void EcdhSample(Tpm2 tpm, TestContext testCtx)
{
//
// Peer A (e.g. local machine):
//
// Template for an ECC key with the ECDH scheme:
var inPub = new TpmPublic(TpmAlgId.Sha256,
ObjectAttr.Decrypt | ObjectAttr.UserWithAuth | ObjectAttr.SensitiveDataOrigin,
null,
new EccParms(new SymDefObject(), new SchemeEcdh(TpmAlgId.Sha256),
EccCurve.NistP256, new NullKdfScheme()),
new EccPoint());
// Boilerplate stuff
var pcrSel = new PcrSelection[0];
CreationData crData;
byte[] crHash;
TkCreation crTk;
// Create a key for ECDH
TpmPublic pubA;
TpmHandle hKeyA = tpm.CreatePrimary(TpmRh.Owner, new SensitiveCreate(), inPub, null, new PcrSelection[0],
out pubA, out crData, out crHash, out crTk);
//
// Peer B (e.g. remote machine):
//
// Receives 'pubA' from peer A
// Load public key
TpmHandle hPubKeyA = tpm.LoadExternal(null, pubA, TpmRh.Owner);
// Create shared secret 'zB', and a public ECC point for exchange
EccPoint ephPubPt;
EccPoint zB = tpm.EcdhKeyGen(hPubKeyA, out ephPubPt);
tpm.FlushContext(hPubKeyA);
//
// Peer A again:
//
// Receives 'ephPubPt' from peer B
// A full key is required here
EccPoint zA = tpm.EcdhZGen(hKeyA, ephPubPt);
testCtx.AssertEqual("SharedSecret", zA, zB);
tpm.FlushContext(hKeyA);
} // EcdhSample
