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PDF DRM removing : Try to parse all objects wether they're or not in xref table

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This commit is contained in:
Grégory Soutadé 2022-03-02 20:38:31 +01:00
parent 16a13eed89
commit 25f5049ab9
1 changed files with 23 additions and 20 deletions
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43
src/libgourou.cpp
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@ -1091,16 +1091,18 @@ namespace gourou
uPDFParser::Integer* ebxVersion; uPDFParser::Integer* ebxVersion;
std::vector<uPDFParser::Object*> objects = parser.objects(); std::vector<uPDFParser::Object*> objects = parser.objects();
std::vector<uPDFParser::Object*>::reverse_iterator it; std::vector<uPDFParser::Object*>::iterator it;
std::vector<uPDFParser::Object*>::reverse_iterator rIt;
unsigned char decryptedKey[RSA_KEY_SIZE]; unsigned char decryptedKey[RSA_KEY_SIZE];
int ebxId;
for(it = objects.rbegin(); it != objects.rend(); it++)
for(rIt = objects.rbegin(); rIt != objects.rend(); rIt++)
{ {
// Update EBX_HANDLER with rights // Update EBX_HANDLER with rights
if ((*it)->hasKey("Filter") && (**it)["Filter"]->str() == "/EBX_HANDLER") if ((*rIt)->hasKey("Filter") && (**rIt)["Filter"]->str() == "/EBX_HANDLER")
{ {
EBXHandlerFound = true; EBXHandlerFound = true;
uPDFParser::Object* ebx = *it; uPDFParser::Object* ebx = *rIt;
ebxVersion = (uPDFParser::Integer*)(*ebx)["V"]; ebxVersion = (uPDFParser::Integer*)(*ebx)["V"];
if (ebxVersion->value() != 4) if (ebxVersion->value() != 4)
@ -1114,8 +1116,13 @@ namespace gourou
} }
uPDFParser::String* licenseObject = (uPDFParser::String*)(*ebx)["ADEPT_LICENSE"]; uPDFParser::String* licenseObject = (uPDFParser::String*)(*ebx)["ADEPT_LICENSE"];
std::string value = licenseObject->value();
ByteArray zippedData = ByteArray::fromBase64(value);
ByteArray zippedData = ByteArray::fromBase64(licenseObject->value()); if (zippedData.size() == 0)
EXCEPTION(DRM_ERR_ENCRYPTION_KEY, "Invalid ADEPT_LICENSE");
ByteArray rightsStr; ByteArray rightsStr;
client->inflate(zippedData, rightsStr); client->inflate(zippedData, rightsStr);
@ -1125,6 +1132,8 @@ namespace gourou
std::string encryptedKey = extractTextElem(rightsDoc, "/adept:rights/licenseToken/encryptedKey"); std::string encryptedKey = extractTextElem(rightsDoc, "/adept:rights/licenseToken/encryptedKey");
decryptADEPTKey(encryptedKey, decryptedKey); decryptADEPTKey(encryptedKey, decryptedKey);
ebxId = ebx->objectId();
break; break;
} }
} }
@ -1134,24 +1143,18 @@ namespace gourou
EXCEPTION(DRM_ERR_ENCRYPTION_KEY, "EBX_HANDLER not found"); EXCEPTION(DRM_ERR_ENCRYPTION_KEY, "EBX_HANDLER not found");
} }
std::vector<uPDFParser::XRefValue> xrefTable = parser.xrefTable(); for(it = objects.begin(); it != objects.end(); it++)
std::vector<uPDFParser::XRefValue>::iterator xrefIt;
for(xrefIt = xrefTable.begin(); xrefIt != xrefTable.end(); xrefIt++)
{ {
GOUROU_LOG(DEBUG, "XREF obj " << (*xrefIt).objectId() << " used " << (*xrefIt).used()); uPDFParser::Object* object = *it;
if (!(*xrefIt).used()) if (object->objectId() == ebxId)
continue; continue;
uPDFParser::Object* object = (*xrefIt).object(); if (object->hasKey("Type") && (*object)["Type"]->str() == "/XRef")
if (!object)
{
GOUROU_LOG(DEBUG, "No object");
continue; continue;
}
GOUROU_LOG(DEBUG, "Obj " << object->objectId());
unsigned char tmpKey[16]; unsigned char tmpKey[16];
generatePDFObjectKey(ebxVersion->value(), generatePDFObjectKey(ebxVersion->value(),
@ -1197,7 +1200,7 @@ namespace gourou
dictionary.replace(dictIt->first, dictIt->second); dictionary.replace(dictIt->first, dictIt->second);
std::vector<uPDFParser::DataType*>::iterator datasIt; std::vector<uPDFParser::DataType*>::iterator datasIt;
std::vector<uPDFParser::DataType*>& datas = (*xrefIt).object()->data(); std::vector<uPDFParser::DataType*>& datas = object->data();
uPDFParser::Stream* stream; uPDFParser::Stream* stream;
for (datasIt = datas.begin(); datasIt != datas.end(); datasIt++) for (datasIt = datas.begin(); datasIt != datas.end(); datasIt++)