Question

我有一个字符串中的编码签名数据（“＆gt; MIILwwYJKoZIhvcNAQcCoIILtDCCC7ACAQExDzANB ........”）

我需要将它与用于签名的pdf结合起来。

我正在使用以下代码

public class MyExternalSignatureContainer  implements ExternalSignatureContainer {
 protected byte[] sig;
 // String b64String;

    public MyExternalSignatureContainer(byte[] sig) {
    this.sig = sig;
}

@Override
public void modifySigningDictionary(PdfDictionary arg0) {
}

/**
String PKCS7Resp = "MIILwwYJKoZIhvcNAQcCoIILtDCCC7ACAQEx.........;
Base64Encoder b = new Base64Encoder();
    byte[] signedData = b.decode(PKCS7Resp.getBytes());

    PdfReader reader = new PdfReader("D:\\AADHAAR.pdf");
    FileOutputStream os = new FileOutputStream("D:\\AADHAAR1.pdf");

    ExternalSignatureContainer external = new MyExternalSignatureContainer(signedData);
    MakeSignature.signDeferred(reader, "}", os, external);

 *
 * @param arg0
 * @return
 * @throws GeneralSecurityException
 */
 @Override
public byte[] sign(java.io.InputStream in) throws GeneralSecurityException {
    throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}

public static void main(String [] args) throws DocumentException, IOException, GeneralSecurityException{
      Base64Encoder b = new Base64Encoder();
        byte[] signedData = b.decode(PKCS7Resp.getBytes());
       PdfReader reader = new PdfReader("D:\\AADHAAR.pdf");
      FileOutputStream os = new FileOutputStream("D:\\AADHAAR1.pdf");          
      ExternalSignatureContainer external = new MyExternalSignatureContainer(signedData);
         MakeSignature.signDeferred(reader, "}", os, external);
         }
          }

但显示错误

Exception in thread "main" com.itextpdf.text.DocumentException: No field
at com.itextpdf.text.pdf.security.MakeSignature.signDeferred(MakeSignature.java:246)
at test.MyExternalSignatureContainer.main(MyExternalSignatureContainer.java:131)
  C:\Users\admin\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1

BUILD FAILED（总时间：1秒）

排队

MakeSignature.signDeferred（reader，“}”，os，external）;

参考代码

KeyStore ks = KeyStore.getInstance("pkcs12");
ks.load(new FileInputStream("my_private_key.pfx"), "my_password".toCharArray());
String alias = (String)ks.aliases().nextElement();
PrivateKey key = (PrivateKey)ks.getKey(alias, "my_password".toCharArray());
Certificate[] chain = ks.getCertificateChain(alias);
PdfReader reader = new PdfReader("original.pdf");
FileOutputStream fout = new FileOutputStream("signed.pdf");
PdfStamper stp = PdfStamper.createSignature(reader, fout, '\0');
PdfSignatureAppearance sap = stp.getSignatureAppearance();
sap.setCrypto(key, chain, null, PdfSignatureAppearance.WINCER_SIGNED);
sap.setReason("I'm the author");
sap.setLocation("Lisbon");
// comment next line to have an invisible signature
sap.setVisibleSignature(new Rectangle(100, 100, 200, 200), 1, null);
sap.setExternalDigest(new byte[128], new byte[20], "RSA");
sap.preClose();
MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
byte buf[] = new byte[8192];
int n;
InputStream inp = sap.getRangeStream();
while ((n = inp.read(buf)) > 0) {
   messageDigest.update(buf, 0, n);
}
byte hash[] = messageDigest.digest();
PdfSigGenericPKCS sg = sap.getSigStandard();
PdfLiteral slit = (PdfLiteral)sg.get(PdfName.CONTENTS);
byte[] outc = new byte[(slit.getPosLength() - 2) / 2];
PdfPKCS7 sig = sg.getSigner();
Signature sign = Signature.getInstance("SHA1withRSA");
sign.initSign(key);
sign.update(hash);
sig.setExternalDigest(sign.sign(), hash, "RSA");
PdfDictionary dic = new PdfDictionary();
byte[] ssig = sig.getEncodedPKCS7();
System.arraycopy(ssig, 0, outc, 0, ssig.length);
dic.put(PdfName.CONTENTS, new PdfString(outc).setHexWriting(true));
sap.close(dic);

我做错了吗？

Answer 1

在第一步中，您将使用自动生成的名称创建签名字段：

sap.setVisibleSignature(new Rectangle(100, 100, 200, 200), 1, null);

授予关联的JavaDocs：

/**
 * Sets the signature to be visible. It creates a new visible signature field.
 * @param pageRect the position and dimension of the field in the page
 * @param page the page to place the field. The fist page is 1
 * @param fieldName the field name or <CODE>null</CODE> to generate automatically a new field name
 */
public void setVisibleSignature(Rectangle pageRect, int page, String fieldName)

稍后，您的行为就好像签名字段名称为“}”：

MakeSignature.signDeferred(reader, "}", os, external);

授予关联的JavaDocs：

/**
 * Signs a PDF where space was already reserved.
 * @param reader the original PDF
 * @param fieldName the field to sign. It must be the last field
 * @param outs the output PDF
 * @param externalSignatureContainer the signature container doing the actual signing. Only the 
 * method ExternalSignatureContainer.sign is used
 * @throws DocumentException
 * @throws IOException
 * @throws GeneralSecurityException 
 */
public static void signDeferred(PdfReader reader, String fieldName, OutputStream outs, ExternalSignatureContainer externalSignatureContainer) throws DocumentException, IOException, GeneralSecurityException

因此，更改代码以使这些名称匹配，即使用您知道不会被文档中的其他表单字段使用的固定名称，或使用PdfSignatureAppearance方法查询iText使用的生成名称

/**
 * Gets the field name.
 * @return the field name
 */
public java.lang.String getFieldName()

使用iText使用pdf嵌入Sigend数据

1 个答案: