Developer Guide and Reference for Intel® Integrated Performance Primitives Cryptography
GFpECTstPointInSubgroup
Checks if a point belongs to a specified subgroup.
Syntax
IppStatus ippsGFpECTstPointInGroup(const IppsGFpECPoint* pP, IppECResult* pResult, IppsGFpECState* pEC, Ipp8u* pScratchBuffer);
Include Files
ippcp.h
Parameters
| pP | Pointer to the IppsGFpECPoint context. | 
| pResult | Pointer to the result received upon the check that the point belongs to the elliptic curve over the finite field. | 
| pEC | Pointer to the context of the elliptic curve. | 
| pScratchBuffer | Pointer to the scratch buffer; can be NULL. | 
Description
This function checks whether a point belongs to the pre-defined subgroup of the elliptic curve defined over the finite field. The result of the testing is returned in pResult and may have the following values:
| ippECValid | The point is in the subgroup of the curve. | 
| ippECPointOutOfGroup | The point is out of the subgroup. | 
If the pointer to the scratch buffer is NULL, the function uses a short internal buffer for computations.
Return Values
| ippStsNoErr | Indicates no error. Any other value indicates an error or warning. | 
| ippStsNullPtrErr | Indicates an error condition if any of the pointers pP, pResult, and pEC is NULL. | 
| ippStsContextMatchErr | Indicates an error condition if any of the specified contexts does not match the operation. | 
| ippStsOutOfRangeErr | Indicates an error condition if the point does not belong to the finite field over which the elliptic curve is initialized. |