nat/pastebin.go

396 lines
10 KiB
Go

// Package pastebin is a simple modern and powerful pastebin service
package pastebin
import (
"crypto/sha1"
"database/sql"
"encoding/base64"
"encoding/json"
"encoding/xml"
"fmt"
"html"
"html/template"
"io"
"io/ioutil"
"log"
"net/http"
"time"
duration "github.com/channelmeter/iso8601duration"
// uniuri is used for easy random string generation
"github.com/dchest/uniuri"
// pygments is used for syntax highlighting
"github.com/ewhal/pygments"
// mysql driver
_ "github.com/go-sql-driver/mysql"
// mux is used for url routing
"github.com/gorilla/mux"
)
const (
// ADDRESS that pastebin will return links for
ADDRESS = "http://localhost:9900"
// LENGTH of paste id
LENGTH = 6
// PORT that pastebin will listen on
PORT = ":9900"
// USERNAME for database
USERNAME = ""
// PASS database password
PASS = ""
// NAME database name
NAME = ""
// DATABASE connection String
DATABASE = USERNAME + ":" + PASS + "@/" + NAME + "?charset=utf8"
)
// Template pages
var templates = template.Must(template.ParseFiles("assets/paste.html", "assets/index.html", "assets/clone.html"))
var syntax, _ = ioutil.ReadFile("assets/syntax.html")
// Response API struct
type Response struct {
ID string `json:"id"`
TITLE string `json:"title"`
HASH string `json:"hash"`
URL string `json:"url"`
SIZE int `json:"size"`
DELKEY string `json:"delkey"`
}
// Page generation struct
type Page struct {
Title string
Body []byte
Raw string
Home string
Download string
Clone string
}
// check error handling function
func Check(err error) {
if err != nil {
log.Println(err)
}
}
// GenerateName uses uniuri to generate a random string that isn't in the
// database
func GenerateName() string {
// use uniuri to generate random string
id := uniuri.NewLen(LENGTH)
db, err := sql.Open("mysql", DATABASE)
Check(err)
defer db.Close()
// query database if id exists and if it does call generateName again
query, err := db.Query("select id from pastebin where id=?", id)
if err != sql.ErrNoRows {
for query.Next() {
GenerateName()
}
}
return id
}
// Sha1 hashes paste into a sha1 hash
func Sha1(paste string) string {
hasher := sha1.New()
hasher.Write([]byte(paste))
sha := base64.URLEncoding.EncodeToString(hasher.Sum(nil))
return sha
}
// DurationFromExpiry takes the expiry in string format and returns the duration
// that the paste will exist for
func DurationFromExpiry(expiry string) time.Duration {
dura, err := duration.FromString(expiry) // dura is time.Duration type
Check(err)
duration := dura.ToDuration()
return duration
}
// Save function handles the saving of each paste.
// raw string is the raw paste input
// lang string is the user specified language for syntax highlighting
// title string user customized title
// expiry string duration that the paste will exist for
// Returns Response struct
func Save(raw string, lang string, title string, expiry string) Response {
db, err := sql.Open("mysql", DATABASE)
Check(err)
defer db.Close()
// hash paste data and query database to see if paste exists
sha := Sha1(raw)
query, err := db.Query("select id, title, hash, data, delkey from pastebin where hash=?", sha)
if err != sql.ErrNoRows {
for query.Next() {
var id, title, hash, paste, delkey string
err := query.Scan(&id, &title, &hash, &paste, &delkey)
Check(err)
url := ADDRESS + "/p/" + id
return Response{id, title, hash, url, len(paste), delkey}
}
}
id := GenerateName()
url := ADDRESS + "/p/" + id
if lang != "" {
url += "/" + lang
}
const timeFormat = "2006-01-02 15:04:05"
expiryTime := time.Now().Add(DurationFromExpiry(expiry)).Format(timeFormat)
delKey := uniuri.NewLen(40)
dataEscaped := html.EscapeString(raw)
stmt, err := db.Prepare("INSERT INTO pastebin(id, title, hash, data, delkey, expiry) values(?,?,?,?,?,?)")
Check(err)
if title == "" {
title = id
}
_, err = stmt.Exec(id, html.EscapeString(title), sha, dataEscaped, delKey, expiryTime)
Check(err)
return Response{id, title, sha, url, len(dataEscaped), delKey}
}
// DelHandler checks to see if delkey and pasteid exist in the database.
// if both exist and are correct the paste will be removed.
func DelHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
id := vars["pasteId"]
delkey := vars["delKey"]
db, err := sql.Open("mysql", DATABASE)
Check(err)
defer db.Close()
stmt, err := db.Prepare("delete from pastebin where delkey=? and id=?")
Check(err)
res, err := stmt.Exec(html.EscapeString(delkey), html.EscapeString(id))
Check(err)
_, err = res.RowsAffected()
if err != sql.ErrNoRows {
io.WriteString(w, id+" deleted")
}
}
// SaveHandler Handles saving pastes and outputing responses
func SaveHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
output := vars["output"]
switch r.Method {
case "POST":
paste := r.FormValue("p")
lang := r.FormValue("lang")
title := r.FormValue("title")
expiry := r.FormValue("expiry")
if paste == "" {
http.Error(w, "Empty paste", 500)
return
}
b := Save(paste, lang, title, expiry)
switch output {
case "json":
w.Header().Set("Content-Type", "application/json")
err := json.NewEncoder(w).Encode(b)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
case "xml":
x, err := xml.MarshalIndent(b, "", " ")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/xml")
w.Write(x)
case "html":
w.Header().Set("Content-Type", "text/html")
io.WriteString(w, "<p><b>URL</b>: <a href='"+b.URL+"'>"+b.URL+"</a></p>")
io.WriteString(w, "<p><b>Delete Key</b>: <a href='"+ADDRESS+"/del/"+b.ID+"/"+b.DELKEY+"'>"+b.DELKEY+"</a></p>")
case "redirect":
http.Redirect(w, r, b.URL, 301)
default:
w.Header().Set("Content-Type", "text/plain; charset=UTF-8; imeanit=yes")
io.WriteString(w, b.URL+"\n")
io.WriteString(w, "delete key: "+b.DELKEY+"\n")
}
}
}
// Highlight uses user specified input to call pygments library to highlight the
// paste
func Highlight(s string, lang string) (string, error) {
highlight, err := pygments.Highlight(html.UnescapeString(s), html.EscapeString(lang), "html", "style=autumn,linenos=True, lineanchors=True,anchorlinenos=True,noclasses=True,", "utf-8")
if err != nil {
return "", err
}
return highlight, nil
}
// GetPaste takes pasteid and language
// queries the database and returns paste data
func GetPaste(paste string, lang string) (string, string) {
param1 := html.EscapeString(paste)
db, err := sql.Open("mysql", DATABASE)
Check(err)
defer db.Close()
var title, s string
var expiry string
err = db.QueryRow("select title, data, expiry from pastebin where id=?", param1).Scan(&title, &s, &expiry)
Check(err)
if time.Now().Format("2006-01-02 15:04:05") > expiry {
stmt, err := db.Prepare("delete from pastebin where id=?")
Check(err)
_, err = stmt.Exec(param1)
Check(err)
return "Error invalid paste", ""
}
if err == sql.ErrNoRows {
return "Error invalid paste", ""
}
if lang != "" {
high, err := Highlight(s, lang)
Check(err)
return high, html.UnescapeString(title)
}
return html.UnescapeString(s), html.UnescapeString(title)
}
// PasteHandler handles the generation of paste pages with the links
func PasteHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
paste := vars["pasteId"]
lang := vars["lang"]
s, title := GetPaste(paste, lang)
// button links
link := ADDRESS + "/raw/" + paste
download := ADDRESS + "/download/" + paste
clone := ADDRESS + "/clone/" + paste
// Page struct
p := &Page{
Title: title,
Body: []byte(s),
Raw: link,
Home: ADDRESS,
Download: download,
Clone: clone,
}
if lang == "" {
err := templates.ExecuteTemplate(w, "paste.html", p)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
} else {
fmt.Fprintf(w, string(syntax), p.Title, p.Title, s, p.Home, p.Download, p.Raw, p.Clone)
}
}
// CloneHandler handles generating the clone pages
func CloneHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
paste := vars["pasteId"]
s, title := GetPaste(paste, "")
// Page links
link := ADDRESS + "/raw/" + paste
download := ADDRESS + "/download/" + paste
clone := ADDRESS + "/clone/" + paste
// Clone page struct
p := &Page{
Title: title,
Body: []byte(s),
Raw: link,
Home: ADDRESS,
Download: download,
Clone: clone,
}
err := templates.ExecuteTemplate(w, "clone.html", p)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
// DownloadHandler forces downloads of selected pastes
func DownloadHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
paste := vars["pasteId"]
s, _ := GetPaste(paste, "")
// Set header to an attachment so browser will automatically download it
w.Header().Set("Content-Disposition", "attachment; filename="+paste)
w.Header().Set("Content-Type", r.Header.Get("Content-Type"))
io.WriteString(w, s)
}
// RawHandler displays the pastes in text/plain format
func RawHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
paste := vars["pasteId"]
s, _ := GetPaste(paste, "")
w.Header().Set("Content-Type", "text/plain; charset=UTF-8; imeanit=yes")
// simply write string to browser
io.WriteString(w, s)
}
// RootHandler handles generating the root page
func RootHandler(w http.ResponseWriter, r *http.Request) {
err := templates.ExecuteTemplate(w, "index.html", &Page{})
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
func main() {
router := mux.NewRouter()
router.HandleFunc("/p/{pasteId}", PasteHandler).Methods("GET")
router.HandleFunc("/raw/{pasteId}", RawHandler).Methods("GET")
router.HandleFunc("/p/{pasteId}/{lang}", PasteHandler).Methods("GET")
router.HandleFunc("/clone/{pasteId}", CloneHandler).Methods("GET")
router.HandleFunc("/download/{pasteId}", DownloadHandler).Methods("GET")
router.HandleFunc("/p", SaveHandler).Methods("POST")
router.HandleFunc("/p/{output}", SaveHandler).Methods("POST")
router.HandleFunc("/p/{pasteId}/{delKey}", DelHandler).Methods("DELETE")
router.HandleFunc("/", RootHandler)
err := http.ListenAndServe(PORT, router)
if err != nil {
log.Fatal(err)
}
}