Developer Guide and Reference for Intel® Integrated Performance Primitives Cryptography
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GFpECGetSubgroup
Extracts the parameters (base point and its order) that define an elliptic curve point subgroup.
Syntax
IppStatus ippsGFpECGetSubGroup(IppsGFpState** const ppGF, IppsGFpElement* pX, IppsGFpElement* pY, IppsBigNumState* pOrder,IppsBigNumState* pCofactor, const IppsGFpECState* pEC);
Include Files
ippcp.h
Parameters
ppGF |
Pointer to the context of the underlying finite field. |
pX, pY |
Pointers to the X and Y coordinates of the base point of the elliptic curve. |
pOrder |
Pointer to the big number context storing the order of the base point. |
pCofactor |
Pointer to the big number context storing the cofactor. |
pEC |
Pointer to the context of the elliptic curve. |
Description
This function extracts parameters of an elliptic curve subgroup. You can get any combination of the following parameters: the X and Y coordinates, the order of the base point, and the value of the cofactor. To turn off extraction of a particular parameter of the elliptic curve, set the appropriate function parameter to NULL.
Return Values
ippStsNoErr |
Indicates no error. Any other value indicates an error or warning. |
ippStsNullPtrErr |
Indicates an error condition if the specified pointer pEC is NULL. |
ippStsContextMatchErr |
Indicates an error condition in the following cases:
|
ippStsOutOfRangeErr |
Indicates an error if the base point coordinates (pX, pY) do not belong to the finite field over which the elliptic curve is initialized. |
ippStsLengthErr |
Indicates an error condition in the following cases:
|