Java - 如何解码 Base64 编码的证书
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Java - How to decode a Base64 encoded Certificate
提问by Sujaikareik
Below is my requirement:
下面是我的要求：
- Program will have an xml file as input with 3 tags: , and . All these data are Base64 encoded. Note: Program is using BC jars
- Program needs to decode them and verify the data for its authenticity using the signature and certificate
- Verified data should be Base64 decoded and written into another file
- 程序将有一个 xml 文件作为输入，其中包含 3 个标签： , 和 . 所有这些数据都是 Base64 编码的。注意：程序使用 BC jars
- 程序需要解码它们并使用签名和证书验证数据的真实性
- 验证后的数据应进行 Base64 解码并写入另一个文件
Below is my code which tries to decode the certificate:
下面是我尝试解码证书的代码：
public void executeTask(InputStream arg0, OutputStream arg1) throws SomeException{
try{
BufferedReader br = null;
br = new BufferedReader(new InputStreamReader(arg0));
String orgContent = "", splitData = "", signContent = "", certContent = "";
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse(arg0);
doc.getDocumentElement().normalize();
NodeList originalContent = doc.getElementsByTagName("OrgContent");
Element originalElement = (Element)originalContent.item(0);
NodeList textOrgContent = originalElement.getChildNodes();
orgContent = ((Node)textOrgContent.item(0)).getNodeValue().trim();
NodeList signature = doc.getElementsByTagName("Signature");
Element signatureElement = (Element)signature.item(0);
NodeList signatureContent = signatureElement.getChildNodes();
signContent = ((Node)signatureContent.item(0)).getNodeValue().trim();
NodeList certificate = doc.getElementsByTagName("Certificate");
Element certificateElement = (Element)certificate.item(0);
NodeList certificateContent = certificateElement.getChildNodes();
certContent = ((Node)certificateContent.item(0)).getNodeValue().trim();
String decodedCertContent = new String(Base64.decode(certContent),StandardCharsets.UTF_8);
byte[] certByteValue = Base64.decode(certContent);
CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
System.out.println("certContent:\n" + new String(certByteValue,StandardCharsets.UTF_8));
InputStream inputStream = new ByteArrayInputStream(Base64.decode(certContent));
X509Certificate cert = (X509Certificate)certFactory.generateCertificate(inputStream);
arg1.write(decodedOrgData.getBytes());
arg1.flush();
}
catch (ParserConfigurationException e){
e.printStackTrace();
}
catch (IOException e){
e.printStackTrace();
}
catch (org.xml.sax.SAXException e){
e.printStackTrace();
}
catch (CertificateException e){
e.printStackTrace();
}
}
}
When I print the value of new String(certByteValue,StandardCharsets.UTF_8) the program is printing some unrecognizable text. When executing the last line of the code X509Certificate cert = (X509Certificate)certFactory.generateCertificate(inputStream);system is throwing java.security.cert.CertificateException: Could not parse certificate: java.io.IOException: Invalid BER/DER data (too huge?).
当我打印 new String(certByteValue,StandardCharsets.UTF_8) 的值时，程序正在打印一些无法识别的文本。当执行代码X509Certificate cert = (X509Certificate)certFactory.generateCertificate(inputStream);系统的最后一行时抛出 java.security.cert.CertificateException:Could not parse certificate: java.io.IOException: Invalid BER/DER data (too huge?)。
Since I am a newbie to these Certificates thing, I have hit a deadlock. I am unable to proceed with the requirement. I would like to know how to achieve my above said requirements.
由于我是这些证书的新手，我陷入了僵局。我无法继续执行该要求。我想知道如何实现我的上述要求。
EditThe input stream to the above code will be an xml file. Another program creates that xml file with base64 encoded data with signature and certificate. In that program, for encoding the certificate the below code is used:
编辑上述代码的输入流将是一个 xml 文件。另一个程序使用带有签名和证书的 base64 编码数据创建该 xml 文件。在该程序中，为了对证书进行编码，使用了以下代码：
KeyStore keyStore = KeyStore.getInstance("JKS");
keyStore.load(new FileInputStream("Filepath/certificate.p12"), "password".toCharArray());
PrivateKey privateKey = (PrivateKey)keyStore.getKey(alias, "password".toCharArray());
CertificateFactory factory = CertificateFactory.getInstance("X.509");
X509Certificate certificate = (X509Certificate) factory.generateCertificate(new FileInputStream("D:/Sujai/Implementation Team/PI/Axis Treds/Certificates/PI_7.5_Cert/Arteria_Certificate-cert.cert"));
byte[] encodedCert = certificate.getEncoded();
String encodedStringCert = new String(Base64.encode(new String(encodedCert).getBytes(StandardCharsets.UTF_8)));
The variable encodedStringCertis passed as the certificate value inside a tag. In the program shared at the top of this question, I need to decode this certificate value.
变量encodingStringCert作为标签内的证书值传递。在这个问题顶部共享的程序中，我需要解码这个证书值。
Sample certificate content: -----BEGIN CERTIFICATE----- MIIDBjCCAe6....IM1g== -----END CERTIFICATE-----
示例证书内容：-----BEGIN CERTIFICATE----- MIIDBjCCAe6....IM1g== -----END CERTIFICATE-----
回答by pedrofb
new String(certByteValue,StandardCharsets.UTF_8)fails because the certificate encoded data is not representable as string
new String(certByteValue,StandardCharsets.UTF_8)失败，因为证书编码的数据不能表示为字符串
The problem could be that the source data is not a base64 X509 certificate, or a encoding issue with your library Base64.decode(). I suggest use the standard decoder of java 8 Base64.getDecoder().decode()or DataTypeConverter.parseBase64Binary()for java >6
问题可能是源数据不是 base64 X509 证书，或者是您的库的编码问题Base64.decode()。我建议使用 java 8Base64.getDecoder().decode()或DataTypeConverter.parseBase64Binary()java > 6的标准解码器
Check also this working code to decode a base64 encoded certificate
还检查此工作代码以解码 base64 编码的证书
String certB64 = "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";
byte encodedCert[] = Base64.getDecoder().decode(certB64);
ByteArrayInputStream inputStream = new ByteArrayInputStream(encodedCert);
CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate)certFactory.generateCertificate(inputStream);
I assume that your certificate does not have the tags ----- BEGIN CERTIFICATE -----and ----- END CERTIFICATE -----
我假设您的证书没有标签----- BEGIN CERTIFICATE -----和----- END CERTIFICATE -----
EDITED
已编辑
You can load directly a .cerfile encoded in base64 PEM (with -----BEGIN CERTIFICATE-----tags).
您可以直接加载.cer以 base64 PEM 编码的文件（带-----BEGIN CERTIFICATE-----标签）。
FileInputStream inputStream = new FileInputStream (pathToYourCert);
CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate)certFactory.generateCertificate(inputStream);
