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

97 lines
3.3 KiB
Go

package certproof
import (
"bytes"
"context"
"encoding/json"
"fmt"
"os"
"os/exec"
"strconv"
"strings"
"time"
log "github.com/sirupsen/logrus"
"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 Mac
// can reach. The root daemon reads the System keychain itself, which is where MDM
// installs device identities, and reaches the console user's login keychain only by
// launching a helper into that user's session. A Mac sitting at the login window
// therefore yields device proofs 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
}
// A helper already runs inside the user's session, so it reads its own keychain
// directly and must never launch another one.
if os.Geteuid() != 0 {
return CollectChallenges(ctx, DefaultStore(), challenges, peerKey)
}
proofs := CollectChallenges(ctx, DefaultStore(), challenges, peerKey)
userProofs, err := collectAsConsoleUser(ctx, challenges, peerKey)
if err != nil {
log.Infof("certificate posture: console user keychain unavailable: %v", err)
}
return mergeProofs(proofs, userProofs)
}
// collectAsConsoleUser runs the helper inside the desktop session of the logged-in
// user. Dropping to their uid is not enough: keychain access is an XPC call to a
// per-session securityd, so the helper has to enter their Mach bootstrap namespace,
// which is what launchctl asuser does.
func collectAsConsoleUser(ctx context.Context, challenges []*proto.CertificateChallenge, peerKey []byte) ([]certposture.Proof, error) {
user, ok := CurrentConsoleUser()
if !ok {
return nil, nil
}
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()
uid := strconv.FormatUint(uint64(user.UID), 10)
cmd := exec.CommandContext(ctx, "launchctl", "asuser", uid, "sudo", "-u", user.Name, "-H", binary, "posture", "cert-proof")
cmd.Stdin = bytes.NewReader(payload)
var stdout, stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
log.Infof("certificate posture: asking the desktop session of %q (uid %s) to answer %d challenges", user.Name, uid, 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: desktop session of %q returned %d proofs", user.Name, len(resp.Proofs))
return resp.Proofs, nil
}
// helperStore is the store the helper reads. On macOS the keychain search list of the
// user's own session already is that user's keychain, so the platform default is right.
func helperStore() Store {
return DefaultStore()
}