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Form.cc
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//========================================================================
//
// Form.cc
//
// This file is licensed under the GPLv2 or later
//
// Copyright 2006-2008 Julien Rebetez <[email protected]>
// Copyright 2007-2012, 2015-2025 Albert Astals Cid <[email protected]>
// Copyright 2007-2008, 2011 Carlos Garcia Campos <[email protected]>
// Copyright 2007, 2013, 2016, 2019, 2022 Adrian Johnson <[email protected]>
// Copyright 2007 Iñigo Martínez <[email protected]>
// Copyright 2008, 2011 Pino Toscano <[email protected]>
// Copyright 2008 Michael Vrable <[email protected]>
// Copyright 2009 Matthias Drochner <[email protected]>
// Copyright 2009 KDAB via Guillermo Amaral <[email protected]>
// Copyright 2010, 2012 Mark Riedesel <[email protected]>
// Copyright 2012 Fabio D'Urso <[email protected]>
// Copyright 2015 André Guerreiro <[email protected]>
// Copyright 2015 André Esser <[email protected]>
// Copyright 2017 Hans-Ulrich Jüttner <[email protected]>
// Copyright 2017 Bernd Kuhls <[email protected]>
// Copyright 2018 Andre Heinecke <[email protected]>
// Copyright 2018 Klarälvdalens Datakonsult AB, a KDAB Group company, <[email protected]>. Work sponsored by the LiMux project of the city of Munich
// Copyright 2018 Chinmoy Ranjan Pradhan <[email protected]>
// Copyright 2018 Adam Reichold <[email protected]>
// Copyright 2018-2022 Nelson Benítez León <[email protected]>
// Copyright 2019, 2020 2024, Oliver Sander <[email protected]>
// Copyright 2019 Tomoyuki Kubota <[email protected]>
// Copyright 2019 João Netto <[email protected]>
// Copyright 2020-2022 Marek Kasik <[email protected]>
// Copyright 2020 Thorsten Behrens <[email protected]>
// Copyright 2020, 2023, 2024 Klarälvdalens Datakonsult AB, a KDAB Group company, <[email protected]>. Work sponsored by Technische Universität Dresden
// Copyright 2021 Georgiy Sgibnev <[email protected]>. Work sponsored by lab50.net.
// Copyright 2021 Theofilos Intzoglou <[email protected]>
// Copyright 2021 Even Rouault <[email protected]>
// Copyright 2022 Alexander Sulfrian <[email protected]>
// Copyright 2022, 2024 Erich E. Hoover <[email protected]>
// Copyright 2023-2025 g10 Code GmbH, Author: Sune Stolborg Vuorela <[email protected]>
// Copyright 2024 Pratham Gandhi <[email protected]>
// Copyright (C) 2024 Vincent Lefevre <[email protected]>
//
//========================================================================
#include <config.h>
#include <array>
#include <set>
#include <limits>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <cctype>
#include "goo/ft_utils.h"
#include "goo/gfile.h"
#include "goo/GooString.h"
#include "Error.h"
#include "ErrorCodes.h"
#include "CharCodeToUnicode.h"
#include "Object.h"
#include "Array.h"
#include "Dict.h"
#include "Gfx.h"
#include "GfxFont.h"
#include "GlobalParams.h"
#include "Form.h"
#include "PDFDoc.h"
#include "DateInfo.h"
#include "CryptoSignBackend.h"
#include "SignatureInfo.h"
#include "CertificateInfo.h"
#include "XRef.h"
#include "PDFDocEncoding.h"
#include "Annot.h"
#include "Link.h"
#include "Lexer.h"
#include "Parser.h"
#include "CIDFontsWidthsBuilder.h"
#include "UTF.h"
#include "fofi/FoFiTrueType.h"
#include "fofi/FoFiIdentifier.h"
#include <ft2build.h>
#include <variant>
#include FT_FREETYPE_H
#include <unordered_set>
// helper for using std::visit to get a dependent false for static_asserts
// to help get compile errors if one ever extends variants
template<class>
inline constexpr bool always_false_v = false;
// return a newly allocated char* containing an UTF16BE string of size length
std::string pdfDocEncodingToUTF16(const std::string &orig)
{
// double size, a unicode char takes 2 char, add 2 for the unicode marker
int length = 2 + 2 * orig.size();
std::string result;
result.reserve(length);
// unicode marker
result.push_back('\xfe');
result.push_back('\xff');
// convert to utf16
for (int i = 2, j = 0; i < (length); i += 2, j++) {
Unicode u = pdfDocEncoding[(unsigned int)((unsigned char)orig[j])] & 0xffff;
result.push_back((u >> 8) & 0xff);
result.push_back(u & 0xff);
}
return result;
}
static std::unique_ptr<GooString> convertToUtf16(GooString *pdfDocEncodingString)
{
std::string tmpStr = pdfDocEncodingToUTF16(pdfDocEncodingString->toStr());
return std::make_unique<GooString>(tmpStr.c_str() + 2, tmpStr.size() - 2); // Remove the unicode BOM
}
FormWidget::FormWidget(PDFDoc *docA, Object *aobj, unsigned num, Ref aref, FormField *fieldA)
{
ref = aref;
ID = 0;
childNum = num;
doc = docA;
xref = doc->getXRef();
obj = aobj->copy();
type = formUndef;
field = fieldA;
widget = nullptr;
}
FormWidget::~FormWidget()
{
if (widget) {
widget->decRefCnt();
}
}
void FormWidget::print(int indent)
{
printf("%*s+ (%d %d): [widget]\n", indent, "", ref.num, ref.gen);
}
void FormWidget::createWidgetAnnotation()
{
if (widget) {
return;
}
Object obj1(ref);
widget = new AnnotWidget(doc, &obj, &obj1, field);
}
bool FormWidget::inRect(double x, double y) const
{
return widget ? widget->inRect(x, y) : false;
}
void FormWidget::getRect(double *x1, double *y1, double *x2, double *y2) const
{
if (widget) {
widget->getRect(x1, y1, x2, y2);
}
}
bool FormWidget::isReadOnly() const
{
return field->isReadOnly();
}
void FormWidget::setReadOnly(bool value)
{
field->setReadOnly(value);
}
int FormWidget::encodeID(unsigned pageNum, unsigned fieldNum)
{
return (pageNum << 4 * sizeof(unsigned)) + fieldNum;
}
void FormWidget::decodeID(unsigned id, unsigned *pageNum, unsigned *fieldNum)
{
*pageNum = id >> 4 * sizeof(unsigned);
*fieldNum = (id << 4 * sizeof(unsigned)) >> 4 * sizeof(unsigned);
}
const GooString *FormWidget::getPartialName() const
{
return field->getPartialName();
}
void FormWidget::setPartialName(const GooString &name)
{
field->setPartialName(name);
}
const GooString *FormWidget::getAlternateUiName() const
{
return field->getAlternateUiName();
}
const GooString *FormWidget::getMappingName() const
{
return field->getMappingName();
}
const GooString *FormWidget::getFullyQualifiedName()
{
return field->getFullyQualifiedName();
}
LinkAction *FormWidget::getActivationAction()
{
return widget ? widget->getAction() : nullptr;
}
std::unique_ptr<LinkAction> FormWidget::getAdditionalAction(Annot::FormAdditionalActionsType t)
{
return widget ? widget->getFormAdditionalAction(t) : nullptr;
}
bool FormWidget::setAdditionalAction(Annot::FormAdditionalActionsType t, const std::string &js)
{
if (!widget) {
return false;
}
return widget->setFormAdditionalAction(t, js);
}
FormWidgetButton::FormWidgetButton(PDFDoc *docA, Object *dictObj, unsigned num, Ref refA, FormField *p) : FormWidget(docA, dictObj, num, refA, p)
{
type = formButton;
onStr = nullptr;
// Find the name of the ON state in the AP dictionary
// The reference say the Off state, if it exists, _must_ be stored in the AP dict under the name /Off
// The "on" state may be stored under any other name
Object obj1 = obj.dictLookup("AP");
if (obj1.isDict()) {
Object obj2 = obj1.dictLookup("N");
if (obj2.isDict()) {
for (int i = 0; i < obj2.dictGetLength(); i++) {
const char *key = obj2.dictGetKey(i);
if (strcmp(key, "Off") != 0) {
onStr = new GooString(key);
break;
}
}
}
}
}
const char *FormWidgetButton::getOnStr() const
{
if (onStr) {
return onStr->c_str();
}
// 12.7.4.2.3 Check Boxes
// Yes should be used as the name for the on state
return parent()->getButtonType() == formButtonCheck ? "Yes" : nullptr;
}
FormWidgetButton::~FormWidgetButton()
{
delete onStr;
}
FormButtonType FormWidgetButton::getButtonType() const
{
return parent()->getButtonType();
}
void FormWidgetButton::setAppearanceState(const char *state)
{
if (!widget) {
return;
}
widget->setAppearanceState(state);
}
void FormWidgetButton::updateWidgetAppearance()
{
// The appearance stream must NOT be regenerated for this widget type
}
void FormWidgetButton::setState(bool astate)
{
// pushButtons don't have state
if (parent()->getButtonType() == formButtonPush) {
return;
}
// Silently return if can't set ON state
if (astate && !getOnStr()) {
return;
}
parent()->setState(astate ? getOnStr() : (char *)"Off");
// Parent will call setAppearanceState()
// Now handle standAlone fields which are related to this one by having the same
// fully qualified name. This is *partially* by spec, as seen in "Field names"
// section inside "8.6.2 Field Dictionaries" in 1.7 PDF spec. Issue #1034
if (!astate) { // We're only interested when this field is being set to ON,
return; // to check if it has related fields and then set them OFF
}
unsigned this_page_num, this_field_num;
decodeID(getID(), &this_page_num, &this_field_num);
Page *this_page = doc->getCatalog()->getPage(this_page_num);
const FormField *this_field = getField();
if (!this_page->hasStandaloneFields() || this_field == nullptr) {
return;
}
auto this_page_widgets = this_page->getFormWidgets();
const FormButtonType this_button_type = getButtonType();
const int tot = this_page_widgets->getNumWidgets();
for (int i = 0; i < tot; i++) {
bool found_related = false;
FormWidget *wid = this_page_widgets->getWidget(i);
const bool same_fqn = wid->getFullyQualifiedName()->cmp(getFullyQualifiedName()) == 0;
const bool same_button_type = wid->getType() == formButton && static_cast<const FormWidgetButton *>(wid)->getButtonType() == this_button_type;
if (same_fqn && same_button_type) {
if (this_field->isStandAlone()) {
//'this_field' is standAlone, so we need to search in both standAlone fields and normal fields
if (this_field != wid->getField()) { // so take care to not choose our same field
found_related = true;
}
} else {
//'this_field' is not standAlone, so we just need to search in standAlone fields
if (wid->getField()->isStandAlone()) {
found_related = true;
}
}
}
if (found_related) {
FormFieldButton *ffb = static_cast<FormFieldButton *>(wid->getField());
if (ffb == nullptr) {
error(errInternal, -1, "FormWidgetButton::setState : FormFieldButton expected");
continue;
}
ffb->setState((char *)"Off", true);
}
}
}
bool FormWidgetButton::getState() const
{
return getOnStr() ? parent()->getState(getOnStr()) : false;
}
FormFieldButton *FormWidgetButton::parent() const
{
return static_cast<FormFieldButton *>(field);
}
FormWidgetText::FormWidgetText(PDFDoc *docA, Object *dictObj, unsigned num, Ref refA, FormField *p) : FormWidget(docA, dictObj, num, refA, p)
{
type = formText;
}
const GooString *FormWidgetText::getContent() const
{
return parent()->getContent();
}
void FormWidgetText::updateWidgetAppearance()
{
if (widget) {
widget->updateAppearanceStream();
}
}
bool FormWidgetText::isMultiline() const
{
return parent()->isMultiline();
}
bool FormWidgetText::isPassword() const
{
return parent()->isPassword();
}
bool FormWidgetText::isFileSelect() const
{
return parent()->isFileSelect();
}
bool FormWidgetText::noSpellCheck() const
{
return parent()->noSpellCheck();
}
bool FormWidgetText::noScroll() const
{
return parent()->noScroll();
}
bool FormWidgetText::isComb() const
{
return parent()->isComb();
}
bool FormWidgetText::isRichText() const
{
return parent()->isRichText();
}
int FormWidgetText::getMaxLen() const
{
return parent()->getMaxLen();
}
double FormWidgetText::getTextFontSize()
{
return parent()->getTextFontSize();
}
void FormWidgetText::setTextFontSize(int fontSize)
{
parent()->setTextFontSize(fontSize);
}
void FormWidgetText::setContent(std::unique_ptr<GooString> new_content)
{
parent()->setContent(std::move(new_content));
}
void FormWidgetText::setAppearanceContent(std::unique_ptr<GooString> new_content)
{
parent()->setAppearanceContent(std::move(new_content));
}
FormFieldText *FormWidgetText::parent() const
{
return static_cast<FormFieldText *>(field);
}
FormWidgetChoice::FormWidgetChoice(PDFDoc *docA, Object *dictObj, unsigned num, Ref refA, FormField *p) : FormWidget(docA, dictObj, num, refA, p)
{
type = formChoice;
}
FormWidgetChoice::~FormWidgetChoice() = default;
bool FormWidgetChoice::_checkRange(int i) const
{
if (i < 0 || i >= parent()->getNumChoices()) {
error(errInternal, -1, "FormWidgetChoice::_checkRange i out of range : {0:d}", i);
return false;
}
return true;
}
void FormWidgetChoice::select(int i)
{
if (!_checkRange(i)) {
return;
}
parent()->select(i);
}
void FormWidgetChoice::toggle(int i)
{
if (!_checkRange(i)) {
return;
}
parent()->toggle(i);
}
void FormWidgetChoice::deselectAll()
{
parent()->deselectAll();
}
const GooString *FormWidgetChoice::getEditChoice() const
{
if (!hasEdit()) {
error(errInternal, -1, "FormFieldChoice::getEditChoice called on a non-editable choice");
return nullptr;
}
return parent()->getEditChoice();
}
void FormWidgetChoice::updateWidgetAppearance()
{
if (widget) {
widget->updateAppearanceStream();
}
}
bool FormWidgetChoice::isSelected(int i) const
{
if (!_checkRange(i)) {
return false;
}
return parent()->isSelected(i);
}
void FormWidgetChoice::setEditChoice(std::unique_ptr<GooString> new_content)
{
if (!hasEdit()) {
error(errInternal, -1, "FormFieldChoice::setEditChoice : trying to edit an non-editable choice");
return;
}
parent()->setEditChoice(std::move(new_content));
}
void FormWidgetChoice::setAppearanceChoiceContent(std::unique_ptr<GooString> new_content)
{
parent()->setAppearanceChoiceContent(std::move(new_content));
}
int FormWidgetChoice::getNumChoices() const
{
return parent()->getNumChoices();
}
const GooString *FormWidgetChoice::getChoice(int i) const
{
return parent()->getChoice(i);
}
const GooString *FormWidgetChoice::getExportVal(int i) const
{
return parent()->getExportVal(i);
}
bool FormWidgetChoice::isCombo() const
{
return parent()->isCombo();
}
bool FormWidgetChoice::hasEdit() const
{
return parent()->hasEdit();
}
bool FormWidgetChoice::isMultiSelect() const
{
return parent()->isMultiSelect();
}
bool FormWidgetChoice::noSpellCheck() const
{
return parent()->noSpellCheck();
}
bool FormWidgetChoice::commitOnSelChange() const
{
return parent()->commitOnSelChange();
}
bool FormWidgetChoice::isListBox() const
{
return parent()->isListBox();
}
FormFieldChoice *FormWidgetChoice::parent() const
{
return static_cast<FormFieldChoice *>(field);
}
FormWidgetSignature::FormWidgetSignature(PDFDoc *docA, Object *dictObj, unsigned num, Ref refA, FormField *p) : FormWidget(docA, dictObj, num, refA, p)
{
type = formSignature;
}
const std::vector<unsigned char> &FormWidgetSignature::getSignature() const
{
return static_cast<FormFieldSignature *>(field)->getSignature();
}
SignatureInfo *FormWidgetSignature::validateSignatureAsync(bool doVerifyCert, bool forceRevalidation, time_t validationTime, bool ocspRevocationCheck, bool enableAIA, const std::function<void()> &doneCallback)
{
return static_cast<FormFieldSignature *>(field)->validateSignatureAsync(doVerifyCert, forceRevalidation, validationTime, ocspRevocationCheck, enableAIA, doneCallback);
}
CertificateValidationStatus FormWidgetSignature::validateSignatureResult()
{
return static_cast<FormFieldSignature *>(field)->validateSignatureResult();
}
// update hash with the specified range of data from the file
static bool hashFileRange(FILE *f, CryptoSign::SigningInterface *handler, Goffset start, Goffset end)
{
if (!handler) {
return false;
}
const int BUF_SIZE = 65536;
unsigned char *buf = new unsigned char[BUF_SIZE];
while (start < end) {
if (Gfseek(f, start, SEEK_SET) != 0) {
delete[] buf;
return false;
}
int len = BUF_SIZE;
if (end - start < len) {
len = static_cast<int>(end - start);
}
if (fread(buf, 1, len, f) != static_cast<size_t>(len)) {
delete[] buf;
return false;
}
handler->addData(buf, len);
start += len;
}
delete[] buf;
return true;
}
std::optional<CryptoSign::SigningError> FormWidgetSignature::signDocument(const std::string &saveFilename, const std::string &certNickname, const std::string &password, const GooString *reason, const GooString *location,
const std::optional<GooString> &ownerPassword, const std::optional<GooString> &userPassword)
{
auto backend = CryptoSign::Factory::createActive();
if (!backend) {
return CryptoSign::SigningError::InternalError;
}
if (certNickname.empty()) {
fprintf(stderr, "signDocument: Empty nickname\n");
return CryptoSign::SigningError::KeyMissing;
}
auto sigHandler = backend->createSigningHandler(certNickname, HashAlgorithm::Sha256);
FormFieldSignature *signatureField = static_cast<FormFieldSignature *>(field);
std::unique_ptr<X509CertificateInfo> certInfo = sigHandler->getCertificateInfo();
if (!certInfo) {
fprintf(stderr, "signDocument: error getting signature info\n");
return CryptoSign::SigningError::KeyMissing;
}
const std::string signerName = certInfo->getSubjectInfo().commonName;
signatureField->setCertificateInfo(certInfo);
updateWidgetAppearance(); // add visible signing info to appearance
Object vObj(new Dict(xref));
Ref vref = xref->addIndirectObject(vObj);
if (!createSignature(vObj, vref, GooString(signerName), CryptoSign::maxSupportedSignatureSize, reason, location, sigHandler->signatureType())) {
return CryptoSign::SigningError::InternalError;
}
// Incremental save to avoid breaking any existing signatures
const GooString fname(saveFilename);
if (doc->saveAs(fname, writeForceIncremental) != errNone) {
fprintf(stderr, "signDocument: error saving to file \"%s\"\n", saveFilename.c_str());
return CryptoSign::SigningError::WriteFailed;
}
// Get start/end offset of signature object in the saved PDF
Goffset objStart, objEnd;
if (!getObjectStartEnd(fname, vref.num, &objStart, &objEnd, ownerPassword, userPassword)) {
fprintf(stderr, "signDocument: unable to get signature object offsets\n");
return CryptoSign::SigningError::InternalError;
}
// Update byte range of signature in the saved PDF
Goffset sigStart, sigEnd, fileSize;
FILE *file = openFile(saveFilename.c_str(), "r+b");
if (!updateOffsets(file, objStart, objEnd, &sigStart, &sigEnd, &fileSize)) {
fprintf(stderr, "signDocument: unable update byte range\n");
fclose(file);
return CryptoSign::SigningError::WriteFailed;
}
// compute hash of byte ranges
if (!hashFileRange(file, sigHandler.get(), 0LL, sigStart)) {
fclose(file);
return CryptoSign::SigningError::InternalError;
}
if (!hashFileRange(file, sigHandler.get(), sigEnd, fileSize)) {
fclose(file);
return CryptoSign::SigningError::InternalError;
}
// and sign it
auto signature = sigHandler->signDetached(password);
if (std::holds_alternative<CryptoSign::SigningError>(signature)) {
fclose(file);
return std::get<CryptoSign::SigningError>(signature);
}
if (std::get<std::vector<unsigned char>>(signature).size() > CryptoSign::maxSupportedSignatureSize) {
error(errInternal, -1, "signature too large\n");
fclose(file);
return CryptoSign::SigningError::InternalError;
}
// pad with zeroes to placeholder length
std::get<std::vector<unsigned char>>(signature).resize(CryptoSign::maxSupportedSignatureSize, '\0');
// write signature to saved file
if (!updateSignature(file, sigStart, sigEnd, std::get<std::vector<unsigned char>>(signature))) {
fprintf(stderr, "signDocument: unable update signature\n");
fclose(file);
return CryptoSign::SigningError::WriteFailed;
}
signatureField->setSignature(std::get<std::vector<unsigned char>>(std::move(signature)));
fclose(file);
return {};
}
static std::tuple<double, double> calculateDxDy(int rot, const PDFRectangle *rect)
{
switch (rot) {
case 90:
return { rect->y2 - rect->y1, rect->x2 - rect->x1 };
case 180:
return { rect->x2 - rect->y2, rect->y2 - rect->y1 };
case 270:
return { rect->y2 - rect->y1, rect->x2 - rect->x1 };
default: // assume rot == 0
return { rect->x2 - rect->x1, rect->y2 - rect->y1 };
}
}
std::optional<CryptoSign::SigningError> FormWidgetSignature::signDocumentWithAppearance(const std::string &saveFilename, const std::string &certNickname, const std::string &password, const GooString *reason, const GooString *location,
const std::optional<GooString> &ownerPassword, const std::optional<GooString> &userPassword, const GooString &signatureText,
const GooString &signatureTextLeft, double fontSize, double leftFontSize, std::unique_ptr<AnnotColor> &&fontColor, double borderWidth,
std::unique_ptr<AnnotColor> &&borderColor, std::unique_ptr<AnnotColor> &&backgroundColor)
{
// Set the appearance
GooString *aux = getField()->getDefaultAppearance();
std::string originalDefaultAppearance = aux ? aux->toStr() : std::string();
Form *form = doc->getCatalog()->getCreateForm();
const std::string pdfFontName = form->findPdfFontNameToUseForSigning();
if (pdfFontName.empty()) {
return CryptoSign::SigningError::InternalError;
}
std::shared_ptr<GfxFont> font = form->getDefaultResources()->lookupFont(pdfFontName.c_str());
double x1, y1, x2, y2;
getRect(&x1, &y1, &x2, &y2);
const PDFRectangle rect(x1, y1, x2, y2);
std::unique_ptr<AnnotAppearanceCharacs> origAppearCharacs = getWidgetAnnotation()->getAppearCharacs() ? getWidgetAnnotation()->getAppearCharacs()->copy() : nullptr;
const int rot = origAppearCharacs ? origAppearCharacs->getRotation() : 0;
const auto dxdy = calculateDxDy(rot, &rect);
const double dx = std::get<0>(dxdy);
const double dy = std::get<1>(dxdy);
const double wMax = dx - 2 * borderWidth - 4;
const double hMax = dy - 2 * borderWidth;
if (fontSize == 0) {
fontSize = Annot::calculateFontSize(form, font.get(), &signatureText, wMax / 2.0, hMax);
}
if (leftFontSize == 0) {
leftFontSize = Annot::calculateFontSize(form, font.get(), &signatureTextLeft, wMax / 2.0, hMax);
}
const DefaultAppearance da { { objName, pdfFontName.c_str() }, fontSize, std::move(fontColor) };
getField()->setDefaultAppearance(da.toAppearanceString());
auto appearCharacs = std::make_unique<AnnotAppearanceCharacs>(nullptr);
appearCharacs->setBorderColor(std::move(borderColor));
appearCharacs->setBackColor(std::move(backgroundColor));
getWidgetAnnotation()->setAppearCharacs(std::move(appearCharacs));
std::unique_ptr<AnnotBorder> origBorderCopy = getWidgetAnnotation()->getBorder() ? getWidgetAnnotation()->getBorder()->copy() : nullptr;
std::unique_ptr<AnnotBorder> border(new AnnotBorderArray());
border->setWidth(borderWidth);
getWidgetAnnotation()->setBorder(std::move(border));
getWidgetAnnotation()->generateFieldAppearance();
getWidgetAnnotation()->updateAppearanceStream();
form->ensureFontsForAllCharacters(&signatureText, pdfFontName);
form->ensureFontsForAllCharacters(&signatureTextLeft, pdfFontName);
::FormFieldSignature *ffs = static_cast<::FormFieldSignature *>(getField());
ffs->setCustomAppearanceContent(signatureText);
ffs->setCustomAppearanceLeftContent(signatureTextLeft);
ffs->setCustomAppearanceLeftFontSize(leftFontSize);
// say that there a now signatures and that we should append only
doc->getCatalog()->getAcroForm()->dictSet("SigFlags", Object(3));
auto signingResult = signDocument(saveFilename, certNickname, password, reason, location, ownerPassword, userPassword);
// Now bring back the annotation appearance back to what it was
ffs->setDefaultAppearance(originalDefaultAppearance);
ffs->setCustomAppearanceContent({});
ffs->setCustomAppearanceLeftContent({});
getWidgetAnnotation()->setAppearCharacs(std::move(origAppearCharacs));
getWidgetAnnotation()->setBorder(std::move(origBorderCopy));
getWidgetAnnotation()->generateFieldAppearance();
getWidgetAnnotation()->updateAppearanceStream();
return signingResult;
}
// Get start and end file position of objNum in the PDF named filename.
bool FormWidgetSignature::getObjectStartEnd(const GooString &filename, int objNum, Goffset *objStart, Goffset *objEnd, const std::optional<GooString> &ownerPassword, const std::optional<GooString> &userPassword)
{
PDFDoc newDoc(filename.copy(), ownerPassword, userPassword);
if (!newDoc.isOk()) {
return false;
}
XRef *newXref = newDoc.getXRef();
XRefEntry *entry = newXref->getEntry(objNum);
if (entry->type != xrefEntryUncompressed) {
return false;
}
*objStart = entry->offset;
newXref->fetch(objNum, entry->gen, 0, objEnd);
return true;
}
// find next offset containing the dummy offset '9999999999' and overwrite with offset
static char *setNextOffset(char *start, Goffset offset)
{
char buf[50];
sprintf(buf, "%lld", offset);
strcat(buf, " "); // add some padding
char *p = strstr(start, "9999999999");
if (p) {
memcpy(p, buf, 10); // overwrite exact size.
p += 10;
} else {
return nullptr;
}
return p;
}
// Updates the ByteRange array of the signature object in the file.
// Returns start/end of signature string and file size.
bool FormWidgetSignature::updateOffsets(FILE *f, Goffset objStart, Goffset objEnd, Goffset *sigStart, Goffset *sigEnd, Goffset *fileSize)
{
if (Gfseek(f, 0, SEEK_END) != 0) {
return false;
}
*fileSize = Gftell(f);
if (objEnd > *fileSize) {
objEnd = *fileSize;
}
// sanity check object offsets
if (objEnd <= objStart || (objEnd - objStart >= INT_MAX)) {
return false;
}
const size_t bufSize = static_cast<size_t>(objEnd - objStart);
if (Gfseek(f, objStart, SEEK_SET) != 0) {
return false;
}
std::vector<char> buf(bufSize + 1);
if (fread(buf.data(), 1, bufSize, f) != bufSize) {
return false;
}
buf[bufSize] = 0; // prevent string functions from searching past the end
// search for the Contents field which contains the signature placeholder
// which always must start with hex digits 000
*sigStart = -1;
*sigEnd = -1;
for (size_t i = 0; i < bufSize - 14; i++) {
if (buf[i] == '/' && strncmp(&buf[i], "/Contents <000", 14) == 0) {
*sigStart = objStart + i + 10;
char *p = strchr(&buf[i], '>');
if (p) {
*sigEnd = objStart + (p - buf.data()) + 1;
}
break;
}
}
if (*sigStart == -1 || *sigEnd == -1) {
return false;
}
// Search for ByteRange array and update offsets
for (size_t i = 0; i < bufSize - 10; i++) {
if (buf[i] == '/' && strncmp(&buf[i], "/ByteRange", 10) == 0) {
// update range
char *p = setNextOffset(&buf[i], *sigStart);
if (!p) {
return false;
}
p = setNextOffset(p, *sigEnd);
if (!p) {
return false;
}
p = setNextOffset(p, *fileSize - *sigEnd);
if (!p) {
return false;
}
break;
}
}
// write buffer back to disk
if (Gfseek(f, objStart, SEEK_SET) != 0) {
return false;
}
fwrite(buf.data(), bufSize, 1, f);
return true;
}
// Overwrite signature string in the file with new signature
bool FormWidgetSignature::updateSignature(FILE *f, Goffset sigStart, Goffset sigEnd, const std::vector<unsigned char> &signature)
{
if (signature.size() * 2 + 2 != size_t(sigEnd - sigStart)) {
return false;
}
if (Gfseek(f, sigStart, SEEK_SET) != 0) {
return false;
}
fprintf(f, "<");
for (unsigned char value : signature) {
fprintf(f, "%2.2x", value);
}
fprintf(f, "> ");
return true;
}
bool FormWidgetSignature::createSignature(Object &vObj, Ref vRef, const GooString &name, int placeholderLength, const GooString *reason, const GooString *location, CryptoSign::SignatureType signatureType)
{
vObj.dictAdd("Type", Object(objName, "Sig"));
vObj.dictAdd("Filter", Object(objName, "Adobe.PPKLite"));
vObj.dictAdd("SubFilter", Object(objName, toStdString(signatureType).c_str()));
vObj.dictAdd("Name", Object(name.copy()));
vObj.dictAdd("M", Object(timeToDateString(nullptr)));
if (reason && (reason->getLength() > 0)) {
vObj.dictAdd("Reason", Object(reason->copy()));
}
if (location && (location->getLength() > 0)) {
vObj.dictAdd("Location", Object(location->copy()));
}
vObj.dictAdd("Contents", Object(objHexString, new GooString(std::string(placeholderLength, '\0'))));
Object bObj(new Array(xref));
// reserve space in byte range for maximum number of bytes
bObj.arrayAdd(Object(static_cast<long long>(0LL)));
bObj.arrayAdd(Object(static_cast<long long>(9999999999LL)));
bObj.arrayAdd(Object(static_cast<long long>(9999999999LL)));
bObj.arrayAdd(Object(static_cast<long long>(9999999999LL)));
vObj.dictAdd("ByteRange", bObj.copy());
obj.dictSet("V", Object(vRef));
xref->setModifiedObject(&obj, ref);
return true;
}
std::vector<Goffset> FormWidgetSignature::getSignedRangeBounds() const
{
return static_cast<FormFieldSignature *>(field)->getSignedRangeBounds();
}
std::optional<GooString> FormWidgetSignature::getCheckedSignature(Goffset *checkedFileSize)
{
return static_cast<FormFieldSignature *>(field)->getCheckedSignature(checkedFileSize);
}
void FormWidgetSignature::updateWidgetAppearance()
{
if (widget) {
widget->updateAppearanceStream();
}
}
//========================================================================
// FormField
//========================================================================
FormField::FormField(PDFDoc *docA, Object &&aobj, const Ref aref, FormField *parentA, std::set<int> *usedParents, FormFieldType ty)
{
doc = docA;
xref = doc->getXRef();
obj = std::move(aobj);
Dict *dict = obj.getDict();
ref = aref;
type = ty;
parent = parentA;
terminal = false;
readOnly = false;
fullyQualifiedName = nullptr;
quadding = VariableTextQuadding::leftJustified;
hasQuadding = false;
standAlone = false;
noExport = false;
// childs
Object obj1 = dict->lookup("Kids");
if (obj1.isArray()) {
// Load children