Added Redis session caching

Added functions so a Redis DB could be pinged for whether the session was valid.
The session tokens also expire due to the timeout built into the Redis DB (when setting)

Signed-off-by: Ethan Wellenreiter <ewellenreiter@gmail.com>

backend/config.yaml

@@ -1,9 +1,9 @@
 redis:
-  address:
+  host: "10.0.20.46"
   port:
   DB:
   protocol:
-  password:
+  password: "banananana"
 database:
   address:
   port:

backend/src/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"signin"
+	"time"
 
 	"github.com/spf13/viper"
 )
@@ -41,8 +42,40 @@ func main() {
 	// fmt.Println(redis["address"])
 
 	err := signin.InitializeRedis(viper.GetStringMapString("redis"))
-	fmt.Println(err)
-	// fmt.Println(rs)
-	// fmt.Println(map[string]int{"a": 1, "b": 2, "c": 3})
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	cookie, _ := signin.Login("monkey")
+	fmt.Println(cookie)
+	valid, err := signin.ValidateSession(cookie)
+	fmt.Println(valid)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	time.Sleep(time.Second * 10)
+	fmt.Println(cookie)
+	valid, err = signin.ValidateSession(cookie)
+	fmt.Println(valid)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	// // fmt.Println(rs)
+	// // fmt.Println(map[string]int{"a": 1, "b": 2, "c": 3})
+
+	// ctx := context.Background()
+
+	// err := client.Set(ctx, "test", "bar", time.Second*30).Err()
+	// if err != nil {
+	// 	panic(err)
+	// }
+
+	// val, err := client.Get(ctx, "foo").Result()
+	// if err != nil {
+	// 	panic(err)
+	// }
+	// fmt.Println("foo", val)
 
 }

backend/src/session_processing/session_check.go

@@ -1,6 +1,9 @@
 package signin
 
 import (
+	"context"
+	"crypto/rand"
+	"encoding/hex"
 	"errors"
 	"strconv"
 	"time"
@@ -10,12 +13,14 @@ import (
 
 // implement a periodic function to clean up the redis database of old tokens
 
-var redis_client *redis.Client = nil
+var redisClient *redis.Client = nil
+var ctx context.Context = nil
+var SessionTime = 2 // in seconds
+var TokenLength = 32
 
-type session_data struct {
-	token     string
-	username  string
-	expiresAt time.Time
+type SessionCookie struct {
+	token    string
+	username string
 }
 
 type redisSettings struct {
@@ -34,11 +39,13 @@ var (
 
 func processSettingsMap(settings map[string]string, setting_struct *redisSettings) error {
 	for key, val := range settings {
+		// fmt.Println(key, val)
 		if val == "" {
 			continue
 		}
 		switch key {
 		case "host":
+			// fmt.Println("entered")
 			setting_struct.host = val
 		case "port":
 			s, err := strconv.ParseUint(val, 10, 16)
@@ -62,15 +69,38 @@ func processSettingsMap(settings map[string]string, setting_struct *redisSetting
 			setting_struct.db = s
 		}
 	}
+	// fmt.Println(setting_struct)
 	return nil
 }
 
-func Login() { // add entry into
-
+func generateSecureToken(length int) string {
+	b := make([]byte, length)
+	if _, err := rand.Read(b); err != nil {
+		return ""
+	}
+	return hex.EncodeToString(b)
 }
 
-func ValidateSession(token string) bool { // check if it's a valid session against the redis database
-	return false
+func Login(username string) (cookie SessionCookie, err error) {
+	// generate token here
+	cookie.token = generateSecureToken(TokenLength)
+	cookie.username = username
+
+	err = redisClient.Set(ctx, cookie.username, cookie.token, time.Second*time.Duration(SessionTime)).Err()
+
+	return cookie, err
+}
+
+func ValidateSession(cookie SessionCookie) (bool, error) { // check if it's a valid session against the redis database
+	val, err := redisClient.Get(ctx, cookie.username).Result()
+	if err != nil || val != cookie.token {
+		if err == redis.Nil {
+			err = nil // override the error. Just to say it's not an error, but in fact it's not in the database
+		}
+		return false, err
+	}
+
+	return true, err
 }
 
 func InitializeRedis(settings map[string]string) error {
@@ -90,12 +120,30 @@ func InitializeRedis(settings map[string]string) error {
 	}
 
 	// initializing redis connection
-	redis_client = redis.NewClient(&redis.Options{
+	redisClient = redis.NewClient(&redis.Options{
 		Addr:     string(strconv.AppendUint([]byte(redis_setup.host+":"), uint64(redis_setup.port), 10)),
 		Password: redis_setup.password,
 		DB:       int(redis_setup.db),
 		Protocol: int(redis_setup.protocol),
 	})
 
+	ctx = context.Background()
+
+	return nil
+}
+
+func ClearSessions() error {
+	err := redisClient.FlushDB(ctx).Err()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func ClearSession(username string) error {
+	err := redisClient.Del(ctx, username).Err()
+	if err != nil {
+		return err
+	}
 	return nil
 }