From 7a5f7e443a51455acb307e9212377d7cfaedefac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Henrique=20Guard=C3=A3o=20Gandarez?=
 <782854+gandarez@users.noreply.github.com>
Date: Sat, 21 Nov 2020 03:46:17 -0300
Subject: [PATCH] Make more libraries available (#1917)

* Make more libraries available to plugin dvelopment

* Add Unzip function to util
---
 cmd/micro/initlua.go    |  3 +++
 internal/lua/lua.go     | 26 +++++++++++++++++++
 internal/util/util.go   | 55 +++++++++++++++++++++++++++++++++++++++++
 runtime/help/plugins.md |  3 +++
 4 files changed, 87 insertions(+)

diff --git a/cmd/micro/initlua.go b/cmd/micro/initlua.go
index 9d90b482..2ed94c3d 100644
--- a/cmd/micro/initlua.go
+++ b/cmd/micro/initlua.go
@@ -144,6 +144,9 @@ func luaImportMicroUtil() *lua.LTable {
 	ulua.L.SetField(pkg, "GetLeadingWhitespace", luar.New(ulua.L, util.LuaGetLeadingWhitespace))
 	ulua.L.SetField(pkg, "IsWordChar", luar.New(ulua.L, util.LuaIsWordChar))
 	ulua.L.SetField(pkg, "String", luar.New(ulua.L, util.String))
+	ulua.L.SetField(pkg, "Unzip", luar.New(ulua.L, util.Unzip))
+	ulua.L.SetField(pkg, "Version", luar.New(ulua.L, util.Version))
+	ulua.L.SetField(pkg, "SemVersion", luar.New(ulua.L, util.SemVersion))
 	ulua.L.SetField(pkg, "CharacterCountInString", luar.New(ulua.L, util.CharacterCountInString))
 	ulua.L.SetField(pkg, "RuneStr", luar.New(ulua.L, func(r rune) string {
 		return string(r)
diff --git a/internal/lua/lua.go b/internal/lua/lua.go
index 9e502533..59ca6c45 100644
--- a/internal/lua/lua.go
+++ b/internal/lua/lua.go
@@ -1,6 +1,7 @@
 package lua
 
 import (
+	"archive/zip"
 	"bytes"
 	"errors"
 	"fmt"
@@ -9,6 +10,7 @@ import (
 	"math"
 	"math/rand"
 	"net"
+	"net/http"
 	"os"
 	"path"
 	"path/filepath"
@@ -74,6 +76,10 @@ func Import(pkg string) *lua.LTable {
 		return importUtf8()
 	case "humanize":
 		return importHumanize()
+	case "net/http", "http":
+		return importHTTP()
+	case "archive/zip":
+		return importArchiveZip()
 	default:
 		return nil
 	}
@@ -383,6 +389,7 @@ func importOs() *lua.LTable {
 	L.SetField(pkg, "Symlink", luar.New(L, os.Symlink))
 	L.SetField(pkg, "TempDir", luar.New(L, os.TempDir))
 	L.SetField(pkg, "Truncate", luar.New(L, os.Truncate))
+	L.SetField(pkg, "UserHomeDir", luar.New(L, os.UserHomeDir))
 
 	return pkg
 }
@@ -570,3 +577,22 @@ func importHumanize() *lua.LTable {
 
 	return pkg
 }
+
+func importHTTP() *lua.LTable {
+	pkg := L.NewTable()
+
+	L.SetField(pkg, "Get", luar.New(L, http.Get))
+	L.SetField(pkg, "Post", luar.New(L, http.Post))
+
+	return pkg
+}
+
+func importArchiveZip() *lua.LTable {
+	pkg := L.NewTable()
+
+	L.SetField(pkg, "OpenReader", luar.New(L, zip.OpenReader))
+	L.SetField(pkg, "NewReader", luar.New(L, zip.NewReader))
+	L.SetField(pkg, "NewWriter", luar.New(L, zip.NewWriter))
+
+	return pkg
+}
diff --git a/internal/util/util.go b/internal/util/util.go
index a40f9062..667b8565 100644
--- a/internal/util/util.go
+++ b/internal/util/util.go
@@ -1,9 +1,11 @@
 package util
 
 import (
+	"archive/zip"
 	"bytes"
 	"errors"
 	"fmt"
+	"io"
 	"os"
 	"os/user"
 	"path/filepath"
@@ -435,3 +437,56 @@ func ParseSpecial(s string) string {
 func String(s []byte) string {
 	return string(s)
 }
+
+// Unzip unzips a file to given folder
+func Unzip(src, dest string) error {
+	r, err := zip.OpenReader(src)
+	if err != nil {
+		return err
+	}
+	defer r.Close()
+
+	os.MkdirAll(dest, 0755)
+
+	// Closure to address file descriptors issue with all the deferred .Close() methods
+	extractAndWriteFile := func(f *zip.File) error {
+		rc, err := f.Open()
+		if err != nil {
+			return err
+		}
+		defer rc.Close()
+
+		path := filepath.Join(dest, f.Name)
+
+		// Check for ZipSlip (Directory traversal)
+		if !strings.HasPrefix(path, filepath.Clean(dest)+string(os.PathSeparator)) {
+			return fmt.Errorf("illegal file path: %s", path)
+		}
+
+		if f.FileInfo().IsDir() {
+			os.MkdirAll(path, f.Mode())
+		} else {
+			os.MkdirAll(filepath.Dir(path), f.Mode())
+			f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
+			if err != nil {
+				return err
+			}
+			defer f.Close()
+
+			_, err = io.Copy(f, rc)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+
+	for _, f := range r.File {
+		err := extractAndWriteFile(f)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/runtime/help/plugins.md b/runtime/help/plugins.md
index eff48d06..1818b96b 100644
--- a/runtime/help/plugins.md
+++ b/runtime/help/plugins.md
@@ -285,6 +285,7 @@ The packages and functions are listed below (in Go type signatures):
        string is a word character.
     - `String(b []byte) string`: converts a byte array to a string.
     - `RuneStr(r rune) string`: converts a rune to a string.
+    - `Unzip(src, dest string) error`: unzips a file to given folder.
 
 This may seem like a small list of available functions but some of the objects
 returned by the functions have many methods. The Lua plugin may access any
@@ -358,6 +359,8 @@ strings
 regexp
 errors
 time
+archive/zip
+net/http
 ```
 
 For documentation for each of these functions, see the Go standard