE[^-]*-+";
private static final Pattern PATTERN = Pattern.compile(HEADER + BASE64_TEXT + FOOTER, Pattern.CASE_INSENSITIVE);
private PemCertificateParser() {
}
/**
* Parse certificates from the specified string.
* @param text the text to parse
* @return the parsed certificates
*/
static List parse(String text) {
if (text == null) {
return null;
}
CertificateFactory factory = getCertificateFactory();
List certs = new ArrayList<>();
readCertificates(text, factory, certs::add);
Assert.state(!CollectionUtils.isEmpty(certs), "Missing certificates or unrecognized format");
return List.copyOf(certs);
}
private static CertificateFactory getCertificateFactory() {
try {
return CertificateFactory.getInstance("X.509");
}
catch (CertificateException ex) {
throw new IllegalStateException("Unable to get X.509 certificate factory", ex);
}
}
private static void readCertificates(String text, CertificateFactory factory, Consumer consumer) {
try {
Matcher matcher = PATTERN.matcher(text);
while (matcher.find()) {
String encodedText = matcher.group(1);
byte[] decodedBytes = decodeBase64(encodedText);
ByteArrayInputStream inputStream = new ByteArrayInputStream(decodedBytes);
while (inputStream.available() > 0) {
consumer.accept((X509Certificate) factory.generateCertificate(inputStream));
}
}
}
catch (CertificateException ex) {
throw new IllegalStateException("Error reading certificate: " + ex.getMessage(), ex);
}
}
private static byte[] decodeBase64(String content) {
byte[] bytes = content.replaceAll("\r", "").replaceAll("\n", "").getBytes();
return Base64.getDecoder().decode(bytes);
}
}