chore: move server package to root

server/common/auth.go

@@ -0,0 +1,50 @@
+package common
+
+import (
+	"github.com/golang-jwt/jwt/v4"
+	"github.com/pkg/errors"
+	"time"
+)
+
+var SecretKey []byte
+
+type UserClaims struct {
+	Username string `json:"username"`
+	jwt.RegisteredClaims
+}
+
+func GenerateToken(username string) (tokenString string, err error) {
+	claim := UserClaims{
+		Username: username,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(12 * time.Hour)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			NotBefore: jwt.NewNumericDate(time.Now()),
+		}}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claim)
+	tokenString, err = token.SignedString(SecretKey)
+	return tokenString, err
+}
+
+func ParseToken(tokenString string) (*UserClaims, error) {
+	token, err := jwt.ParseWithClaims(tokenString, &UserClaims{}, func(token *jwt.Token) (interface{}, error) {
+		return SecretKey, nil
+	})
+	if err != nil {
+		if ve, ok := err.(*jwt.ValidationError); ok {
+			if ve.Errors&jwt.ValidationErrorMalformed != 0 {
+				return nil, errors.New("that's not even a token")
+			} else if ve.Errors&jwt.ValidationErrorExpired != 0 {
+				return nil, errors.New("token is expired")
+			} else if ve.Errors&jwt.ValidationErrorNotValidYet != 0 {
+				return nil, errors.New("token not active yet")
+			} else {
+				return nil, errors.New("couldn't handle this token")
+			}
+		}
+	}
+	if claims, ok := token.Claims.(*UserClaims); ok && token.Valid {
+		return claims, nil
+	}
+	return nil, errors.New("couldn't handle this token")
+}