add password related functions to luna.crypto module

1 files changed, 58 insertions, 2 deletions

diff --git a/main.go b/main.go
index 35ed343..7939ac9 100644
--- a/main.go
+++ b/main.go
@@ -2,8 +2,8 @@ package main
 
 import (
 	"bufio"
-	"database/sql"
 	"crypto/sha1"
+	"database/sql"
 	"encoding/hex"
 	"errors"
 	"flag"
@@ -13,18 +13,20 @@ import (
 	"image/png"
 	"io"
 	"log"
+	"math/rand"
 	"net/http"
 	"net/url"
 	"os"
-	"unicode/utf8"
 	"runtime"
 	"runtime/cgo"
 	"strings"
 	"sync"
 	"time"
+	"unicode/utf8"
 
 	_ "github.com/mattn/go-sqlite3"
 	"github.com/nfnt/resize"
+	"golang.org/x/crypto/bcrypt"
 )
 
 var debug bool
@@ -532,6 +534,60 @@ func main() {
 		io.WriteString(h, str)
 		return luaOk(l, hex.EncodeToString(h.Sum(nil)))
 	}
+	cryptoModule["password-hash"] = func (l *Lua) int {
+		var pass string
+		err := l.Scan(&pass)
+		if err != nil {
+			return luaErr(l, err)
+		}
+		saltbuf := make([]byte, 16)
+		rand.Read(saltbuf)
+		salt := hex.EncodeToString(saltbuf)
+		res, err := bcrypt.GenerateFromPassword([]byte(pass+salt), 5)
+		if err != nil {
+			return luaErr(l, err)
+		}
+		return luaOk(l, string(res)+salt)
+	}
+	cryptoModule["passwordHash"] = cryptoModule["password-hash"]
+	cryptoModule["check-password"] = func (l *Lua) int {
+		var pass, hash string
+		err := l.Scan(&pass, &hash)
+		if err != nil {
+			return luaErr(l, err)
+		}
+		hashbytes := []byte(hash)
+		if (len(hashbytes) < 32) {
+			return luaErr(l, errors.New("hash is too short"))
+		}
+		salt := hashbytes[len(hashbytes)-32:]
+		passbytes := []byte(pass+string(salt))
+		hashbytesWithoutSalt := hashbytes[:len(hashbytes)-32]
+		err = bcrypt.CompareHashAndPassword(hashbytesWithoutSalt, passbytes)
+		if err != nil && err != bcrypt.ErrMismatchedHashAndPassword {
+			return luaErr(l, err)
+		}
+		return luaOk(l, err == nil)
+	}
+	cryptoModule["checkPassword"] = cryptoModule["check-password"]
+	cryptoModule["random-string"] = func (l *Lua) int {
+		var length int
+		err := l.Scan(&length)
+		if err != nil {
+			return luaErr(l, err)
+		}
+		if length <= 0 {
+			return luaErr(l, errors.New("length must be positive"))
+		}
+		const charset = "abcdefghijklmnopqrstuvwxyz" +
+			"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+		result := make([]byte, length)
+		for i := 0; i < length; i++ {
+			result[i] = charset[rand.Intn(len(charset))]
+		}
+		return luaOk(l, string(result))
+	}
+	cryptoModule["randomString"] = cryptoModule["random-string"]
 
 	module := make(map[string]any)
 	module["router"] = routeModule