Web and pdflib enhancements

Author: dcbr

packages/examples/src/pdf-lib.js

@@ -20,19 +20,17 @@ function work() {
         // Add a placeholder for a signature.
         pdflibAddPlaceholder({
             pdfDoc: pdfDoc,
-            reason: 'The user is decalaring consent through JavaScript.',
+            reason: 'The user is declaring consent through JavaScript.',
             contactInfo: 'signpdf@example.com',
             name: 'John Doe',
             location: 'Free Text Str., Free World',
         });
 
-        // Convert the PDF-LIB PDFDocument to Buffer
-        pdfDoc.save({useObjectStreams: false}).then(function (pdfBytes) {
-            var pdfWithPlaceholder = Buffer.from(pdfBytes);
-
+        // Get the modified PDFDocument bytes
+        pdfDoc.save().then(function (pdfWithPlaceholderBytes) {
             // And finally sign the document.
             signpdf
-                .sign(pdfWithPlaceholder, signer)
+                .sign(pdfWithPlaceholderBytes, signer)
                 .then(function (signedPdf) {
                     // signedPdf is a Buffer of an electronically signed PDF. Store it.
                     var targetPath = path.join(__dirname, '/../output/pdf-lib.pdf');

packages/placeholder-pdf-lib/dist/pdflibAddPlaceholder.d.ts

@@ -1,11 +1,13 @@
-export function pdflibAddPlaceholder({ pdfDoc, reason, contactInfo, name, location, signatureLength, byteRangePlaceholder, subFilter, widgetRect, }: InputType): void;
+export function pdflibAddPlaceholder({ pdfDoc, pdfPage, reason, contactInfo, name, location, signingTime, signatureLength, byteRangePlaceholder, subFilter, widgetRect, appName, }: InputType): void;
 export type PDFDocument = import('pdf-lib').PDFDocument;
 export type InputType = {
     pdfDoc: PDFDocument;
+    pdfPage: PDFPage;
     reason: string;
     contactInfo: string;
     name: string;
     location: string;
+    signingTime?: Date;
     signatureLength?: number;
     byteRangePlaceholder?: string;
     /**
@@ -16,5 +18,9 @@ export type InputType = {
      * [x1, y1, x2, y2] widget rectangle
      */
     widgetRect?: number[];
+    /**
+     * Name of the application generating the signature
+     */
+    appName?: string;
 };
 //# sourceMappingURL=pdflibAddPlaceholder.d.ts.map

packages/placeholder-pdf-lib/dist/pdflibAddPlaceholder.d.ts.map

@@ -13,14 +13,17 @@ var _pdfLib = require("pdf-lib");
 /**
 * @typedef {object} InputType
 * @property {PDFDocument} pdfDoc
+* @property {PDFPage} pdfPage
 * @property {string} reason
 * @property {string} contactInfo
 * @property {string} name
 * @property {string} location
+* @property {Date} [signingTime]
 * @property {number} [signatureLength]
 * @property {string} [byteRangePlaceholder]
 * @property {string} [subFilter] One of SUBFILTER_* from \@signpdf/utils
 * @property {number[]} [widgetRect] [x1, y1, x2, y2] widget rectangle
+* @property {string} [appName] Name of the application generating the signature
 */
 
 /**
@@ -32,21 +35,28 @@ var _pdfLib = require("pdf-lib");
  * @returns {void}
  */
 const pdflibAddPlaceholder = ({
-  pdfDoc,
+  pdfDoc = undefined,
+  pdfPage = undefined,
   reason,
   contactInfo,
   name,
   location,
+  signingTime = undefined,
   signatureLength = _utils.DEFAULT_SIGNATURE_LENGTH,
   byteRangePlaceholder = _utils.DEFAULT_BYTE_RANGE_PLACEHOLDER,
   subFilter = _utils.SUBFILTER_ADOBE_PKCS7_DETACHED,
-  widgetRect = [0, 0, 0, 0]
+  widgetRect = [0, 0, 0, 0],
+  appName = undefined
 }) => {
-  const page = pdfDoc.getPage(0);
+  if (pdfDoc === undefined && pdfPage === undefined) {
+    throw new _utils.SignPdfError('PDFDoc or PDFPage must be set.', _utils.SignPdfError.TYPE_INPUT);
+  }
+  const doc = pdfDoc !== null && pdfDoc !== void 0 ? pdfDoc : pdfPage.doc;
+  const page = pdfPage !== null && pdfPage !== void 0 ? pdfPage : doc.getPages()[0];
 
   // Create a placeholder where the the last 3 parameters of the
   // actual range will be replaced when signing is done.
-  const byteRange = _pdfLib.PDFArray.withContext(pdfDoc.context);
+  const byteRange = _pdfLib.PDFArray.withContext(doc.context);
   byteRange.push(_pdfLib.PDFNumber.of(0));
   byteRange.push(_pdfLib.PDFName.of(byteRangePlaceholder));
   byteRange.push(_pdfLib.PDFName.of(byteRangePlaceholder));
@@ -56,52 +66,77 @@ const pdflibAddPlaceholder = ({
   const placeholder = _pdfLib.PDFHexString.of(String.fromCharCode(0).repeat(signatureLength));
 
   // Create a signature dictionary to be referenced in the signature widget.
-  const signatureDict = pdfDoc.context.obj({
+  const appBuild = appName ? {
+    App: {
+      Name: appName
+    }
+  } : {};
+  const signatureDict = doc.context.obj({
     Type: 'Sig',
     Filter: 'Adobe.PPKLite',
     SubFilter: subFilter,
     ByteRange: byteRange,
     Contents: placeholder,
     Reason: _pdfLib.PDFString.of(reason),
-    M: _pdfLib.PDFString.fromDate(new Date()),
+    M: _pdfLib.PDFString.fromDate(signingTime !== null && signingTime !== void 0 ? signingTime : new Date()),
     ContactInfo: _pdfLib.PDFString.of(contactInfo),
     Name: _pdfLib.PDFString.of(name),
-    Location: _pdfLib.PDFString.of(location)
-  }, pdfDoc.index);
-  const signatureDictRef = pdfDoc.context.register(signatureDict);
+    Location: _pdfLib.PDFString.of(location),
+    Prop_Build: {
+      Filter: {
+        Name: 'Adobe.PPKLite'
+      },
+      ...appBuild
+    }
+  });
+  // Register signatureDict as a PDFInvalidObject to prevent PDFLib from serializing it
+  // in an object stream.
+  const signatureBuffer = new Uint8Array(signatureDict.sizeInBytes());
+  signatureDict.copyBytesInto(signatureBuffer, 0);
+  const signatureObj = _pdfLib.PDFInvalidObject.of(signatureBuffer);
+  const signatureDictRef = doc.context.register(signatureObj);
 
   // Create the signature widget
-  const rect = _pdfLib.PDFArray.withContext(pdfDoc.context);
+  const rect = _pdfLib.PDFArray.withContext(doc.context);
   widgetRect.forEach(c => rect.push(_pdfLib.PDFNumber.of(c)));
-  const widgetDict = pdfDoc.context.obj({
+  const apStream = doc.context.formXObject([], {
+    BBox: widgetRect,
+    Resources: {} // Necessary to avoid Acrobat bug (see https://stackoverflow.com/a/73011571)
+  });
+
+  const widgetDict = doc.context.obj({
     Type: 'Annot',
     Subtype: 'Widget',
     FT: 'Sig',
     Rect: rect,
     V: signatureDictRef,
     T: _pdfLib.PDFString.of('Signature1'),
     F: _utils.ANNOTATION_FLAGS.PRINT,
-    P: page.ref
-  }, pdfDoc.index);
-  const widgetDictRef = pdfDoc.context.register(widgetDict);
+    P: page.ref,
+    AP: {
+      N: doc.context.register(apStream)
+    } // Required for PDF/A compliance
+  });
+
+  const widgetDictRef = doc.context.register(widgetDict);
 
-  // Annotate the widget on the first page
+  // Annotate the widget on the given page
   let annotations = page.node.lookupMaybe(_pdfLib.PDFName.of('Annots'), _pdfLib.PDFArray);
   if (typeof annotations === 'undefined') {
-    annotations = pdfDoc.context.obj([]);
+    annotations = doc.context.obj([]);
   }
   annotations.push(widgetDictRef);
   page.node.set(_pdfLib.PDFName.of('Annots'), annotations);
 
   // Add an AcroForm or update the existing one
-  let acroForm = pdfDoc.catalog.lookupMaybe(_pdfLib.PDFName.of('AcroForm'), _pdfLib.PDFDict);
+  let acroForm = doc.catalog.lookupMaybe(_pdfLib.PDFName.of('AcroForm'), _pdfLib.PDFDict);
   if (typeof acroForm === 'undefined') {
     // Need to create a new AcroForm
-    acroForm = pdfDoc.context.obj({
+    acroForm = doc.context.obj({
       Fields: []
     });
-    const acroFormRef = pdfDoc.context.register(acroForm);
-    pdfDoc.catalog.set(_pdfLib.PDFName.of('AcroForm'), acroFormRef);
+    const acroFormRef = doc.context.register(acroForm);
+    doc.catalog.set(_pdfLib.PDFName.of('AcroForm'), acroFormRef);
   }
 
   /**

packages/placeholder-pdf-lib/dist/pdflibAddPlaceholder.js

@@ -4,9 +4,10 @@ import {
     DEFAULT_SIGNATURE_LENGTH,
     SIG_FLAGS,
     SUBFILTER_ADOBE_PKCS7_DETACHED,
+    SignPdfError,
 } from '@signpdf/utils';
 import {
-    PDFArray, PDFDict, PDFHexString, PDFName, PDFNumber, PDFString,
+    PDFArray, PDFDict, PDFHexString, PDFName, PDFNumber, PDFInvalidObject, PDFString,
 } from 'pdf-lib';
 
 /**
@@ -16,14 +17,17 @@ import {
 /**
 * @typedef {object} InputType
 * @property {PDFDocument} pdfDoc
+* @property {PDFPage} pdfPage
 * @property {string} reason
 * @property {string} contactInfo
 * @property {string} name
 * @property {string} location
+* @property {Date} [signingTime]
 * @property {number} [signatureLength]
 * @property {string} [byteRangePlaceholder]
 * @property {string} [subFilter] One of SUBFILTER_* from \@signpdf/utils
 * @property {number[]} [widgetRect] [x1, y1, x2, y2] widget rectangle
+* @property {string} [appName] Name of the application generating the signature
 */
 
 /**
@@ -35,21 +39,31 @@ import {
  * @returns {void}
  */
 export const pdflibAddPlaceholder = ({
-    pdfDoc,
+    pdfDoc = undefined,
+    pdfPage = undefined,
     reason,
     contactInfo,
     name,
     location,
+    signingTime = undefined,
     signatureLength = DEFAULT_SIGNATURE_LENGTH,
     byteRangePlaceholder = DEFAULT_BYTE_RANGE_PLACEHOLDER,
     subFilter = SUBFILTER_ADOBE_PKCS7_DETACHED,
     widgetRect = [0, 0, 0, 0],
+    appName = undefined,
 }) => {
-    const page = pdfDoc.getPage(0);
+    if (pdfDoc === undefined && pdfPage === undefined) {
+        throw new SignPdfError(
+            'PDFDoc or PDFPage must be set.',
+            SignPdfError.TYPE_INPUT,
+        );
+    }
+    const doc = pdfDoc ?? pdfPage.doc;
+    const page = pdfPage ?? doc.getPages()[0];
 
     // Create a placeholder where the the last 3 parameters of the
     // actual range will be replaced when signing is done.
-    const byteRange = PDFArray.withContext(pdfDoc.context);
+    const byteRange = PDFArray.withContext(doc.context);
     byteRange.push(PDFNumber.of(0));
     byteRange.push(PDFName.of(byteRangePlaceholder));
     byteRange.push(PDFName.of(byteRangePlaceholder));
@@ -59,24 +73,38 @@ export const pdflibAddPlaceholder = ({
     const placeholder = PDFHexString.of(String.fromCharCode(0).repeat(signatureLength));
 
     // Create a signature dictionary to be referenced in the signature widget.
-    const signatureDict = pdfDoc.context.obj({
+    const appBuild = appName ? {App: {Name: appName}} : {};
+    const signatureDict = doc.context.obj({
         Type: 'Sig',
         Filter: 'Adobe.PPKLite',
         SubFilter: subFilter,
         ByteRange: byteRange,
         Contents: placeholder,
         Reason: PDFString.of(reason),
-        M: PDFString.fromDate(new Date()),
+        M: PDFString.fromDate(signingTime ?? new Date()),
         ContactInfo: PDFString.of(contactInfo),
         Name: PDFString.of(name),
         Location: PDFString.of(location),
-    }, pdfDoc.index);
-    const signatureDictRef = pdfDoc.context.register(signatureDict);
+        Prop_Build: {
+            Filter: {Name: 'Adobe.PPKLite'},
+            ...appBuild,
+        },
+    });
+    // Register signatureDict as a PDFInvalidObject to prevent PDFLib from serializing it
+    // in an object stream.
+    const signatureBuffer = new Uint8Array(signatureDict.sizeInBytes());
+    signatureDict.copyBytesInto(signatureBuffer, 0);
+    const signatureObj = PDFInvalidObject.of(signatureBuffer);
+    const signatureDictRef = doc.context.register(signatureObj);
 
     // Create the signature widget
-    const rect = PDFArray.withContext(pdfDoc.context);
+    const rect = PDFArray.withContext(doc.context);
     widgetRect.forEach((c) => rect.push(PDFNumber.of(c)));
-    const widgetDict = pdfDoc.context.obj({
+    const apStream = doc.context.formXObject([], {
+        BBox: widgetRect,
+        Resources: {}, // Necessary to avoid Acrobat bug (see https://stackoverflow.com/a/73011571)
+    });
+    const widgetDict = doc.context.obj({
         Type: 'Annot',
         Subtype: 'Widget',
         FT: 'Sig',
@@ -85,24 +113,25 @@ export const pdflibAddPlaceholder = ({
         T: PDFString.of('Signature1'),
         F: ANNOTATION_FLAGS.PRINT,
         P: page.ref,
-    }, pdfDoc.index);
-    const widgetDictRef = pdfDoc.context.register(widgetDict);
+        AP: {N: doc.context.register(apStream)}, // Required for PDF/A compliance
+    });
+    const widgetDictRef = doc.context.register(widgetDict);
 
-    // Annotate the widget on the first page
+    // Annotate the widget on the given page
     let annotations = page.node.lookupMaybe(PDFName.of('Annots'), PDFArray);
     if (typeof annotations === 'undefined') {
-        annotations = pdfDoc.context.obj([]);
+        annotations = doc.context.obj([]);
     }
     annotations.push(widgetDictRef);
     page.node.set(PDFName.of('Annots'), annotations);
 
     // Add an AcroForm or update the existing one
-    let acroForm = pdfDoc.catalog.lookupMaybe(PDFName.of('AcroForm'), PDFDict);
+    let acroForm = doc.catalog.lookupMaybe(PDFName.of('AcroForm'), PDFDict);
     if (typeof acroForm === 'undefined') {
         // Need to create a new AcroForm
-        acroForm = pdfDoc.context.obj({Fields: []});
-        const acroFormRef = pdfDoc.context.register(acroForm);
-        pdfDoc.catalog.set(PDFName.of('AcroForm'), acroFormRef);
+        acroForm = doc.context.obj({Fields: []});
+        const acroFormRef = doc.context.register(acroForm);
+        doc.catalog.set(PDFName.of('AcroForm'), acroFormRef);
     }
 
     /**