GFpECGetPointOctString

Developer Reference for Intel® Integrated Performance Primitives Cryptography

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

Syntax

IppStatus ippsGFpECGetPointOctString(const IppsGFpECPointState* pPoint, Ipps8u* pStr, int lenStr, IppsGFpECState* pEC);

Include Files

ippcp.h

Parameters

pPoint	Pointer to the context of the elliptic curve point.
pStr	Pointer to the target string of octets.
lenStr	Available length of pStr, in bytes.
pEC	Pointer to the context of the elliptic curve cryptosystem.

Description

This function retrieves the coordinates of pPoint on the pEC elliptic curve from the point context, converts each X and Y coordinate into the octet string and stores them in pStr so that left half contains X and right half contains Y point's coordinate. Before using this function, define the elliptic curve domain parameters using one of the following functions: ECCPSet, or ECCPSetStd and GFpECSetSubgroup.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or warning.
ippStsNullPtrErr	Indicates an error when pPoint or pEC is NULL.
ippStsContextMatchErr	Indicates an error when one of the contexts pointed by pPoint or pEC is not valid or not a defined subgroup.
ippStsNotSupportedModeErr	Indicates an error when the finite field over which the elliptic curve is initialized is not prime.
ippStsOutOfRangeErr	Indicates an error when the size of a point coordinate is not equal to the size of the GF(`p`) element.
ippStsSizeErr	Indicates an error when strLen != 2*gfelementLen, where gfelementLen is the size of the GF(`p`) element.