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Add DRM removal for ePub only

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This commit is contained in:
Grégory Soutadé
2021-11-26 15:01:26 +01:00
parent 55ab41613e
commit a751327dab
8 changed files with 262 additions and 56 deletions
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78
src/libgourou.cpp
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@@ -597,7 +597,7 @@ namespace gourou
GOUROU_LOG(INFO, "Download into " << path);
std::string rightsStr = item->getRights();
ByteArray rightsStr(item->getRights());
if (item->getMetadata("format").find("application/pdf") != std::string::npos)
res = PDF;
@@ -925,4 +925,80 @@ namespace gourou
int DRMProcessor::getLogLevel() {return (int)gourou::logLevel;}
void DRMProcessor::setLogLevel(int logLevel) {gourou::logLevel = (GOUROU_LOG_LEVEL)logLevel;}
void DRMProcessor::removeEPubDRM(const std::string& ePubFile)
{
ByteArray zipData;
void* zipHandler = client->zipOpen(ePubFile);
client->zipReadFile(zipHandler, "META-INF/rights.xml", zipData);
pugi::xml_document rightsDoc;
rightsDoc.load_string((const char*)zipData.data());
std::string encryptedKey = extractTextElem(rightsDoc, "/adept:rights/licenseToken/encryptedKey");
ByteArray arrayEncryptedKey = ByteArray::fromBase64(encryptedKey);
unsigned char decryptedKey[RSA_KEY_SIZE];
std::string privateKeyData = user->getPrivateLicenseKey();
ByteArray privateRSAKey = ByteArray::fromBase64(privateKeyData);
ByteArray deviceKey(device->getDeviceKey(), Device::DEVICE_KEY_SIZE);
std::string pkcs12 = user->getPKCS12();
client->RSAPrivateDecrypt(privateRSAKey.data(), privateRSAKey.length(),
RSAInterface::RSA_KEY_PKCS12, deviceKey.toBase64().data(),
arrayEncryptedKey.data(), arrayEncryptedKey.length(), decryptedKey);
if (decryptedKey[0] != 0x00 || decryptedKey[1] != 0x02 ||
decryptedKey[RSA_KEY_SIZE-16-1] != 0x00)
EXCEPTION(CLIENT_DRM_ERR_ENCRYPTION_KEY, "Unable to retrieve encryption key");
client->zipReadFile(zipHandler, "META-INF/encryption.xml", zipData);
pugi::xml_document encryptionDoc;
encryptionDoc.load_string((const char*)zipData.data());
pugi::xpath_node_set nodeSet = encryptionDoc.select_nodes("//CipherReference");
for (pugi::xpath_node_set::const_iterator it = nodeSet.begin();
it != nodeSet.end(); ++it)
{
std::string encryptedFile = it->node().attribute("URI").value();
GOUROU_LOG(DEBUG, "Encrypted file " << encryptedFile);
client->zipReadFile(zipHandler, encryptedFile, zipData, false);
unsigned char* _data = zipData.data();
ByteArray clearData(zipData.length()-16+1); /* Reserve 1 byte for 'Z' */
unsigned char* _clearData = clearData.data();
gourou::ByteArray inflateData(true);
unsigned int dataOutLength;
client->AESDecrypt(CryptoInterface::CHAIN_CBC,
decryptedKey+RSA_KEY_SIZE-16, 16, /* Key */
_data, 16, /* IV */
&_data[16], zipData.length()-16,
_clearData, &dataOutLength);
// Add 'Z' at the end, done in ineptepub.py
_clearData[dataOutLength] = 'Z';
client->inflate(clearData, inflateData);
client->zipWriteFile(zipHandler, encryptedFile, inflateData);
}
client->zipDeleteFile(zipHandler, "META-INF/rights.xml");
client->zipDeleteFile(zipHandler, "META-INF/encryption.xml");
client->zipClose(zipHandler);
}
void DRMProcessor::removeDRM(const std::string& ePubFile, ITEM_TYPE type)
{
if (type == EPUB)
removeEPubDRM(ePubFile);
else
EXCEPTION(CLIENT_DRM_FORMAT_NOT_SUPPORTED, "Can't remove DRM in PDF");
}
}