From f1c03e27c47366c974322e9db2904edd0ffcb9de Mon Sep 17 00:00:00 2001
From: Yong Wen Chua <me@yongwen.xyz>
Date: Mon, 18 Sep 2017 15:00:56 +0800
Subject: [PATCH] Percent decode path for static file handler

Fixes #405
---
 Cargo.toml                     |  1 +
 src/lib.rs                     |  1 +
 src/static_files_handler.rs    | 52 ++++++++++++++++++++++------------
 tests/examples/static_files.rs |  7 +++++
 4 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 692e4c7a14..d5d156b67d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,6 +27,7 @@ groupable = "0.2"
 mustache = "0.8"
 lazy_static = "0.2"
 modifier = "0.1"
+percent-encoding = "1.0.0"
 
 [dependencies.hyper]
 version = "0.10"
diff --git a/src/lib.rs b/src/lib.rs
index e6eb6fec04..ee3ef18831 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,6 +11,7 @@ extern crate url;
 extern crate mustache;
 extern crate groupable;
 extern crate modifier;
+extern crate percent_encoding;
 
 #[macro_use] extern crate log;
 #[macro_use] extern crate lazy_static;
diff --git a/src/static_files_handler.rs b/src/static_files_handler.rs
index bebd4223ab..cfcc14114b 100644
--- a/src/static_files_handler.rs
+++ b/src/static_files_handler.rs
@@ -1,9 +1,13 @@
+use std::borrow::Cow;
 use std::path::{Path, PathBuf};
 use std::io::ErrorKind::NotFound;
 use std::fs;
+use std::str::Utf8Error;
 
 use hyper::method::Method::{Get, Head};
+use percent_encoding;
 
+use NickelError;
 use status::StatusCode;
 use request::Request;
 use response::Response;
@@ -20,7 +24,18 @@ impl<D> Middleware<D> for StaticFilesHandler {
     fn invoke<'a>(&self, req: &mut Request<D>, res: Response<'a, D>)
             -> MiddlewareResult<'a, D> {
         match req.origin.method {
-            Get | Head => self.with_file(self.extract_path(req), res),
+            Get | Head => {
+                match self.extract_path(req) {
+                    Some(path) => {
+                        let path = Self::percent_decode(path);
+                        match path {
+                            Ok(path) => self.with_file(Path::new(path.as_ref()), res),
+                            Err(e) => Err(NickelError::new(res, e.to_string(), StatusCode::BadRequest))
+                        }
+                    }
+                    None => res.next_middleware()
+                }
+            },
             _ => res.next_middleware()
         }
     }
@@ -56,28 +71,29 @@ impl StaticFilesHandler {
         })
     }
 
+    fn percent_decode<'a>(path: &'a str) -> Result<Cow<'a, str>, Utf8Error> {
+        percent_encoding::percent_decode(path.as_bytes()).decode_utf8()
+    }
+
     fn with_file<'a, 'b, D, P>(&self,
-                            relative_path: Option<P>,
+                            path: P,
                             res: Response<'a, D>)
             -> MiddlewareResult<'a, D> where P: AsRef<Path> {
-        if let Some(path) = relative_path {
-            let path = path.as_ref();
-            if !safe_path(path) {
-                let log_msg = format!("The path '{:?}' was denied access.", path);
-                return res.error(StatusCode::BadRequest, log_msg);
-            }
+        let path = path.as_ref();
+        if !safe_path(path) {
+            let log_msg = format!("The path '{:?}' was denied access.", path);
+            return res.error(StatusCode::BadRequest, log_msg);
+        }
 
-            let path = self.root_path.join(path);
-            match fs::metadata(&path) {
-                Ok(ref attr) if attr.is_file() => return res.send_file(&path),
-                Err(ref e) if e.kind() != NotFound => debug!("Error getting metadata \
-                                                              for file '{:?}': {:?}",
-                                                              path, e),
-                _ => {}
+        let path = self.root_path.join(path);
+        match fs::metadata(&path) {
+            Ok(ref attr) if attr.is_file() => res.send_file(&path),
+            Err(ref e) if e.kind() != NotFound => {
+                debug!("Error getting metadata for file '{:?}': {:?}", path, e);
+                res.next_middleware()
             }
-        };
-
-        res.next_middleware()
+            _ => res.next_middleware()
+        }
     }
 }
 
diff --git a/tests/examples/static_files.rs b/tests/examples/static_files.rs
index 3a4c439768..af8b83852a 100644
--- a/tests/examples/static_files.rs
+++ b/tests/examples/static_files.rs
@@ -56,3 +56,10 @@ fn fallthroughs_with_same_prefix() {
         assert_eq!(s, "Not Found");
     });
 }
+
+#[test]
+fn percent_decode_path() {
+    with_path("/nested/file%20with%20space.js", |res| {
+        assert_eq!(res.status, StatusCode::Ok);
+    });
+}