feat: TPM2_RSA_Encrypt and TPM2_RSA_Decrypt (#356)

tpm2/structures.go

@@ -2299,6 +2299,20 @@ type TPMTRSAScheme struct {
 	Details TPMUAsymScheme `gotpm:"tag=Scheme"`
 }
 
+// TPMIAlgRSADecrypt represents a TPMI_ALG_RSA_DECRYPT.
+// See definition in Part 2: Structures, section 11.2.4.3.
+type TPMIAlgRSADecrypt = TPMAlgID
+
+// TPMTRSADecrypt represents a TPMT_RSA_DECRYPT.
+// See definition in Part 2: Structures, section 11.2.4.4.
+type TPMTRSADecrypt struct {
+	marshalByReflection
+	// scheme selector
+	Scheme TPMIAlgRSADecrypt `gotpm:"nullable"`
+	// scheme parameters
+	Details TPMUAsymScheme `gotpm:"tag=Scheme"`
+}
+
 // TPM2BPublicKeyRSA represents a TPM2B_PUBLIC_KEY_RSA.
 // See definition in Part 2: Structures, section 11.2.4.5.
 type TPM2BPublicKeyRSA TPM2BData

tpm2/test/rsa_encryption_test.go

@@ -0,0 +1,137 @@
+package tpm2test
+
+import (
+	"bytes"
+	"testing"
+
+	. "github.com/google/go-tpm/tpm2"
+	"github.com/google/go-tpm/tpm2/transport/simulator"
+)
+
+func TestRSAEncryption(t *testing.T) {
+	theTpm, err := simulator.OpenSimulator()
+	if err != nil {
+		t.Fatalf("could not connect to TPM simulator: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := theTpm.Close(); err != nil {
+			t.Errorf("%v", err)
+		}
+	})
+
+	createPrimaryCmd := CreatePrimary{
+		PrimaryHandle: TPMRHOwner,
+		InPublic:      New2B(RSASRKTemplate),
+	}
+	createPrimaryRsp, err := createPrimaryCmd.Execute(theTpm)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	t.Cleanup(func() {
+		flushContextCmd := FlushContext{FlushHandle: createPrimaryRsp.ObjectHandle}
+		if _, err := flushContextCmd.Execute(theTpm); err != nil {
+			t.Errorf("%v", err)
+		}
+	})
+
+	createCmd := Create{
+		ParentHandle: NamedHandle{
+			Handle: createPrimaryRsp.ObjectHandle,
+			Name:   createPrimaryRsp.Name,
+		},
+		InPublic: New2B(TPMTPublic{
+			Type:    TPMAlgRSA,
+			NameAlg: TPMAlgSHA256,
+			ObjectAttributes: TPMAObject{
+				FixedTPM:             true,
+				STClear:              false,
+				FixedParent:          true,
+				SensitiveDataOrigin:  true,
+				UserWithAuth:         true,
+				AdminWithPolicy:      false,
+				NoDA:                 true,
+				EncryptedDuplication: false,
+				Restricted:           false,
+				Decrypt:              true,
+				SignEncrypt:          true,
+			},
+			Parameters: NewTPMUPublicParms(
+				TPMAlgRSA,
+				&TPMSRSAParms{
+					KeyBits: 2048,
+				},
+			),
+			Unique: NewTPMUPublicID(
+				TPMAlgRSA,
+				&TPM2BPublicKeyRSA{
+					Buffer: make([]byte, 256),
+				},
+			),
+		}),
+	}
+	createRsp, err := createCmd.Execute(theTpm)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	loadCmd := Load{
+		ParentHandle: NamedHandle{
+			Handle: createPrimaryRsp.ObjectHandle,
+			Name:   createPrimaryRsp.Name,
+		},
+		InPrivate: createRsp.OutPrivate,
+		InPublic:  createRsp.OutPublic,
+	}
+	loadRsp, err := loadCmd.Execute(theTpm)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	t.Cleanup(func() {
+		flushContextCmd := FlushContext{FlushHandle: loadRsp.ObjectHandle}
+		if _, err := flushContextCmd.Execute(theTpm); err != nil {
+			t.Errorf("%v", err)
+		}
+	})
+
+	message := []byte("secret")
+
+	encryptCmd := RSAEncrypt{
+		KeyHandle: loadRsp.ObjectHandle,
+		Message:   TPM2BPublicKeyRSA{Buffer: message},
+		InScheme: TPMTRSADecrypt{
+			Scheme: TPMAlgOAEP,
+			Details: NewTPMUAsymScheme(
+				TPMAlgOAEP,
+				&TPMSEncSchemeOAEP{
+					HashAlg: TPMAlgSHA256,
+				},
+			),
+		},
+	}
+	encryptRsp, err := encryptCmd.Execute(theTpm)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	decryptCmd := RSADecrypt{
+		KeyHandle:  loadRsp.ObjectHandle,
+		CipherText: TPM2BPublicKeyRSA{Buffer: encryptRsp.OutData.Buffer},
+		InScheme: TPMTRSADecrypt{
+			Scheme: TPMAlgOAEP,
+			Details: NewTPMUAsymScheme(
+				TPMAlgOAEP,
+				&TPMSEncSchemeOAEP{
+					HashAlg: TPMAlgSHA256,
+				},
+			),
+		},
+	}
+	decryptRsp, err := decryptCmd.Execute(theTpm)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	if !bytes.Equal(message, decryptRsp.Message.Buffer) {
+		t.Errorf("want %x got %x", message, decryptRsp.Message.Buffer)
+	}
+}

tpm2/tpm2.go

@@ -452,6 +452,68 @@ type CreateLoadedResponse struct {
 	Name TPM2BName
 }
 
+// RSAEncrypt is the input to TPM2_RSA_Encrypt
+// See definition in Part 3, Commands, section 14.2.
+type RSAEncrypt struct {
+	// reference to public portion of RSA key to use for encryption
+	KeyHandle handle `gotpm:"handle"`
+	// message to be encrypted
+	Message TPM2BPublicKeyRSA
+	// the padding scheme to use if scheme associated with keyHandle is TPM_ALG_NULL
+	InScheme TPMTRSADecrypt `gotpm:"nullable"`
+	// optional label L to be associated with the message
+	Label TPM2BData `gotpm:"optional"`
+}
+
+// Command implements the Command interface.
+func (RSAEncrypt) Command() TPMCC { return TPMCCRSAEncrypt }
+
+// Execute executes the command and returns the response.
+func (cmd RSAEncrypt) Execute(t transport.TPM, s ...Session) (*RSAEncryptResponse, error) {
+	var rsp RSAEncryptResponse
+	if err := execute[RSAEncryptResponse](t, cmd, &rsp, s...); err != nil {
+		return nil, err
+	}
+	return &rsp, nil
+}
+
+// RSAEncryptResponse is the response from TPM2_RSA_Encrypt
+type RSAEncryptResponse struct {
+	// encrypted output
+	OutData TPM2BPublicKeyRSA
+}
+
+// RSADecrypt is the input to TPM2_RSA_Decrypt
+// See definition in Part 3, Commands, section 14.3.
+type RSADecrypt struct {
+	// RSA key to use for decryption
+	KeyHandle handle `gotpm:"handle,auth"`
+	// cipher text to be decrypted
+	CipherText TPM2BPublicKeyRSA
+	// the padding scheme to use if scheme associated with keyHandle is TPM_ALG_NULL
+	InScheme TPMTRSADecrypt `gotpm:"nullable"`
+	// label whose association with the message is to be verified
+	Label TPM2BData `gotpm:"optional"`
+}
+
+// Command implements the Command interface.
+func (RSADecrypt) Command() TPMCC { return TPMCCRSADecrypt }
+
+// Execute executes the command and returns the response.
+func (cmd RSADecrypt) Execute(t transport.TPM, s ...Session) (*RSADecryptResponse, error) {
+	var rsp RSADecryptResponse
+	if err := execute[RSADecryptResponse](t, cmd, &rsp, s...); err != nil {
+		return nil, err
+	}
+	return &rsp, nil
+}
+
+// RSADecryptResponse is the response from TPM2_RSA_Decrypt
+type RSADecryptResponse struct {
+	// decrypted output
+	Message TPM2BPublicKeyRSA
+}
+
 // ECDHZGen is the input to TPM2_ECDHZGen.
 // See definition in Part 3, Commands, section 14.5
 type ECDHZGen struct {