soutade/libgourou
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Add a private option into adept_remove to provide encryption key

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This commit is contained in:
Grégory Soutadé 2022-03-12 23:04:16 +01:00
parent 9b946a62b4
commit 0f475423c0
4 changed files with 100 additions and 21 deletions
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14
include/libgourou.h
View File

@ -185,10 +185,16 @@ namespace gourou
DRMProcessorClient* getClient() { return client; }
/**
* @brief Remove ADEPT DRM.
* @brief Remove ADEPT DRM
* Warning: for PDF format, filenameIn must be different than filenameOut
*
* @param filenameIn Input file (with ADEPT DRM)
* @param filenameOut Output file (without ADEPT DRM)
* @param type Type of file (ePub or PDF)
* @param encryptionKey Optional encryption key, do not try to decrypt the one inside input file
* @param encryptionKeySize Size of encryption key (if provided)
*/
void removeDRM(const std::string& filenameIn, const std::string& filenameOut, ITEM_TYPE type);
void removeDRM(const std::string& filenameIn, const std::string& filenameOut, ITEM_TYPE type, const unsigned char* encryptionKey=0, unsigned encryptionKeySize=0);
private:
gourou::DRMProcessorClient* client;
@ -214,12 +220,12 @@ namespace gourou
void fetchLicenseServiceCertificate(const std::string& licenseURL,
const std::string& operatorURL);
void decryptADEPTKey(const std::string& encryptedKey, unsigned char* decryptedKey);
void removeEPubDRM(const std::string& filenameIn, const std::string& filenameOut);
void removeEPubDRM(const std::string& filenameIn, const std::string& filenameOut, const unsigned char* encryptionKey, unsigned encryptionKeySize);
void generatePDFObjectKey(int version,
const unsigned char* masterKey, unsigned int masterKeyLength,
int objectId, int objectGenerationNumber,
unsigned char* keyOut);
void removePDFDRM(const std::string& filenameIn, const std::string& filenameOut);
void removePDFDRM(const std::string& filenameIn, const std::string& filenameOut, const unsigned char* encryptionKey, unsigned encryptionKeySize);
};
}

1
include/libgourou_common.h
View File

@ -92,6 +92,7 @@ namespace gourou
USER_INVALID_ACTIVATION_FILE,
USER_NO_AUTHENTICATION_URL,
USER_NO_PROPERTY,
USER_INVALID_INPUT,
};
enum FULFILL_ITEM_ERROR {

41
src/libgourou.cpp
View File

@ -949,7 +949,8 @@ namespace gourou
}
void DRMProcessor::removeEPubDRM(const std::string& filenameIn, const std::string& filenameOut)
void DRMProcessor::removeEPubDRM(const std::string& filenameIn, const std::string& filenameOut,
const unsigned char* encryptionKey, unsigned encryptionKeySize)
{
ByteArray zipData;
bool removeEncryptionXML = true;
@ -962,7 +963,16 @@ namespace gourou
std::string encryptedKey = extractTextElem(rightsDoc, "/adept:rights/licenseToken/encryptedKey");
unsigned char decryptedKey[RSA_KEY_SIZE];
decryptADEPTKey(encryptedKey, decryptedKey);
if (!encryptionKey)
decryptADEPTKey(encryptedKey, decryptedKey);
else
{
GOUROU_LOG(DEBUG, "Use provided encryption key");
if (encryptionKeySize != 16)
EXCEPTION(DRM_ERR_ENCRYPTION_KEY, "Provided encryption key must be 16 bytes");
memcpy(&decryptedKey[sizeof(decryptedKey)-16], encryptionKey, encryptionKeySize);
}
client->zipReadFile(zipHandler, "META-INF/encryption.xml", zipData);
pugi::xml_document encryptionDoc;
@ -1001,7 +1011,7 @@ namespace gourou
unsigned int dataOutLength;
client->Decrypt(CryptoInterface::ALGO_AES, CryptoInterface::CHAIN_CBC,
decryptedKey+RSA_KEY_SIZE-16, 16, /* Key */
decryptedKey+sizeof(decryptedKey)-16, 16, /* Key */
_data, 16, /* IV */
&_data[16], zipData.length()-16,
_clearData, &dataOutLength);
@ -1068,7 +1078,8 @@ namespace gourou
}
}
void DRMProcessor::removePDFDRM(const std::string& filenameIn, const std::string& filenameOut)
void DRMProcessor::removePDFDRM(const std::string& filenameIn, const std::string& filenameOut,
const unsigned char* encryptionKey, unsigned encryptionKeySize)
{
uPDFParser::Parser parser;
bool EBXHandlerFound = false;
@ -1134,7 +1145,17 @@ namespace gourou
std::string encryptedKey = extractTextElem(rightsDoc, "/adept:rights/licenseToken/encryptedKey");
decryptADEPTKey(encryptedKey, decryptedKey);
if (!encryptionKey)
decryptADEPTKey(encryptedKey, decryptedKey);
else
{
GOUROU_LOG(DEBUG, "Use provided encryption key");
if (encryptionKeySize != 16)
EXCEPTION(DRM_ERR_ENCRYPTION_KEY, "Provided encryption key must be 16 bytes");
memcpy(&decryptedKey[sizeof(decryptedKey)-16], encryptionKey, encryptionKeySize);
}
ebxId = ebx->objectId();
break;
@ -1168,7 +1189,7 @@ namespace gourou
unsigned char tmpKey[16];
generatePDFObjectKey(ebxVersion->value(),
decryptedKey+RSA_KEY_SIZE-16, 16,
decryptedKey+sizeof(decryptedKey)-16, 16,
object->objectId(), object->generationNumber(),
tmpKey);
@ -1233,6 +1254,8 @@ namespace gourou
clearData, &dataOutLength);
stream->setData(clearData, dataOutLength, true);
if (dataOutLength != dataLength)
GOUROU_LOG(DEBUG, "New size " << dataOutLength);
}
}
@ -1243,11 +1266,11 @@ namespace gourou
}
void DRMProcessor::removeDRM(const std::string& filenameIn, const std::string& filenameOut,
ITEM_TYPE type)
ITEM_TYPE type, const unsigned char* encryptionKey, unsigned encryptionKeySize)
{
if (type == PDF)
removePDFDRM(filenameIn, filenameOut);
removePDFDRM(filenameIn, filenameOut, encryptionKey, encryptionKeySize);
else
removeEPubDRM(filenameIn, filenameOut);
removeEPubDRM(filenameIn, filenameOut, encryptionKey, encryptionKeySize);
}
}

59
utils/adept_remove.cpp
View File

@ -55,6 +55,23 @@ static const char* defaultDirs[] = {
"./adobe-digital-editions/",
"./.adobe-digital-editions/"
};
static char* encryptionKeyUser = 0;
static unsigned char* encryptionKey = 0;
static unsigned encryptionKeySize = 0;
static inline unsigned char htoi(unsigned char c)
{
if (c >= '0' && c <= '9')
c -= '0';
else if (c >= 'a' && c <= 'f')
c -= 'a' - 10;
else if (c >= 'A' && c <= 'F')
c -= 'A' - 10;
else
EXCEPTION(gourou::USER_INVALID_INPUT, "Invalid character " << c << " in encryption key");
return c;
}
static inline bool endsWith(const std::string& s, const std::string& suffix)
{
@ -110,7 +127,7 @@ public:
{
EXCEPTION(gourou::DRM_FILE_ERROR, "Unable to copy " << inputFile << " into " << filename);
}
processor.removeDRM(inputFile, filename, type);
processor.removeDRM(inputFile, filename, type, encryptionKey, encryptionKeySize);
std::cout << "DRM removed into new file " << filename << std::endl;
}
else
@ -121,7 +138,7 @@ public:
QTemporaryFile tempFile;
tempFile.open();
tempFile.setAutoRemove(false); // In case of failure
processor.removeDRM(inputFile, tempFile.fileName().toStdString(), type);
processor.removeDRM(inputFile, tempFile.fileName().toStdString(), type, encryptionKey, encryptionKeySize);
/* Original file must be removed before doing a copy... */
QFile origFile(inputFile);
origFile.remove();
@ -132,7 +149,7 @@ public:
tempFile.setAutoRemove(true);
}
else
processor.removeDRM(inputFile, filename, type);
processor.removeDRM(inputFile, filename, type, encryptionKey, encryptionKeySize);
std::cout << "DRM removed from " << filename << std::endl;
}
} catch(std::exception& e)
@ -213,14 +230,14 @@ int main(int argc, char** argv)
{"output-dir", required_argument, 0, 'O' },
{"output-file", required_argument, 0, 'o' },
{"input-file", required_argument, 0, 'f' },
{"export-private-key",no_argument, 0, 'e' },
{"encryption-key", required_argument, 0, 'K' }, // Private option
{"verbose", no_argument, 0, 'v' },
{"version", no_argument, 0, 'V' },
{"help", no_argument, 0, 'h' },
{0, 0, 0, 0 }
};
c = getopt_long(argc, argv, "d:a:k:O:o:f:evVh",
c = getopt_long(argc, argv, "d:a:k:O:o:f:K:vVh",
long_options, &option_index);
if (c == -1)
break;
@ -244,6 +261,9 @@ int main(int argc, char** argv)
case 'o':
outputFile = optarg;
break;
case 'K':
encryptionKeyUser = optarg;
break;
case 'v':
verbose++;
break;
@ -286,6 +306,32 @@ int main(int argc, char** argv)
}
}
if (encryptionKeyUser)
{
int size = std::string(encryptionKeyUser).size();
if ((size % 2))
{
std::cout << "Error : Encryption key must be odd length" << std::endl;
goto end;
}
if (encryptionKeyUser[0] == '0' && encryptionKeyUser[1] == 'x')
{
encryptionKeyUser += 2;
size -= 2;
}
encryptionKey = new unsigned char[size/2];
for(i=0; i<size; i+=2)
{
encryptionKey[i/2] = htoi(encryptionKeyUser[i]) << 4;
encryptionKey[i/2] |= htoi(encryptionKeyUser[i+1]);
}
encryptionKeySize = size/2;
}
if (hasErrors)
goto end;
@ -300,5 +346,8 @@ end:
free((void*)*files[i]);
}
if (encryptionKey)
free(encryptionKey);
return ret;
}