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Itext对pdf模板进行电子签名

Itext对pdf模板进行电子签名-IT大道
最近在研究Itext对pdf进行签章,记录一下。
可参照:http://developers.itextpdf.com/examples/security-itext5/digital-signatures-white-paper中的例子
一。准备相关文件:
1.背景色为空的印章图片
2.扩展名为.p12的证书(可自行百度keytool 生成证书 pkcs12)
3.一个使用acrobat处理过的pdf模板(使用数字签名表单)
二。引入相关maven依赖:
  

com.itextpdf

itextpdf

5.5.11

com.itextpdf

itext-asian

5.2.0

org.bouncycastle

bcprov-jdk15on

1.49

org.bouncycastle

bcpkix-jdk15on

1.49

三。编写相关代码,
1.编写签章类,收集签章相关信息

package com.example.itext.utils;

import com.itextpdf.text.pdf.PdfSignatureAppearance;
import com.itextpdf.text.pdf.security.MakeSignature;
import lombok.Data;

import java.security.PrivateKey;
import java.security.cert.Certificate;

@Data
public class SignatureInfo {
private String reason; //理由
private String location;//位置
private String digestAlgorithm;//摘要类型
private String imagePath;//图章路径
private String fieldName;//表单域名称
private Certificate[] chain;//证书链
private PrivateKey pk;//私钥
private int certificationLevel = 0; //批准签章
private PdfSignatureAppearance.RenderingMode renderingMode;//表现形式:仅描述,仅图片,图片和描述,签章者和描述
private MakeSignature.CryptoStandard subfilter;//支持标准,CMS,CADES
}
2.编写工具类,红色字体为完成签章的主体逻辑,以ByteArrayOutputStream充当输出流是为了完成多次签章,期间不会生成临时文件。MakeSignature.signDetached()方法每调用一次,必须重新获取
PdfSignatureAppearance对象,因为分析源码方法可知,该方法调用时,appearance对象的preClosed参数会被置为false。
package com.example.itext.utils;

import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfSignatureAppearance;
import com.itextpdf.text.pdf.PdfStamper;
import com.itextpdf.text.pdf.security.BouncyCastleDigest;
import com.itextpdf.text.pdf.security.DigestAlgorithms;
import com.itextpdf.text.pdf.security.ExternalDigest;
import com.itextpdf.text.pdf.security.ExternalSignature;
import com.itextpdf.text.pdf.security.MakeSignature;
import com.itextpdf.text.pdf.security.PrivateKeySignature;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.cert.Certificate;

public class ItextUtil {

public static final char[] PASSWORD = "123456".toCharArray();//keystory密码

/**

  • 单多次签章通用
  • @param src
  • @param target
  • @param signatureInfos
  • @throws GeneralSecurityException
  • @throws IOException
  • @throws DocumentException
    */
    public void sign(String src, String target, SignatureInfo... signatureInfos){
    InputStream inputStream = null;
    FileOutputStream outputStream = null;
    ByteArrayOutputStream result = new ByteArrayOutputStream();
    try {
    inputStream = new FileInputStream(src);
    for (SignatureInfo signatureInfo : signatureInfos) {
    ByteArrayOutputStream tempArrayOutputStream = new ByteArrayOutputStream();
    PdfReader reader = new PdfReader(inputStream);
    //创建签章工具PdfStamper ,最后一个boolean参数是否允许被追加签名
    PdfStamper stamper = PdfStamper.createSignature(reader, tempArrayOutputStream, '\0', null, true);
    // 获取数字签章属性对象
    PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
    appearance.setReason(signatureInfo.getReason());
    appearance.setLocation(signatureInfo.getLocation());
    //设置签名的签名域名称,多次追加签名的时候,签名预名称不能一样,图片大小受表单域大小影响(过小导致压缩)
    appearance.setVisibleSignature(signatureInfo.getFieldName());
    //读取图章图片
    Image image = Image.getInstance(signatureInfo.getImagePath());
    appearance.setSignatureGraphic(image);
    appearance.setCertificationLevel(signatureInfo.getCertificationLevel());
    //设置图章的显示方式,如下选择的是只显示图章(还有其他的模式,可以图章和签名描述一同显示)
    appearance.setRenderingMode(signatureInfo.getRenderingMode());
    // 摘要算法
    ExternalDigest digest = new BouncyCastleDigest();
    // 签名算法
    ExternalSignature signature = new PrivateKeySignature(signatureInfo.getPk(), signatureInfo.getDigestAlgorithm(), null);
    // 调用itext签名方法完成pdf签章
    MakeSignature.signDetached(appearance, digest, signature, signatureInfo.getChain(), null, null, null, 0, signatureInfo.getSubfilter());
    //定义输入流为生成的输出流内容,以完成多次签章的过程
             inputStream = new ByteArrayInputStream(tempArrayOutputStream.toByteArray());
    result = tempArrayOutputStream;
    }
    outputStream = new FileOutputStream(new File(target));
    outputStream.write(result.toByteArray());
    outputStream.flush();
    } catch (Exception e) {
    e.printStackTrace();
    } finally {
    try {
    if(null!=outputStream){
    outputStream.close();
    }
    if(null!=inputStream){
    inputStream.close();
    }
    if(null!=result){
    result.close();
    }
    } catch (IOException e) {
    e.printStackTrace();
    }
    }
    }

public static void main(String[] args) {
try {
ItextUtil app = new ItextUtil();
//将证书文件放入指定路径,并读取keystore ,获得私钥和证书链
String pkPath = app.getClass().getResource("/template/zhengshu.p12").getPath();
KeyStore ks = KeyStore.getInstance("PKCS12");
ks.load(new FileInputStream(pkPath), PASSWORD);
String alias = ks.aliases().nextElement();
PrivateKey pk = (PrivateKey) ks.getKey(alias, PASSWORD);
Certificate[] chain = ks.getCertificateChain(alias);
String src = http://www.cnblogs.com/watershine/p/app.getClass().getResource("/template/check.pdf").getPath();
     //封装签章信息
SignatureInfo info = new SignatureInfo();
info.setReason("理由");
info.setLocation("位置");
info.setPk(pk);
info.setChain(chain);
info.setCertificationLevel(PdfSignatureAppearance.NOT_CERTIFIED);
info.setDigestAlgorithm(DigestAlgorithms.SHA1);
info.setFieldName("sig1");
info.setImagePath(app.getClass().getResource("/template/yinzhang.png").getPath());
info.setRenderingMode(PdfSignatureAppearance.RenderingMode.GRAPHIC);

SignatureInfo info1 = new SignatureInfo();
info1.setReason("理由1");
info1.setLocation("位置1");
info1.setPk(pk);
info1.setChain(chain);
info1.setCertificationLevel(PdfSignatureAppearance.NOT_CERTIFIED);
info1.setDigestAlgorithm(DigestAlgorithms.SHA1);
info1.setFieldName("sig2");
info1.setImagePath(app.getClass().getResource("/template/yinzhang.png").getPath());
info1.setRenderingMode(PdfSignatureAppearance.RenderingMode.GRAPHIC);

app.sign(src, "D://sign.pdf", info,info1);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
至此,电子签章的代码整理完毕。
Tags:itext pdf 签名

正文到此结束