Implemented presign logic for file manager

security/generator.go

@@ -0,0 +1,52 @@
+package security
+
+import (
+	"errors"
+	"github.com/golang-jwt/jwt"
+	"os"
+	"time"
+)
+
+type PresignToken struct {
+	Path string
+}
+
+func CreateToken(tokenInfo PresignToken, duration time.Duration) (string, error) {
+	// jwt token
+	atClaims := jwt.MapClaims{}
+	atClaims["authorized"] = true
+	// user info
+	atClaims["path"] = tokenInfo.Path
+	// expiration
+	atClaims["exp"] = time.Now().Add(duration).Unix()
+	at := jwt.NewWithClaims(jwt.SigningMethodHS256, atClaims)
+
+	secret := getSecret()
+	return at.SignedString([]byte(secret))
+}
+
+func ParseToken(token string) (PresignToken, error) {
+	secret := getSecret()
+	parsedToken, err := jwt.Parse(token, func(t *jwt.Token) (interface{}, error) {
+		return []byte(secret), nil
+	})
+	if err != nil {
+		return PresignToken{}, err
+	}
+	claims, ok := parsedToken.Claims.(jwt.MapClaims)
+	if ok {
+		return PresignToken{
+			Path: claims["path"].(string),
+		}, nil
+	} else {
+		return PresignToken{}, errors.New("failed parsing token")
+	}
+}
+
+func getSecret() string {
+	secret, exists := os.LookupEnv("JWT_SECRET")
+	if !exists {
+		panic("env variable JWT_SECRET not set")
+	}
+	return secret
+}