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 ofpPoint on the pEC elliptic
curvefrom the point context, converts each X and Y coordinate
intothe octet string and stores them in pStrso 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 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. |
ippStsOutOfRangeErr |
Indicates an error when the size of a point coordinate is not equal to the size of the GF( |
ippStsSizeErr |
Indicates an error when strLen != 2*gfelementLen, where gfelementLen is the size of the GF( |