我想执行数字签名程序并签名pdf。 为了那个原因 1.我使用以下源代码 Java Code 2.对于证书，使用此链接创建自签名证书并导出到pfx。 How to create self signed certi 3.现在尝试执行以下程序但仍然给出以下错误
/*
* This class is part of the book "iText in Action - 2nd Edition"
* written by Bruno Lowagie (ISBN: 9781935182610)
* For more info, go to: http://itextpdf.com/examples/
* This example only works with the AGPL version of iText.
*/
package iText;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.Security;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.Properties;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.AcroFields;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfSignatureAppearance;
import com.itextpdf.text.pdf.PdfStamper;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.pdf.security.BouncyCastleDigest;
import com.itextpdf.text.pdf.security.CertificateInfo;
import com.itextpdf.text.pdf.security.CertificateVerification;
import com.itextpdf.text.pdf.security.ExternalDigest;
import com.itextpdf.text.pdf.security.ExternalSignature;
import com.itextpdf.text.pdf.security.MakeSignature.CryptoStandard;
import com.itextpdf.text.pdf.security.PrivateKeySignature;
import com.itextpdf.text.pdf.security.MakeSignature;
import com.itextpdf.text.pdf.security.PdfPKCS7;
import com.itextpdf.text.pdf.security.VerificationException;
public class Signatures {
/**
* The resulting PDF
*/
public static String ORIGINAL = "C:\\Users\\02948\\Desktop\\hello.pdf";
/**
* The resulting PDF
*/
public static String SIGNED1 = "C:\\Users\\02948\\Desktop\\signature_1.pdf";
/**
* The resulting PDF
*/
public static String SIGNED2 = "C:\\Users\\02948\\Desktop\\signature_2.pdf";
/**
* Info after verification of a signed PDF
*/
public static String VERIFICATION = "C:\\Users\\02948\\Desktop\\verify.txt";
/**
* The resulting PDF
*/
public static String REVISION = "C:\\Users\\02948\\Desktop\\revision_1.pdf";
/**
* A properties file that is PRIVATE. You should make your own properties
* file and adapt this line.
*/
public static String PATH = "C:\\Users\\02948\\Documents\\NetBeansProjects\\DigiSig\\src\\digisig\\key.properties";
/**
* Some properties used when signing.
*/
public static Properties properties = new Properties();
/**
* One of the resources.
*/
// public static final String RESOURCE = "resources/img/logo.gif";
/**
* Creates a PDF document.
*
* @param filename the path to the new PDF document
* @throws DocumentException
* @throws IOException
*/
public void createPdf(String filename) throws IOException, DocumentException {
Document document = new Document();
PdfWriter.getInstance(document, new FileOutputStream(filename));
document.open();
document.add(new Paragraph("Hello World!"));
document.close();
}
/**
* Manipulates a PDF file src with the file dest as result
*
* @param src the original PDF
* @param dest the resulting PDF
* @throws IOException
* @throws DocumentException
* @throws GeneralSecurityException
*/
public void signPdfFirstTime(String src, String dest)
throws IOException, DocumentException, GeneralSecurityException {
// String path = properties.getProperty("PRIVATE");
// String keystore_password = properties.getProperty("PASSWORD");
// String key_password = properties.getProperty("PASSWORD");
String path = "C:\\Users\\02948\\Desktop\\kandarp.pfx";
String keystore_password = "kandarp";
String key_password = "kandarp";
KeyStore ks = KeyStore.getInstance("pkcs12", "BC");
ks.load(new FileInputStream(path), keystore_password.toCharArray());
String alias = (String) ks.aliases().nextElement();
PrivateKey pk = (PrivateKey) ks.getKey(alias, key_password.toCharArray());
Certificate[] chain = ks.getCertificateChain(alias);
// reader and stamper
PdfReader reader = new PdfReader(src);
FileOutputStream os = new FileOutputStream(dest);
PdfStamper stamper = PdfStamper.createSignature(reader, os, '\0');
// appearance
PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
// appearance.setImage(Image.getInstance(RESOURCE));
appearance.setReason("I've written this.");
appearance.setLocation("Foobar");
appearance.setVisibleSignature(new Rectangle(72, 732, 144, 780), 1, "first");
// digital signature
ExternalSignature es = new PrivateKeySignature(pk, "SHA-256", "BC");
ExternalDigest digest = new BouncyCastleDigest();
MakeSignature.signDetached(appearance, digest, es, chain, null, null, null, 0, CryptoStandard.CMS);
}
/**
* Manipulates a PDF file src with the file dest as result
*
* @param src the original PDF
* @param dest the resulting PDF
* @throws IOException
* @throws DocumentException
* @throws GeneralSecurityException
*/
public void signPdfSecondTime(String src, String dest)
throws IOException, DocumentException, GeneralSecurityException {
String path = "resources/encryption/.keystore";
String keystore_password = "f00b4r";
String key_password = "f1lmf3st";
String alias = "foobar";
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(new FileInputStream(path), keystore_password.toCharArray());
PrivateKey pk = (PrivateKey) ks.getKey(alias, key_password.toCharArray());
Certificate[] chain = ks.getCertificateChain(alias);
// reader / stamper
PdfReader reader = new PdfReader(src);
FileOutputStream os = new FileOutputStream(dest);
PdfStamper stamper = PdfStamper.createSignature(reader, os, '\0', null, true);
// appearance
PdfSignatureAppearance appearance = stamper
.getSignatureAppearance();
appearance.setReason("I'm approving this.");
appearance.setLocation("Foobar");
appearance.setVisibleSignature(new Rectangle(160, 732, 232, 780), 1, "second");
// digital signature
ExternalSignature es = new PrivateKeySignature(pk, "SHA-256", "BC");
ExternalDigest digest = new BouncyCastleDigest();
MakeSignature.signDetached(appearance, digest, es, chain, null, null, null, 0, CryptoStandard.CMS);
}
/**
* Verifies the signatures of a PDF we've signed twice.
*
* @throws GeneralSecurityException
* @throws IOException
*/
public void verifySignatures() throws GeneralSecurityException, IOException {
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(null, null);
CertificateFactory cf = CertificateFactory.getInstance("X509");
FileInputStream is1 = new FileInputStream(properties.getProperty("ROOTCERT"));
X509Certificate cert1 = (X509Certificate) cf.generateCertificate(is1);
ks.setCertificateEntry("cacert", cert1);
FileInputStream is2 = new FileInputStream("resources/encryption/foobar.cer");
X509Certificate cert2 = (X509Certificate) cf.generateCertificate(is2);
ks.setCertificateEntry("foobar", cert2);
PrintWriter out = new PrintWriter(new FileOutputStream(VERIFICATION));
PdfReader reader = new PdfReader(SIGNED2);
AcroFields af = reader.getAcroFields();
ArrayList<String> names = af.getSignatureNames();
for (String name : names) {
out.println("Signature name: " + name);
out.println("Signature covers whole document: " + af.signatureCoversWholeDocument(name));
out.println("Document revision: " + af.getRevision(name) + " of " + af.getTotalRevisions());
PdfPKCS7 pk = af.verifySignature(name);
Calendar cal = pk.getSignDate();
Certificate[] pkc = pk.getCertificates();
out.println("Subject: " + CertificateInfo.getSubjectFields(pk.getSigningCertificate()));
out.println("Revision modified: " + !pk.verify());
List<VerificationException> errors = CertificateVerification.verifyCertificates(pkc, ks, null, cal);
if (errors.size() == 0) {
out.println("Certificates verified against the KeyStore");
} else {
out.println(errors);
}
}
out.flush();
out.close();
}
/**
* Extracts the first revision of a PDF we've signed twice.
*
* @throws IOException
*/
public void extractFirstRevision() throws IOException {
PdfReader reader = new PdfReader(SIGNED2);
AcroFields af = reader.getAcroFields();
FileOutputStream os = new FileOutputStream(REVISION);
byte bb[] = new byte[1028];
InputStream ip = af.extractRevision("first");
int n = 0;
while ((n = ip.read(bb)) > 0) {
os.write(bb, 0, n);
}
os.close();
ip.close();
}
/**
* Main method.
*
* @param args no arguments needed
* @throws DocumentException
* @throws IOException
* @throws GeneralSecurityException
*/
public static void main(String[] args)
throws IOException, DocumentException, GeneralSecurityException {
Security.addProvider(new BouncyCastleProvider());
FileInputStream fis = new FileInputStream("C:\\Users\\02948\\Desktop\\kandarp.pfx");
String password = "kandarp";
properties.load(new FileInputStream(PATH));
Signatures signatures = new Signatures();
signatures.createPdf(ORIGINAL);
signatures.signPdfFirstTime(ORIGINAL, SIGNED1);
signatures.signPdfSecondTime(SIGNED1, SIGNED2);
signatures.verifySignatures();
signatures.extractFirstRevision();
}
}
错误来了。帮助
Exception in thread "main" java.lang.NullPointerException
at com.itextpdf.text.pdf.security.PrivateKeySignature.<init>(PrivateKeySignature.java:77)
at iText.Signatures.signPdfFirstTime(Signatures.java:135)
at iText.Signatures.main(Signatures.java:252)
Java结果：1 建立成功（总时间：1秒）
答案 0 :(得分：0)
我也遇到了同样的问题。更改 Security.Provider 在创建 KeyStore 时起作用。 要么更改您的代码
KeyStore ks = KeyStore.getInstance("pkcs12", "BC");
到
KeyStore ks = KeyStore.getInstance("pkcs12");
或使用任何其他提供商：SunRsaSign、SunEC、SunJSSE、SunJGSS 有关提供程序类的更多信息：https://docs.oracle.com/javase/7/docs/api/java/security/Provider.html