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Merged
BKSSMVenkateswarlu merged 1 commit into from
Aug 19, 2020
Merged

For AES GCM Decryption operation hold last 16 bytes of data in update… #25

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27 changes: 19 additions & 8 deletions HAL/keymaster/4.1/JavacardKeymaster4Device.cpp
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Original file line numberDiff line numberDiff line change
Expand Up@@ -1085,16 +1085,27 @@ Return<void> JavacardKeymaster4Device::begin(KeyPurpose purpose, const hidl_vec<
cborConverter_.addHardwareAuthToken(array, authToken);
std::vector<uint8_t> cborData = array.encode();

/* keyCharacteristics.hardwareEnforced is required to store algorithm, digest and padding values in operationInfo
* structure. To retrieve keyCharacteristics.hardwareEnforced, parse the keyBlob.
*/
/* TODO if keyBlob is corrupted it crashes in cbor */
std::tie(blobItem, errorCode) = cborConverter_.decodeData(std::vector<uint8_t>(keyBlob), false);
// keyCharacteristics.hardwareEnforced is required to store algorithm, digest and padding values in operationInfo
// structure. To retrieve keyCharacteristics.hardwareEnforced, call getKeyCharacateristics.
// By calling getKeyCharacateristics also helps in finding a corrupted keyblob.
hidl_vec<uint8_t> applicationId;
hidl_vec<uint8_t> applicationData;
if(getTag(inParams, Tag::APPLICATION_ID, param)) {
applicationId = param.blob;
}
if(getTag(inParams, Tag::APPLICATION_DATA, param)) {
applicationData = param.blob;
}
//Call to getKeyCharacteristics.
getKeyCharacteristics(keyBlob, applicationId, applicationData,
[&](ErrorCode error, KeyCharacteristics keyChars) {
errorCode = error;
keyCharacteristics = keyChars;
});

if(blobItem != nullptr) {
if(errorCode == ErrorCode::OK) {
errorCode = ErrorCode::UNKNOWN_ERROR;
if(cborConverter_.getKeyCharacteristics(blobItem, 3, keyCharacteristics) &&
getTag(keyCharacteristics.hardwareEnforced, Tag::ALGORITHM, param)) {
if(getTag(keyCharacteristics.hardwareEnforced, Tag::ALGORITHM, param)) {
errorCode = sendData(Instruction::INS_BEGIN_OPERATION_CMD, cborData, cborOutData);
if((errorCode == ErrorCode::OK) && (cborOutData.size() > 2)) {
//Skip last 2 bytes in cborData, it contains status.
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10 changes: 6 additions & 4 deletions HAL/keymaster/4.1/JavacardOperationContext.cpp
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Original file line numberDiff line numberDiff line change
Expand Up@@ -229,12 +229,14 @@ ErrorCode OperationContext::getBlockAlignedData(uint64_t operHandle, uint8_t* in
/*Update */
//Calculate the block sized length on combined input of both buffered data and input data.
uint32_t blockAlignedLen = ((data.buf_len + input_len)/blockSize) * blockSize;
//For symmetric ciphers, decryption operation and PKCS7 padding mode save last 16 bytes of block and send this
//block in finish operation. This is done to make sure that there will be always a 16 bytes data to finish
//operation so that javacard Applet may remove PKCS7 padding if any.
//For symmetric ciphers, decryption operation and PKCS7 padding mode or AES GCM operation save the last 16 bytes
//of block and send this block in finish operation. This is done to make sure that there will be always a 16
//bytes of data left for finish operation so that javacard Applet may remove PKCS7 padding if any or get the tag
//data for AES GCM operation for authentication purpose.
if(((operationTable[operHandle].info.alg == Algorithm::AES) ||
(operationTable[operHandle].info.alg == Algorithm::TRIPLE_DES)) &&
(operationTable[operHandle].info.pad == PaddingMode::PKCS7) &&
(operationTable[operHandle].info.pad == PaddingMode::PKCS7 ||
operationTable[operHandle].info.mode == BlockMode::GCM) &&
(operationTable[operHandle].info.purpose == KeyPurpose::DECRYPT)) {
if(blockAlignedLen >= blockSize) blockAlignedLen -= blockSize;
}
Expand Down