1 files changed, 262 insertions, 0 deletions
diff --git a/mpaste.go b/mpaste.go
new file mode 100644
index 0000000..eec6a20
--- /dev/null
+++ b/mpaste.go
@@ -0,0 +1,262 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/Mango0x45/getgopt"
+	"github.com/alecthomas/chroma/formatters/html"
+	"github.com/alecthomas/chroma/lexers"
+	"github.com/alecthomas/chroma/styles"
+	"github.com/dgrijalva/jwt-go"
+)
+
+const (
+	URL_HOMEPAGE = iota
+	URL_INVALID
+	URL_SYNTAX
+	URL_VALID
+)
+
+var (
+	counter      int
+	counter_file string
+	domain       string
+	file_prefix  string
+	index_file   string
+	mutex        sync.Mutex
+	secret_key   = os.Getenv("MPASTE_SECRET")
+	user_file    string
+)
+
+var (
+	style     = styles.Get("pygments")
+	formatter = html.New(html.Standalone(true), html.WithClasses(true),
+		html.WithLineNumbers(true), html.LineNumbersInTable(true))
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr,
+		"Usage: %s [-c file] [-f directory] [-i file] [-u file] domain port\n",
+		os.Args[0])
+	os.Exit(1)
+}
+
+func error_and_die(e interface{}) {
+	fmt.Fprintln(os.Stderr, e)
+	os.Exit(1)
+}
+
+func remove_ext(s string) string {
+	return strings.TrimSuffix(s, path.Ext(s))
+}
+
+func allowed_user(name string) bool {
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	if _, err := os.Stat(user_file); os.IsNotExist(err) {
+		return false
+	}
+
+	file, err := os.Open(user_file)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return false
+	}
+
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	scanner.Split(bufio.ScanLines)
+
+	for scanner.Scan() {
+		if scanner.Text() == name {
+			return true
+		}
+	}
+
+	return false
+}
+
+func validate_token(r *http.Request) bool {
+	token, _ := jwt.Parse(r.Header.Get("Authorization"), func(t *jwt.Token) (interface{}, error) {
+		if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("Something went wrong\n")
+		}
+		return []byte(secret_key), nil
+	})
+
+	if token == nil {
+		return false
+	}
+
+	claims, ok := token.Claims.(jwt.MapClaims)
+
+	if !(ok && token.Valid) {
+		return false
+	}
+
+	if user_file == "" {
+		return true
+	}
+
+	return allowed_user(claims["name"].(string))
+}
+
+func is_valid_url(s string) int {
+	var i int
+	var c rune
+	for i, c = range s {
+		if c == '.' && i > 0 {
+			return URL_SYNTAX
+		} else if c < '0' || c > '9' {
+			return URL_INVALID
+		}
+	}
+
+	if c != 0 {
+		return URL_VALID
+	}
+	return URL_HOMEPAGE
+}
+
+func syntax_highlighting(w http.ResponseWriter, r *http.Request) {
+	lexer := lexers.Match(r.URL.Path[1:])
+	if lexer == nil {
+		http.ServeFile(w, r, file_prefix+r.URL.Path[1:])
+		return
+	}
+
+	data, err := ioutil.ReadFile(file_prefix + remove_ext(r.URL.Path[1:]))
+	if err != nil {
+		WRITE_HEADER(http.StatusNotFound, "404 page not found")
+	}
+
+	iterator, err := lexer.Tokenise(nil, string(data))
+	if err != nil {
+		WRITE_HEADER(http.StatusInternalServerError, "Failed to tokenize output")
+	}
+
+	if err := formatter.Format(w, style, iterator); err != nil {
+		WRITE_HEADER(http.StatusInternalServerError, "Failed to format output")
+	}
+}
+
+func endpoint(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case http.MethodGet:
+		switch is_valid_url(r.URL.Path[1:]) {
+		case URL_HOMEPAGE:
+			http.ServeFile(w, r, index_file)
+		case URL_INVALID:
+			WRITE_HEADER(http.StatusNotFound, "404 page not found")
+		case URL_SYNTAX:
+			w.Header().Set("Content-Type", "text/html")
+			syntax_highlighting(w, r)
+		case URL_VALID:
+			w.Header().Set("Content-Type", "text/plain")
+			http.ServeFile(w, r, file_prefix+r.URL.Path[1:])
+		}
+	case http.MethodPost:
+		if secret_key != "" && !validate_token(r) {
+			WRITE_HEADER(http.StatusForbidden, "Invalid API key")
+		}
+
+		file, _, err := r.FormFile("data")
+		defer file.Close()
+		if err != nil {
+			WRITE_HEADER(http.StatusInternalServerError, "Failed to parse form")
+		}
+
+		mutex.Lock()
+
+		fname := file_prefix + strconv.Itoa(counter)
+		nfile, err := os.Create(fname)
+		defer nfile.Close()
+		if err != nil {
+			WRITE_HEADER(http.StatusInternalServerError, "Failed to create file")
+		}
+
+		if _, err = io.Copy(nfile, file); err != nil {
+			WRITE_HEADER(http.StatusInternalServerError, "Failed to write file")
+		}
+
+		if err = os.WriteFile(counter_file, []byte(strconv.Itoa(counter+1)), 0644); err != nil {
+			WRITE_HEADER(http.StatusInternalServerError, "Failed to update counter")
+		}
+
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprintf(w, domain+"/%d\n", counter)
+
+		counter++
+		mutex.Unlock()
+	default:
+		WRITE_HEADER(http.StatusMethodNotAllowed, "Only GET and POST requests are supported")
+	}
+}
+
+func main() {
+	for opt := byte(0); getgopt.Getopt(len(os.Args), os.Args, ":c:f:i:u:", &opt); {
+		switch opt {
+		case 'c':
+			counter_file = getgopt.Optarg
+		case 'f':
+			file_prefix = getgopt.Optarg
+		case 'i':
+			index_file = getgopt.Optarg
+		case 'u':
+			user_file = getgopt.Optarg
+		default:
+			usage()
+		}
+	}
+
+	argv := os.Args[getgopt.Optind:]
+	if len(argv) != 2 {
+		usage()
+	}
+	domain = argv[0]
+	port := argv[1]
+
+	if file_prefix == "" {
+		file_prefix = "files/"
+	} else if file_prefix[len(file_prefix)-1] != '/' {
+		file_prefix += "/"
+	}
+
+	if index_file == "" {
+		index_file = "index.html"
+	}
+
+	if _, err := os.Stat(index_file); os.IsNotExist(err) {
+		error_and_die(err)
+	}
+
+	if _, err := os.Stat(file_prefix); os.IsNotExist(err) {
+		if err = os.MkdirAll(file_prefix, 0755); err != nil {
+			error_and_die(err)
+		}
+	}
+
+	if _, err := os.Stat(counter_file); os.IsNotExist(err) {
+		counter = 0
+	} else {
+		data, err := ioutil.ReadFile(counter_file)
+		if err != nil {
+			error_and_die(err)
+		}
+		counter, _ = strconv.Atoi(string(data))
+	}
+
+	http.HandleFunc("/", endpoint)
+	error_and_die(http.ListenAndServe(":"+port, nil))
+}