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send_https_get_after_tcp3way_tlshandshake.go
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/
send_https_get_after_tcp3way_tlshandshake.go
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package debugging
import (
"bytes"
"log"
p "github.com/ddddddO/packemon"
"golang.org/x/sys/unix"
)
// SendTCP3wayAndTLShandshake とほぼ同じ。違いは client から送る Application Data が http のフォーマット
func (dnw *debugNetworkInterface) SendHTTPSGetAfterTCP3wayAndTLShandshake(firsthopMACAddr [6]byte) error {
var srcPort uint16 = 0xa32f
var dstPort uint16 = 0x28cb // 10443
// var dstPort uint16 = 0x01bb // 443
// var srcIPAddr uint32 = 0xac184fcf // 172.23.242.78 / 旧PC
var srcIPAddr uint32 = 0xac163718 // 172.22.55.24 / 新PC
var dstIPAddr uint32 = 0xc0a80a6e // raspberry pi . raspberry pi 上で https-server 起動で、うまくいった
dstMACAddr := p.HardwareAddr(firsthopMACAddr)
srcMACAddr := p.HardwareAddr(dnw.Intf.HardwareAddr)
tcp := p.NewTCPSyn(srcPort, dstPort)
ipv4 := p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame := p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
tlsClientHello := p.NewTLSClientHello()
var tlsServerHello *p.TLSServerHello
var tlsClientKeyExchange *p.TLSClientKeyExchange
var tlsClientFinished []byte
var keyblock *p.KeyBlock
var clientSequence int
var master []byte
for {
log.Println("in loop")
recieved := make([]byte, 1500)
n, _, err := unix.Recvfrom(dnw.Socket, recieved, 0)
if err != nil {
if n == -1 {
continue
}
return err
}
ethernetFrame := p.ParsedEthernetFrame(recieved)
switch ethernetFrame.Header.Typ {
case p.ETHER_TYPE_IPv4:
ipv4 := p.ParsedIPv4(ethernetFrame.Data)
switch ipv4.Protocol {
case p.IPv4_PROTO_TCP:
tcp := p.ParsedTCP(ipv4.Data)
switch tcp.DstPort {
case srcPort: // synパケットの送信元ポート
if tcp.Flags == p.TCP_FLAGS_SYN_ACK {
log.Println("passive TCP_FLAGS_SYN_ACK")
// syn/ackを受け取ったのでack送信
tcp := p.NewTCPAck(srcPort, dstPort, tcp.Sequence, tcp.Acknowledgment)
ipv4 := p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame := p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
// ここで TLS Client Helloを送る
if err := dnw.SendTLSClientHello(tlsClientHello, srcPort, dstPort, srcIPAddr, dstIPAddr, firsthopMACAddr, tcp.Sequence, tcp.Acknowledgment); err != nil {
return err
}
continue
}
// ここでのServer Hello(ack)受信後の処理はうまくいった
// 関連: https://github.com/ddddddO/packemon/issues/64
// Wireshark 見るに、このackのパケットを後続のpsh/ackのパケット2つのtcp data部分をつなげて、ServerHello/Certificate/ServerHelloDone みたい
// 上記リンクの、1パケットパターンのパケットと2パケットパターンのパケット見比べて確認した
if tcp.Flags == p.TCP_FLAGS_ACK {
log.Println("passive TCP_FLAGS_ACK")
tlsHandshakeType := []byte{tcp.Data[5]}
tlsContentType := []byte{tcp.Data[0]}
// ServerHello/Certificate/ServerHelloDone がセグメント分割されたパケットで届くことが多々あるため、このブロック内で連続して受信している
// TODO: (10)443ポートがdstで絞った方がいいかも
if bytes.Equal(tlsHandshakeType, []byte{0x02}) && bytes.Equal(tlsContentType, []byte{p.TLS_CONTENT_TYPE_HANDSHAKE}) {
log.Println("[ACK] passive TLS ServerHello(with Certificate/ServerHelloDone ?)")
log.Printf("\tTCP data: %x\n", tcp.Data)
for {
recieved := make([]byte, 1500)
n, _, err := unix.Recvfrom(dnw.Socket, recieved, 0)
if err != nil {
if n == -1 {
continue
}
return err
}
eth := p.ParsedEthernetFrame(recieved)
ip := p.ParsedIPv4(eth.Data)
t := p.ParsedTCP(ip.Data)
if t.Flags == p.TCP_FLAGS_PSH_ACK {
log.Println("[PSH_ACK] passive TLS ServerHello(with Certificate/ServerHelloDone !!!???)")
// tcp data の末尾の0パディングを取り除く
tmp1 := tcp.Data
for offset := len(tcp.Data) - 2; bytes.Equal(tcp.Data[offset:offset+2], []byte{00, 00}); offset -= 2 {
tmp1 = tmp1[:len(tmp1)-2]
}
tmp2 := t.Data
for offset := len(t.Data) - 4; bytes.Equal(t.Data[offset:offset+4], []byte{00, 00, 00, 00}); offset -= 4 {
tmp2 = tmp2[:len(tmp2)-4]
}
mergedTCPData := append(tmp1, tmp2...)
tlsServerHello = p.ParsedTLSServerHello(mergedTCPData)
if err := tlsServerHello.Certificate.Validate(); err != nil {
return err
}
// ackを返し
tcp := p.NewTCPAck(srcPort, dstPort, t.Sequence, t.Acknowledgment)
ipv4 := p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame := p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
// さらに ClientKeyExchange や Finished などを返す
tlsClientKeyExchange, keyblock, clientSequence, master, tlsClientFinished = p.NewTLSClientKeyExchangeAndChangeCipherSpecAndFinished(
tlsClientHello,
tlsServerHello,
)
tcp = p.NewTCPWithData(srcPort, dstPort, tlsClientKeyExchange.Bytes(), tcp.Sequence, tcp.Acknowledgment)
ipv4 = p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame = p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
break
}
}
continue
}
continue
}
if tcp.Flags == p.TCP_FLAGS_PSH_ACK {
log.Println("passive TCP_FLAGS_PSH_ACK")
tlsHandshakeType := []byte{tcp.Data[5]}
tlsContentType := []byte{tcp.Data[0]}
log.Printf("\ttcp data: %x\n\n", tcp.Data[0:10])
log.Printf("\ttlsHandshakeType: %x\n", tlsHandshakeType)
log.Printf("\ttlsContentType: %x\n", tlsContentType)
// ServerHelloを受信
// TODO: (10)443ポートがdstで絞った方がいいかも
// SeverHello(0x02)
if bytes.Equal(tlsHandshakeType, []byte{0x02}) && bytes.Equal(tlsContentType, []byte{p.TLS_CONTENT_TYPE_HANDSHAKE}) {
log.Printf("tlsHandshakeType: %x\n", tlsHandshakeType)
log.Println("passive TLS ServerHello")
// TODO: server から、ServerHello/Certificate/ServerHelloDone でひとまとまりで返ってくればパースできるが、ServerHello と Certificate/ServerHelloDone がわかれて返ってくることがある。それで失敗してるよう？
// 分かれてるとき、ServerHell はフラグが ACK だけど、分かれてないとき PSH/ACK
tlsServerHello = p.ParsedTLSServerHello(tcp.Data)
if err := tlsServerHello.Certificate.Validate(); err != nil {
return err
}
// ackを返し
tcp := p.NewTCPAck(srcPort, dstPort, tcp.Sequence, tcp.Acknowledgment)
ipv4 := p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame := p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
// さらに ClientKeyExchange や Finished などを返す
tlsClientKeyExchange, keyblock, clientSequence, master, tlsClientFinished = p.NewTLSClientKeyExchangeAndChangeCipherSpecAndFinished(
tlsClientHello,
tlsServerHello,
)
tcp = p.NewTCPWithData(srcPort, dstPort, tlsClientKeyExchange.Bytes(), tcp.Sequence, tcp.Acknowledgment)
ipv4 = p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame = p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
continue
}
// ChangeCipherSpec/Finishedを受信
// TODO: (10)443ポートがdstとかもっと絞った方がいいかも
if bytes.Equal(tlsContentType, []byte{p.TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC}) {
log.Println("recieved ChangeCipherSpec/Finished !!")
verifingData := &p.ForVerifing{
Master: master,
ClientHello: tlsClientHello,
ServerHello: tlsServerHello,
ClientKeyExchange: tlsClientKeyExchange.ClientKeyExchange,
ClientFinished: tlsClientFinished,
}
tlsChangeCiperSpecAndFinished := p.ParsedTLSChangeCipherSpecAndFinished(tcp.Data, keyblock, clientSequence, verifingData)
log.Printf("\tChangeCipherSpecProtocol.RecordLayer.ContentType: %x\n", tlsChangeCiperSpecAndFinished.ChangeCipherSpecProtocol.RecordLayer.ContentType)
log.Printf("\tFinished.RawEncrypted:\n%x\n", tlsChangeCiperSpecAndFinished.Finished.RawEncrypted)
// TODO: 上のParsed内でserverからきたFinishedの検証してるけど、この辺りに持ってきた方がいいかも
// Finishedの検証が成功したので、以降からApplicationDataをやりとり
log.Println("Send TLS Application DATA")
clientSequence++
httpGetReq := p.NewHTTP()
tlsApplicationData := p.NewTLSApplicationData(httpGetReq.Bytes(), keyblock, clientSequence)
tcp = p.NewTCPWithData(srcPort, dstPort, tlsApplicationData, tcp.Acknowledgment, tcp.Sequence)
ipv4 = p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame = p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
continue
}
}
if tcp.Flags == p.TCP_FLAGS_FIN_ACK {
log.Println("passive TCP_FLAGS_FIN_ACK")
// それにack
tcp := p.NewTCPAck(srcPort, dstPort, tcp.Sequence, tcp.Acknowledgment)
ipv4 := p.NewIPv4(p.IPv4_PROTO_TCP, srcIPAddr, dstIPAddr)
tcp.CalculateChecksum(ipv4)
ipv4.Data = tcp.Bytes()
ipv4.CalculateTotalLength()
ipv4.CalculateChecksum()
ethernetFrame := p.NewEthernetFrame(dstMACAddr, srcMACAddr, p.ETHER_TYPE_IPv4, ipv4.Bytes())
if err := dnw.Send(ethernetFrame); err != nil {
return err
}
return nil
}
// dnw.PassiveCh <- &p.Passive{
// EthernetFrame: ethernetFrame,
// IPv4: ipv4,
// TCP: tcp,
// }
continue
default:
// dnw.PassiveCh <- &p.Passive{
// EthernetFrame: ethernetFrame,
// IPv4: ipv4,
// TCP: tcp,
// }
}
}
}
}
return nil
}