Developer Reference

Contents

GFpECGetPointOctString

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.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.