status-go/vendor/github.com/pion/dtls/v2/flight5handler.go

335 lines
12 KiB
Go

package dtls
import (
"bytes"
"context"
"crypto"
"crypto/x509"
"github.com/pion/dtls/v2/pkg/crypto/prf"
"github.com/pion/dtls/v2/pkg/crypto/signaturehash"
"github.com/pion/dtls/v2/pkg/protocol"
"github.com/pion/dtls/v2/pkg/protocol/alert"
"github.com/pion/dtls/v2/pkg/protocol/handshake"
"github.com/pion/dtls/v2/pkg/protocol/recordlayer"
)
func flight5Parse(ctx context.Context, c flightConn, state *State, cache *handshakeCache, cfg *handshakeConfig) (flightVal, *alert.Alert, error) {
_, msgs, ok := cache.fullPullMap(state.handshakeRecvSequence,
handshakeCachePullRule{handshake.TypeFinished, cfg.initialEpoch + 1, false, false},
)
if !ok {
// No valid message received. Keep reading
return 0, nil, nil
}
var finished *handshake.MessageFinished
if finished, ok = msgs[handshake.TypeFinished].(*handshake.MessageFinished); !ok {
return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, nil
}
plainText := cache.pullAndMerge(
handshakeCachePullRule{handshake.TypeClientHello, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeServerHello, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificate, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeServerKeyExchange, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificateRequest, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeServerHelloDone, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificate, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeClientKeyExchange, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeCertificateVerify, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeFinished, cfg.initialEpoch + 1, true, false},
)
expectedVerifyData, err := prf.VerifyDataServer(state.masterSecret, plainText, state.cipherSuite.HashFunc())
if err != nil {
return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
if !bytes.Equal(expectedVerifyData, finished.VerifyData) {
return 0, &alert.Alert{Level: alert.Fatal, Description: alert.HandshakeFailure}, errVerifyDataMismatch
}
if len(state.SessionID) > 0 {
s := Session{
ID: state.SessionID,
Secret: state.masterSecret,
}
cfg.log.Tracef("[handshake] save new session: %x", s.ID)
if err := cfg.sessionStore.Set(c.sessionKey(), s); err != nil {
return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
}
return flight5, nil, nil
}
func flight5Generate(c flightConn, state *State, cache *handshakeCache, cfg *handshakeConfig) ([]*packet, *alert.Alert, error) { //nolint:gocognit
var certBytes [][]byte
var privateKey crypto.PrivateKey
if len(cfg.localCertificates) > 0 {
certificate, err := cfg.getCertificate(cfg.serverName)
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.HandshakeFailure}, err
}
certBytes = certificate.Certificate
privateKey = certificate.PrivateKey
}
var pkts []*packet
if state.remoteRequestedCertificate {
pkts = append(pkts,
&packet{
record: &recordlayer.RecordLayer{
Header: recordlayer.Header{
Version: protocol.Version1_2,
},
Content: &handshake.Handshake{
Message: &handshake.MessageCertificate{
Certificate: certBytes,
},
},
},
})
}
clientKeyExchange := &handshake.MessageClientKeyExchange{}
if cfg.localPSKCallback == nil {
clientKeyExchange.PublicKey = state.localKeypair.PublicKey
} else {
clientKeyExchange.IdentityHint = cfg.localPSKIdentityHint
}
pkts = append(pkts,
&packet{
record: &recordlayer.RecordLayer{
Header: recordlayer.Header{
Version: protocol.Version1_2,
},
Content: &handshake.Handshake{
Message: clientKeyExchange,
},
},
})
serverKeyExchangeData := cache.pullAndMerge(
handshakeCachePullRule{handshake.TypeServerKeyExchange, cfg.initialEpoch, false, false},
)
serverKeyExchange := &handshake.MessageServerKeyExchange{}
// handshakeMessageServerKeyExchange is optional for PSK
if len(serverKeyExchangeData) == 0 {
alertPtr, err := handleServerKeyExchange(c, state, cfg, &handshake.MessageServerKeyExchange{})
if err != nil {
return nil, alertPtr, err
}
} else {
rawHandshake := &handshake.Handshake{}
err := rawHandshake.Unmarshal(serverKeyExchangeData)
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.UnexpectedMessage}, err
}
switch h := rawHandshake.Message.(type) {
case *handshake.MessageServerKeyExchange:
serverKeyExchange = h
default:
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.UnexpectedMessage}, errInvalidContentType
}
}
// Append not-yet-sent packets
merged := []byte{}
seqPred := uint16(state.handshakeSendSequence)
for _, p := range pkts {
h, ok := p.record.Content.(*handshake.Handshake)
if !ok {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, errInvalidContentType
}
h.Header.MessageSequence = seqPred
seqPred++
raw, err := h.Marshal()
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
merged = append(merged, raw...)
}
if alertPtr, err := initalizeCipherSuite(state, cache, cfg, serverKeyExchange, merged); err != nil {
return nil, alertPtr, err
}
// If the client has sent a certificate with signing ability, a digitally-signed
// CertificateVerify message is sent to explicitly verify possession of the
// private key in the certificate.
if state.remoteRequestedCertificate && len(cfg.localCertificates) > 0 {
plainText := append(cache.pullAndMerge(
handshakeCachePullRule{handshake.TypeClientHello, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeServerHello, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificate, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeServerKeyExchange, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificateRequest, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeServerHelloDone, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificate, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeClientKeyExchange, cfg.initialEpoch, true, false},
), merged...)
// Find compatible signature scheme
signatureHashAlgo, err := signaturehash.SelectSignatureScheme(cfg.localSignatureSchemes, privateKey)
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InsufficientSecurity}, err
}
certVerify, err := generateCertificateVerify(plainText, privateKey, signatureHashAlgo.Hash)
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
state.localCertificatesVerify = certVerify
p := &packet{
record: &recordlayer.RecordLayer{
Header: recordlayer.Header{
Version: protocol.Version1_2,
},
Content: &handshake.Handshake{
Message: &handshake.MessageCertificateVerify{
HashAlgorithm: signatureHashAlgo.Hash,
SignatureAlgorithm: signatureHashAlgo.Signature,
Signature: state.localCertificatesVerify,
},
},
},
}
pkts = append(pkts, p)
h, ok := p.record.Content.(*handshake.Handshake)
if !ok {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, errInvalidContentType
}
h.Header.MessageSequence = seqPred
// seqPred++ // this is the last use of seqPred
raw, err := h.Marshal()
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
merged = append(merged, raw...)
}
pkts = append(pkts,
&packet{
record: &recordlayer.RecordLayer{
Header: recordlayer.Header{
Version: protocol.Version1_2,
},
Content: &protocol.ChangeCipherSpec{},
},
})
if len(state.localVerifyData) == 0 {
plainText := cache.pullAndMerge(
handshakeCachePullRule{handshake.TypeClientHello, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeServerHello, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificate, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeServerKeyExchange, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificateRequest, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeServerHelloDone, cfg.initialEpoch, false, false},
handshakeCachePullRule{handshake.TypeCertificate, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeClientKeyExchange, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeCertificateVerify, cfg.initialEpoch, true, false},
handshakeCachePullRule{handshake.TypeFinished, cfg.initialEpoch + 1, true, false},
)
var err error
state.localVerifyData, err = prf.VerifyDataClient(state.masterSecret, append(plainText, merged...), state.cipherSuite.HashFunc())
if err != nil {
return nil, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
}
pkts = append(pkts,
&packet{
record: &recordlayer.RecordLayer{
Header: recordlayer.Header{
Version: protocol.Version1_2,
Epoch: 1,
},
Content: &handshake.Handshake{
Message: &handshake.MessageFinished{
VerifyData: state.localVerifyData,
},
},
},
shouldEncrypt: true,
resetLocalSequenceNumber: true,
})
return pkts, nil, nil
}
func initalizeCipherSuite(state *State, cache *handshakeCache, cfg *handshakeConfig, h *handshake.MessageServerKeyExchange, sendingPlainText []byte) (*alert.Alert, error) { //nolint:gocognit
if state.cipherSuite.IsInitialized() {
return nil, nil
}
clientRandom := state.localRandom.MarshalFixed()
serverRandom := state.remoteRandom.MarshalFixed()
var err error
if state.extendedMasterSecret {
var sessionHash []byte
sessionHash, err = cache.sessionHash(state.cipherSuite.HashFunc(), cfg.initialEpoch, sendingPlainText)
if err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
state.masterSecret, err = prf.ExtendedMasterSecret(state.preMasterSecret, sessionHash, state.cipherSuite.HashFunc())
if err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.IllegalParameter}, err
}
} else {
state.masterSecret, err = prf.MasterSecret(state.preMasterSecret, clientRandom[:], serverRandom[:], state.cipherSuite.HashFunc())
if err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
}
if state.cipherSuite.AuthenticationType() == CipherSuiteAuthenticationTypeCertificate {
// Verify that the pair of hash algorithm and signiture is listed.
var validSignatureScheme bool
for _, ss := range cfg.localSignatureSchemes {
if ss.Hash == h.HashAlgorithm && ss.Signature == h.SignatureAlgorithm {
validSignatureScheme = true
break
}
}
if !validSignatureScheme {
return &alert.Alert{Level: alert.Fatal, Description: alert.InsufficientSecurity}, errNoAvailableSignatureSchemes
}
expectedMsg := valueKeyMessage(clientRandom[:], serverRandom[:], h.PublicKey, h.NamedCurve)
if err = verifyKeySignature(expectedMsg, h.Signature, h.HashAlgorithm, state.PeerCertificates); err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.BadCertificate}, err
}
var chains [][]*x509.Certificate
if !cfg.insecureSkipVerify {
if chains, err = verifyServerCert(state.PeerCertificates, cfg.rootCAs, cfg.serverName); err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.BadCertificate}, err
}
}
if cfg.verifyPeerCertificate != nil {
if err = cfg.verifyPeerCertificate(state.PeerCertificates, chains); err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.BadCertificate}, err
}
}
}
if err = state.cipherSuite.Init(state.masterSecret, clientRandom[:], serverRandom[:], true); err != nil {
return &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, err
}
cfg.writeKeyLog(keyLogLabelTLS12, clientRandom[:], state.masterSecret)
return nil, nil
}