Apache PDFBox-无法解密PDF

Question

package com.test;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.pdmodel.encryption.StandardDecryptionMaterial;
import org.apache.pdfbox.pdmodel.encryption.StandardProtectionPolicy;

public class PdfEncDecTest {

    static String pdfPath = "G:\\files\\filed5b3.pdf";
    public final static String PDF_OWNER_PASSWORD = "cd1j";
    public final static String PDF_USER_PASSWORD = "";  

    public static void main(String[] args) throws Exception {

        PDDocument document = PDDocument.load(pdfPath);
        AccessPermission ap = new AccessPermission();
        ap.setCanPrint(true);
        ap.setCanExtractContent(false);
        ap.setCanExtractForAccessibility(false);
        StandardProtectionPolicy spp = new StandardProtectionPolicy(PDF_OWNER_PASSWORD, PDF_USER_PASSWORD, ap);
        document.protect(spp);
        document.save(pdfPath+".pdf");
        document.close();

        PDDocument doc = PDDocument.load(pdfPath+".pdf");
        if(doc.isEncrypted()) {
            StandardDecryptionMaterial sdm = new StandardDecryptionMaterial(PDF_OWNER_PASSWORD);
            doc.openProtection(sdm); // org.apache.pdfbox.exceptions.CryptographyException: Error: The supplied password does not match either the owner or user password in the document.
            doc.decrypt(PDF_OWNER_PASSWORD); // the same like above
        }
        doc.close();
    }

}

Exception in thread "main" org.apache.pdfbox.exceptions.CryptographyException: Error: The supplied password does not match either the owner or user password in the document.
    at org.apache.pdfbox.pdmodel.encryption.StandardSecurityHandler.prepareForDecryption(StandardSecurityHandler.java:265)
    at org.apache.pdfbox.pdmodel.encryption.StandardSecurityHandler.decryptDocument(StandardSecurityHandler.java:156)
    at org.apache.pdfbox.pdmodel.PDDocument.openProtection(PDDocument.java:1595)
    at org.apache.pdfbox.pdmodel.PDDocument.decrypt(PDDocument.java:942)
    at com.test.PdfEncDecTest.main(PdfEncDecTest.java:29)

我已经将示例项目放入GitHub：https://github.com/marioosh-net/pdfbox

Answer 1

您需要用户密码。

    if (doc.isEncrypted())
    {
        StandardDecryptionMaterial sdm = new StandardDecryptionMaterial(PDF_USER_PASSWORD);
        doc.openProtection(sdm);
        // don't call decrypt() here
    }

即使用户密码不为NULL,也可以执行此操作。用户密码是普通人认为的加密，所有者密码是安全权限的加密。

编辑：对不起，我的答案是错误的，虽然它是有帮助的。您可以使用用户密码（您可能获得受限权限）或所有者密码（您将获得完全权限）打开PDF。可能发生的情况是存在一个与40bit密钥匹配所有者密码的bug（这是默认值）。目前正在调查此错误，请参阅PDFBOX-2456并搜索“MD5”。