Better mime type probing

pull/82/head
Philipp Heckel 2022-01-10 13:38:51 -05:00
parent b5183612be
commit e8cb9e7fde
7 changed files with 53 additions and 39 deletions

1
go.mod
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@ -30,6 +30,7 @@ require (
github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 // indirect
github.com/envoyproxy/go-control-plane v0.10.1 // indirect
github.com/envoyproxy/protoc-gen-validate v0.6.2 // indirect
github.com/gabriel-vasile/mimetype v1.4.0 // indirect
github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
github.com/golang/protobuf v1.5.2 // indirect
github.com/google/go-cmp v0.5.6 // indirect

3
go.sum
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@ -106,6 +106,8 @@ github.com/envoyproxy/go-control-plane v0.10.1/go.mod h1:AY7fTTXNdv/aJ2O5jwpxAPO
github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
github.com/envoyproxy/protoc-gen-validate v0.6.2 h1:JiO+kJTpmYGjEodY7O1Zk8oZcNz1+f30UtwtXoFUPzE=
github.com/envoyproxy/protoc-gen-validate v0.6.2/go.mod h1:2t7qjJNvHPx8IjnBOzl9E9/baC+qXE/TeeyBRzgJDws=
github.com/gabriel-vasile/mimetype v1.4.0 h1:Cn9dkdYsMIu56tGho+fqzh7XmvY2YyGU0FnbhiOsEro=
github.com/gabriel-vasile/mimetype v1.4.0/go.mod h1:fA8fi6KUiG7MgQQ+mEWotXoEOvmxRtOJlERCzSmRvr8=
github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
@ -323,6 +325,7 @@ golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v
golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLdyRGr576XBO4/greRjx4P4O3yc=
golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20210505024714-0287a6fb4125/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d h1:LO7XpTYMwTqxjLcGWPijK3vRXg1aWdlNOVOHRq45d7c=
golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=

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@ -150,9 +150,10 @@ var (
)
const (
firebaseControlTopic = "~control" // See Android if changed
emptyMessageBody = "triggered"
fcmMessageLimit = 4000 // see maybeTruncateFCMMessage for details
firebaseControlTopic = "~control" // See Android if changed
emptyMessageBody = "triggered"
fcmMessageLimit = 4000 // see maybeTruncateFCMMessage for details
defaultAttachmentMessage = "You received a file: %s"
)
// New instantiates a new Server. It creates the cache and adds a Firebase
@ -436,7 +437,7 @@ func (s *Server) handleFile(w http.ResponseWriter, r *http.Request, _ *visitor)
return err
}
defer f.Close()
_, err = io.Copy(util.NewContentTypeWriter(w), f)
_, err = io.Copy(util.NewContentTypeWriter(w, r.URL.Path), f)
return err
}
@ -609,6 +610,9 @@ func (s *Server) handleBodyAsMessage(m *message, body *util.PeakedReadCloser) er
if len(body.PeakedBytes) > 0 { // Empty body should not override message (publish via GET!)
m.Message = strings.TrimSpace(string(body.PeakedBytes)) // Truncates the message to the peak limit if required
}
if m.Attachment != nil && m.Attachment.Name != "" && m.Message == "" {
m.Message = fmt.Sprintf(defaultAttachmentMessage, m.Attachment.Name)
}
return nil
}
@ -622,16 +626,16 @@ func (s *Server) handleBodyAsAttachment(v *visitor, m *message, body *util.Peake
m.Attachment = &attachment{}
}
var err error
var ext string
m.Attachment.Owner = v.ip // Important for attachment rate limiting
m.Attachment.Expires = time.Now().Add(s.config.AttachmentExpiryDuration).Unix()
m.Attachment.Type = http.DetectContentType(body.PeakedBytes)
ext := util.ExtensionByType(m.Attachment.Type)
m.Attachment.Type, ext = util.DetectContentType(body.PeakedBytes, m.Attachment.Name)
m.Attachment.URL = fmt.Sprintf("%s/file/%s%s", s.config.BaseURL, m.ID, ext)
if m.Attachment.Name == "" {
m.Attachment.Name = fmt.Sprintf("attachment%s", ext)
}
if m.Message == "" {
m.Message = fmt.Sprintf("You received a file: %s", m.Attachment.Name)
m.Message = fmt.Sprintf(defaultAttachmentMessage, m.Attachment.Name)
}
// TODO do not allowed delayed delivery for attachments
visitorAttachmentsSize, err := s.cache.AttachmentsSize(v.ip)

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@ -12,8 +12,8 @@ import (
)
const (
peakAttachmentTimeout = 2500 * time.Millisecond
peakAttachmeantReadBytes = 128
peakAttachmentTimeout = 2500 * time.Millisecond
peakAttachmentReadBytes = 128
)
func maybePeakAttachmentURL(m *message) error {
@ -47,20 +47,21 @@ func maybePeakAttachmentURLInternal(m *message, timeout time.Duration) error {
if size, err := strconv.ParseInt(resp.Header.Get("Content-Length"), 10, 64); err == nil {
m.Attachment.Size = size
}
buf := make([]byte, peakAttachmentReadBytes)
io.ReadFull(resp.Body, buf) // Best effort: We don't care about the error
mimeType, ext := util.DetectContentType(buf, m.Attachment.URL)
m.Attachment.Type = resp.Header.Get("Content-Type")
if m.Attachment.Type == "" || m.Attachment.Type == "application/octet-stream" {
buf := make([]byte, peakAttachmeantReadBytes)
io.ReadFull(resp.Body, buf) // Best effort: We don't care about the error
m.Attachment.Type = http.DetectContentType(buf)
if m.Attachment.Type == "" {
m.Attachment.Type = mimeType
}
if m.Attachment.Name == "" {
u, err := url.Parse(m.Attachment.URL)
if err != nil {
m.Attachment.Name = fmt.Sprintf("attachment%s", util.ExtensionByType(m.Attachment.Type))
m.Attachment.Name = fmt.Sprintf("attachment%s", ext)
} else {
m.Attachment.Name = path.Base(u.Path)
if m.Attachment.Name == "." || m.Attachment.Name == "/" {
m.Attachment.Name = fmt.Sprintf("attachment%s", util.ExtensionByType(m.Attachment.Type))
m.Attachment.Name = fmt.Sprintf("attachment%s", ext)
}
}
}

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@ -11,13 +11,14 @@ import (
// It will always set a Content-Type based on http.DetectContentType, but will never send the "text/html"
// content type.
type ContentTypeWriter struct {
w http.ResponseWriter
sniffed bool
w http.ResponseWriter
filename string
sniffed bool
}
// NewContentTypeWriter creates a new ContentTypeWriter
func NewContentTypeWriter(w http.ResponseWriter) *ContentTypeWriter {
return &ContentTypeWriter{w, false}
func NewContentTypeWriter(w http.ResponseWriter, filename string) *ContentTypeWriter {
return &ContentTypeWriter{w, filename, false}
}
func (w *ContentTypeWriter) Write(p []byte) (n int, err error) {
@ -27,7 +28,7 @@ func (w *ContentTypeWriter) Write(p []byte) (n int, err error) {
// Detect and set Content-Type header
// Fix content types that we don't want to inline-render in the browser. In particular,
// we don't want to render HTML in the browser for security reasons.
contentType := http.DetectContentType(p)
contentType, _ := DetectContentType(p, w.filename)
if strings.HasPrefix(contentType, "text/html") {
contentType = strings.ReplaceAll(contentType, "text/html", "text/plain")
} else if contentType == "application/octet-stream" {

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@ -9,14 +9,14 @@ import (
func TestSniffWriter_WriteHTML(t *testing.T) {
rr := httptest.NewRecorder()
sw := NewContentTypeWriter(rr)
sw := NewContentTypeWriter(rr, "")
sw.Write([]byte("<script>alert('hi')</script>"))
require.Equal(t, "text/plain; charset=utf-8", rr.Header().Get("Content-Type"))
}
func TestSniffWriter_WriteTwoWriteCalls(t *testing.T) {
rr := httptest.NewRecorder()
sw := NewContentTypeWriter(rr)
sw := NewContentTypeWriter(rr, "")
sw.Write([]byte{0x25, 0x50, 0x44, 0x46, 0x2d, 0x11, 0x22, 0x33})
sw.Write([]byte("<script>alert('hi')</script>"))
require.Equal(t, "application/pdf", rr.Header().Get("Content-Type"))
@ -34,7 +34,7 @@ func TestSniffWriter_WriteHTMLSplitIntoTwoWrites(t *testing.T) {
// This test shows how splitting the HTML into two Write() calls will still yield text/plain
rr := httptest.NewRecorder()
sw := NewContentTypeWriter(rr)
sw := NewContentTypeWriter(rr, "")
sw.Write([]byte("<scr"))
sw.Write([]byte("ipt>alert('hi')</script>"))
require.Equal(t, "text/plain; charset=utf-8", rr.Header().Get("Content-Type"))
@ -42,9 +42,16 @@ func TestSniffWriter_WriteHTMLSplitIntoTwoWrites(t *testing.T) {
func TestSniffWriter_WriteUnknownMimeType(t *testing.T) {
rr := httptest.NewRecorder()
sw := NewContentTypeWriter(rr)
sw := NewContentTypeWriter(rr, "")
randomBytes := make([]byte, 199)
rand.Read(randomBytes)
sw.Write(randomBytes)
require.Equal(t, "application/octet-stream", rr.Header().Get("Content-Type"))
}
func TestSniffWriter_WriteWithFilenameAPK(t *testing.T) {
rr := httptest.NewRecorder()
sw := NewContentTypeWriter(rr, "https://example.com/ntfy.apk")
sw.Write([]byte{0x50, 0x4B, 0x03, 0x04})
require.Equal(t, "application/vnd.android.package-archive", rr.Header().Get("Content-Type"))
}

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@ -3,8 +3,8 @@ package util
import (
"errors"
"fmt"
"github.com/gabriel-vasile/mimetype"
"math/rand"
"mime"
"os"
"regexp"
"strconv"
@ -21,7 +21,6 @@ var (
random = rand.New(rand.NewSource(time.Now().UnixNano()))
randomMutex = sync.Mutex{}
sizeStrRegex = regexp.MustCompile(`(?i)^(\d+)([gmkb])?$`)
extRegex = regexp.MustCompile(`^\.[-_A-Za-z0-9]+$`)
errInvalidPriority = errors.New("invalid priority")
)
@ -168,20 +167,18 @@ func ShortTopicURL(s string) string {
return strings.TrimPrefix(strings.TrimPrefix(s, "https://"), "http://")
}
// ExtensionByType is a wrapper around mime.ExtensionByType with a few sensible corrections
func ExtensionByType(contentType string) string {
switch contentType {
case "image/jpeg":
return ".jpg"
case "video/mp4":
return ".mp4"
default:
exts, err := mime.ExtensionsByType(contentType)
if err == nil && len(exts) > 0 && extRegex.MatchString(exts[0]) {
return exts[0]
}
return ".bin"
// DetectContentType probes the byte array b and returns mime type and file extension.
// The filename is only used to override certain special cases.
func DetectContentType(b []byte, filename string) (mimeType string, ext string) {
if strings.HasSuffix(strings.ToLower(filename), ".apk") {
return "application/vnd.android.package-archive", ".apk"
}
m := mimetype.Detect(b)
mimeType, ext = m.String(), m.Extension()
if ext == "" {
ext = ".bin"
}
return
}
// ParseSize parses a size string like 2K or 2M into bytes. If no unit is found, e.g. 123, bytes is assumed.