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Encryption settings dialog, authorization as owner

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Jakub Melka
2021-05-24 19:29:02 +02:00
parent 759d5c7793
commit 936fe2fbe7
9 changed files with 342 additions and 27 deletions
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91
Pdf4QtLib/sources/pdfsecurityhandler.cpp
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@ -508,6 +508,11 @@ PDFSecurityHandlerPointer PDFSecurityHandler::createSecurityHandler(const PDFObj
return PDFSecurityHandlerPointer(new PDFStandardSecurityHandler(qMove(handler)));
}
PDFSecurityHandler* PDFStandardSecurityHandler::clone() const
{
return new PDFStandardSecurityHandler(*this);
}
PDFSecurityHandler::AuthorizationResult PDFStandardSecurityHandler::authenticate(const std::function<QString(bool*)>& getPasswordCallback, bool authorizeOwnerOnly)
{
QByteArray password;
@ -664,7 +669,7 @@ PDFSecurityHandler::AuthorizationResult PDFStandardSecurityHandler::authenticate
return AuthorizationResult::Failed;
}
password = adjustPassword(getPasswordCallback(&passwordObtained));
password = adjustPassword(getPasswordCallback(&passwordObtained), m_R);
}
return AuthorizationResult::Cancelled;
@ -1375,11 +1380,11 @@ PDFStandardSecurityHandler::UserOwnerData_r6 PDFStandardSecurityHandler::parsePa
return result;
}
QByteArray PDFStandardSecurityHandler::adjustPassword(const QString& password)
QByteArray PDFStandardSecurityHandler::adjustPassword(const QString& password, int revision)
{
QByteArray result;
switch (m_R)
switch (revision)
{
case 2:
case 3:
@ -1486,4 +1491,84 @@ bool PDFStandardSecurityHandler::isUnicodeMappedToNothing(ushort unicode)
}
}
PDFSecurityHandlerPointer PDFSecurityHandlerFactory::createSecurityHandler(const PDFSecurityHandlerFactory::SecuritySettings& settings)
{
return nullptr;
}
int PDFSecurityHandlerFactory::getPasswordOptimalEntropy()
{
return 128;
}
int PDFSecurityHandlerFactory::getPasswordEntropy(const QString& password, Algorithm algorithm)
{
if (algorithm == None)
{
return 0;
}
QByteArray adjustedPassword = PDFStandardSecurityHandler::adjustPassword(password, getRevisionFromAlgorithm(algorithm));
if (adjustedPassword.isEmpty())
{
return 0;
}
const int length = adjustedPassword.length();
std::sort(adjustedPassword.begin(), adjustedPassword.end());
int charCount = 0;
char lastChar = adjustedPassword.front();
PDFReal entropy = 0.0;
for (int i = 0; i < length; ++i)
{
const char currentChar = adjustedPassword[i];
if (currentChar == lastChar)
{
++charCount;
}
else
{
const PDFReal probability = PDFReal(charCount) / PDFReal(length);
entropy += -probability * std::log2(probability);
charCount = 1;
lastChar = currentChar;
}
}
// Jakub Melka: last character
const PDFReal probability = PDFReal(charCount) / PDFReal(length);
entropy += -probability * std::log2(probability);
return entropy * length;
}
int PDFSecurityHandlerFactory::getRevisionFromAlgorithm(Algorithm algorithm)
{
switch (algorithm)
{
case None:
return 0;
case RC4:
return 3;
case AES_128:
return 4;
case AES_256:
return 6;
default:
Q_ASSERT(false);
break;
}
return 0;
}
} // namespace pdf