本文介绍了带检查CRL的iText验证签名的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在设置验证器,该验证器可以检查签名的有效性。
我所做的签名基于DSS级别LT,因此吊销检查内置于文档中。
我现在遇到的问题是在我用iText开发的验证器级别。它允许对签名的有效性进行核实,但可以对撤销信息进行核实。根据我的研究,IText允许基于以下条件在签名本身中验证此信息:pkcs7.getCrl()。
但是,DSS签名将吊销信息合并到词典中。
以下是我用来验证签名的代码:
import com.itextpdf.text.pdf.AcroFields;
import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfString;
import com.itextpdf.text.pdf.security.PdfPKCS7;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.Principal;
import java.security.cert.X509Certificate;
import java.util.Calendar;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.security.Security;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
public class TestCheck {
public static String pdf_file = "CURRENT_SIGNATURE.pdf";
public static final boolean verifySignature(PdfReader pdfReader)
throws GeneralSecurityException, IOException {
boolean valid = false;
AcroFields acroFields = pdfReader.getAcroFields();
PdfDictionary sigDict = acroFields.getSignatureDictionary("Signature1");
System.out.println(sigDict);
PdfString contents = sigDict.getAsString(PdfName.CONTENTS);
List<String> signatureNames = acroFields.getSignatureNames();
if (!signatureNames.isEmpty()) {
for (String name : signatureNames) {
// if (acroFields.signatureCoversWholeDocument(name)) {
PdfPKCS7 pkcs7 = acroFields.verifySignature(name);
valid = pkcs7.verify();
String reason = pkcs7.getReason();
Calendar signedAt = pkcs7.getSignDate();
X509Certificate signingCertificate = pkcs7.getSigningCertificate();
Principal issuerDN = signingCertificate.getIssuerDN();
Principal subjectDN = signingCertificate.getSubjectDN();
System.out.println("valid = "+valid);
//System.out.println("date = "+signedAt.getTime());
////System.out.println("reason = "+reason);
//System.out.println("issuer = "+issuerDN);
//System.out.println("subject = "+subjectDN);
System.out.println("CRL : " + pkcs7.getCRLs());
break;
}
// }
}
return valid;
}
public static void main(String[] args) throws Exception {
BouncyCastleProvider provider = new BouncyCastleProvider();
Security.addProvider(provider);
InputStream is = new FileInputStream(new File(pdf_file));
PdfReader reader = new PdfReader(is);
boolean ok = verifySignature(reader);
System.out.println("Ver : "+ ok);
}
}
推荐答案
最初我只想指向iText 5和iText 7提供的LtvVerifier
类。然而,使用该类进行测试后,发现它不适用于当前的PADES基线配置文件,而是专为较旧的PADES-LTV配置文件设计的(请参阅ETSI TS102778-4第4节PADES-LTV&Q;配置文件)。
PdfReader pdfReader = new PdfReader(...);
PdfDictionary dss = pdfReader.getCatalog().getAsDict(PdfName.DSS);
if (dss == null)
System.out.println("No DSS in PDF");
else {
PdfArray crlarray = dss.getAsArray(PdfName.CRLS);
if (crlarray == null || crlarray.size() == 0)
System.out.println("No CRLs in DSS");
else {
System.out.println("CRLs:");
CertificateFactory cf = CertificateFactory.getInstance("X.509");
for (int i = 0; i < crlarray.size(); i++) {
PRStream stream = (PRStream) crlarray.getAsStream(i);
X509CRL crl = (X509CRL)cf.generateCRL(new ByteArrayInputStream(PdfReader.getStreamBytes(stream)));
System.out.printf(" '%s' update %s
", crl.getIssuerX500Principal(), crl.getThisUpdate());
}
}
PdfArray ocsparray = dss.getAsArray(PdfName.OCSPS);
if (ocsparray == null || ocsparray.size() == 0)
System.out.println("
No OCSP responses in DSS");
else {
System.out.println("
OCSP Responses:");
for (int i = 0; i < ocsparray.size(); i++) {
PRStream stream = (PRStream) ocsparray.getAsStream(i);
OCSPResp ocspResponse = new OCSPResp(PdfReader.getStreamBytes(stream));
if (ocspResponse.getStatus() == 0) {
try {
BasicOCSPResp basicOCSPResp = (BasicOCSPResp) ocspResponse.getResponseObject();
System.out.printf(" '%s' update %s
", basicOCSPResp.getResponderId(), basicOCSPResp.getProducedAt());
} catch (OCSPException e) {
throw new GeneralSecurityException(e);
}
}
}
}
}
(VerifyLtv测试testExtractRevocationInformationCURRENT_SIGNATURE
)
您当然可以收集CRL和OCSP响应并照常处理它们,而不是将信息打印到System.out
。
PdfPKCS7
对象检索的吊销数据和从DSS检索的数据。Adobe Acrobat在验证过程中也同时使用这两种工具。 这篇关于带检查CRL的iText验证签名的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!