GFpECGetPointOctString
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 ofpStr, 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 whenpPointorpECisNULL.
- ippStsContextMatchErr
- Indicates an error when one of the contexts pointed bypPointorpECis 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 whenstrLen!= 2*gfelementLen, wheregfelementLenis the size of the GF(p) element.