Add JWT authentication for admin dashboard login

cmd/main.go

@@ -49,6 +49,7 @@ func main() {
 			runFetchPosts()
 		}
 	}()
+	
 	// Run initial fetch on startup
 	go func() {
 		runFetchPosts()

internal/AppContext.go

@@ -1,6 +1,7 @@
 package internal
 
 import (
+	"CatsOfMastodonBotGo/internal/auth"
 	"CatsOfMastodonBotGo/internal/services"
 
 	"gorm.io/gorm"
@@ -10,6 +11,7 @@ import (
 type AppContext struct {
 	Db *gorm.DB
 	PostService *services.PostService
+	Jwt *auth.JwtTokenGenerator
 	AdminPassword string
 	Instance string
 	Tag string

internal/AppWebContext.go

@@ -1,11 +0,0 @@
-package internal
-
-import (
-	// "github.com/gin-gonic/gin"
-	// "gorm.io/gorm"
-)
-
-// type AppWebContext struct {
-// 	Db *gorm.DB
-// 	GinEngine *gin.Engine	
-// }

internal/auth/jwt.go

@@ -1,2 +1,58 @@
 package auth
 
+import (
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+)
+
+type JwtTokenGenerator struct {
+	Key  string
+	Issuer string
+	Audience string
+}
+
+func NewJwtTokenGenerator(key string, issuer string, audience string) *JwtTokenGenerator {
+	return &JwtTokenGenerator{
+		Key: key,
+		Issuer: issuer,
+		Audience: audience,
+	}
+}
+
+func (j *JwtTokenGenerator) GenerateToken(claims map[string]interface{}) (string, error) {
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
+		"exp": time.Now().AddDate(0, 0, 3).Unix(),
+		"iat": time.Now().Unix(),
+		"iss": j.Issuer,
+		"aud": j.Audience,
+	})
+	for k, v := range claims {
+		token.Claims.(jwt.MapClaims)[k] = v
+	}
+
+	return token.SignedString([]byte(j.Key))
+}
+
+// Gin middleware
+func (j *JwtTokenGenerator) GinMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		token, err := c.Request.Cookie("token")
+		if err != nil {
+			c.AbortWithStatusJSON(401, gin.H{"error": "Unauthorized"})
+			return
+		}
+		_, err = jwt.Parse(token.Value, func(t *jwt.Token) (interface{}, error) {
+			if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
+				return nil, jwt.ErrSignatureInvalid
+			}
+			return []byte(j.Key), nil
+		})
+		if err != nil {
+			c.AbortWithStatusJSON(401, gin.H{"error": "Unauthorized"})
+			return
+		}
+		c.Next()
+	}
+}

internal/helpers/SetupAppContext.go

@@ -2,6 +2,7 @@ package helpers
 
 import (
 	"CatsOfMastodonBotGo/internal"
+	"CatsOfMastodonBotGo/internal/auth"
 	"CatsOfMastodonBotGo/internal/services"
 	"log"
 	"os"
@@ -27,6 +28,22 @@ func SetupAppContext() *internal.AppContext {
 		adminPassword = "catsaregood"
 	}
 
+	// Jwt params
+	secret := os.Getenv("CAOM_JWT_SECRET")
+	if secret == "" {
+		log.Fatal("No jwt secret provided, using default secret 'secret'")
+	}
+	issuer := os.Getenv("CAOM_JWT_ISSUER")
+	if issuer == "" {
+		log.Println("No jwt issuer provided, using default issuer 'CatsOfMastodonBotGo'")
+		issuer = "CatsOfMastodonBotGo"
+	}
+	audience := os.Getenv("CAOM_JWT_AUDIENCE")
+	if audience == "" {
+		log.Println("No jwt audience provided, using default audience 'CatsOfMastodonBotGo'")
+		audience = "CatsOfMastodonBotGo"
+	}
+
 	// Setup database
 	db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{Logger: logger.Default.LogMode(logger.Warn)})
 	if err != nil {
@@ -37,10 +54,15 @@ func SetupAppContext() *internal.AppContext {
 	//Setup PostService
 	var postService = services.NewPostService(db)
 
+	// Setup Jwt
+	var jwt = auth.NewJwtTokenGenerator(secret, issuer, audience)
+
 	// Inititlize AppContext
 	var appContext = &internal.AppContext{
 		Db:          db,
 		PostService: postService,
+		Jwt:         jwt,
+		AdminPassword: adminPassword,
 		Instance:    instance,
 		Tag:         tag,
 	}

internal/web/handlers/admin/adminDash.go

@@ -47,8 +47,18 @@ func (appContext *AdminDashboardHandler) Login(c *gin.Context) {
 	}
 
 	if input.Password == appContext.AppContext.AdminPassword {
-		c.JSON(200, gin.H{
+		token, err := appContext.AppContext.Jwt.GenerateToken(map[string]interface{}{"role": "admin"})
-			"YouAreOn": "AdminDashboardHomePage",
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "Token generation failed"})
+			return
+		}
+
+		c.SetCookie("token", token, 3600, "/", "", false, true)
+		c.JSON(http.StatusOK, gin.H{"message": "Login successful"})
+
+	} else {
+		c.JSON(401, gin.H{
+			"YouAreOn": "Unauthorized",
 		})
 	}