🐛 Fix: EnvVar middleware parses base64 incorrectly (#2069)

* Fix: EnvVar middleware parses base64 incorrectly

* Chore: fix typo in README.md

* Chore: standardize and simplify response

middleware/envvar/README.md

@@ -44,10 +44,12 @@ app.Use("/expose/envvars", envvar.New())
 ### Custom Config
 
 ```go
-app.Use("/expose/envvars", envvar.New(envvar.Config{
-    ExportVars:  map[string]string{"testKey": "", "testDefaultKey": "testDefaultVal"},
-    ExcludeVars: map[string]string{"excludeKey": ""}}
-}))
+app.Use("/expose/envvars", envvar.New(
+	envvar.Config{
+		ExportVars:  map[string]string{"testKey": "", "testDefaultKey": "testDefaultVal"},
+		ExcludeVars: map[string]string{"excludeKey": ""},
+	}),
+)
 ```
 
 ### Response
@@ -57,23 +59,21 @@ Http response contract:
 {
   "vars": {
     "someEnvVariable": "someValue",
-    "anotherEnvVariable": "anotherValue",
+    "anotherEnvVariable": "anotherValue"
   }
 }
-
 ```
 
 ## Config
 
 ```go
 // Config defines the config for middleware.
 type Config struct {
-    // ExportVars specifies the environment variables that should export
-    ExportVars map[string]string
-    // ExcludeVars specifies the environment variables that should not export
-    ExcludeVars map[string]string
+	// ExportVars specifies the environment variables that should export
+	ExportVars map[string]string
+	// ExcludeVars specifies the environment variables that should not export
+	ExcludeVars map[string]string
 }
-
 ```
 
 ## Default Config

middleware/envvar/envvar.go

@@ -1,10 +1,10 @@
 package envvar
 
 import (
-	"github.com/gofiber/fiber/v2"
-	"github.com/gofiber/fiber/v2/utils"
 	"os"
 	"strings"
+
+	"github.com/gofiber/fiber/v2"
 )
 
 // Config defines the config for middleware.
@@ -39,14 +39,10 @@ func New(config ...Config) fiber.Handler {
 		envVar := newEnvVar(cfg)
 		varsByte, err := c.App().Config().JSONEncoder(envVar)
 		if err != nil {
-			c.Response().SetBodyRaw(utils.UnsafeBytes(err.Error()))
-			c.Response().SetStatusCode(fiber.StatusInternalServerError)
-			return nil
+			return c.Status(fiber.StatusInternalServerError).SendString(err.Error())
 		}
-		c.Response().SetBodyRaw(varsByte)
-		c.Response().SetStatusCode(fiber.StatusOK)
-		c.Response().Header.Set("Content-Type", "application/json; charset=utf-8")
-		return nil
+		c.Set(fiber.HeaderContentType, fiber.MIMEApplicationJSONCharsetUTF8)
+		return c.Send(varsByte)
 	}
 }
 
@@ -62,7 +58,7 @@ func newEnvVar(cfg Config) *EnvVar {
 		}
 	} else {
 		for _, envVal := range os.Environ() {
-			keyVal := strings.Split(envVal, "=")
+			keyVal := strings.SplitN(envVal, "=", 2)
 			if _, exists := cfg.ExcludeVars[keyVal[0]]; !exists {
 				vars.set(keyVal[0], keyVal[1])
 			}

middleware/envvar/envvar_test.go

@@ -2,12 +2,13 @@ package envvar
 
 import (
 	"encoding/json"
-	"github.com/gofiber/fiber/v2"
-	"github.com/gofiber/fiber/v2/utils"
 	"io/ioutil"
 	"net/http"
 	"os"
 	"testing"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/utils"
 )
 
 func TestEnvVarStructWithExportVarsExcludeVars(t *testing.T) {
@@ -102,3 +103,38 @@ func TestEnvVarHandlerMethod(t *testing.T) {
 	utils.AssertEqual(t, nil, err)
 	utils.AssertEqual(t, fiber.StatusMethodNotAllowed, resp.StatusCode)
 }
+
+func TestEnvVarHandlerSpecialValue(t *testing.T) {
+	testEnvKey := "testEnvKey"
+	fakeBase64 := "testBase64:TQ=="
+	os.Setenv(testEnvKey, fakeBase64)
+	defer os.Unsetenv(testEnvKey)
+
+	app := fiber.New()
+	app.Use("/envvars", New())
+	app.Use("/envvars/export", New(Config{ExportVars: map[string]string{testEnvKey: ""}}))
+
+	req, _ := http.NewRequest("GET", "http://localhost/envvars", nil)
+	resp, err := app.Test(req)
+	utils.AssertEqual(t, nil, err)
+
+	respBody, err := ioutil.ReadAll(resp.Body)
+	utils.AssertEqual(t, nil, err)
+
+	var envVars EnvVar
+	utils.AssertEqual(t, nil, json.Unmarshal(respBody, &envVars))
+	val := envVars.Vars[testEnvKey]
+	utils.AssertEqual(t, fakeBase64, val)
+
+	req, _ = http.NewRequest("GET", "http://localhost/envvars/export", nil)
+	resp, err = app.Test(req)
+	utils.AssertEqual(t, nil, err)
+
+	respBody, err = ioutil.ReadAll(resp.Body)
+	utils.AssertEqual(t, nil, err)
+
+	var envVarsExport EnvVar
+	utils.AssertEqual(t, nil, json.Unmarshal(respBody, &envVarsExport))
+	val = envVarsExport.Vars[testEnvKey]
+	utils.AssertEqual(t, fakeBase64, val)
+}