Initial backend repository commit.

Set up project files and add .gitignore to exclude local build/runtime artifacts.

Made-with: Cursor

internal/pkg/jwt/jwt.go

@@ -0,0 +1,105 @@
+package jwt
+
+import (
+	"errors"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+var (
+	ErrInvalidToken = errors.New("invalid token")
+	ErrExpiredToken = errors.New("token has expired")
+)
+
+// Claims JWT 声明
+type Claims struct {
+	UserID   string `json:"user_id"`
+	Username string `json:"username"`
+	jwt.RegisteredClaims
+}
+
+// JWT JWT工具
+type JWT struct {
+	secretKey          string
+	accessTokenExpire  time.Duration
+	refreshTokenExpire time.Duration
+}
+
+// New 创建JWT实例
+func New(secret string, accessExpire, refreshExpire time.Duration) *JWT {
+	return &JWT{
+		secretKey:          secret,
+		accessTokenExpire:  accessExpire,
+		refreshTokenExpire: refreshExpire,
+	}
+}
+
+// GenerateAccessToken 生成访问令牌
+func (j *JWT) GenerateAccessToken(userID, username string) (string, error) {
+	now := time.Now()
+	claims := Claims{
+		UserID:   userID,
+		Username: username,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(now.Add(j.accessTokenExpire)),
+			IssuedAt:  jwt.NewNumericDate(now),
+			NotBefore: jwt.NewNumericDate(now),
+			Issuer:    "carrot_bbs",
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(j.secretKey))
+}
+
+// GenerateRefreshToken 生成刷新令牌
+func (j *JWT) GenerateRefreshToken(userID, username string) (string, error) {
+	now := time.Now()
+	claims := Claims{
+		UserID:   userID,
+		Username: username,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(now.Add(j.refreshTokenExpire)),
+			IssuedAt:  jwt.NewNumericDate(now),
+			NotBefore: jwt.NewNumericDate(now),
+			Issuer:    "carrot_bbs",
+			ID:        "refresh",
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(j.secretKey))
+}
+
+// ParseToken 解析令牌
+func (j *JWT) ParseToken(tokenString string) (*Claims, error) {
+	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
+		return []byte(j.secretKey), nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
+		return claims, nil
+	}
+
+	return nil, ErrInvalidToken
+}
+
+// ValidateToken 验证令牌
+func (j *JWT) ValidateToken(tokenString string) error {
+	claims, err := j.ParseToken(tokenString)
+	if err != nil {
+		return err
+	}
+
+	// 检查是否是刷新令牌
+	if claims.ID == "refresh" {
+		return errors.New("cannot use refresh token as access token")
+	}
+
+	return nil
+}