implement certificate posture check

management/server/posture/certificate.go

@@ -0,0 +1,36 @@
+package posture
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	nbpeer "github.com/netbirdio/netbird/management/server/peer"
+	"github.com/netbirdio/netbird/shared/management/certposture"
+)
+
+// CertificateCheck passes when the peer holds a certificate, proven at meta ingestion,
+// that chains to one of the configured PEM encoded CA certificates.
+type CertificateCheck struct {
+	CACertificates []string
+}
+
+var _ Check = (*CertificateCheck)(nil)
+
+func (c *CertificateCheck) Check(_ context.Context, peer nbpeer.Peer) (bool, error) {
+	return certposture.AnyChainMatchesCAs(peer.Meta.Certificates, c.CACertificates, time.Now()), nil
+}
+
+func (c *CertificateCheck) Name() string {
+	return CertificateCheckName
+}
+
+func (c *CertificateCheck) Validate() error {
+	if len(c.CACertificates) == 0 {
+		return fmt.Errorf("%s ca certificates shouldn't be empty", c.Name())
+	}
+	if _, err := certposture.ParseCAs(c.CACertificates); err != nil {
+		return fmt.Errorf("%s: %w", c.Name(), err)
+	}
+	return nil
+}

management/server/posture/certificate_test.go

@@ -0,0 +1,68 @@
+package posture
+
+import (
+	"context"
+	"crypto/x509"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/management/server/peer"
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+)
+
+func TestCertificateCheck_Check(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	otherCA := certtest.NewCA(t, "other-root")
+	chain := certposture.EncodeChainPEM([]*x509.Certificate{ca.Issue(t, certtest.ECDSAKey(t), "device")})
+
+	tests := []struct {
+		name         string
+		certificates []string
+		cas          []string
+		want         bool
+	}{
+		{"chains to configured CA", []string{chain}, []string{ca.PEM}, true},
+		{"one of several CAs matches", []string{chain}, []string{otherCA.PEM, ca.PEM}, true},
+		{"unrelated CA", []string{chain}, []string{otherCA.PEM}, false},
+		{"no certificates proven", nil, []string{ca.PEM}, false},
+		{"garbage entry does not hide a valid one", []string{"garbage", chain}, []string{ca.PEM}, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			check := CertificateCheck{CACertificates: tt.cas}
+			got, err := check.Check(context.Background(), peer.Peer{Meta: peer.PeerSystemMeta{Certificates: tt.certificates}})
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func TestCertificateCheck_Validate(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+
+	assert.Error(t, (&CertificateCheck{}).Validate())
+	assert.Error(t, (&CertificateCheck{CACertificates: []string{"not a pem"}}).Validate())
+	assert.NoError(t, (&CertificateCheck{CACertificates: []string{ca.PEM}}).Validate())
+}
+
+func TestChecks_CertificateCheckRegistered(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	checks := &Checks{Name: "cert", Checks: ChecksDefinition{CertificateCheck: &CertificateCheck{CACertificates: []string{ca.PEM}}}}
+
+	require.NoError(t, checks.Validate())
+	require.Len(t, checks.GetChecks(), 1)
+	assert.Equal(t, CertificateCheckName, checks.GetChecks()[0].Name())
+
+	copied := checks.Copy()
+	checks.Checks.CertificateCheck.CACertificates[0] = "mutated"
+	assert.Equal(t, ca.PEM, copied.Checks.CertificateCheck.CACertificates[0])
+
+	api := checks.ToAPIResponse()
+	require.NotNil(t, api.Checks.CertificateCheck)
+	roundTrip, err := NewChecksFromAPIPostureCheck(*api)
+	require.NoError(t, err)
+	assert.Equal(t, checks.Checks.CertificateCheck.CACertificates, roundTrip.Checks.CertificateCheck.CACertificates)
+}

management/server/posture/checks.go

@@ -19,6 +19,7 @@ const (
 	GeoLocationCheckName      = "GeoLocationCheck"
 	PeerNetworkRangeCheckName = "PeerNetworkRangeCheck"
 	ProcessCheckName          = "ProcessCheck"
+	CertificateCheckName      = "CertificateCheck"
 
 	CheckActionAllow string = "allow"
 	CheckActionDeny  string = "deny"
@@ -61,6 +62,7 @@ type ChecksDefinition struct {
 	GeoLocationCheck      *GeoLocationCheck      `json:",omitempty"`
 	PeerNetworkRangeCheck *PeerNetworkRangeCheck `json:",omitempty"`
 	ProcessCheck          *ProcessCheck          `json:",omitempty"`
+	CertificateCheck      *CertificateCheck      `json:",omitempty"`
 }
 
 // Copy returns a copy of a checks definition.
@@ -113,6 +115,12 @@ func (cd ChecksDefinition) Copy() ChecksDefinition {
 		}
 		copy(cdCopy.ProcessCheck.Processes, processCheck.Processes)
 	}
+	if cd.CertificateCheck != nil {
+		cdCopy.CertificateCheck = &CertificateCheck{
+			CACertificates: make([]string, len(cd.CertificateCheck.CACertificates)),
+		}
+		copy(cdCopy.CertificateCheck.CACertificates, cd.CertificateCheck.CACertificates)
+	}
 	return cdCopy
 }
 
@@ -157,6 +165,9 @@ func (pc *Checks) GetChecks() []Check {
 	if pc.Checks.ProcessCheck != nil {
 		checks = append(checks, pc.Checks.ProcessCheck)
 	}
+	if pc.Checks.CertificateCheck != nil {
+		checks = append(checks, pc.Checks.CertificateCheck)
+	}
 	return checks
 }
 
@@ -212,6 +223,10 @@ func buildPostureCheck(postureChecksID string, name string, description string,
 		postureChecks.Checks.ProcessCheck = toProcessCheck(processCheck)
 	}
 
+	if certificateCheck := checks.CertificateCheck; certificateCheck != nil {
+		postureChecks.Checks.CertificateCheck = &CertificateCheck{CACertificates: certificateCheck.CaCertificates}
+	}
+
 	return &postureChecks, nil
 }
 
@@ -246,6 +261,10 @@ func (pc *Checks) ToAPIResponse() *api.PostureCheck {
 		checks.ProcessCheck = toProcessCheckResponse(pc.Checks.ProcessCheck)
 	}
 
+	if pc.Checks.CertificateCheck != nil {
+		checks.CertificateCheck = &api.CertificateCheck{CaCertificates: pc.Checks.CertificateCheck.CACertificates}
+	}
+
 	return &api.PostureCheck{
 		Id:          pc.ID,
 		Name:        pc.Name,