Files
netbird/client/internal/certproof/store_tpm_test.go
T
2026-09-16 23:00:44 +02:00

99 lines
3.7 KiB
Go

package certproof
import (
"context"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"encoding/pem"
"os"
"testing"
"time"
"github.com/google/go-tpm/legacy/tpm2"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"go.step.sm/crypto/tpm/tss2"
"github.com/netbirdio/netbird/client/internal/tpm"
"github.com/netbirdio/netbird/client/internal/tpm/tpmtest"
"github.com/netbirdio/netbird/shared/management/certposture"
"github.com/netbirdio/netbird/shared/management/certposture/certtest"
"github.com/netbirdio/netbird/shared/management/proto"
)
func TestFileStore_TPMKeyFile(t *testing.T) {
ca := certtest.NewCA(t, "corp")
key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
require.NoError(t, err)
leaf := ca.Issue(t, key, "device")
dir := t.TempDir()
writeFile(t, dir, "device.pem", certtest.CertPEM(leaf))
writeFile(t, dir, "device.key", tpmtest.KeyPEM(t, &key.PublicKey))
// A key that needs a password can never be used silently, so its certificate is skipped.
locked := certtest.ECDSAKey(t)
withAuth := func(k *tss2.TPMKey) { k.EmptyAuth = false }
writeFile(t, dir, "locked.pem", certtest.CertPEM(ca.Issue(t, locked, "locked")))
writeFile(t, dir, "locked.key", tpmtest.KeyPEM(t, locked.Public().(*ecdsa.PublicKey), withAuth))
candidates, err := NewFileStore(dir).Candidates(context.Background())
require.NoError(t, err)
require.Len(t, candidates, 1, "only the key without an authorization value is usable")
assert.True(t, leaf.Equal(candidates[0].Chain[0]), "candidate must carry the device certificate")
assert.True(t, key.PublicKey.Equal(candidates[0].Signer.Public()), "signer must report the certificate's key")
}
// TestCollect_TPMKeyEndToEnd runs against the TPM named by NB_TPM_DEVICE, for example a
// swtpm started with:
//
// swtpm socket --tpm2 --server type=unixio,path=/tmp/swtpm.sock \
// --ctrl type=unixio,path=/tmp/swtpm.ctrl --flags not-need-init,startup-clear
//
// It creates a key the way tpm2-openssl does, under a transient ECC primary in the owner
// hierarchy, and proves the certificate for it through the regular file store.
func TestCollect_TPMKeyEndToEnd(t *testing.T) {
if os.Getenv(tpm.DeviceEnv) == "" {
t.Skipf("set %s to a TPM device or swtpm socket to run", tpm.DeviceEnv)
}
public, private := createTPMKey(t)
keyPEM := tpmtest.EncodePEM(t, public, private)
block, _ := pem.Decode([]byte(keyPEM))
require.NotNil(t, block)
signer, err := tpm.ParseKey(block.Bytes)
require.NoError(t, err)
ca := certtest.NewCA(t, "corp")
leaf := ca.Issue(t, signer, "device")
dir := t.TempDir()
writeFile(t, dir, "device.pem", certtest.CertPEM(leaf))
writeFile(t, dir, "device.key", keyPEM)
challenger := certposture.NewChallenger([]byte("secret"))
now := time.Now()
nonce := challenger.Nonce(peerKey, now)
checks := []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{Nonce: nonce, CaCertificates: []string{ca.PEM}}}}
proofs := Collect(context.Background(), NewFileStore(dir), checks, peerKey)
require.Len(t, proofs, 1, "the TPM-held key must prove the certificate")
chain, err := challenger.Verify(proofs[0], peerKey, now)
require.NoError(t, err)
assert.True(t, leaf.Equal(chain[0]), "proof must carry the device certificate")
}
func createTPMKey(t *testing.T) (public, private []byte) {
t.Helper()
rwc, err := tpm.Open()
require.NoError(t, err)
defer func() { _ = rwc.Close() }()
parent, _, err := tpm2.CreatePrimary(rwc, tpm2.HandleOwner, tpm2.PCRSelection{}, "", "", tss2.ECCSRKTemplate)
require.NoError(t, err)
defer func() { _ = tpm2.FlushContext(rwc, parent) }()
private, public, _, _, _, err = tpm2.CreateKey(rwc, parent, tpm2.PCRSelection{}, "", "", tpmtest.SigningTemplate())
require.NoError(t, err)
return public, private
}