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

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804