9178f9d1ee
These are found with: `pcregrep -M "}\n\n}" **/*.go` Sometimes a unneeded newline is inserted, remove those. Signed-off-by: Miek Gieben <miek@miek.nl>
117 lines
2.6 KiB
Go
117 lines
2.6 KiB
Go
package doh
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/base64"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"net/http"
|
|
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
// MimeType is the DoH mimetype that should be used.
|
|
const MimeType = "application/dns-message"
|
|
|
|
// Path is the URL path that should be used.
|
|
const Path = "/dns-query"
|
|
|
|
// NewRequest returns a new DoH request given a method, URL (without any paths, so exclude /dns-query) and dns.Msg.
|
|
func NewRequest(method, url string, m *dns.Msg) (*http.Request, error) {
|
|
buf, err := m.Pack()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
switch method {
|
|
case http.MethodGet:
|
|
b64 := base64.RawURLEncoding.EncodeToString(buf)
|
|
|
|
req, err := http.NewRequest(http.MethodGet, "https://"+url+Path+"?dns="+b64, nil)
|
|
if err != nil {
|
|
return req, err
|
|
}
|
|
|
|
req.Header.Set("content-type", MimeType)
|
|
req.Header.Set("accept", MimeType)
|
|
return req, nil
|
|
|
|
case http.MethodPost:
|
|
req, err := http.NewRequest(http.MethodPost, "https://"+url+Path+"?bla=foo:443", bytes.NewReader(buf))
|
|
if err != nil {
|
|
return req, err
|
|
}
|
|
|
|
req.Header.Set("content-type", MimeType)
|
|
req.Header.Set("accept", MimeType)
|
|
return req, nil
|
|
|
|
default:
|
|
return nil, fmt.Errorf("method not allowed: %s", method)
|
|
}
|
|
}
|
|
|
|
// ResponseToMsg converts a http.Response to a dns message.
|
|
func ResponseToMsg(resp *http.Response) (*dns.Msg, error) {
|
|
defer resp.Body.Close()
|
|
|
|
return toMsg(resp.Body)
|
|
}
|
|
|
|
// RequestToMsg converts a http.Request to a dns message.
|
|
func RequestToMsg(req *http.Request) (*dns.Msg, error) {
|
|
switch req.Method {
|
|
case http.MethodGet:
|
|
return requestToMsgGet(req)
|
|
|
|
case http.MethodPost:
|
|
return requestToMsgPost(req)
|
|
|
|
default:
|
|
return nil, fmt.Errorf("method not allowed: %s", req.Method)
|
|
}
|
|
}
|
|
|
|
// requestToMsgPost extracts the dns message from the request body.
|
|
func requestToMsgPost(req *http.Request) (*dns.Msg, error) {
|
|
defer req.Body.Close()
|
|
return toMsg(req.Body)
|
|
}
|
|
|
|
// requestToMsgGet extract the dns message from the GET request.
|
|
func requestToMsgGet(req *http.Request) (*dns.Msg, error) {
|
|
values := req.URL.Query()
|
|
b64, ok := values["dns"]
|
|
if !ok {
|
|
return nil, fmt.Errorf("no 'dns' query parameter found")
|
|
}
|
|
if len(b64) != 1 {
|
|
return nil, fmt.Errorf("multiple 'dns' query values found")
|
|
}
|
|
return base64ToMsg(b64[0])
|
|
}
|
|
|
|
func toMsg(r io.ReadCloser) (*dns.Msg, error) {
|
|
buf, err := ioutil.ReadAll(r)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
m := new(dns.Msg)
|
|
err = m.Unpack(buf)
|
|
return m, err
|
|
}
|
|
|
|
func base64ToMsg(b64 string) (*dns.Msg, error) {
|
|
buf, err := b64Enc.DecodeString(b64)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
m := new(dns.Msg)
|
|
err = m.Unpack(buf)
|
|
|
|
return m, err
|
|
}
|
|
|
|
var b64Enc = base64.RawURLEncoding
|