/
dns.go
415 lines (375 loc) · 8.54 KB
/
dns.go
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package phantomtcp
import (
"crypto/tls"
"encoding/binary"
"log"
"net"
"strings"
"time"
)
var DNS string = ""
var DNS64 string = ""
func TCPlookup(request []byte, address string) ([]byte, error) {
server, err := net.DialTimeout("tcp", address, time.Second*5)
if err != nil {
return nil, err
}
defer server.Close()
data := make([]byte, 1024)
binary.BigEndian.PutUint16(data[:2], uint16(len(request)))
copy(data[2:], request)
_, err = server.Write(data[:len(request)+2])
if err != nil {
return nil, err
}
length := 0
recvlen := 0
for {
if recvlen >= 1024 {
return nil, nil
}
n, err := server.Read(data[recvlen:])
if err != nil {
return nil, err
}
if length == 0 {
length = int(binary.BigEndian.Uint16(data[:2]) + 2)
}
recvlen += n
if recvlen >= length {
return data[2:recvlen], nil
}
}
return nil, nil
}
func TCPlookupDNS64(request []byte, address string, offset int, prefix []byte) ([]byte, error) {
response6 := make([]byte, 1024)
offset6 := offset
offset4 := offset
binary.BigEndian.PutUint16(request[offset-4:offset-2], 1)
response, err := TCPlookup(request, address)
if err != nil {
return nil, err
}
copy(response6, response[:offset])
binary.BigEndian.PutUint16(response6[offset-4:offset-2], 28)
count := int(binary.BigEndian.Uint16(response[6:8]))
for i := 0; i < count; i++ {
for {
if offset >= len(response) {
log.Println(offset)
return nil, nil
}
length := response[offset]
offset++
if length == 0 {
break
}
if length < 63 {
offset += int(length)
if offset+2 > len(response) {
log.Println(offset)
return nil, nil
}
} else {
offset++
break
}
}
if offset+2 > len(response) {
log.Println(offset)
return nil, nil
}
copy(response6[offset6:], response[offset4:offset])
offset6 += offset - offset4
offset4 = offset
AType := binary.BigEndian.Uint16(response[offset : offset+2])
offset += 8
if offset+2 > len(response) {
log.Println(offset)
return nil, nil
}
DataLength := binary.BigEndian.Uint16(response[offset : offset+2])
offset += 2
offset += int(DataLength)
if AType == 1 {
if offset > len(response) {
log.Println(offset)
return nil, nil
}
binary.BigEndian.PutUint16(response6[offset6:], 28)
offset6 += 2
offset4 += 2
copy(response6[offset6:], response[offset4:offset4+6])
offset6 += 6
offset4 += 6
binary.BigEndian.PutUint16(response6[offset6:], DataLength+12)
offset6 += 2
offset4 += 2
copy(response6[offset6:], prefix[:12])
offset6 += 12
copy(response6[offset6:], response[offset4:offset])
offset6 += offset - offset4
offset4 = offset
} else {
copy(response6[offset6:], response[offset4:offset])
offset6 += offset - offset4
offset4 = offset
}
}
return response6[:offset6], nil
}
func TLSlookup(request []byte, address string) ([]byte, error) {
conf := &tls.Config{
InsecureSkipVerify: true,
}
conn, err := tls.Dial("tcp", address, conf)
if err != nil {
return nil, err
}
defer conn.Close()
data := make([]byte, 1024)
binary.BigEndian.PutUint16(data[:2], uint16(len(request)))
copy(data[2:], request)
_, err = conn.Write(data[:len(request)+2])
if err != nil {
return nil, err
}
length := 0
recvlen := 0
for {
if recvlen >= 1024 {
return nil, nil
}
n, err := conn.Read(data[recvlen:])
if err != nil {
return nil, err
}
if length == 0 {
length = int(binary.BigEndian.Uint16(data[:2]) + 2)
}
recvlen += n
if recvlen >= length {
return data[2:recvlen], nil
}
}
return nil, nil
}
func GetQName(buf []byte) (string, int, int) {
bufflen := len(buf)
if bufflen < 13 {
return "", 0, 0
}
length := buf[12]
off := 13
end := off + int(length)
qname := string(buf[off:end])
off = end
for {
if off >= bufflen {
return "", 0, 0
}
length := buf[off]
off++
if length == 0x00 {
break
}
end := off + int(length)
if end > bufflen {
return "", 0, 0
}
qname += "." + string(buf[off:end])
off = end
}
end = off + 4
if end > bufflen {
return "", 0, 0
}
qtype := int(binary.BigEndian.Uint16(buf[off : off+2]))
return qname, qtype, end
}
func getAnswers(answers []byte, count int) []net.IP {
ips := make([]net.IP, 0)
offset := 0
for i := 0; i < count; i++ {
for {
if offset >= len(answers) {
return nil
}
length := answers[offset]
offset++
if length == 0 {
break
}
if length < 63 {
offset += int(length)
if offset+2 > len(answers) {
return nil
}
} else {
offset++
break
}
}
if offset+2 > len(answers) {
return nil
}
AType := binary.BigEndian.Uint16(answers[offset : offset+2])
offset += 8
if offset+2 > len(answers) {
return nil
}
DataLength := binary.BigEndian.Uint16(answers[offset : offset+2])
offset += 2
if AType == 1 {
if offset+4 > len(answers) {
return nil
}
data := answers[offset : offset+4]
ip := net.IPv4(data[0], data[1], data[2], data[3])
ips = append(ips, ip)
} else if AType == 28 {
var data [16]byte
if offset+16 > len(answers) {
return nil
}
copy(data[:], answers[offset:offset+16])
ip := net.IP(answers[offset : offset+16])
ips = append(ips, ip)
}
offset += int(DataLength)
}
return ips
}
func packAnswers(ips []string, qtype int) (int, []byte) {
totalLen := 0
count := 0
for _, ip := range ips {
ip4 := net.ParseIP(ip).To4()
if ip4 != nil && qtype == 1 {
count++
totalLen += 16
} else if qtype == 28 {
count++
totalLen += 28
}
}
answers := make([]byte, totalLen)
length := 0
for _, strIP := range ips {
ip := net.ParseIP(strIP)
ip4 := ip.To4()
if ip4 != nil {
if qtype == 1 {
answer := []byte{0xC0, 0x0C, 0x00, 1,
0x00, 0x01, 0x00, 0x00, 0x0E, 0x10, 0x00, 0x04,
ip4[0], ip4[1], ip4[2], ip4[3]}
copy(answers[length:], answer)
length += 16
}
} else {
if qtype == 28 {
answer := []byte{0xC0, 0x0C, 0x00, 28,
0x00, 0x01, 0x00, 0x00, 0x0E, 0x10, 0x00, 0x10}
copy(answers[length:], answer)
length += 12
copy(answers[length:], ip)
length += 16
}
}
}
return count, answers
}
func BuildLie(request []byte, id int, qtype int) []byte {
response := make([]byte, 1024)
copy(response, request)
length := len(request)
response[2] = 0x81
response[3] = 0x80
if qtype == 1 {
answer := []byte{0xC0, 0x0C, 0x00, 1,
0x00, 0x01, 0x00, 0x00, 0x00, 0x10, 0x00, 0x04,
7, 0}
copy(response[length:], answer)
length += 14
binary.BigEndian.PutUint16(response[length:], uint16(id))
length += 2
binary.BigEndian.PutUint16(response[6:], 1)
} else if qtype == 28 {
answer := []byte{0xC0, 0x0C, 0x00, 28,
0x00, 0x01, 0x00, 0x00, 0x00, 0x10, 0x00, 0x10,
0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00}
copy(response[length:], answer)
length += 24
binary.BigEndian.PutUint32(response[length:], uint32(id))
length += 4
binary.BigEndian.PutUint16(response[6:], 1)
}
return response[:length]
}
func PackQName(name string) []byte {
length := strings.Count(name, "")
QName := make([]byte, length+1)
copy(QName[1:], []byte(name))
o, l := 0, 0
for i := 1; i < length; i++ {
if QName[i] == '.' {
QName[o] = byte(l)
l = 0
o = i
} else {
l++
}
}
QName[o] = byte(l)
return QName
}
func PackRequest(name string, qtype uint16) []byte {
Request := make([]byte, 512)
binary.BigEndian.PutUint16(Request[:], 0) //ID
binary.BigEndian.PutUint16(Request[2:], 0x0100) //Flag
binary.BigEndian.PutUint16(Request[4:], 1) //QDCount
binary.BigEndian.PutUint16(Request[6:], 0) //ANCount
binary.BigEndian.PutUint16(Request[8:], 0) //NSCount
binary.BigEndian.PutUint16(Request[10:], 0) //ARCount
qname := PackQName(name)
length := len(qname)
copy(Request[12:], qname)
length += 12
binary.BigEndian.PutUint16(Request[length:], qtype)
length += 2
binary.BigEndian.PutUint16(Request[length:], 0x01) //QClass
length += 2
return Request[:length]
}
func NSLookup(name string, qtype uint16) (int, []net.IP) {
ans, ok := DNSCache[name]
if ok {
return ans.Index, ans.Addresses
}
offset := 0
for i := 0; i < SubdomainDepth; i++ {
off := strings.Index(name[offset:], ".")
if off == -1 {
break
}
offset += off
ans, ok = DNSCache[name[offset:]]
if ok {
return ans.Index, ans.Addresses
}
offset++
}
request := PackRequest(name, qtype)
response, err := TLSlookup(request, DNS)
if err != nil {
log.Println(err)
return 0, nil
}
count := int(binary.BigEndian.Uint16(response[6:8]))
ips := getAnswers(response[len(request):], count)
index := len(Nose)
DNSCache[name] = Answer{index, ips}
return index, ips
}