Performing Elliptic Curve Operations
282 RSA BSAFE Crypto-C Developer’s Guide
Because you have the EC parameters in the A_EC_PARAMS structure ecParams, the
appropriate AI that describes the data is
AI_ECParameters:
Step 2b (optional): Set Acceleration Table Info
If you are using an acceleration table, you need to set the algorithm object with the
appropriate acceleration table. Once you have gone through the steps in “Generating
Acceleration Tables” on page 273 and have an
ITEM structure containing the
acceleration table, you can pass a pointer to the
ITEM structure as the third argument
to
B_SetAlgorithmInfo:
Step 3: Initialize
Initialize the algorithm object to perform the key agreement protocol. The Reference
Manual Chapter 2 entry for
AI_EC_DHKeyAgree states which algorithm methods to
include in your chooser:
typedef struct {
B_INFO_TYPE parameterInfoType;
POINTER parameterInfoValue;
} B_EC_PARAMS;
B_EC_PARAMS commonECParams;
commonECParams.parameterInfoType = AI_ECParameters;
commonECParams.parameterInfoValue = (POINTER)&ecParams;
if ((status = B_SetAlgorithmInfo(alice, AI_EC_DHKeyAgree,
(POINTER)&commonECParams)) != 0)
break;
if ((status = B_SetAlgorithmInfo (alice, AI_ECAcceleratorTable,
(POINTER)&aTableItem)) != 0)
break;
B_ALGORITHM_METHOD *EC_DH_CHOOSER[] = {
&AM_ECFP_DH_KEY_AGREE,
&AM_ECF2POLY_DH_KEY_AGREE,
(B_ALGORITHM_METHOD *)NULL_PTR
};
