Added wip exponent login time handler

mod/auth/auth.go

@@ -1,22 +1,22 @@
 package auth
 
 /*
-ArOZ Online Authentication Module
-author: tobychui
+	ArOZ Online Authentication Module
+	author: tobychui
 
-This system make use of sessions (similar to PHP SESSION) to remember the user login.
-See https://gowebexamples.com/sessions/ for detail.
+	This system make use of sessions (similar to PHP SESSION) to remember the user login.
+	See https://gowebexamples.com/sessions/ for detail.
 
-Auth database are stored as the following key
+	Auth database are stored as the following key
 
-auth/login/{username}/passhash => hashed password
-auth/login/{username}/permission => permission level
+	auth/login/{username}/passhash => hashed password
+	auth/login/{username}/permission => permission level
 
-Other system variables related to auth
+	Other system variables related to auth
 
-auth/users/usercount => Number of users in the system
+	auth/users/usercount => Number of users in the system
 
-Pre-requirement: imuslab.com/arozos/mod/database
+	Pre-requirement: imuslab.com/arozos/mod/database
 */
 
 import (

mod/auth/explogin/explogin.go

@@ -0,0 +1,51 @@
+package explogin
+
+import (
+	"math"
+	"sync"
+)
+
+/*
+	Explogin.go
+	Package to handle expotential login time
+	so as to prevent someone from brute forcing your password
+
+	Author: tobychui
+*/
+
+type UserLoginEntry struct {
+	Username   string
+	TargetIP   string
+	Timestamp  int64
+	RetryCount int64
+}
+
+type ExpLoginHandler struct {
+	LoginRecord  *sync.Map //Sync map to store UserLoginEntry, username+ip as key
+	BaseDelay    int       //Base delay exponent
+	DelayCeiling int       //Max delay time
+}
+
+//Create a new exponential login handler object
+func NewExponentialLoginHandler(baseDelay int) *ExpLoginHandler {
+	recordMap := sync.Map{}
+
+	return &ExpLoginHandler{
+		LoginRecord: &recordMap,
+		BaseDelay:   baseDelay,
+	}
+}
+
+//Check allow access now, if false return how many seconds till next retry
+func (e *ExpLoginHandler) AllowImmediateAccess(username string, ip string) (bool, int64) {
+
+}
+
+func (e *ExpLoginHandler) getDelayTimeFromRetryCount(retryCount int) int64 {
+	delaySecs := int64(math.Floor((math.Pow(2, float64(retryCount)) - 1) * 0.5))
+	if delaySecs > int64(e.DelayCeiling) {
+		delaySecs = int64(e.DelayCeiling)
+	}
+
+	return delaySecs
+}