makeShareByFile

In two-party operations, this function is called to split the original data of node 0 (compute party) and node 1 (non-compute party) into shares. When node 0 calls this function, it sets isRecvShare to 1 to receive the shares sent by node 1, and then sets isRecvShare to 0 to split its own data into shares. When the non-compute party calls this function, it sets isRecvShare to 0 to split its own data into shares and then sends the shares to the compute party. In three-party operations, this function is called to split the original data of any two nodes among node 0 (compute party) and nodes 1 and 2 (non-compute parties) into shares. Assume that nodes 0 and 1 have data. When node 0 calls this function, it sets isRecvShare to 1 to receive the shares sent by node 1, and then sets isRecvShare to 0 to split its own data into shares. When node 1 calls this function, it sets isRecvShare to 0 to split its own data into shares and sends the shares to node 0, and sets isRecvShare to 1 to receive the shares sent by node 0. Then, node 2 sets isRecvShare to 1 to receive the shares sent by node 0 and sets isRecvShare to 1 to receive the shares sent by node 1.

int makeShareByFile(
    DG_TeeCtx *dgTeeCtx, 
    int isRecvShare, 
    const DG_MpcFileInput *input, 
    DG_MpcFileOutput *output
)

Parameters

Parameter	Description	Value Range	Input/Output
dgTeeCtx	KCAL context	Context initialized in section initTeeCtx.	Input
isRecvShare	0: Splits the original data of a node itself into shares. 1: Receives data shares of the other node.	0 or 1.	Input
input	DG_MpcFileInput	The value is not null.	Input
output	DG_MpcFileOutput	The value is not null.	Output

**Table 1** DG_MpcFileInput structure
Name	Type	Description
filePath	char*	File path
pathLen	uint32_t	Path length
dataSize	uint64_t	Data size

**Table 2** DG_MpcFileOutput structure
Name	Type	Description
filePath	char*	File path
pathLen	uint32_t	Path length
dataSize	uint64_t	Data size

Return Values

Success: 0 is returned.
Failure: The error code is returned.

Error Codes

**Table 3** Error codes
Error Code	Value	Description	Remarks
DG_ERR_MPC_TEE_INVALID_PARAM 4516	4501 DG_ERR_MPC_TEE_TMP_PATH_SET_ERROR	Invalid parameter Incorrect temporary directory settings	-
DG_ERR_MPC_TEE_INVALID_ALGORITHM_TYPE 4514	4502 DG_ERR_MPC_TEE_CHUNK_SIZE_SET_ERROR	Invalid algorithm type Incorrect file chunk size	-

Dependency

dgTeeCtx depends on the successful initialization of initTeeCtx.
The dependent header file is data_guard_mpc.h.

Example

Call the makeShareByFile API using the aritOpts output of the successful DG_InitArithmeticOpts call.
If either node (compute node 0 or 1) returns an error code when calling an API, the node needs to use a task scheduling mechanism to notify the other node to terminate the service process. For example, if compute node 1 returns an error code when calling the makeShareByFile API and compute node 0 is waiting to receive shares, compute node 1 needs to notify compute node 0 to stop receiving.

#include  "data_guard_mpc.h" 
 // Compute party
DG_MpcFileInput teeFileInput;
teeFileInput.filePath = const_cast<char *>(inputFilePath.c_str());
teeFileInput.pathLen = static_cast<uint32_t>(inputFilePath.length());

DG_MpcFileOutput teeFileOutput;
teeFileOutput.filePath = const_cast<char *>(shareFilePath.c_str());
teeFileOutput.pathLen = static_cast<uint32_t>(shareFilePath.length());
int ret = opts_->makeShareByFile(dgTeeCtx_, isRecvShare, &teeFileInput, &teeFileOutput);

Parent topic: Arithmetic Operators