local-server/cmd/dkl-local-server/secrets.go
2023-01-27 06:42:39 +01:00

425 lines
7.5 KiB
Go

package main
import (
"crypto"
"crypto/rand"
"encoding/base32"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net"
"os"
"path/filepath"
"sort"
"sync"
"time"
"github.com/cespare/xxhash"
"github.com/cloudflare/cfssl/certinfo"
"github.com/cloudflare/cfssl/config"
"github.com/cloudflare/cfssl/csr"
"github.com/cloudflare/cfssl/helpers"
"github.com/cloudflare/cfssl/initca"
"github.com/cloudflare/cfssl/log"
"github.com/cloudflare/cfssl/signer"
"github.com/cloudflare/cfssl/signer/local"
"k8s.io/apimachinery/pkg/util/validation"
"k8s.io/apimachinery/pkg/util/validation/field"
)
var (
secretData *SecretData
DontSave = false
)
type SecretData struct {
l sync.Mutex
prevHash uint64
clusters map[string]*ClusterSecrets
changed bool
config *config.Config
}
type ClusterSecrets struct {
CAs map[string]*CA
Tokens map[string]string
Passwords map[string]string
SSHKeyPairs map[string][]SSHKeyPair
}
type CA struct {
Key []byte
Cert []byte
Signed map[string]*KeyCert
}
type KeyCert struct {
Key []byte
Cert []byte
ReqHash string
}
func secretDataPath() string {
return filepath.Join(*dataDir, "secret-data.json")
}
func loadSecretData(config *config.Config) (err error) {
log.Info("Loading secret data")
sd := &SecretData{
clusters: make(map[string]*ClusterSecrets),
changed: false,
config: config,
}
ba, err := ioutil.ReadFile(secretDataPath())
if err != nil {
if os.IsNotExist(err) {
sd.changed = true
err = nil
secretData = sd
return
}
return
}
if err = json.Unmarshal(ba, &sd.clusters); err != nil {
return
}
sd.prevHash = xxhash.Sum64(ba)
secretData = sd
return
}
func (sd *SecretData) Changed() bool {
return sd.changed
}
func (sd *SecretData) Save() (err error) {
if DontSave {
return
}
sd.l.Lock()
defer sd.l.Unlock()
ba, err := json.Marshal(sd.clusters)
if err != nil {
return
}
h := xxhash.Sum64(ba)
if h == sd.prevHash {
return
}
log.Info("Saving secret data")
err = ioutil.WriteFile(secretDataPath(), ba, 0600)
if err == nil {
sd.prevHash = h
}
return
}
func newClusterSecrets() *ClusterSecrets {
return &ClusterSecrets{
CAs: make(map[string]*CA),
Tokens: make(map[string]string),
Passwords: make(map[string]string),
}
}
func (sd *SecretData) cluster(name string) (cs *ClusterSecrets) {
cs, ok := sd.clusters[name]
if ok {
return
}
sd.l.Lock()
defer sd.l.Unlock()
log.Info("secret-data: new cluster: ", name)
cs = newClusterSecrets()
sd.clusters[name] = cs
sd.changed = true
return
}
func (sd *SecretData) Passwords(cluster string) (passwords []string) {
cs := sd.cluster(cluster)
passwords = make([]string, 0, len(cs.Passwords))
for name := range cs.Passwords {
passwords = append(passwords, name)
}
sort.Strings(passwords)
return
}
func (sd *SecretData) Password(cluster, name string) (password string) {
cs := sd.cluster(cluster)
if cs.Passwords == nil {
cs.Passwords = make(map[string]string)
}
password = cs.Passwords[name]
return
}
func (sd *SecretData) SetPassword(cluster, name, password string) {
cs := sd.cluster(cluster)
if cs.Passwords == nil {
cs.Passwords = make(map[string]string)
}
cs.Passwords[name] = password
sd.changed = true
}
func (sd *SecretData) Token(cluster, name string) (token string, err error) {
cs := sd.cluster(cluster)
token = cs.Tokens[name]
if token != "" {
return
}
sd.l.Lock()
defer sd.l.Unlock()
log.Info("secret-data: new token in cluster ", cluster, ": ", name)
b := make([]byte, 16)
_, err = rand.Read(b)
if err != nil {
return
}
token = base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(b)
cs.Tokens[name] = token
sd.changed = true
return
}
func (sd *SecretData) RenewCACert(cluster, name string) (err error) {
cs := sd.cluster(cluster)
ca := cs.CAs[name]
var signer crypto.Signer
signer, err = helpers.ParsePrivateKeyPEM(ca.Key)
if err != nil {
return
}
newCert, _, err := initca.NewFromSigner(newCACertReq(), signer)
if err != nil {
return
}
sd.l.Lock()
defer sd.l.Unlock()
cs.CAs[name].Cert = newCert
sd.changed = true
return
}
func newCACertReq() *csr.CertificateRequest {
return &csr.CertificateRequest{
CN: "Direktil Local Server",
KeyRequest: &csr.KeyRequest{
A: "ecdsa",
S: 521, // 256, 384, 521
},
Names: []csr.Name{
{
C: "NC",
O: "novit.nc",
},
},
}
}
func (sd *SecretData) CA(cluster, name string) (ca *CA, err error) {
defer func() {
if err != nil {
err = fmt.Errorf("cluster %s CA %s: %w", cluster, name, err)
}
}()
cs := sd.cluster(cluster)
ca, ok := cs.CAs[name]
if ok {
checkErr := checkCertUsable(ca.Cert)
if checkErr != nil {
log.Infof("secret-data cluster %s: CA %s: regenerating certificate: %v", cluster, name, checkErr)
err = sd.RenewCACert(cluster, name)
if err != nil {
err = fmt.Errorf("renew: %w", err)
}
}
return
}
sd.l.Lock()
defer sd.l.Unlock()
log.Info("secret-data: new CA in cluster ", cluster, ": ", name)
req := newCACertReq()
cert, _, key, err := initca.New(req)
if err != nil {
err = fmt.Errorf("initca: %w", err)
return
}
ca = &CA{
Key: key,
Cert: cert,
Signed: make(map[string]*KeyCert),
}
cs.CAs[name] = ca
sd.changed = true
return
}
func checkCertUsable(certPEM []byte) error {
cert, err := certinfo.ParseCertificatePEM(certPEM)
if err != nil {
return err
}
certDuration := cert.NotAfter.Sub(cert.NotBefore)
delayBeforeRegen := certDuration / 3 // TODO allow configuration
if cert.NotAfter.Sub(time.Now()) < delayBeforeRegen {
return errors.New("too old")
}
return nil
}
func (sd *SecretData) KeyCert(cluster, caName, name, profile, label string, req *csr.CertificateRequest) (kc *KeyCert, err error) {
for idx, host := range req.Hosts {
if ip := net.ParseIP(host); ip != nil {
// valid IP (v4 or v6)
continue
}
if host == "*" {
continue
}
if errs := validation.IsDNS1123Subdomain(host); len(errs) == 0 {
continue
}
if errs := validation.IsWildcardDNS1123Subdomain(host); len(errs) == 0 {
continue
}
path := field.NewPath(cluster, name, "hosts").Index(idx)
return nil, fmt.Errorf("%v: %q is not an IP or FQDN", path, host)
}
if req.CA != nil {
err = errors.New("no CA section allowed here")
return
}
ca, err := sd.CA(cluster, caName)
if err != nil {
return
}
logPrefix := fmt.Sprintf("secret-data: cluster %s: CA %s:", cluster, caName)
rh := hash(req)
kc, ok := ca.Signed[name]
if ok && rh == kc.ReqHash {
err = checkCertUsable(kc.Cert)
if err == nil {
return
}
log.Infof("%s regenerating certificate: ", err)
} else if ok {
log.Infof("%s CSR changed for %s: hash=%q previous=%q", name, rh, kc.ReqHash)
} else {
log.Infof("%s new CSR for %s", logPrefix, name)
}
sd.l.Lock()
defer sd.l.Unlock()
sgr, err := ca.Signer(sd.config.Signing)
if err != nil {
return
}
generator := &csr.Generator{Validator: func(_ *csr.CertificateRequest) error { return nil }}
csr, key, err := generator.ProcessRequest(req)
if err != nil {
return
}
signReq := signer.SignRequest{
Request: string(csr),
Profile: profile,
Label: label,
}
cert, err := sgr.Sign(signReq)
if err != nil {
return
}
kc = &KeyCert{
Key: key,
Cert: cert,
ReqHash: rh,
}
ca.Signed[name] = kc
sd.changed = true
return
}
func (ca *CA) Signer(policy *config.Signing) (result *local.Signer, err error) {
caCert, err := helpers.ParseCertificatePEM(ca.Cert)
if err != nil {
return
}
caKey, err := helpers.ParsePrivateKeyPEM(ca.Key)
if err != nil {
return
}
return local.NewSigner(caKey, caCert, signer.DefaultSigAlgo(caKey), policy)
}