Files
netbird/client/internal/certproof/collect_windows.go
T
2026-09-21 14:59:39 +02:00

102 lines
3.3 KiB
Go

package certproof
import (
"bytes"
"context"
"encoding/json"
"fmt"
"os"
"os/exec"
"strings"
"syscall"
"time"
log "github.com/sirupsen/logrus"
"golang.org/x/sys/windows"
"github.com/netbirdio/netbird/shared/management/certposture"
"github.com/netbirdio/netbird/shared/management/proto"
)
const helperTimeout = 30 * time.Second
// CollectProofs answers the certificate challenges in checks from every store this
// machine can reach. The service reads the local machine store itself, where AD and
// Intune enrol device certificates, and reaches the signed-in user's store by launching
// a helper with that session's token. A machine at the sign-in screen therefore proves
// device certificates alone.
func CollectProofs(ctx context.Context, checks []*proto.Checks, peerKey []byte, _ PKCS11Config) []certposture.Proof {
challenges := certificateChallenges(checks)
if len(challenges) == 0 {
logNoChallenges(checks)
return nil
}
proofs := CollectChallenges(ctx, DefaultStore(), challenges, peerKey)
// The helper already runs as the signed-in user, and an ordinary process has no
// right to a session token, so only the service goes looking for one.
if !runningAsLocalSystem() {
return proofs
}
userProofs, err := collectAsDesktopUser(ctx, challenges, peerKey)
if err != nil {
log.Infof("certificate posture: user certificate store unavailable: %v", err)
}
return mergeProofs(proofs, userProofs)
}
// helperStore is the store the helper reads. It runs as the signed-in user, so it wants
// that user's store rather than the machine store the service already read.
func helperStore() Store {
return NewUserStore()
}
// collectAsDesktopUser runs the helper inside the interactive session of the signed-in
// user. Unlike a keychain on macOS, a Windows service can assume a user identity
// directly, so the session token goes straight into the child process.
func collectAsDesktopUser(ctx context.Context, challenges []*proto.CertificateChallenge, peerKey []byte) ([]certposture.Proof, error) {
user, ok := CurrentDesktopUser()
if !ok {
return nil, nil
}
defer user.Close()
binary, err := os.Executable()
if err != nil {
return nil, fmt.Errorf("resolve own binary: %w", err)
}
payload, err := json.Marshal(helperRequest(challenges, peerKey))
if err != nil {
return nil, fmt.Errorf("encode helper request: %w", err)
}
ctx, cancel := context.WithTimeout(ctx, helperTimeout)
defer cancel()
cmd := exec.CommandContext(ctx, binary, "posture", "cert-proof")
cmd.SysProcAttr = &syscall.SysProcAttr{
Token: syscall.Token(user.Token),
HideWindow: true,
CreationFlags: windows.CREATE_NO_WINDOW,
}
cmd.Stdin = bytes.NewReader(payload)
var stdout, stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
log.Infof("certificate posture: asking the session of %q (session %d) to answer %d challenges", user.Name, user.Session, len(challenges))
if err := cmd.Run(); err != nil {
return nil, fmt.Errorf("run helper as %s: %w: %s", user.Name, err, strings.TrimSpace(stderr.String()))
}
var resp HelperResponse
if err := json.Unmarshal(stdout.Bytes(), &resp); err != nil {
return nil, fmt.Errorf("decode helper response: %w", err)
}
log.Infof("certificate posture: session of %q returned %d proofs", user.Name, len(resp.Proofs))
return resp.Proofs, nil
}