Add URI::percent_decoding helper method. Safeguard Pathbuf FromSegments implementation.

examples/static_files/src/main.rs

@@ -4,9 +4,10 @@
 extern crate rocket;
 
 use std::io;
-use rocket::response::NamedFile;
 use std::path::{Path, PathBuf};
 
+use rocket::response::NamedFile;
+
 #[get("/")]
 fn index() -> io::Result<NamedFile> {
     NamedFile::open("static/index.html")

lib/src/config/mod.rs

@@ -85,7 +85,7 @@
 //! [global]
 //! address = "1.2.3.4"
 //!
-//! [devolopment]
+//! [development]
 //! address = "localhost"
 //!
 //! [production]

lib/src/http/uri.rs

@@ -1,9 +1,12 @@
 //! Borrowed and owned string types for absolute URIs.
-//!
 
 use std::cell::Cell;
 use std::convert::From;
 use std::fmt;
+use std::borrow::Cow;
+use std::str::Utf8Error;
+
+use url;
 
 use router::Collider;
 
@@ -77,7 +80,8 @@ impl<'a> URI<'a> {
         })
     }
 
-    /// Returns an iterator over the segments of this URI. Skips empty segments.
+    /// Returns an iterator over the segments of the path in this URI. Skips
+    /// empty segments.
     ///
     /// ### Examples
     ///
@@ -118,6 +122,32 @@ impl<'a> URI<'a> {
         Segments(self.path)
     }
 
+    /// Returns the path part of this URI.
+    ///
+    /// ### Examples
+    ///
+    /// A URI with only a path:
+    ///
+    /// ```rust
+    /// use rocket::http::uri::URI;
+    ///
+    /// let uri = URI::new("/a/b/c");
+    /// assert_eq!(uri.path(), "/a/b/c");
+    /// ```
+    ///
+    /// A URI with other components:
+    ///
+    /// ```rust
+    /// use rocket::http::uri::URI;
+    ///
+    /// let uri = URI::new("/a/b/c?name=bob#done");
+    /// assert_eq!(uri.path(), "/a/b/c");
+    /// ```
+    #[inline(always)]
+    pub fn path(&self) -> &'a str {
+        self.path
+    }
+
     /// Returns the query part of this URI without the question mark, if there is
     /// any.
     ///
@@ -172,6 +202,41 @@ impl<'a> URI<'a> {
         self.fragment
     }
 
+    /// Returns a URL-decoded version of the string. If the percent encoded
+    /// values are not valid UTF-8, an `Err` is returned.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use rocket::http::uri::URI;
+    ///
+    /// let uri = URI::new("/Hello%2C%20world%21");
+    /// let decoded_path = URI::percent_decode(uri.path().as_bytes()).expect("decoded");
+    /// assert_eq!(decoded_path, "/Hello, world!");
+    /// ```
+    pub fn percent_decode<'s>(string: &'s [u8]) -> Result<Cow<'s, str>, Utf8Error>  {
+        let decoder = url::percent_encoding::percent_decode(string);
+        decoder.decode_utf8()
+    }
+
+    /// Returns a URL-decoded version of the path. Any invalid UTF-8
+    /// percent-encoded byte sequences will be replaced <20> U+FFFD, the
+    /// replacement character.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use rocket::http::uri::URI;
+    ///
+    /// let uri = URI::new("/Hello%2C%20world%21");
+    /// let decoded_path = URI::percent_decode_lossy(uri.path().as_bytes());
+    /// assert_eq!(decoded_path, "/Hello, world!");
+    /// ```
+    pub fn percent_decode_lossy<'s>(string: &'s [u8]) -> Cow<'s, str> {
+        let decoder = url::percent_encoding::percent_decode(string);
+        decoder.decode_utf8_lossy()
+    }
+
     /// Returns the inner string of this URI.
     ///
     /// The returned string is in raw form. It contains empty segments. If you'd

lib/src/request/form/from_form_value.rs

@@ -1,9 +1,9 @@
-use url;
-
-use error::Error;
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddrV4, SocketAddrV6, SocketAddr};
 use std::str::FromStr;
 
+use error::Error;
+use http::uri::URI;
+
 /// Trait to create instance of some type from a form value; expected from field
 /// types in structs deriving `FromForm`.
 ///
@@ -72,20 +72,20 @@ impl<'v> FromFormValue<'v> for String {
 
     // This actually parses the value according to the standard.
     fn from_form_value(v: &'v str) -> Result<Self, Self::Error> {
-        let decoder = url::percent_encoding::percent_decode(v.as_bytes());
-        let res = decoder.decode_utf8().map_err(|_| v).map(|s| s.into_owned());
-        match res {
-            e@Err(_) => e,
+        let result = URI::percent_decode(v.as_bytes());
+        match result {
+            Err(_) => Err(v),
             Ok(mut string) => Ok({
+                // Entirely safe because we're changing the single-byte '+'.
                 unsafe {
-                    for c in string.as_mut_vec() {
+                    for c in string.to_mut().as_mut_vec() {
                         if *c == b'+' {
                             *c = b' ';
                         }
                     }
                 }
 
-                string
+                string.into_owned()
             })
         }
     }

lib/src/request/param.rs

@@ -1,11 +1,9 @@
-use std::str::FromStr;
+use std::str::{Utf8Error, FromStr};
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddrV4, SocketAddrV6, SocketAddr};
 use std::path::PathBuf;
 use std::fmt::Debug;
 
-use url;
-
-use http::uri::Segments;
+use http::uri::{URI, Segments};
 
 /// Trait to convert a dynamic path segment string to a concrete value.
 ///
@@ -68,8 +66,7 @@ impl<'a> FromParam<'a> for &'a str {
 impl<'a> FromParam<'a> for String {
     type Error = &'a str;
     fn from_param(p: &'a str) -> Result<String, Self::Error> {
-        let decoder = url::percent_encoding::percent_decode(p.as_bytes());
-        decoder.decode_utf8().map_err(|_| p).map(|s| s.into_owned())
+        URI::percent_decode(p.as_bytes()).map_err(|_| p).map(|s| s.into_owned())
     }
 }
 
@@ -133,10 +130,26 @@ impl<'a> FromSegments<'a> for Segments<'a> {
     }
 }
 
+/// Creates a `PathBuf` from a `Segments` iterator. The returned `PathBuf` is
+/// percent-decoded. If a segment is equal to "..", the previous segment (if
+/// any) is skipped. For security purposes, any other segments that begin with
+/// "*" or "." are ignored.  If a percent-decoded segment results in invalid
+/// UTF8, an `Err` is returned.
 impl<'a> FromSegments<'a> for PathBuf {
-    type Error = ();
-    fn from_segments(segments: Segments<'a>) -> Result<PathBuf, ()> {
-        Ok(segments.collect())
+    type Error = Utf8Error;
+
+    fn from_segments(segments: Segments<'a>) -> Result<PathBuf, Utf8Error> {
+        let mut buf = PathBuf::new();
+        for segment in segments {
+            let decoded = URI::percent_decode(segment.as_bytes())?;
+            if decoded == ".." {
+                buf.pop();
+            } else if !(decoded.starts_with(".") || decoded.starts_with("*")) {
+                buf.push(&*decoded)
+            }
+        }
+
+        Ok(buf)
     }
 }