Isolate more the mfa service (#16925)

* Isolate more the mfa service

* Simplifing the mfa service

* Removing channels and adding waitgroup

* Migrating mfa service to regular errors

* Fixing tests

* i18n extract

* Addressing PR review comments

* Removing unneeded struct

model/utils.go

@@ -185,14 +185,6 @@ func NewRandomString(length int) string {
 	return encoding.EncodeToString(data)[:length]
 }
 
-// NewRandomBase32String returns a base32 encoded string of a random slice
-// of bytes of the given size. The resulting entropy will be (8 * size) bits.
-func NewRandomBase32String(size int) string {
-	data := make([]byte, size)
-	rand.Read(data)
-	return base32.StdEncoding.EncodeToString(data)
-}
-
 // GetMillis is a convenience method to get milliseconds since epoch.
 func GetMillis() int64 {
 	return time.Now().UnixNano() / int64(time.Millisecond)

model/utils_test.go

@@ -5,7 +5,6 @@ package model
 
 import (
 	"bytes"
-	"encoding/base32"
 	"fmt"
 	"net/http"
 	"reflect"
@@ -32,13 +31,6 @@ func TestRandomString(t *testing.T) {
 	}
 }
 
-func TestRandomBase32String(t *testing.T) {
-	for i := 0; i < 1000; i++ {
-		str := NewRandomBase32String(i)
-		require.Len(t, str, base32.StdEncoding.EncodedLen(i))
-	}
-}
-
 func TestGetMillisForTime(t *testing.T) {
 	thisTimeMillis := int64(1471219200000)
 	thisTime := time.Date(2016, time.August, 15, 0, 0, 0, 0, time.UTC)