Files
authentik/internal/outpost/radius/eap/protocol/tls/payload.go
Jens Langhammer f5eb827d14 start reworking response modification
Signed-off-by: Jens Langhammer <jens@goauthentik.io>
2025-07-01 22:43:03 +02:00

280 lines
7.5 KiB
Go

package tls
import (
"context"
"crypto/tls"
"encoding/binary"
"errors"
"fmt"
"os"
"slices"
"time"
"github.com/avast/retry-go/v4"
log "github.com/sirupsen/logrus"
"goauthentik.io/internal/outpost/radius/eap/debug"
"goauthentik.io/internal/outpost/radius/eap/protocol"
"layeh.com/radius"
"layeh.com/radius/vendors/microsoft"
)
const maxChunkSize = 1000
const staleConnectionTimeout = 10
const TypeTLS protocol.Type = 13
func Protocol() protocol.Payload {
return &Payload{}
}
type Payload struct {
Flags Flag
Length uint32
Data []byte
st *State
Inner protocol.Payload
}
func (p *Payload) Type() protocol.Type {
return TypeTLS
}
func (p *Payload) HasInner() protocol.Payload {
return p.Inner
}
func (p *Payload) Offerable() bool {
return true
}
func (p *Payload) Decode(raw []byte) error {
p.Flags = Flag(raw[0])
raw = raw[1:]
if p.Flags&FlagLengthIncluded != 0 {
if len(raw) < 4 {
return errors.New("invalid size")
}
p.Length = binary.BigEndian.Uint32(raw)
p.Data = raw[4:]
} else {
p.Data = raw[0:]
}
log.WithField("raw", debug.FormatBytes(p.Data)).WithField("size", len(p.Data)).WithField("flags", p.Flags).Trace("TLS: decode raw")
return nil
}
func (p *Payload) Encode() ([]byte, error) {
l := 1
if p.Flags&FlagLengthIncluded != 0 {
l += 4
}
buff := make([]byte, len(p.Data)+l)
buff[0] = byte(p.Flags)
if p.Flags&FlagLengthIncluded != 0 {
buff[1] = byte(p.Length >> 24)
buff[2] = byte(p.Length >> 16)
buff[3] = byte(p.Length >> 8)
buff[4] = byte(p.Length)
}
if len(p.Data) > 0 {
copy(buff[5:], p.Data)
}
return buff, nil
}
func (p *Payload) Handle(ctx protocol.Context) protocol.Payload {
defer func() {
ctx.SetProtocolState(TypeTLS, p.st)
}()
if ctx.IsProtocolStart(TypeTLS) {
p.st = NewState(ctx).(*State)
return &Payload{
Flags: FlagTLSStart,
}
}
p.st = ctx.GetProtocolState(TypeTLS).(*State)
if p.st.TLS == nil {
p.tlsInit(ctx)
} else if len(p.Data) > 0 {
ctx.Log().Debug("TLS: Updating buffer with new TLS data from packet")
if p.Flags&FlagLengthIncluded != 0 && p.st.Conn.expectedWriterByteCount == 0 {
ctx.Log().Debugf("TLS: Expecting %d total bytes, will buffer", p.Length)
p.st.Conn.expectedWriterByteCount = int(p.Length)
} else if p.Flags&FlagLengthIncluded != 0 {
ctx.Log().Debug("TLS: No length included, not buffering")
p.st.Conn.expectedWriterByteCount = 0
}
p.st.Conn.UpdateData(p.Data)
if !p.st.Conn.NeedsMoreData() && !p.st.HandshakeDone {
// Wait for outbound data to be available
p.st.Conn.OutboundData()
}
}
// If we need more data, send the client the go-ahead
if p.st.Conn.NeedsMoreData() {
return &Payload{
Flags: FlagNone,
Length: 0,
Data: []byte{},
}
}
if p.st.HasMore() {
return p.sendNextChunk()
}
if p.st.Conn.writer.Len() == 0 && p.st.HandshakeDone {
if p.Inner != nil {
ctx.Log().Debug("TLS: Handshake is done, delegating to inner protocol")
p.innerHandler(ctx)
return p.startChunkedTransfer(p.st.Conn.OutboundData())
}
defer p.st.ContextCancel()
// If we don't have a final status from the handshake finished function, stall for time
pst, _ := retry.DoWithData(
func() (protocol.Status, error) {
if p.st.FinalStatus == protocol.StatusUnknown {
return p.st.FinalStatus, errStall
}
return p.st.FinalStatus, nil
},
retry.Context(p.st.Context),
retry.Delay(10*time.Microsecond),
retry.DelayType(retry.BackOffDelay),
retry.MaxDelay(100*time.Millisecond),
retry.Attempts(0),
)
ctx.EndInnerProtocol(pst)
return nil
}
return p.startChunkedTransfer(p.st.Conn.OutboundData())
}
func (p *Payload) ModifyRADIUSResponse(r *radius.Packet, q *radius.Packet) error {
if r.Code != radius.CodeAccessAccept {
return nil
}
if p.st == nil || !p.st.HandshakeDone {
return nil
}
log.Debug("TLS: Adding MPPE Keys")
// TLS overrides other protocols' MPPE keys
if len(microsoft.MSMPPERecvKey_Get(r, q)) > 0 {
microsoft.MSMPPERecvKey_Del(r)
}
if len(microsoft.MSMPPESendKey_Get(r, q)) > 0 {
microsoft.MSMPPESendKey_Del(r)
}
microsoft.MSMPPERecvKey_Set(r, p.st.MPPEKey[:32])
microsoft.MSMPPESendKey_Set(r, p.st.MPPEKey[64:64+32])
return nil
}
func (p *Payload) tlsInit(ctx protocol.Context) {
ctx.Log().Debug("TLS: no TLS connection in state yet, starting connection")
p.st.Context, p.st.ContextCancel = context.WithTimeout(context.Background(), staleConnectionTimeout*time.Second)
p.st.Conn = NewBuffConn(p.Data, p.st.Context)
cfg := ctx.ProtocolSettings().(TLSConfig).TLSConfig().Clone()
if klp, ok := os.LookupEnv("SSLKEYLOGFILE"); ok {
kl, err := os.OpenFile(klp, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0600)
if err != nil {
panic(err)
}
cfg.KeyLogWriter = kl
}
cfg.GetConfigForClient = func(chi *tls.ClientHelloInfo) (*tls.Config, error) {
ctx.Log().Debugf("TLS: ClientHello: %+v\n", chi)
p.st.ClientHello = chi
return nil, nil
}
p.st.TLS = tls.Server(p.st.Conn, cfg)
p.st.TLS.SetDeadline(time.Now().Add(staleConnectionTimeout * time.Second))
go func() {
err := p.st.TLS.HandshakeContext(p.st.Context)
if err != nil {
ctx.Log().WithError(err).Debug("TLS: Handshake error")
p.st.FinalStatus = protocol.StatusError
ctx.EndInnerProtocol(protocol.StatusError)
return
}
ctx.Log().Debug("TLS: handshake done")
p.tlsHandshakeFinished(ctx)
}()
}
func (p *Payload) tlsHandshakeFinished(ctx protocol.Context) {
cs := p.st.TLS.ConnectionState()
label := "client EAP encryption"
var context []byte
switch cs.Version {
case tls.VersionTLS10:
ctx.Log().Debugf("TLS: Version %d (1.0)", cs.Version)
case tls.VersionTLS11:
ctx.Log().Debugf("TLS: Version %d (1.1)", cs.Version)
case tls.VersionTLS12:
ctx.Log().Debugf("TLS: Version %d (1.2)", cs.Version)
case tls.VersionTLS13:
ctx.Log().Debugf("TLS: Version %d (1.3)", cs.Version)
label = "EXPORTER_EAP_TLS_Key_Material"
context = []byte{byte(TypeTLS)}
}
ksm, err := cs.ExportKeyingMaterial(label, context, 64+64)
ctx.Log().Debugf("TLS: ksm % x %v", ksm, err)
p.st.MPPEKey = ksm
p.st.HandshakeDone = true
if p.Inner == nil {
p.st.FinalStatus = ctx.ProtocolSettings().(Settings).HandshakeSuccessful(ctx, cs.PeerCertificates)
}
}
func (p *Payload) startChunkedTransfer(data []byte) *Payload {
if len(data) > maxChunkSize {
log.WithField("length", len(data)).Debug("TLS: Data needs to be chunked")
p.st.RemainingChunks = append(p.st.RemainingChunks, slices.Collect(slices.Chunk(data, maxChunkSize))...)
p.st.TotalPayloadSize = len(data)
return p.sendNextChunk()
}
log.WithField("length", len(data)).Debug("TLS: Sending data un-chunked")
p.st.Conn.writer.Reset()
return &Payload{
Flags: FlagLengthIncluded,
Length: uint32(len(data)),
Data: data,
}
}
func (p *Payload) sendNextChunk() *Payload {
nextChunk := p.st.RemainingChunks[0]
log.WithField("raw", debug.FormatBytes(nextChunk)).Debug("TLS: Sending next chunk")
p.st.RemainingChunks = p.st.RemainingChunks[1:]
flags := FlagLengthIncluded
if p.st.HasMore() {
log.WithField("chunks", len(p.st.RemainingChunks)).Debug("TLS: More chunks left")
flags += FlagMoreFragments
} else {
// Last chunk, reset the connection buffers and pending payload size
defer func() {
log.Debug("TLS: Sent last chunk")
p.st.Conn.writer.Reset()
p.st.TotalPayloadSize = 0
}()
}
log.WithField("length", p.st.TotalPayloadSize).Debug("TLS: Total payload size")
return &Payload{
Flags: flags,
Length: uint32(p.st.TotalPayloadSize),
Data: nextChunk,
}
}
func (p *Payload) String() string {
return fmt.Sprintf(
"<TLS Packet HandshakeDone=%t, FinalStatus=%d, ClientHello=%v>",
p.st.HandshakeDone,
p.st.FinalStatus,
p.st.ClientHello,
)
}