Introduce Direct TPM2 API

direct/helpers/crypto.go

@@ -0,0 +1,46 @@
+package helpers
+
+import (
+	"crypto/elliptic"
+	"crypto/rsa"
+	"math/big"
+
+	"github.com/google/go-tpm/direct/structures/tpm2b"
+	"github.com/google/go-tpm/direct/structures/tpms"
+)
+
+// RSAPub converts a TPM RSA public key into one recognized by the rsa package.
+func RSAPub(parms *tpms.RSAParms, pub *tpm2b.PublicKeyRSA) (*rsa.PublicKey, error) {
+	result := rsa.PublicKey{
+		N: big.NewInt(0).SetBytes(pub.Buffer),
+		E: int(parms.Exponent),
+	}
+	// TPM considers 65537 to be the default RSA public exponent, and 0 in
+	// the parms
+	// indicates so.
+	if result.E == 0 {
+		result.E = 65537
+	}
+	return &result, nil
+}
+
+// ECDHPub is a convenience wrapper around the necessary info to perform point
+// multiplication with the elliptic package.
+type ECDHPub struct {
+	Curve elliptic.Curve
+	X, Y  *big.Int
+}
+
+// ECCPub converts a TPM ECC public key into one recognized by the elliptic
+// package's point-multiplication functions, for use in ECDH.
+func ECCPub(parms *tpms.ECCParms, pub *tpms.ECCPoint) (*ECDHPub, error) {
+	curve, err := parms.CurveID.Curve()
+	if err != nil {
+		return nil, err
+	}
+	return &ECDHPub{
+		Curve: curve,
+		X:     big.NewInt(0).SetBytes(pub.X.Buffer),
+		Y:     big.NewInt(0).SetBytes(pub.Y.Buffer),
+	}, nil
+}

direct/helpers/names.go

@@ -0,0 +1,14 @@
+package helpers
+
+import (
+	"encoding/binary"
+
+	"github.com/google/go-tpm/direct/structures/tpm"
+)
+
+// PrimaryHandleName returns the TPM Name of a primary handle.
+func PrimaryHandleName(h tpm.Handle) []byte {
+	result := make([]byte, 4)
+	binary.BigEndian.PutUint32(result, uint32(h))
+	return result
+}

direct/helpers/wrappers.go

@@ -0,0 +1,12 @@
+package helpers
+
+import "github.com/google/go-tpm/direct/structures/tpm"
+
+// This file provides wrapper functions for concrete types used by tpm2, for
+// setting union member pointers.
+
+// NewKeyBits allocates and returns the address of a new tpm.KeyBits.
+func NewKeyBits(v tpm.KeyBits) *tpm.KeyBits { return &v }
+
+// NewAlgID allocates and returns the address of a new tpm.AlgID.
+func NewAlgID(v tpm.AlgID) *tpm.AlgID { return &v }