mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-25 01:41:00 +00:00
[security] Implement allowFiles fs for better isolation of ffmpeg / ffprobe (#3251)
* [chore] Implement readOneFile fs * further isolation * remove fmt call * tweaks
This commit is contained in:
tobi
GitHub
parent
e10aa76612
commit
cd93a5baf3
2 changed files with 104 additions and 31 deletions
|
|
@ -21,6 +21,7 @@ import (
|
|||
"context"
|
||||
"encoding/json"
|
||||
"errors"
|
||||
"os"
|
||||
"path"
|
||||
"strconv"
|
||||
"strings"
|
||||
|
|
@ -39,10 +40,7 @@ import (
|
|||
// any metadata encoded into the media stream itself will not be cleared. This is the best we
|
||||
// can do without absolutely tanking performance by requiring transcodes :(
|
||||
func ffmpegClearMetadata(ctx context.Context, outpath, inpath string) error {
|
||||
// Get directory from filepath.
|
||||
dirpath := path.Dir(inpath)
|
||||
|
||||
return ffmpeg(ctx, dirpath,
|
||||
return ffmpeg(ctx, inpath, outpath,
|
||||
|
||||
// Only log errors.
|
||||
"-loglevel", "error",
|
||||
|
|
@ -66,18 +64,15 @@ func ffmpegClearMetadata(ctx context.Context, outpath, inpath string) error {
|
|||
}
|
||||
|
||||
// ffmpegGenerateWebpThumb generates a thumbnail webp from input media of any type, useful for any media.
|
||||
func ffmpegGenerateWebpThumb(ctx context.Context, filepath, outpath string, width, height int, pixfmt string) error {
|
||||
// Get directory from filepath.
|
||||
dirpath := path.Dir(filepath)
|
||||
|
||||
func ffmpegGenerateWebpThumb(ctx context.Context, inpath, outpath string, width, height int, pixfmt string) error {
|
||||
// Generate thumb with ffmpeg.
|
||||
return ffmpeg(ctx, dirpath,
|
||||
return ffmpeg(ctx, inpath, outpath,
|
||||
|
||||
// Only log errors.
|
||||
"-loglevel", "error",
|
||||
|
||||
// Input file.
|
||||
"-i", filepath,
|
||||
"-i", inpath,
|
||||
|
||||
// Encode using libwebp.
|
||||
// (NOT as libwebp_anim).
|
||||
|
|
@ -116,27 +111,24 @@ func ffmpegGenerateWebpThumb(ctx context.Context, filepath, outpath string, widt
|
|||
}
|
||||
|
||||
// ffmpegGenerateStatic generates a static png from input image of any type, useful for emoji.
|
||||
func ffmpegGenerateStatic(ctx context.Context, filepath string) (string, error) {
|
||||
func ffmpegGenerateStatic(ctx context.Context, inpath string) (string, error) {
|
||||
var outpath string
|
||||
|
||||
// Generate thumb output path REPLACING extension.
|
||||
if i := strings.IndexByte(filepath, '.'); i != -1 {
|
||||
outpath = filepath[:i] + "_static.png"
|
||||
if i := strings.IndexByte(inpath, '.'); i != -1 {
|
||||
outpath = inpath[:i] + "_static.png"
|
||||
} else {
|
||||
return "", gtserror.New("input file missing extension")
|
||||
}
|
||||
|
||||
// Get directory from filepath.
|
||||
dirpath := path.Dir(filepath)
|
||||
|
||||
// Generate static with ffmpeg.
|
||||
if err := ffmpeg(ctx, dirpath,
|
||||
if err := ffmpeg(ctx, inpath, outpath,
|
||||
|
||||
// Only log errors.
|
||||
"-loglevel", "error",
|
||||
|
||||
// Input file.
|
||||
"-i", filepath,
|
||||
"-i", inpath,
|
||||
|
||||
// Only first frame.
|
||||
"-frames:v", "1",
|
||||
|
|
@ -157,18 +149,45 @@ func ffmpegGenerateStatic(ctx context.Context, filepath string) (string, error)
|
|||
return outpath, nil
|
||||
}
|
||||
|
||||
// ffmpeg calls `ffmpeg [args...]` (WASM) with directory path mounted in runtime.
|
||||
func ffmpeg(ctx context.Context, dirpath string, args ...string) error {
|
||||
// ffmpeg calls `ffmpeg [args...]` (WASM) with in + out paths mounted in runtime.
|
||||
func ffmpeg(ctx context.Context, inpath string, outpath string, args ...string) error {
|
||||
var stderr byteutil.Buffer
|
||||
rc, err := _ffmpeg.Ffmpeg(ctx, _ffmpeg.Args{
|
||||
Stderr: &stderr,
|
||||
Args: args,
|
||||
Config: func(modcfg wazero.ModuleConfig) wazero.ModuleConfig {
|
||||
fscfg := wazero.NewFSConfig() // needs /dev/urandom
|
||||
fscfg = fscfg.WithReadOnlyDirMount("/dev", "/dev")
|
||||
fscfg = fscfg.WithDirMount(dirpath, dirpath)
|
||||
modcfg = modcfg.WithFSConfig(fscfg)
|
||||
return modcfg
|
||||
fscfg := wazero.NewFSConfig()
|
||||
|
||||
// Needs read-only access to
|
||||
// /dev/urandom for some types.
|
||||
urandom := &allowFiles{
|
||||
{
|
||||
abs: "/dev/urandom",
|
||||
flag: os.O_RDONLY,
|
||||
perm: 0,
|
||||
},
|
||||
}
|
||||
fscfg = fscfg.WithFSMount(urandom, "/dev")
|
||||
|
||||
// In+out dirs are always the same (tmp),
|
||||
// so we can share one file system for
|
||||
// both + grant different perms to inpath
|
||||
// (read only) and outpath (read+write).
|
||||
shared := &allowFiles{
|
||||
{
|
||||
abs: inpath,
|
||||
flag: os.O_RDONLY,
|
||||
perm: 0,
|
||||
},
|
||||
{
|
||||
abs: outpath,
|
||||
flag: os.O_RDWR | os.O_CREATE | os.O_TRUNC,
|
||||
perm: 0666,
|
||||
},
|
||||
}
|
||||
fscfg = fscfg.WithFSMount(shared, path.Dir(inpath))
|
||||
|
||||
return modcfg.WithFSConfig(fscfg)
|
||||
},
|
||||
})
|
||||
if err != nil {
|
||||
|
|
@ -183,9 +202,6 @@ func ffmpeg(ctx context.Context, dirpath string, args ...string) error {
|
|||
func ffprobe(ctx context.Context, filepath string) (*result, error) {
|
||||
var stdout byteutil.Buffer
|
||||
|
||||
// Get directory from filepath.
|
||||
dirpath := path.Dir(filepath)
|
||||
|
||||
// Run ffprobe on our given file at path.
|
||||
_, err := _ffmpeg.Ffprobe(ctx, _ffmpeg.Args{
|
||||
Stdout: &stdout,
|
||||
|
|
@ -222,9 +238,19 @@ func ffprobe(ctx context.Context, filepath string) (*result, error) {
|
|||
|
||||
Config: func(modcfg wazero.ModuleConfig) wazero.ModuleConfig {
|
||||
fscfg := wazero.NewFSConfig()
|
||||
fscfg = fscfg.WithReadOnlyDirMount(dirpath, dirpath)
|
||||
modcfg = modcfg.WithFSConfig(fscfg)
|
||||
return modcfg
|
||||
|
||||
// Needs read-only access
|
||||
// to file being probed.
|
||||
in := &allowFiles{
|
||||
{
|
||||
abs: filepath,
|
||||
flag: os.O_RDONLY,
|
||||
perm: 0,
|
||||
},
|
||||
}
|
||||
fscfg = fscfg.WithFSMount(in, path.Dir(filepath))
|
||||
|
||||
return modcfg.WithFSConfig(fscfg)
|
||||
},
|
||||
})
|
||||
if err != nil {
|
||||
|
|
|
|||
|
|
@ -22,13 +22,60 @@ import (
|
|||
"errors"
|
||||
"fmt"
|
||||
"io"
|
||||
"io/fs"
|
||||
"os"
|
||||
"path"
|
||||
|
||||
"codeberg.org/gruf/go-bytesize"
|
||||
"codeberg.org/gruf/go-iotools"
|
||||
"codeberg.org/gruf/go-mimetypes"
|
||||
)
|
||||
|
||||
// file represents one file
|
||||
// with the given flag and perms.
|
||||
type file struct {
|
||||
abs string
|
||||
flag int
|
||||
perm os.FileMode
|
||||
}
|
||||
|
||||
// allowFiles implements fs.FS to allow
|
||||
// access to a specified slice of files.
|
||||
type allowFiles []file
|
||||
|
||||
// Open implements fs.FS.
|
||||
func (af allowFiles) Open(name string) (fs.File, error) {
|
||||
for _, file := range af {
|
||||
var (
|
||||
abs = file.abs
|
||||
flag = file.flag
|
||||
perm = file.perm
|
||||
)
|
||||
|
||||
// Allowed to open file
|
||||
// at absolute path.
|
||||
if name == file.abs {
|
||||
return os.OpenFile(abs, flag, perm)
|
||||
}
|
||||
|
||||
// Check for other valid reads.
|
||||
thisDir, thisFile := path.Split(file.abs)
|
||||
|
||||
// Allowed to read directory itself.
|
||||
if name == thisDir || name == "." {
|
||||
return os.OpenFile(thisDir, flag, perm)
|
||||
}
|
||||
|
||||
// Allowed to read file
|
||||
// itself (at relative path).
|
||||
if name == thisFile {
|
||||
return os.OpenFile(abs, flag, perm)
|
||||
}
|
||||
}
|
||||
|
||||
return nil, os.ErrPermission
|
||||
}
|
||||
|
||||
// getExtension splits file extension from path.
|
||||
func getExtension(path string) string {
|
||||
for i := len(path) - 1; i >= 0 && path[i] != '/'; i-- {
|
||||
|
|
|
|||
Loading…
Reference in a new issue