GFpECSetPointOctString

Sets the coordinates of a point on an elliptic curve defined over GF(p).

Syntax

IppStatus ippsGFpECSetPointOctString(const Ipp8u* pStr, int strLen, IppsGFpECPoint* pPoint, IppsGFpECState* pEC);

Include Files

ippcp.h

Parameters

pStr	Pointer octet string containing `X` and `Y` coordinates of the point on the elliptic curve.
strLen	Length of the input pStr string, in bytes.
pPoint	Pointer to the context of the elliptic curve point.
pEC	Pointer to the context of the elliptic cryptosystem.

Description

This function sets the coordinates of a point on the elliptic curve defined over a prime finite field GF(p). The input data is the octet string containing the pair (X, Y) of coordinates. The left half of the pStr string represents an X-coordinate and the right half represents a Y-coordinate.The left byte in X and Y representations corresponds to the most significant byte of coordinates. The length of each part equals the length of the GF(p) field element in bytes. Before using this function, you need to:

Define the elliptic curve domain parameters using the GFpECSet or GFpECSetStd and GFpECSetSubgroup functions
Create the context of the point on the elliptic curve using the GFpECPointGetSize and GFpECPointInit functions

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or warning.
ippStsNullPtrErr	Indicates an error when any of the specified pointers is NULL.
ippStsContextMatchErr	Indicates an error when one of the contexts pointed bypPoint orpEC is not valid or not a definedsubgroup.
ippStsNotSupportedModeErr	Indicates an error when the finite field over which the elliptic curve is initialized is not prime.