This commit is contained in:
Artur Gurgul 2025-04-24 20:53:37 +02:00 committed by Artur Gurgul
commit a0a338067b
16 changed files with 898 additions and 0 deletions

8
Makefile Normal file
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# /usr/share/webdav/templates
all:
go build -o webdav ./src
mkdir -p /srv/bin
mv webdav /srv/bin/
cp webdav.service /etc/systemd/system/
systemctl enable webdav
systemctl start webdav

7
go.mod Normal file
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module webdav
go 1.23.0
toolchain go1.23.1
require golang.org/x/net v0.37.0

2
go.sum Normal file
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golang.org/x/net v0.37.0 h1:1zLorHbz+LYj7MQlSf1+2tPIIgibq2eL5xkrGk6f+2c=
golang.org/x/net v0.37.0/go.mod h1:ivrbrMbzFq5J41QOQh0siUuly180yBYtLp+CKbEaFx8=

20
misc/default Normal file
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server {
listen 80 default_server;
listen [::]:80 default_server;
root /var/www/html;
server_name _;
location / {
proxy_pass http://unix:/run/webdav.sock:/;
proxy_http_version 1.1;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_pass_request_headers on;
client_max_body_size 2G;
}
}

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misc/webdav.service Normal file
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[Unit]
Description = WebDAV Server
After=network.target
[Service]
User = root
Group = root
Type = simple
ExecStart = /srv/bin/webdav
#Restart = on-abort
Restart=on-failure
RestartSec = 5
[Install]
WantedBy = multi-user.target

250
question.md Normal file
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Im having a problem with the WebDAV implementation I demonstrated below. The server works, but when it creates files, the content is empty.
Files:
```go: main.go
package main
import "C"
import (
"fmt"
"log"
"net/http"
"os"
"os/user"
"golang.org/x/net/webdav"
)
// WebDAV handler with authentication
func webdavHandler(w http.ResponseWriter, r *http.Request) {
username, password, ok := r.BasicAuth()
if !ok {
w.Header().Set("WWW-Authenticate", `Basic realm="WebDAV"`)
http.Error(w, "Unauthorized", http.StatusUnauthorized)
return
}
if !PAMAuthenticate(username, password) {
http.Error(w, "Forbidden", http.StatusForbidden)
return
}
// Get the user's home directory
userInfo, err := user.Lookup(username)
if err != nil {
http.Error(w, "User not found", http.StatusNotFound)
return
}
// webdavPath := userInfo.HomeDir + "/website"
webdavPath := userInfo.HomeDir
// Check if the directory exists
if _, err := os.Stat(webdavPath); os.IsNotExist(err) {
http.Error(w, "WebDAV directory not found", http.StatusNotFound)
return
}
/*
handler := &webdav.Handler{
Prefix: "/",
FileSystem: webdav.Dir(webdavPath),
LockSystem: webdav.NewMemLS(),
}
fmt.Println("new connection")
*/
uid, gid, err := GetUserData(username)
if err != nil {
http.Error(w, "WebDAV directory not found", http.StatusForbidden)
return
}
handler := &webdav.Handler{
Prefix: "/",
FileSystem: WebDavDir{Dir: webdav.Dir(webdavPath), UID: uid, GID: gid},
LockSystem: webdav.NewMemLS(),
}
fmt.Printf("New connection: %s\n", username)
handler.ServeHTTP(w, r)
}
func main() {
fmt.Println("WebDAV server running on :8800")
http.HandleFunc("/", webdavHandler)
// This binds to 127.0.0.1
log.Fatal(http.ListenAndServe(":8800", nil))
//log.Fatal(http.ListenAndServe("0.0.0.0:8800", nil))
}
```
```go: fs.go
package main
import (
"context"
"log"
"os"
"path/filepath"
"os/user"
"strconv"
"golang.org/x/net/webdav"
)
type WebDavFile struct {
webdav.File
FullPath string
}
type WebDavDir struct {
webdav.Dir
UID int
GID int
}
func GetUserData(username string) (int, int, error) {
userInfo, err := user.Lookup(username)
if err != nil {
log.Fatalf("User not found: %v", err)
}
uid, err := strconv.Atoi(userInfo.Uid)
if err != nil {
return 0, 0, err
}
gid, err := strconv.Atoi(userInfo.Gid)
if err != nil {
return 0, 0, err
}
return uid, gid, nil
}
func (fs WebDavDir) Mkdir(ctx context.Context, name string, perm os.FileMode) error {
err := fs.Dir.Mkdir(ctx, name, perm)
if err != nil {
return err
}
fullPath := filepath.Join(string(fs.Dir), name)
if chownErr := os.Chown(fullPath, fs.UID, fs.GID); chownErr != nil {
return chownErr
log.Printf("Mkdir chown error: %v", chownErr)
}
return nil
}
func (fs WebDavDir) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (webdav.File, error) {
fullPath := filepath.Join(string(fs.Dir), name)
log.Printf("OpenFile: %s, flag=%d, perm=%o", fullPath, flag, perm)
f, err := fs.Dir.OpenFile(ctx, name, flag, perm)
if err != nil {
log.Printf("File opening error: %v", err)
return nil, err
}
log.Printf("open file for: uid=%d, gid=%o", fs.UID, fs.GID)
if chownErr := os.Chown(fullPath, fs.UID, fs.GID); chownErr != nil {
log.Printf("File chown error: %v", chownErr)
}
return WebDavFile{
File: f,
FullPath: fullPath,
}, nil
}
func (f WebDavFile) Write(p []byte) (int, error) {
log.Printf("Writing %d bytes to %s", len(p), f.FullPath)
return f.File.Write(p)
}
```
```c: pam.c
#define _POSIX_C_SOURCE 200809L // Ensure strdup() is available
#include <security/pam_appl.h>
#include <stdlib.h>
#include <string.h>
// PAM Conversation Function
int pam_conv_func(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr) {
struct pam_response *responses = (struct pam_response *)malloc(num_msg * sizeof(struct pam_response));
if (!responses) return PAM_CONV_ERR;
char *password = (char *)appdata_ptr;
for (int i = 0; i < num_msg; i++) {
responses[i].resp_retcode = 0;
if (msg[i]->msg_style == PAM_PROMPT_ECHO_OFF) {
responses[i].resp = strdup(password);
} else {
responses[i].resp = NULL;
}
}
*resp = responses;
return PAM_SUCCESS;
}
// Function to authenticate user with PAM
int authenticate_pam(const char *username, const char *password) {
struct pam_conv conv = { pam_conv_func, (void *)password };
pam_handle_t *pamh = NULL;
int retval = pam_start("login", username, &conv, &pamh);
if (retval != PAM_SUCCESS) return retval;
retval = pam_authenticate(pamh, 0);
pam_end(pamh, retval);
return retval;
}
```
```go: pam.go
package main
/*
#cgo CFLAGS: -std=c11
#cgo LDFLAGS: -lpam
#include <stdlib.h>
#include <security/pam_appl.h>
extern int authenticate_pam(const char *username, const char *password);
// Define PAM_SUCCESS explicitly for cgo
static const int CGO_PAM_SUCCESS = PAM_SUCCESS;
*/
import "C"
import (
"unsafe"
)
// Authenticate using PAM (directly linked C function)
func PAMAuthenticate(username, password string) bool {
cUsername := C.CString(username)
cPassword := C.CString(password)
defer C.free(unsafe.Pointer(cUsername))
defer C.free(unsafe.Pointer(cPassword))
result := C.authenticate_pam(cUsername, cPassword)
return result == C.PAM_SUCCESS
//return result == C.CGO_PAM_SUCCESS
}
```

21
readme.md Normal file
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```bash
useradd -mg users -s /usr/bin/zsh test
passwd test
# make it accessible for to the Nginx
chmod 755 /home/test
chmod 755 /home/test/website
```
curl -u youruser:yourpass -T test.txt http://localhost:8800/test.txt
```
GOTOOLCHAIN=auto go mod vendor
GOTOOLCHAIN=auto go run .
```
apt install libpam0g-dev

93
src/file-manager.go Normal file
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package main
import (
"errors"
"fmt"
"io"
"net/http"
"html/template"
"os"
"encoding/json"
)
var templates = template.Must(template.ParseGlob("templates/*.html"))
// curl -H "Accept: application/json" http://localhost:9988/
func getRoot(w http.ResponseWriter, r *http.Request) {
fmt.Printf("got / request\n")
//io.WriteString(w, "This is my website!\n")
c := ListFiles("")
fmt.Println(c)
context := struct {
IsLoggedIn bool ; Files []struct {FileName string}}{
IsLoggedIn: false,
Files: c,
}
// Check if request wants JSON
if r.Header.Get("Accept") == "application/json" {
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(context)
return
}
//tmpl, _ := templates.ParseFiles("templates/venue.html")
templates.ExecuteTemplate(w, "index.html", context)
}
func ListFiles(dir string) []struct {FileName string} {
context := []struct {FileName string} {}
entries, err := os.ReadDir(".")
if err != nil {
fmt.Println("Error:", err)
return context
}
for _, entry := range entries {
info, err := entry.Info()
if err != nil {
fmt.Println("Error getting info:", err)
continue
}
context = append(context, struct {FileName string}{
FileName: info.Name(),
})
//fmt.Printf("Name: %s, Size: %d bytes, IsDir: %t\n", info.Name(), info.Size(), info.IsDir())
}
return context
}
func getHello(w http.ResponseWriter, r *http.Request) {
fmt.Printf("got /hello request\n")
io.WriteString(w, "Hello, HTTP!\n")
}
func GetMenusHandler(w http.ResponseWriter, r *http.Request) {
//fmt.Fprintf(w, "Hello, World!")
templates.ExecuteTemplate(w, "index.html", nil)
}
func HTTPmain() {
http.HandleFunc("/", getRoot)
http.HandleFunc("/hello", getHello)
err := http.ListenAndServe(":3333", nil)
if errors.Is(err, http.ErrServerClosed) {
fmt.Printf("server closed\n")
} else if err != nil {
fmt.Printf("error starting server: %s\n", err)
os.Exit(1)
}
}

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package main
import (
"context"
"log"
"os"
"path/filepath"
"os/user"
"strconv"
"golang.org/x/net/webdav"
)
var globalLockSystem = webdav.NewMemLS()
type WebDavFile struct {
//webdav.File
FullPath string
File *os.File
}
type WebDavDir struct {
webdav.Dir
UID int
GID int
}
func GetUserData(username string) (int, int, error) {
userInfo, err := user.Lookup(username)
if err != nil {
log.Fatalf("User not found: %v", err)
}
uid, err := strconv.Atoi(userInfo.Uid)
if err != nil {
return 0, 0, err
}
gid, err := strconv.Atoi(userInfo.Gid)
if err != nil {
return 0, 0, err
}
return uid, gid, nil
}
func (fs WebDavDir) Mkdir(ctx context.Context, name string, perm os.FileMode) error {
err := fs.Dir.Mkdir(ctx, name, perm)
if err != nil {
return err
}
fullPath := filepath.Join(string(fs.Dir), name)
if chownErr := os.Chown(fullPath, fs.UID, fs.GID); chownErr != nil {
log.Printf("Mkdir chown error: %v", chownErr)
return chownErr
}
return nil
}
func (fs WebDavDir) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (webdav.File, error) {
fullPath := filepath.Join(string(fs.Dir), name)
log.Printf("OpenFile: %s, flag=%d, perm=%o", fullPath, flag, perm)
//f, err := os.OpenFile(fullPath, os.O_WRONLY | os.O_CREATE | os.O_TRUNC, 0666)
f, err := os.OpenFile(fullPath, flag, perm)
if err != nil {
return nil, err
}
if chownErr := os.Chown(fullPath, fs.UID, fs.GID); chownErr != nil {
log.Printf("OpenFile chown error: %v", chownErr)
}
return &WebDavFile{
File: f,
FullPath: fullPath,
}, nil
}
func (f *WebDavFile) Read(p []byte) (int, error) { return f.File.Read(p) }
func (f *WebDavFile) Write(p []byte) (int, error) {
log.Printf("Writing %d bytes to %s", len(p), f.FullPath)
return f.File.Write(p)
}
func (f *WebDavFile) Seek(offset int64, whence int) (int64, error) { return f.File.Seek(offset, whence) }
func (f *WebDavFile) Close() error { return f.File.Close() }
func (f *WebDavFile) Readdir(count int) ([]os.FileInfo, error) { return f.File.Readdir(count) }
func (f *WebDavFile) Stat() (os.FileInfo, error) { return f.File.Stat() }
/*
func (fs WebDavDir) Mkdir(ctx context.Context, name string, perm os.FileMode) error {
err := fs.Dir.Mkdir(ctx, name, perm)
if err != nil {
return err
}
fullPath := filepath.Join(string(fs.Dir), name)
if chownErr := os.Chown(fullPath, fs.UID, fs.GID); chownErr != nil {
return chownErr
log.Printf("Mkdir chown error: %v", chownErr)
}
return nil
}
func (fs WebDavDir) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (webdav.File, error) {
fullPath := filepath.Join(string(fs.Dir), name)
log.Printf("OpenFile: %s, flag=%d, perm=%o", fullPath, flag, perm)
f, err := fs.Dir.OpenFile(ctx, name, flag, perm)
if err != nil {
log.Printf("File opening error: %v", err)
return nil, err
}
log.Printf("open file for: uid=%d, gid=%o", fs.UID, fs.GID)
if chownErr := os.Chown(fullPath, fs.UID, fs.GID); chownErr != nil {
log.Printf("File chown error: %v", chownErr)
}
return WebDavFile{
File: f,
FullPath: fullPath,
}, nil
}
func (f WebDavFile) Write(p []byte) (int, error) {
log.Printf("Writing %d bytes to %s", len(p), f.FullPath)
return f.File.Write(p)
}*/

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package main
import "C"
import (
"fmt"
"log"
"time"
"net/http"
"os"
"os/user"
"strconv"
"runtime"
"strings"
"golang.org/x/net/webdav"
)
// WebDAV handler with authentication
func webdavHandler(w http.ResponseWriter, r *http.Request) {
if runtime.GOOS != "linux" {
handler := &webdav.Handler{
FileSystem: webdav.Dir("."),
LockSystem: webdav.NewMemLS(),
}
handler.ServeHTTP(w, r)
return
}
username, password, ok := r.BasicAuth()
if !ok {
w.Header().Set("WWW-Authenticate", `Basic realm="WebDAV"`)
http.Error(w, "Unauthorized", http.StatusUnauthorized)
return
}
start := time.Now()
if !PAMAuthenticate(username, password) {
http.Error(w, "Forbidden", http.StatusForbidden)
return
}
elapsed := time.Since(start)
fmt.Printf("PAM checking time: %dms\n", elapsed.Milliseconds())
// start = time.Now()
// isValid, _ := checkPassword("user", "pass")
// elapsed = time.Since(start)
// fmt.Printf("Direct checking time: %dms\n %d", elapsed.Milliseconds(), isValid)
// start = time.Now()
// isValid, _ = checkPassword("user", "pass1")
// elapsed = time.Since(start)
// fmt.Printf("Direct checking time: %dms\n %d", elapsed.Milliseconds(), isValid)
// Get the user's home directory
userInfo, err := user.Lookup(username)
if err != nil {
http.Error(w, "User not found", http.StatusNotFound)
return
}
// webdavPath := userInfo.HomeDir + "/website"
webdavPath := userInfo.HomeDir
// Check if the directory exists
if _, err := os.Stat(webdavPath); os.IsNotExist(err) {
http.Error(w, "WebDAV directory not found", http.StatusNotFound)
return
}
/*
handler := &webdav.Handler{
Prefix: "/",
FileSystem: webdav.Dir(webdavPath),
LockSystem: webdav.NewMemLS(),
}
fmt.Println("new connection")
*/
uid, gid, err := GetUserData(username)
if err != nil {
http.Error(w, "WebDAV directory not found", http.StatusForbidden)
return
}
/*
handler := &webdav.Handler{
Prefix: "/",
FileSystem: WebDavDir{Dir: webdav.Dir(webdavPath), UID: uid, GID: gid},
LockSystem: webdav.NewMemLS(),
}
*/
handler := &webdav.Handler{
Prefix: "/",
FileSystem: WebDavDir{Dir: webdav.Dir(webdavPath), UID: uid, GID: gid},
//LockSystem: webdav.NewMemLS(),
//LockSystem: nil, // disable locking
LockSystem: globalLockSystem,
Logger: func(r *http.Request, err error) {
log.Printf("%s %s, error: %v", r.Method, r.URL.Path, err)
},
}
fmt.Printf("New connection: %s\n", username)
handler.ServeHTTP(w, r)
}
// TODO: this method might not work corractly with gnome or other clients
func isWebDAVRequest(r *http.Request) bool {
switch r.Method {
case "PROPFIND", "PROPPATCH", "MKCOL", "COPY", "MOVE", "LOCK", "UNLOCK":
return true
}
// Finder sends GET/OPTIONS with Depth header when doing WebDAV
if r.Header.Get("Depth") != "" {
return true
}
// Optional: check User-Agent or other headers if needed
ua := r.UserAgent()
if strings.Contains(ua, "WebDAV") || strings.Contains(ua, "Microsoft-WebDAV") {
return true
}
return false
}
func main() {
// http.HandleFunc("/", webdavHandler)
// http.HandleFunc("/", getRoot)
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
if isWebDAVRequest(r) {
webdavHandler(w, r)
} else {
getRoot(w, r)
}
})
// This binds to 127.0.0.1 prevents for accessing the app from the outside
//log.Fatal(http.ListenAndServe(":8800", nil))
//
envValue := os.Getenv("WEBDAV_SERV_PORT")
if port, err := strconv.ParseInt(envValue, 10, 64); err == nil {
fmt.Printf("WebDAV server running on :%d\n", port)
log.Fatal(http.ListenAndServe(fmt.Sprintf("0.0.0.0:%d", port), nil))
} else {
fmt.Println("WebDAV server running socket")
startUnixSocket()
}
}

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// +build linux
// it works with file ending file_linux.go (and c probably as well)
#define _POSIX_C_SOURCE 200809L // Ensure strdup() is available
#include <security/pam_appl.h>
#include <stdlib.h>
#include <string.h>
// PAM Conversation Function
int pam_conv_func(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr) {
struct pam_response *responses = (struct pam_response *)malloc(num_msg * sizeof(struct pam_response));
if (!responses) return PAM_CONV_ERR;
char *password = (char *)appdata_ptr;
for (int i = 0; i < num_msg; i++) {
responses[i].resp_retcode = 0;
if (msg[i]->msg_style == PAM_PROMPT_ECHO_OFF) {
responses[i].resp = strdup(password);
} else {
responses[i].resp = NULL;
}
}
*resp = responses;
return PAM_SUCCESS;
}
// Function to authenticate user with PAM
int authenticate_pam(const char *username, const char *password) {
struct pam_conv conv = { pam_conv_func, (void *)password };
pam_handle_t *pamh = NULL;
int retval = pam_start("login", username, &conv, &pamh);
if (retval != PAM_SUCCESS) return retval;
retval = pam_authenticate(pamh, 0);
pam_end(pamh, retval);
return retval;
}

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// +build linux
package main
/*
#cgo CFLAGS: -std=c11
#cgo LDFLAGS: -lpam
#include <stdlib.h>
#include <security/pam_appl.h>
extern int authenticate_pam(const char *username, const char *password);
// Define PAM_SUCCESS explicitly for cgo
static const int CGO_PAM_SUCCESS = PAM_SUCCESS;
*/
import "C"
import (
"unsafe"
)
// Authenticate using PAM (directly linked C function)
func PAMAuthenticate(username, password string) bool {
cUsername := C.CString(username)
cPassword := C.CString(password)
defer C.free(unsafe.Pointer(cUsername))
defer C.free(unsafe.Pointer(cPassword))
result := C.authenticate_pam(cUsername, cPassword)
return result == C.PAM_SUCCESS
//return result == C.CGO_PAM_SUCCESS
}

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package main
// https://www.youtube.com/watch?v=mIfzwTfXnWI
func PAMAuthenticate(username, password string) bool {
return true
}

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// +build linux
package main
/*
#cgo LDFLAGS: -lcrypt
#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <crypt.h>
#include <shadow.h>
#include <errno.h>
#include <stdlib.h>
int check_password(const char* username, const char* password) {
struct spwd *shadow_entry = getspnam(username);
if (!shadow_entry) {
return -1; // User not found or error
}
const char *shadow_hash = shadow_entry->sp_pwdp;
if (!shadow_hash) {
return -2;
}
char *calculated_hash = crypt(password, shadow_hash);
if (!calculated_hash) {
return -3; // Error in crypt
}
return strcmp(shadow_hash, calculated_hash) == 0;
}
*/
import "C"
import (
"fmt"
//"os"
"unsafe"
)
func checkPassword(username, password string) (bool, error) {
cUsername := C.CString(username)
cPassword := C.CString(password)
defer C.free(unsafe.Pointer(cUsername))
defer C.free(unsafe.Pointer(cPassword))
result := C.check_password(cUsername, cPassword)
switch result {
case 1: return true, nil
case 0: return false, nil
default: return false, fmt.Errorf("Auth Error")
}
}

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package main
import (
"fmt"
"net"
"log"
"net/http"
"os"
)
func startUnixSocket() {
socketPath := "/run/webdav.sock"
// Remove the socket if it exists
if err := os.RemoveAll(socketPath); err != nil {
log.Fatalf("Failed to remove old socket: %v", err)
}
listener, err := net.Listen("unix", socketPath)
if err != nil {
log.Fatalf("Failed to listen on socket: %v", err)
}
// Make socket accessible to Nginx
if err := os.Chmod(socketPath, 0666); err != nil {
log.Fatalf("Failed to chmod socket: %v", err)
}
fmt.Printf("WebDAV server listening on %s\n", socketPath)
log.Fatal(http.Serve(listener, nil))
}

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<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>File List</title>
</head>
<body>
{{if .IsLoggedIn}}
<p>Welcome back!</p>
{{else}}
<p>Please log in to access more features.</p>
{{end}}
<h2>Files</h2>
{{if .Files}}
<ul>
{{range .Files}}
<li>{{.FileName}}</li>
{{end}}
</ul>
{{else}}
<p>No files available.</p>
{{end}}
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