Added auth (login/logout) system

internal/auth.go

@@ -0,0 +1,79 @@
+package internal
+
+import (
+	"crypto/sha256"
+	"errors"
+	"fmt"
+
+	"github.com/gin-gonic/gin"
+)
+
+type User struct {
+	Email    string `json:"email" bson:"email"`
+	Password string `json:"password" bson:"password"`
+}
+
+var USERS_LOCATION = Location{Database: "gohcms", Collection: "users"}
+
+func getUserHashedPassword(user User) string {
+	password := sha256.New()
+	password.Write([]byte(user.Password))
+	return fmt.Sprintf("%x", password.Sum(nil))
+}
+
+func isUserLoggedIn(user User) bool {
+	for i := 0; i < len(SESSIONS); i++ {
+		hash1 := fmt.Sprint(SESSIONS[i].Token.Sum(nil))
+		hash2 := fmt.Sprint(generateSessionToken(user).Sum(nil))
+		if hash1 != hash2 {
+			continue
+		}
+		return !isSessionExpired(SESSIONS[i])
+	}
+	return false
+}
+
+func isUserReal(user User) bool {
+	docUsers, _ := getDocuments(USERS_LOCATION, user)
+	return len(docUsers) == 1
+}
+
+func parseUserFromContext(c *gin.Context) (User, error) {
+	var user User
+	if c.BindJSON(&user) != nil {
+		SendErrorMessageToClient(c, "Could not correctly parse user crendentials.")
+		return User{}, errors.New("could not correctly parse user crendentials")
+	}
+	user.Password = getUserHashedPassword(user)
+	return user, nil
+}
+
+func LoginUser(c *gin.Context) {
+	user, err := parseUserFromContext(c)
+	if err != nil {
+		return
+	}
+	if isUserLoggedIn(user) {
+		SendErrorMessageToClient(c, "User is already logged in!")
+		return
+	}
+	if !isUserReal(user) {
+		SendErrorMessageToClient(c, "Unknown email or wrong password.")
+		return
+	}
+	addSession(user)
+	SendOkMessageToClient(c, "User successfully logged in.")
+}
+
+func LogoutUser(c *gin.Context) {
+	user, err := parseUserFromContext(c)
+	if err != nil {
+		return
+	}
+	if !isUserLoggedIn(user) {
+		SendErrorMessageToClient(c, "User is not logged in!")
+		return
+	}
+	removeSession(user)
+	SendOkMessageToClient(c, "User successfully logged out.")
+}

internal/sessions.go

@@ -0,0 +1,51 @@
+package internal
+
+import (
+	"crypto"
+	"fmt"
+	"hash"
+	"time"
+)
+
+type Session struct {
+	Token               hash.Hash `json:"token"`
+	ExpirationTimestamp int64     `json:"expirationTimestamp"`
+}
+
+var SESSIONS []Session
+
+const SESSION_DURATION int64 = 3600
+
+func generateSessionToken(user User) hash.Hash {
+	token := crypto.SHA256.New()
+	stringToHash := fmt.Sprintf(user.Email + user.Password)
+	token.Write([]byte(stringToHash))
+	return token
+}
+
+func isSessionExpired(session Session) bool {
+	return session.ExpirationTimestamp < time.Now().Unix()
+}
+
+func addSession(user User) {
+	SESSIONS = append(SESSIONS, Session{
+		Token:               generateSessionToken(user),
+		ExpirationTimestamp: time.Now().Unix() + SESSION_DURATION,
+	})
+}
+
+func removeSession(user User) {
+	index := 0
+	sessLen := len(SESSIONS)
+	for i := 0; i < sessLen; i++ {
+		if SESSIONS[i].Token == generateSessionToken(user) {
+			index = i
+			break
+		}
+	}
+	fmt.Println(SESSIONS)
+	SESSIONS[index] = SESSIONS[sessLen-1]
+	SESSIONS[sessLen-1] = Session{} //TODO PAS SUR QUE ÇA FONCTIONNE
+	SESSIONS = SESSIONS[:sessLen-1]
+	fmt.Println(SESSIONS)
+}