用java对PDF进行数字签名和时间戳

Question

我想用Java将数字签名附加到PDF文件，然后用可信的时间戳权威机构对该文件进行时间戳。

我该怎么做？

Answer 1

将带有私钥的数字证书导出到pfx文件。

将iText与BouncyCastle一起使用：

Document document = new Document();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfWriter.getInstance(document, baos);
document.open();
document.add(new Paragraph("Hello World!"));
document.close();

    PdfReader reader = new PdfReader(baos.toByteArray());
    OutputStream os = new FileOutputStream("c:\temp\sign\test.pdf");
    PdfStamper stamper = PdfStamper.createSignature(reader, os, '');
    // Creating the appearance
    PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
    appearance.setReason("REASON");
    appearance.setLocation("LOCATION");
    appearance.setVisibleSignature(new Rectangle(36, 748, 144, 780), 1, "sig");
    Security.addProvider(new BouncyCastleProvider());
    FileInputStream fis = new FileInputStream("c:\ssl\test.pfx");
    String password = "myPassword";
    KeyStore ks = KeyStore.getInstance("pkcs12");
    ks.load(fis, password.toCharArray());
    String alias = ks.aliases().nextElement();
    PrivateKey pk = (PrivateKey) ks.getKey(alias, password.toCharArray());
    X509Certificate cert = (X509Certificate) ks.getCertificate(alias);
    TSAClient tsc = new TSAClientBouncyCastle("http://timestampserverURL/");
    ExternalDigest digest = new BouncyCastleDigest();
    ExternalSignature signature = new PrivateKeySignature(pk, "SHA-1", "BC");
    MakeSignature.signDetached(appearance, digest, signature, new Certificate[] { cert }, null, null, tsc, 0,
            CryptoStandard.CMS);

Maven依赖项：

<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.49</version>
</dependency>
<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcmail-jdk15on</artifactId>
    <version>1.49</version>
</dependency>
<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bctsp-jdk15on</artifactId>
    <version>1.46</version>
</dependency>

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.4.2</version>
</dependency>

Answer 2

您可以通过其HTTP RESTful接口使用Securo API。

应用的时间戳采用RFC3161分离格式，所有时间戳均由欧盟认可的合格认证机构颁发。

免责声明：securo的联合创始人

Answer 3

DigiStamp在SecureTime API工具包中提供PDF签名和时间戳功能，当您创建免费测试帐户时，您可以获得该功能的链接（并访问测试服务器）。该工具包使用BouncyCastle和旧的免费iText版本。

Qoppa有一个更新的工具包，包含一系列PDF功能，但使用它需要付费。

免责声明：我在DigiStamp