Changeset 0.28.4 (#190)

server/middleware/validate.go

@@ -0,0 +1,33 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+const maxParamLen = 255
+
+// ValidatePathParams rejects requests with null bytes or excessively long
+// path parameters. This prevents 500s from invalid UUIDs reaching the
+// database layer.
+func ValidatePathParams() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		for _, p := range c.Params {
+			if len(p.Value) > maxParamLen {
+				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
+					"error": "path parameter too long",
+				})
+				return
+			}
+			if strings.ContainsRune(p.Value, 0) {
+				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
+					"error": "invalid character in path parameter",
+				})
+				return
+			}
+		}
+		c.Next()
+	}
+}