mirror of
https://source.quilibrium.com/quilibrium/ceremonyclient.git
synced 2024-11-11 02:35:18 +00:00
271 lines
8.2 KiB
Go
271 lines
8.2 KiB
Go
package libp2ptls
|
|
|
|
import (
|
|
"crypto"
|
|
"crypto/ecdsa"
|
|
"crypto/elliptic"
|
|
"crypto/rand"
|
|
"crypto/tls"
|
|
"crypto/x509"
|
|
"crypto/x509/pkix"
|
|
"encoding/asn1"
|
|
"errors"
|
|
"fmt"
|
|
"math/big"
|
|
"os"
|
|
"runtime/debug"
|
|
"time"
|
|
|
|
ic "github.com/libp2p/go-libp2p/core/crypto"
|
|
"github.com/libp2p/go-libp2p/core/peer"
|
|
)
|
|
|
|
const certValidityPeriod = 100 * 365 * 24 * time.Hour // ~100 years
|
|
const certificatePrefix = "libp2p-tls-handshake:"
|
|
const alpn string = "libp2p"
|
|
|
|
var extensionID = getPrefixedExtensionID([]int{1, 1})
|
|
var extensionCritical bool // so we can mark the extension critical in tests
|
|
|
|
type signedKey struct {
|
|
PubKey []byte
|
|
Signature []byte
|
|
}
|
|
|
|
// Identity is used to secure connections
|
|
type Identity struct {
|
|
config tls.Config
|
|
}
|
|
|
|
// IdentityConfig is used to configure an Identity
|
|
type IdentityConfig struct {
|
|
CertTemplate *x509.Certificate
|
|
}
|
|
|
|
// IdentityOption transforms an IdentityConfig to apply optional settings.
|
|
type IdentityOption func(r *IdentityConfig)
|
|
|
|
// WithCertTemplate specifies the template to use when generating a new certificate.
|
|
func WithCertTemplate(template *x509.Certificate) IdentityOption {
|
|
return func(c *IdentityConfig) {
|
|
c.CertTemplate = template
|
|
}
|
|
}
|
|
|
|
// NewIdentity creates a new identity
|
|
func NewIdentity(privKey ic.PrivKey, opts ...IdentityOption) (*Identity, error) {
|
|
config := IdentityConfig{}
|
|
for _, opt := range opts {
|
|
opt(&config)
|
|
}
|
|
|
|
var err error
|
|
if config.CertTemplate == nil {
|
|
config.CertTemplate, err = certTemplate()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
cert, err := keyToCertificate(privKey, config.CertTemplate)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &Identity{
|
|
config: tls.Config{
|
|
MinVersion: tls.VersionTLS13,
|
|
InsecureSkipVerify: true, // This is not insecure here. We will verify the cert chain ourselves.
|
|
ClientAuth: tls.RequireAnyClientCert,
|
|
Certificates: []tls.Certificate{*cert},
|
|
VerifyPeerCertificate: func(_ [][]byte, _ [][]*x509.Certificate) error {
|
|
panic("tls config not specialized for peer")
|
|
},
|
|
NextProtos: []string{alpn},
|
|
SessionTicketsDisabled: true,
|
|
},
|
|
}, nil
|
|
}
|
|
|
|
// ConfigForPeer creates a new single-use tls.Config that verifies the peer's
|
|
// certificate chain and returns the peer's public key via the channel. If the
|
|
// peer ID is empty, the returned config will accept any peer.
|
|
//
|
|
// It should be used to create a new tls.Config before securing either an
|
|
// incoming or outgoing connection.
|
|
func (i *Identity) ConfigForPeer(remote peer.ID) (*tls.Config, <-chan ic.PubKey) {
|
|
keyCh := make(chan ic.PubKey, 1)
|
|
// We need to check the peer ID in the VerifyPeerCertificate callback.
|
|
// The tls.Config it is also used for listening, and we might also have concurrent dials.
|
|
// Clone it so we can check for the specific peer ID we're dialing here.
|
|
conf := i.config.Clone()
|
|
// We're using InsecureSkipVerify, so the verifiedChains parameter will always be empty.
|
|
// We need to parse the certificates ourselves from the raw certs.
|
|
conf.VerifyPeerCertificate = func(rawCerts [][]byte, _ [][]*x509.Certificate) (err error) {
|
|
defer func() {
|
|
if rerr := recover(); rerr != nil {
|
|
fmt.Fprintf(os.Stderr, "panic when processing peer certificate in TLS handshake: %s\n%s\n", rerr, debug.Stack())
|
|
err = fmt.Errorf("panic when processing peer certificate in TLS handshake: %s", rerr)
|
|
|
|
}
|
|
}()
|
|
|
|
defer close(keyCh)
|
|
|
|
chain := make([]*x509.Certificate, len(rawCerts))
|
|
for i := 0; i < len(rawCerts); i++ {
|
|
cert, err := x509.ParseCertificate(rawCerts[i])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
chain[i] = cert
|
|
}
|
|
|
|
pubKey, err := PubKeyFromCertChain(chain)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if remote != "" && !remote.MatchesPublicKey(pubKey) {
|
|
peerID, err := peer.IDFromPublicKey(pubKey)
|
|
if err != nil {
|
|
peerID = peer.ID(fmt.Sprintf("(not determined: %s)", err.Error()))
|
|
}
|
|
return fmt.Errorf("peer IDs don't match: expected %s, got %s", remote, peerID)
|
|
}
|
|
keyCh <- pubKey
|
|
return nil
|
|
}
|
|
return conf, keyCh
|
|
}
|
|
|
|
// PubKeyFromCertChain verifies the certificate chain and extract the remote's public key.
|
|
func PubKeyFromCertChain(chain []*x509.Certificate) (ic.PubKey, error) {
|
|
if len(chain) != 1 {
|
|
return nil, errors.New("expected one certificates in the chain")
|
|
}
|
|
cert := chain[0]
|
|
pool := x509.NewCertPool()
|
|
pool.AddCert(cert)
|
|
var found bool
|
|
var keyExt pkix.Extension
|
|
// find the libp2p key extension, skipping all unknown extensions
|
|
for _, ext := range cert.Extensions {
|
|
if extensionIDEqual(ext.Id, extensionID) {
|
|
keyExt = ext
|
|
found = true
|
|
for i, oident := range cert.UnhandledCriticalExtensions {
|
|
if oident.Equal(ext.Id) {
|
|
// delete the extension from UnhandledCriticalExtensions
|
|
cert.UnhandledCriticalExtensions = append(cert.UnhandledCriticalExtensions[:i], cert.UnhandledCriticalExtensions[i+1:]...)
|
|
break
|
|
}
|
|
}
|
|
break
|
|
}
|
|
}
|
|
if !found {
|
|
return nil, errors.New("expected certificate to contain the key extension")
|
|
}
|
|
if _, err := cert.Verify(x509.VerifyOptions{Roots: pool}); err != nil {
|
|
// If we return an x509 error here, it will be sent on the wire.
|
|
// Wrap the error to avoid that.
|
|
return nil, fmt.Errorf("certificate verification failed: %s", err)
|
|
}
|
|
|
|
var sk signedKey
|
|
if _, err := asn1.Unmarshal(keyExt.Value, &sk); err != nil {
|
|
return nil, fmt.Errorf("unmarshalling signed certificate failed: %s", err)
|
|
}
|
|
pubKey, err := ic.UnmarshalPublicKey(sk.PubKey)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("unmarshalling public key failed: %s", err)
|
|
}
|
|
certKeyPub, err := x509.MarshalPKIXPublicKey(cert.PublicKey)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
valid, err := pubKey.Verify(append([]byte(certificatePrefix), certKeyPub...), sk.Signature)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("signature verification failed: %s", err)
|
|
}
|
|
if !valid {
|
|
return nil, errors.New("signature invalid")
|
|
}
|
|
return pubKey, nil
|
|
}
|
|
|
|
// GenerateSignedExtension uses the provided private key to sign the public key, and returns the
|
|
// signature within a pkix.Extension.
|
|
// This extension is included in a certificate to cryptographically tie it to the libp2p private key.
|
|
func GenerateSignedExtension(sk ic.PrivKey, pubKey crypto.PublicKey) (pkix.Extension, error) {
|
|
keyBytes, err := ic.MarshalPublicKey(sk.GetPublic())
|
|
if err != nil {
|
|
return pkix.Extension{}, err
|
|
}
|
|
certKeyPub, err := x509.MarshalPKIXPublicKey(pubKey)
|
|
if err != nil {
|
|
return pkix.Extension{}, err
|
|
}
|
|
signature, err := sk.Sign(append([]byte(certificatePrefix), certKeyPub...))
|
|
if err != nil {
|
|
return pkix.Extension{}, err
|
|
}
|
|
value, err := asn1.Marshal(signedKey{
|
|
PubKey: keyBytes,
|
|
Signature: signature,
|
|
})
|
|
if err != nil {
|
|
return pkix.Extension{}, err
|
|
}
|
|
|
|
return pkix.Extension{Id: extensionID, Critical: extensionCritical, Value: value}, nil
|
|
}
|
|
|
|
// keyToCertificate generates a new ECDSA private key and corresponding x509 certificate.
|
|
// The certificate includes an extension that cryptographically ties it to the provided libp2p
|
|
// private key to authenticate TLS connections.
|
|
func keyToCertificate(sk ic.PrivKey, certTmpl *x509.Certificate) (*tls.Certificate, error) {
|
|
certKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// after calling CreateCertificate, these will end up in Certificate.Extensions
|
|
extension, err := GenerateSignedExtension(sk, certKey.Public())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
certTmpl.ExtraExtensions = append(certTmpl.ExtraExtensions, extension)
|
|
|
|
certDER, err := x509.CreateCertificate(rand.Reader, certTmpl, certTmpl, certKey.Public(), certKey)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &tls.Certificate{
|
|
Certificate: [][]byte{certDER},
|
|
PrivateKey: certKey,
|
|
}, nil
|
|
}
|
|
|
|
// certTemplate returns the template for generating an Identity's TLS certificates.
|
|
func certTemplate() (*x509.Certificate, error) {
|
|
bigNum := big.NewInt(1 << 62)
|
|
sn, err := rand.Int(rand.Reader, bigNum)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
subjectSN, err := rand.Int(rand.Reader, bigNum)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &x509.Certificate{
|
|
SerialNumber: sn,
|
|
NotBefore: time.Now().Add(-time.Hour),
|
|
NotAfter: time.Now().Add(certValidityPeriod),
|
|
// According to RFC 3280, the issuer field must be set,
|
|
// see https://datatracker.ietf.org/doc/html/rfc3280#section-4.1.2.4.
|
|
Subject: pkix.Name{SerialNumber: subjectSN.String()},
|
|
}, nil
|
|
}
|