Split simulator transport into separate module

Make it easier to reuse the DpeSimulator transport interface without
needing to depend on all the dependencies of the verification tests.

verification/sim/go.mod

@@ -0,0 +1,7 @@
+module github.com/chipsalliance/caliptra-dpe/verification/sim
+
+go 1.18
+
+replace github.com/chipsalliance/caliptra-dpe/verification/client => ../client
+
+require github.com/chipsalliance/caliptra-dpe/verification/client v0.0.0-20240216212309-5c9f6edaeb55

verification/sim/transport.go

@@ -0,0 +1,230 @@
+// Licensed under the Apache-2.0 license
+
+// Package sim implements DPE transport for the DPE software simulator
+package sim
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"io"
+	"net"
+	"os"
+	"os/exec"
+	"syscall"
+	"time"
+
+	"github.com/chipsalliance/caliptra-dpe/verification/client"
+)
+
+// Constants for configuring expected values from the DPE simulator
+const (
+	simulatorSocketPath = "/tmp/dpe-sim.socket"
+
+	DPESimulatorAutoInitLocality    uint32 = 0
+	DPESimulatorOtherLocality       uint32 = 0x4f544852
+	DPESimulatorMaxTCINodes         uint32 = 24
+	DPESimulatorMajorProfileVersion uint16 = client.CurrentProfileMajorVersion
+	DPESimulatorMinorProfileVersion uint16 = client.CurrentProfileMinorVersion
+	DPESimulatorVendorID            uint32 = 0
+	DPESimulatorVendorSKU           uint32 = 0
+)
+
+// DpeSimulator is a handle to a DPE simulator instance
+//
+// DpeSimulator implements the client.Transport and verification.TestTarget
+// interfaces.
+type DpeSimulator struct {
+	exePath         string
+	cmd             *exec.Cmd
+	supports        client.Support
+	currentLocality uint32
+	isInitialized   bool
+	client.Transport
+}
+
+func NewSimulator(exe string, support client.Support) DpeSimulator {
+	return DpeSimulator{exePath: exe, supports: support}
+}
+
+// HasPowerControl returns whether the simulator can be started and stopped.
+func (s *DpeSimulator) HasPowerControl() bool {
+	return true
+}
+
+// PowerOn starts the simulator.
+func (s *DpeSimulator) PowerOn() error {
+	args := []string{}
+	if s.supports.Simulation {
+		args = append(args, "--supports-simulation")
+	}
+	if s.supports.Recursive {
+		args = append(args, "--supports-recursive")
+	}
+	if s.supports.AutoInit {
+		args = append(args, "--supports-auto-init")
+	}
+	if s.supports.RotateContext {
+		args = append(args, "--supports-rotate-context")
+	}
+	if s.supports.X509 {
+		args = append(args, "--supports-x509")
+	}
+	if s.supports.Csr {
+		args = append(args, "--supports-csr")
+	}
+	if s.supports.IsCA {
+		args = append(args, "--supports-is-ca")
+	}
+	if s.supports.IsSymmetric {
+		args = append(args, "--supports-is-symmetric")
+	}
+	if s.supports.InternalInfo {
+		args = append(args, "--supports-internal-info")
+	}
+	if s.supports.InternalDice {
+		args = append(args, "--supports-internal-dice")
+	}
+	if s.supports.RetainParentContext {
+		args = append(args, "--supports-retain-parent-context")
+	}
+
+	s.cmd = exec.Command(s.exePath, args...)
+	s.cmd.Stdout = os.Stdout
+	err := s.cmd.Start()
+	if err != nil {
+		return err
+	}
+	if !s.waitForPower( /*on=*/ true) {
+		return errors.New("the simulator never started")
+	}
+	return nil
+}
+
+// PowerOff kills the simulator in a way that it can cleanup before closing.
+func (s *DpeSimulator) PowerOff() error {
+	if s.cmd != nil {
+		err := s.cmd.Process.Signal(syscall.SIGTERM)
+		if err != nil {
+			return err
+		}
+		if !s.waitForPower( /*on=*/ false) {
+			return errors.New("the simulator never stopped")
+		}
+	}
+	return nil
+}
+
+// Wait for the simulator to come alive. Timeout at 15 seconds.
+func (s *DpeSimulator) waitForPower(on bool) bool {
+	timeoutSeconds := 15
+	checksPerSec := 50
+
+	for i := 0; i < checksPerSec*timeoutSeconds; i++ {
+		// Check if the socket file has been created.
+		if fileExists(simulatorSocketPath) == on {
+			return true
+		}
+		time.Sleep(time.Duration(1000/checksPerSec) * time.Millisecond)
+	}
+	return false
+}
+
+func fileExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return !info.IsDir()
+}
+
+// SendCmd sends a DPE command to the simulator
+func (s *DpeSimulator) SendCmd(buf []byte) ([]byte, error) {
+	// Connect to DPE instance.
+	conn, err := net.Dial("unix", simulatorSocketPath)
+	if err != nil {
+		return nil, err
+	}
+
+	// Prepend the command with the locality.
+	prepended := bytes.NewBuffer(make([]byte, 0, 4+len(buf)))
+	if err := binary.Write(prepended, binary.LittleEndian, s.currentLocality); err != nil {
+		return nil, err
+	}
+	if _, err := prepended.Write(buf); err != nil {
+		return nil, err
+	}
+
+	// Send the prepended command.
+	numSent, err := conn.Write(prepended.Bytes())
+	if err != nil {
+		return nil, err
+	}
+	if numSent != len(prepended.Bytes()) {
+		return nil, errors.New("didn't send the whole command")
+	}
+
+	// Get the response.
+	return io.ReadAll(conn)
+}
+
+// GetSupport gets supported DPE features from the simulator
+func (s *DpeSimulator) GetSupport() *client.Support {
+	return &s.supports
+}
+
+// GetIsInitialized gets whether DPE is initialized
+func (s *DpeSimulator) GetIsInitialized() bool {
+	return s.supports.AutoInit || s.isInitialized
+}
+
+// SetIsInitialized sets whether DPE is initialized
+func (s *DpeSimulator) SetIsInitialized(isInitialized bool) {
+	s.isInitialized = isInitialized
+}
+
+// GetSupportedLocalities gets the list of localities the simulator supports
+func (s *DpeSimulator) GetSupportedLocalities() []uint32 {
+	return []uint32{DPESimulatorAutoInitLocality, DPESimulatorOtherLocality}
+}
+
+// HasLocalityControl returns whether the simulator can artificially set the
+// locality of the caller. The simulator target can always control the locality.
+func (s *DpeSimulator) HasLocalityControl() bool {
+	return true
+}
+
+// SetLocality sets the locality of this caller
+func (s *DpeSimulator) SetLocality(locality uint32) {
+	s.currentLocality = locality
+}
+
+// GetLocality gets the locality of the current caller
+func (s *DpeSimulator) GetLocality() uint32 {
+	return s.currentLocality
+}
+
+// GetMaxTciNodes gets the max number of TCI nodes the DPE supports
+func (s *DpeSimulator) GetMaxTciNodes() uint32 {
+	return DPESimulatorMaxTCINodes
+}
+
+// GetProfileMajorVersion gets the major profile version supported by this DPE
+func (s *DpeSimulator) GetProfileMajorVersion() uint16 {
+	return DPESimulatorMajorProfileVersion
+}
+
+// GetProfileMinorVersion gets the minor profile version supported by this DPE
+func (s *DpeSimulator) GetProfileMinorVersion() uint16 {
+	return DPESimulatorMinorProfileVersion
+}
+
+// GetProfileVendorID gets the vendor ID of this DPE
+func (s *DpeSimulator) GetProfileVendorID() uint32 {
+	return DPESimulatorVendorID
+}
+
+// GetProfileVendorSku gets the vendor SKU of this DPE
+func (s *DpeSimulator) GetProfileVendorSku() uint32 {
+	return DPESimulatorVendorSKU
+}

verification/testing/go.mod

@@ -4,8 +4,11 @@ go 1.20
 
 replace github.com/chipsalliance/caliptra-dpe/verification/client => ../client
 
+replace github.com/chipsalliance/caliptra-dpe/verification/sim => ../sim
+
 require (
-	github.com/chipsalliance/caliptra-dpe/verification/client v0.0.0-00010101000000-000000000000
+	github.com/chipsalliance/caliptra-dpe/verification/client v0.0.0-20240216212309-5c9f6edaeb55
+	github.com/chipsalliance/caliptra-dpe/verification/sim v0.0.0-00010101000000-000000000000
 	github.com/github/smimesign v0.2.0
 	github.com/google/go-tpm v0.9.0
 	github.com/google/go-tpm-tools v0.4.1