storj/pkg/provider/identity.go
Dennis Coyle e4baec8fce
Coyle/tls verify (#612)
* add nodeID to dial opts

* fix tests to use real identity
2018-11-09 17:08:33 -05:00

386 lines
11 KiB
Go

// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information.
package provider
import (
"context"
"crypto"
"crypto/tls"
"crypto/x509"
"encoding/base64"
"fmt"
"io/ioutil"
"math/bits"
"net"
"os"
"github.com/zeebo/errs"
"go.uber.org/zap"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/peer"
"storj.io/storj/pkg/peertls"
"storj.io/storj/pkg/utils"
)
const (
// IdentityLength is the number of bytes required to represent node id
IdentityLength = uint16(256 / 8) // 256 bits
)
// PeerIdentity represents another peer on the network.
type PeerIdentity struct {
RestChain []*x509.Certificate
// CA represents the peer's self-signed CA
CA *x509.Certificate
// Leaf represents the leaf they're currently using. The leaf should be
// signed by the CA. The leaf is what is used for communication.
Leaf *x509.Certificate
// The ID taken from the CA public key
ID nodeID
}
// FullIdentity represents you on the network. In addition to a PeerIdentity,
// a FullIdentity also has a Key, which a PeerIdentity doesn't have.
type FullIdentity struct {
RestChain []*x509.Certificate
// CA represents the peer's self-signed CA. The ID is taken from this cert.
CA *x509.Certificate
// Leaf represents the leaf they're currently using. The leaf should be
// signed by the CA. The leaf is what is used for communication.
Leaf *x509.Certificate
// The ID taken from the CA public key
ID nodeID
// Key is the key this identity uses with the leaf for communication.
Key crypto.PrivateKey
// PeerCAWhitelist is a whitelist of CA certs which, if present, restricts which peers this identity will verify as valid;
// peer certs must be signed by a CA in this list to pass peer certificate verification.
PeerCAWhitelist []*x509.Certificate
// VerfyAuthExtSig if true, client leafs which handshake with this identity must contain a valid "authority signature extension"
// (NB: authority signature extensions are verified against certs in the `PeerCAWhitelist`; i.e. if true, a whitelist must be provided)
VerifyAuthExtSig bool
}
// IdentitySetupConfig allows you to run a set of Responsibilities with the given
// identity. You can also just load an Identity from disk.
type IdentitySetupConfig struct {
CertPath string `help:"path to the certificate chain for this identity" default:"$CONFDIR/identity.cert"`
KeyPath string `help:"path to the private key for this identity" default:"$CONFDIR/identity.key"`
Overwrite bool `help:"if true, existing identity certs AND keys will overwritten for" default:"false"`
Version string `help:"semantic version of identity storage format" default:"0"`
}
// IdentityConfig allows you to run a set of Responsibilities with the given
// identity. You can also just load an Identity from disk.
type IdentityConfig struct {
CertPath string `help:"path to the certificate chain for this identity" default:"$CONFDIR/identity.cert"`
KeyPath string `help:"path to the private key for this identity" default:"$CONFDIR/identity.key"`
PeerCAWhitelistPath string `help:"path to the CA cert whitelist (peer identities must be signed by one these to be verified)"`
VerifyAuthExtSig bool `help:"if true, client leafs must contain a valid \"authority signature extension\" (NB: authority signature extensions are verified against certs in the peer ca whitelist; i.e. if true, a whitelist must be provided)" default:"false"`
Address string `help:"address to listen on" default:":7777"`
}
// FullIdentityFromPEM loads a FullIdentity from a certificate chain and
// private key file
func FullIdentityFromPEM(chainPEM, keyPEM, CAWhitelistPEM []byte) (*FullIdentity, error) {
cb, err := decodePEM(chainPEM)
if err != nil {
return nil, errs.Wrap(err)
}
if len(cb) < 2 {
return nil, errs.New("too few certificates in chain")
}
kb, err := decodePEM(keyPEM)
if err != nil {
return nil, errs.Wrap(err)
}
// NB: there shouldn't be multiple keys in the key file but if there
// are, this uses the first one
k, err := x509.ParseECPrivateKey(kb[0])
if err != nil {
return nil, errs.New("unable to parse EC private key: %v", err)
}
ch, err := ParseCertChain(cb)
if err != nil {
return nil, errs.Wrap(err)
}
i, err := idFromKey(ch[1].PublicKey)
if err != nil {
return nil, err
}
var (
wb [][]byte
whitelist []*x509.Certificate
)
if CAWhitelistPEM != nil {
wb, err = decodePEM(CAWhitelistPEM)
if err != nil {
return nil, errs.Wrap(err)
}
whitelist, err = ParseCertChain(wb)
if err != nil {
return nil, errs.Wrap(err)
}
}
return &FullIdentity{
RestChain: ch[2:],
CA: ch[1],
Leaf: ch[0],
Key: k,
ID: i,
PeerCAWhitelist: whitelist,
}, nil
}
// ParseCertChain converts a chain of certificate bytes into x509 certs
func ParseCertChain(chain [][]byte) ([]*x509.Certificate, error) {
c := make([]*x509.Certificate, len(chain))
for i, ct := range chain {
cp, err := x509.ParseCertificate(ct)
if err != nil {
return nil, errs.Wrap(err)
}
c[i] = cp
}
return c, nil
}
// PeerIdentityFromCerts loads a PeerIdentity from a pair of leaf and ca x509 certificates
func PeerIdentityFromCerts(leaf, ca *x509.Certificate, rest []*x509.Certificate) (*PeerIdentity, error) {
i, err := idFromKey(ca.PublicKey.(crypto.PublicKey))
if err != nil {
return nil, err
}
return &PeerIdentity{
RestChain: rest,
CA: ca,
ID: i,
Leaf: leaf,
}, nil
}
// PeerIdentityFromPeer loads a PeerIdentity from a peer connection
func PeerIdentityFromPeer(peer *peer.Peer) (*PeerIdentity, error) {
tlsInfo := peer.AuthInfo.(credentials.TLSInfo)
c := tlsInfo.State.PeerCertificates
if len(c) < 2 {
return nil, Error.New("invalid certificate chain")
}
pi, err := PeerIdentityFromCerts(c[0], c[1], c[2:])
if err != nil {
return nil, err
}
return pi, nil
}
// PeerIdentityFromContext loads a PeerIdentity from a ctx TLS credentials
func PeerIdentityFromContext(ctx context.Context) (*PeerIdentity, error) {
p, ok := peer.FromContext(ctx)
if !ok {
return nil, Error.New("unable to get grpc peer from contex")
}
return PeerIdentityFromPeer(p)
}
// Stat returns the status of the identity cert/key files for the config
func (is IdentitySetupConfig) Stat() TLSFilesStatus {
return statTLSFiles(is.CertPath, is.KeyPath)
}
// Create generates and saves a CA using the config
func (is IdentitySetupConfig) Create(ca *FullCertificateAuthority) (*FullIdentity, error) {
fi, err := ca.NewIdentity()
if err != nil {
return nil, err
}
fi.CA = ca.Cert
ic := IdentityConfig{
CertPath: is.CertPath,
KeyPath: is.KeyPath,
}
return fi, ic.Save(fi)
}
// Load loads a FullIdentity from the config
func (ic IdentityConfig) Load() (*FullIdentity, error) {
c, err := ioutil.ReadFile(ic.CertPath)
if err != nil {
return nil, peertls.ErrNotExist.Wrap(err)
}
k, err := ioutil.ReadFile(ic.KeyPath)
if err != nil {
return nil, peertls.ErrNotExist.Wrap(err)
}
w, err := ioutil.ReadFile(ic.PeerCAWhitelistPath)
if err != nil && !os.IsNotExist(err) {
return nil, err
}
fi, err := FullIdentityFromPEM(c, k, w)
if err != nil {
return nil, errs.New("failed to load identity %#v, %#v: %v",
ic.CertPath, ic.KeyPath, err)
}
return fi, nil
}
// Save saves a FullIdentity according to the config
func (ic IdentityConfig) Save(fi *FullIdentity) error {
f := os.O_WRONLY | os.O_CREATE
c, err := openCert(ic.CertPath, f)
if err != nil {
return err
}
defer utils.LogClose(c)
k, err := openKey(ic.KeyPath, f)
if err != nil {
return err
}
defer utils.LogClose(k)
chain := []*x509.Certificate{fi.Leaf, fi.CA}
chain = append(chain, fi.RestChain...)
if err = peertls.WriteChain(c, chain...); err != nil {
return err
}
if err = peertls.WriteKey(k, fi.Key); err != nil {
return err
}
return nil
}
// Run will run the given responsibilities with the configured identity.
func (ic IdentityConfig) Run(ctx context.Context, interceptor grpc.UnaryServerInterceptor, responsibilities ...Responsibility) (err error) {
defer mon.Task()(&ctx)(&err)
pi, err := ic.Load()
if err != nil {
return err
}
lis, err := net.Listen("tcp", ic.Address)
if err != nil {
return err
}
defer func() { _ = lis.Close() }()
s, err := NewProvider(pi, lis, interceptor, responsibilities...)
if err != nil {
return err
}
defer func() { _ = s.Close() }()
zap.S().Infof("Node %s started", s.Identity().ID)
return s.Run(ctx)
}
// RestChainRaw returns the rest (excluding leaf and CA) of the certficate chain as a 2d byte slice
func (fi *FullIdentity) RestChainRaw() [][]byte {
var chain [][]byte
for _, cert := range fi.RestChain {
chain = append(chain, cert.Raw)
}
return chain
}
// ServerOption returns a grpc `ServerOption` for incoming connections
// to the node with this full identity
func (fi *FullIdentity) ServerOption(pcvFuncs ...peertls.PeerCertVerificationFunc) (grpc.ServerOption, error) {
ch := [][]byte{fi.Leaf.Raw, fi.CA.Raw}
ch = append(ch, fi.RestChainRaw()...)
c, err := peertls.TLSCert(ch, fi.Leaf, fi.Key)
if err != nil {
return nil, err
}
pcvFuncs = append(
[]peertls.PeerCertVerificationFunc{peertls.VerifyPeerCertChains},
pcvFuncs...,
)
tlsConfig := &tls.Config{
Certificates: []tls.Certificate{*c},
InsecureSkipVerify: true,
ClientAuth: tls.RequireAnyClientCert,
VerifyPeerCertificate: peertls.VerifyPeerFunc(
pcvFuncs...,
),
}
return grpc.Creds(credentials.NewTLS(tlsConfig)), nil
}
// DialOption returns a grpc `DialOption` for making outgoing connections
// to the node with this peer identity
// id is an optional id of the node we are dialing
func (fi *FullIdentity) DialOption(id string) (grpc.DialOption, error) {
// TODO(coyle): add ID
ch := [][]byte{fi.Leaf.Raw, fi.CA.Raw}
ch = append(ch, fi.RestChainRaw()...)
c, err := peertls.TLSCert(ch, fi.Leaf, fi.Key)
if err != nil {
return nil, err
}
tlsConfig := &tls.Config{
Certificates: []tls.Certificate{*c},
InsecureSkipVerify: true,
VerifyPeerCertificate: peertls.VerifyPeerFunc(
peertls.VerifyPeerCertChains,
func(_ [][]byte, parsedChains [][]*x509.Certificate) error {
if id == "" {
return nil
}
peer, err := PeerIdentityFromCerts(parsedChains[0][0], parsedChains[0][1], parsedChains[0][2:])
if err != nil {
return err
}
if peer.ID.String() != id {
return Error.New("peer ID did not match requested ID")
}
return nil
},
),
}
return grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)), nil
}
type nodeID string
func (n nodeID) String() string { return string(n) }
func (n nodeID) Bytes() []byte { return []byte(n) }
func (n nodeID) Difficulty() uint16 {
hash, err := base64.URLEncoding.DecodeString(n.String())
if err != nil {
zap.S().Error(errs.Wrap(err))
}
for i := 1; i < len(hash); i++ {
b := hash[len(hash)-i]
if b != 0 {
zeroBits := bits.TrailingZeros16(uint16(b))
if zeroBits == 16 {
zeroBits = 0
}
return uint16((i-1)*8 + zeroBits)
}
}
// NB: this should never happen
reason := fmt.Sprintf("difficulty matches hash length! hash: %s", hash)
zap.S().Error(reason)
panic(reason)
}