Implemented and Tested go-tpm direct functions for TPM2_ContextSave a…

…nd TPM2_ContextLoad

direct/structures/internal/structures.go

@@ -397,6 +397,10 @@ type TPMISHPolicy = TPMHandle
 // See definition in Part 2: Structures, section 9.11.
 type TPMIDHContext = TPMHandle
 
+// TPMIDHSaved represents a TPMI_DH_SAVED.
+// See definition in Part 2: Structures, section 9.12.
+type TPMIDHSaved = TPMHandle
+
 // TPMIRHHierarchy represents a TPMI_RH_HIERARCHY.
 // See definition in Part 2: Structures, section 9.13.
 type TPMIRHHierarchy = TPMHandle
@@ -1591,6 +1595,42 @@ type TPM2BNVPublic struct {
 	NVPublic TPMSNVPublic `gotpm:"sized"`
 }
 
+// TPM2BContextSensitive represents a TPM2B_CONTEXT_SENSITIVE
+// See definition in Part 2: Structures, section 14.2.
+type TPM2BContextSensitive struct {
+	Size uint16
+	// the sensitive data
+	Buffer []byte
+}
+
+// TPMSContextData represents a TPMS_CONTEXT_DATA
+// See definition in Part 2: Structures, section 14.3.
+type TPMSContextData struct {
+	// the integrity value
+	Integrity TPM2BDigest
+	// the sensitive area
+	Encrypted TPM2BContextSensitive
+}
+
+// TPM2BContextData represents a TPM2B_CONTEXT_DATA
+// See definition in Part 2: Structures, section 14.4.
+type TPM2BContextData struct {
+	Buffer TPMSContextData `gotpm:"sized"`
+}
+
+// TPMSContext represents a TPMS_CONTEXT
+// See definition in Part 2: Structures, section 14.5.
+type TPMSContext struct {
+	// the sequence number of the context
+	Sequence uint64
+	// a handle indicating if the context is a session, object, or sequence object
+	SavedHandle TPMIDHSaved
+	// the hierarchy of the context
+	Hierarchy TPMIRHHierarchy
+	// the context data and integrity HMAC
+	ContextBlob TPM2BContextData
+}
+
 // TPM2BCreationData represents a TPM2B_CREATION_DATA.
 // See definition in Part 2: Structures, section 15.2.
 type TPM2BCreationData struct {

direct/structures/tpm2b/tpm2b.go

@@ -102,6 +102,10 @@ type Private = internal.TPM2BPrivate
 // See definition in Part 2: Structures, section 13.6.
 type NVPublic = internal.TPM2BNVPublic
 
+// ContextSensitive represents a TPM2B_CONTEXT_SENSITIVE.
+// See definition in Part 2: Structures, section 14.2.
+type ContextSensitive = internal.TPM2BContextSensitive
+
 // CreationData represents a TPM2B_CREATION_DATA.
 // See definition in Part 2: Structures, section 15.2.
 type CreationData = internal.TPM2BCreationData

direct/structures/tpms/tpms.go

@@ -183,6 +183,14 @@ type ECCParms = internal.TPMSECCParms
 // See definition in Part 2: Structures, section 13.5.
 type NVPublic = internal.TPMSNVPublic
 
+// ContextData represents a TPMS_CONTEXT_DATA
+// See definition in Part 2: Structures, section 14.3.
+type ContextData = internal.TPMSContextData
+
+// Context represents a TPMS_CONTEXT
+// See definition in Part 2: Structures, section 14.5.
+type Context = internal.TPMSContext
+
 // CreationData represents a TPMS_CREATION_DATA.
 // See definition in Part 2: Structures, section 15.1.
 type CreationData = internal.TPMSCreationData

direct/tpm2/combined_context_test.go

@@ -0,0 +1,118 @@
+package tpm2
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-tpm/direct/structures/tpm"
+	"github.com/google/go-tpm/direct/structures/tpm2b"
+	"github.com/google/go-tpm/direct/structures/tpma"
+	"github.com/google/go-tpm/direct/structures/tpms"
+	"github.com/google/go-tpm/direct/structures/tpmt"
+	"github.com/google/go-tpm/direct/structures/tpmu"
+	"github.com/google/go-tpm/direct/transport/simulator"
+)
+
+func CombinedContextTest(t *testing.T) {
+	thetpm, err := simulator.OpenSimulator()
+	if err != nil {
+		t.Fatalf("could not connect to TPM simulator: %v", err)
+	}
+	defer thetpm.Close()
+
+	createPrimary := CreatePrimary{
+		PrimaryHandle: tpm.RHOwner,
+		InPublic: tpm2b.Public{
+			PublicArea: tpmt.Public{
+				Type:    tpm.AlgECC,
+				NameAlg: tpm.AlgSHA256,
+				ObjectAttributes: tpma.Object{
+					FixedTPM:            true,
+					FixedParent:         true,
+					SensitiveDataOrigin: true,
+					UserWithAuth:        true,
+					SignEncrypt:         true,
+				},
+				Parameters: tpmu.PublicParms{
+					ECCDetail: &tpms.ECCParms{
+						Scheme: tpmt.ECCScheme{
+							Scheme: tpm.AlgECDSA,
+							Details: tpmu.AsymScheme{
+								ECDSA: &tpms.SigSchemeECDSA{
+									HashAlg: tpm.AlgSHA256,
+								},
+							},
+						},
+						CurveID: tpm.ECCNistP256,
+					},
+				},
+			},
+		},
+	}
+
+	rspCP, err := createPrimary.Execute(thetpm)
+	if err != nil {
+		t.Fatalf("CreatePrimary failed: %v", err)
+	}
+
+	flushContextCP := FlushContext{FlushHandle: rspCP.ObjectHandle}
+	defer flushContextCP.Execute(thetpm)
+
+	cl := CreateLoaded{
+		ParentHandle: rspCP.ObjectHandle,
+		InPublic: tpm2b.Template{
+			Template: tpmt.Public{
+				Type:    tpm.AlgKeyedHash,
+				NameAlg: tpm.AlgSHA256,
+				ObjectAttributes: tpma.Object{
+					SensitiveDataOrigin: true,
+					UserWithAuth:        true,
+					Decrypt:             true,
+					Restricted:          true,
+				},
+				Parameters: tpmu.PublicParms{
+					KeyedHashDetail: &tpms.KeyedHashParms{
+						Scheme: tpmt.KeyedHashScheme{
+							Scheme: tpm.AlgXOR,
+							Details: tpmu.SchemeKeyedHash{
+								XOR: &tpms.SchemeXOR{
+									HashAlg: tpm.AlgSHA256,
+									KDF:     tpm.AlgKDF1SP800108,
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	rspCrL, err := cl.Execute(thetpm)
+	if err != nil {
+		t.Fatalf("could not create derivation parent: %v:", err)
+	}
+
+	contextSave := ContextSave{
+		SaveHandle: rspCrL.ObjectHandle,
+	}
+	rspCS, err := contextSave.Execute(thetpm)
+	if err != nil {
+		t.Fatalf("ContextSave failed: %v", err)
+	}
+
+	flushContextCL := FlushContext{FlushHandle: rspCrL.ObjectHandle}
+	flushContextCL.Execute(thetpm)
+
+	contextLoad := ContextLoad{
+		Context: rspCS.Context,
+	}
+
+	rspCoL, err := contextLoad.Execute(thetpm)
+	if err != nil {
+		t.Fatalf("ContextLoad failed: %v", err)
+	}
+
+	if !cmp.Equal(rspCoL.LoadedHandle, rspCrL.ObjectHandle) {
+		t.Error("Mismatch between public returned from ContextLoad & CreateLoaded")
+	}
+}

direct/tpm2/tpm2.go

@@ -1012,6 +1012,61 @@ type CreatePrimaryResponse struct {
 // Response implements the Response interface.
 func (*CreatePrimaryResponse) Response() tpm.CC { return tpm.CCCreatePrimary }
 
+// ContextSave is the input to TPM2_ContextSave.
+// See definition in Part 3, Commands, section 28.2
+type ContextSave struct {
+	// handle of the resource to save Auth Index: None
+	SaveHandle tpmi.DHContext
+}
+
+// Command implements the Command interface.
+func (*ContextSave) Command() tpm.CC { return tpm.CCContextSave }
+
+// Execute executes the command and returns the response.
+func (cmd *ContextSave) Execute(t transport.TPM, s ...Session) (*ContextSaveResponse, error) {
+	var rsp ContextSaveResponse
+	if err := execute(t, cmd, &rsp, s...); err != nil {
+		return nil, err
+	}
+	return &rsp, nil
+}
+
+// ContextSaveResponse is the response from TPM2_ContextSave.
+type ContextSaveResponse struct {
+	Context tpms.Context
+}
+
+// Response implements the Response interface.
+func (*ContextSaveResponse) Response() tpm.CC { return tpm.CCContextSave }
+
+// ContextLoad is the input to TPM2_ContextLoad.
+// See definition in Part 3, Commands, section 28.3
+type ContextLoad struct {
+	// the context blob
+	Context tpms.Context
+}
+
+// Command implements the Command interface.
+func (*ContextLoad) Command() tpm.CC { return tpm.CCContextLoad }
+
+// Execute executes the command and returns the response.
+func (cmd *ContextLoad) Execute(t transport.TPM, s ...Session) (*ContextLoadResponse, error) {
+	var rsp ContextLoadResponse
+	if err := execute(t, cmd, &rsp, s...); err != nil {
+		return nil, err
+	}
+	return &rsp, nil
+}
+
+// ContextLoadResponse is the response from TPM2_ContextLoad.
+type ContextLoadResponse struct {
+	// the handle assigned to the resource after it has been successfully loaded
+	LoadedHandle tpmi.DHContext
+}
+
+// Response implements the Response interface.
+func (*ContextLoadResponse) Response() tpm.CC { return tpm.CCContextLoad }
+
 // FlushContext is the input to TPM2_FlushContext.
 // See definition in Part 3, Commands, section 28.4
 type FlushContext struct {