Add Metadata pop-up (extract encryption dictionary)

src/core/crypto.js

@@ -1183,6 +1183,16 @@ class CipherTransformFactory {
     }
   }
 
+  getEncryptionDictionary() {
+    const encryptionDict = {};
+    ["V", "R", "O", "U", "OE", "UE", "P"]
+      .forEach((key) => {
+        const value = this.dict.get(key);
+        if (value != null) encryptionDict[key] = value;
+      });
+    return encryptionDict;
+  }
+
   createCipherTransform(num, gen) {
     if (this.algorithm === 4 || this.algorithm === 5) {
       return new CipherTransform(

src/core/document.js

@@ -2131,6 +2131,10 @@ class ExtendedPDFDocument extends PDFDocument {
   get structureTree() {
     return shadow(this, "structureTree", this.catalog.structureTree);
   }
+
+  get encryptionDictionary() {
+    return shadow(this, "encryptionDictionary", this.xref.getEncryptionDictionary());
+  }
 }
 
 export { Page, ExtendedPDFDocument as PDFDocument };

src/core/worker.js

@@ -177,18 +177,19 @@ class WorkerMessageHandler {
         finishWorkerTask(task);
       }
 
-      const [numPages, fingerprints, structureTree] = await Promise.all([
+      const [numPages, fingerprints, structureTree, encryptionDictionary] = await Promise.all([
         pdfManager.ensureDoc("numPages"),
         pdfManager.ensureDoc("fingerprints"),
         pdfManager.ensureDoc("structureTree"),
+        pdfManager.ensureDoc("encryptionDictionary"),
       ]);
 
       // Get htmlForXfa after numPages to avoid to create HTML twice.
       const htmlForXfa = isPureXfa
         ? await pdfManager.ensureDoc("htmlForXfa")
         : null;
 
-      return { numPages, fingerprints, htmlForXfa, structureTree };
+      return { numPages, fingerprints, htmlForXfa, structureTree, encryptionDictionary };
     }
 
     async function getPdfManager({

src/core/xref.js

@@ -163,6 +163,10 @@ class XRef {
     throw new InvalidPDFException("Invalid Root reference.");
   }
 
+  getEncryptionDictionary() {
+    return this.encrypt?.getEncryptionDictionary();
+  }
+
   processXRefTable(parser) {
     if (!("tableState" in this)) {
       // Stores state of the table as we process it so we can resume