使用IText7将数字签名添加到PDF

Question

对于IText5，添加数字签名相当容易。其留档的链接是：http://developers.itextpdf.com/examples/security/digital-signatures-white-paper/digital-signatures-chapter-2

有人可以在ITEXT 7中共享文档链接吗？我试过各种方法，但都没有用。在网上找不到任何链接。我可以取消签名并检查签名，但不能添加。

Answer 1

iText 7的数字签名白皮书代码示例的端口可以在iText 7 Java签名示例github repository test sources包com中找到。itextpdf。样品。签名，例如简单C2_01_SignHelloWorld示例的摘录：

public void sign(String src, String dest,
                 Certificate[] chain,
                 PrivateKey pk, String digestAlgorithm, String provider,
                 PdfSigner.CryptoStandard subfilter,
                 String reason, String location)
        throws GeneralSecurityException, IOException {
    // Creating the reader and the signer
    PdfReader reader = new PdfReader(src);
    PdfSigner signer = new PdfSigner(reader, new FileOutputStream(dest), false);
    // Creating the appearance
    PdfSignatureAppearance appearance = signer.getSignatureAppearance()
            .setReason(reason)
            .setLocation(location)
            .setReuseAppearance(false);
    Rectangle rect = new Rectangle(36, 648, 200, 100);
    appearance
            .setPageRect(rect)
            .setPageNumber(1);
    signer.setFieldName("sig");
    // Creating the signature
    IExternalSignature pks = new PrivateKeySignature(pk, digestAlgorithm, provider);
    IExternalDigest digest = new BouncyCastleDigest();
    signer.signDetached(digest, pks, chain, null, null, null, 0, subfilter);
}