core/nebula/api/manager.go

package main

import (
	"context"
	"crypto"
	"crypto/ed25519"
	"crypto/rand"
	"errors"
	"fmt"

	"inet.af/netaddr"

	"github.com/slackhq/nebula/cert"

	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"

	nebulav1 "github.com/giolekva/pcloud/core/nebula/controller/apis/nebula/v1"
	clientset "github.com/giolekva/pcloud/core/nebula/controller/generated/clientset/versioned"
)

type nebulaCA struct {
	Name      string
	Namespace string
	Nodes     []nebulaNode
}

type nebulaNode struct {
	Name      string
	Namespace string
	IP        string
}

type Manager struct {
	kubeClient   kubernetes.Interface
	nebulaClient clientset.Interface
	namespace    string
	caSecretName string
}

func (m *Manager) ListAll() ([]*nebulaCA, error) {
	ret := make([]*nebulaCA, 0)
	cas, err := m.nebulaClient.LekvaV1().NebulaCAs("").List(context.TODO(), metav1.ListOptions{})
	if err != nil {
		return nil, err
	}
	for _, ca := range cas.Items {
		ret = append(ret, &nebulaCA{
			Name:      ca.Name,
			Namespace: ca.Namespace,
			Nodes:     make([]nebulaNode, 0),
		})
	}
	nodes, err := m.nebulaClient.LekvaV1().NebulaNodes("").List(context.TODO(), metav1.ListOptions{})
	if err != nil {
		return nil, err
	}
	for _, node := range nodes.Items {
		for _, ca := range ret {
			if ca.Name == node.Spec.CAName {
				ca.Nodes = append(ca.Nodes, nebulaNode{
					Name:      node.Name,
					Namespace: node.Namespace,
					IP:        node.Spec.IPCidr,
				})
			}
		}
	}
	return ret, nil
}

func (m *Manager) CreateNode(namespace, name, caNamespace, caName, ipCidr, pubKey string) (string, string, error) {
	node := &nebulav1.NebulaNode{
		ObjectMeta: metav1.ObjectMeta{
			Name:      name,
			Namespace: namespace,
		},
		Spec: nebulav1.NebulaNodeSpec{
			CAName:      caName,
			CANamespace: caNamespace,
			IPCidr:      ipCidr,
			PubKey:      pubKey,
			SecretName:  fmt.Sprintf("%s-cert", name),
		},
	}
	node, err := m.nebulaClient.LekvaV1().NebulaNodes(namespace).Create(context.TODO(), node, metav1.CreateOptions{})
	if err != nil {
		return "", "", err
	}
	return node.Namespace, node.Name, nil
}

func (m *Manager) GetNodeCertQR(namespace, name string) ([]byte, error) {
	secret, err := m.getNodeSecret(namespace, name)
	if err != nil {
		return nil, err
	}
	return secret.Data["host.png"], nil
}

func (m *Manager) GetCACertQR(namespace, name string) ([]byte, error) {
	ca, err := m.nebulaClient.LekvaV1().NebulaCAs(namespace).Get(context.TODO(), name, metav1.GetOptions{})
	if err != nil {
		return nil, err
	}
	secret, err := m.kubeClient.CoreV1().Secrets(namespace).Get(context.TODO(), ca.Spec.SecretName, metav1.GetOptions{})
	if err != nil {
		return nil, err
	}
	return secret.Data["ca.png"], nil
}

func (m *Manager) getNextIP() (netaddr.IP, error) {
	nodes, err := m.nebulaClient.LekvaV1().NebulaNodes(m.namespace).List(context.TODO(), metav1.ListOptions{})
	if err != nil {
		return netaddr.IP{}, err
	}
	var max netaddr.IP
	for _, node := range nodes.Items {
		ip := netaddr.MustParseIPPrefix(node.Spec.IPCidr)
		if max.Less(ip.IP()) {
			max = ip.IP()
		}
	}
	n := max.Next()
	if n.IsZero() {
		return n, errors.New("IP address range exhausted")
	}
	return n, nil
}

func (m *Manager) Sign(message []byte) ([]byte, error) {
	secret, err := m.kubeClient.CoreV1().Secrets(m.namespace).Get(context.TODO(), m.caSecretName, metav1.GetOptions{})
	if err != nil {
		return nil, err
	}
	edPriv, _, err := cert.UnmarshalEd25519PrivateKey(secret.Data["ca.key"])
	if err != nil {
		return nil, err
	}
	return edPriv.Sign(rand.Reader, message, crypto.Hash(0))
}

func (m *Manager) VerifySignature(message, signature []byte) (bool, error) {
	secret, err := m.kubeClient.CoreV1().Secrets(m.namespace).Get(context.TODO(), m.caSecretName, metav1.GetOptions{})
	if err != nil {
		return false, err
	}
	edPriv, _, err := cert.UnmarshalEd25519PrivateKey(secret.Data["ca.key"])
	if err != nil {
		return false, err
	}
	return ed25519.Verify(edPriv.Public().(ed25519.PublicKey), message, signature), nil
}

func (m *Manager) getNodeSecret(namespace, name string) (*corev1.Secret, error) {
	node, err := m.nebulaClient.LekvaV1().NebulaNodes(namespace).Get(context.TODO(), name, metav1.GetOptions{})
	if err != nil {
		return nil, err
	}
	return m.kubeClient.CoreV1().Secrets(namespace).Get(context.TODO(), node.Spec.SecretName, metav1.GetOptions{})
}