Security Fix: clean paths correctly to avoid circumvention of BlacklistedPaths

This commit is contained in:
Moritz Marquardt 2023-08-27 10:13:15 +02:00
parent d720d25e42
commit 56d3e291c4
3 changed files with 72 additions and 4 deletions

View file

@ -48,11 +48,9 @@ func (c *Context) Redirect(uri string, statusCode int) {
http.Redirect(c.RespWriter, c.Req, uri, statusCode) http.Redirect(c.RespWriter, c.Req, uri, statusCode)
} }
// Path returns requested path. // Path returns the cleaned requested path.
//
// The returned bytes are valid until your request handler returns.
func (c *Context) Path() string { func (c *Context) Path() string {
return c.Req.URL.Path return utils.CleanPath(c.Req.URL.Path)
} }
func (c *Context) Host() string { func (c *Context) Host() string {

View file

@ -1,6 +1,8 @@
package utils package utils
import ( import (
"net/url"
"path"
"strings" "strings"
) )
@ -11,3 +13,15 @@ func TrimHostPort(host string) string {
} }
return host return host
} }
func CleanPath(uriPath string) string {
unescapedPath, _ := url.PathUnescape(uriPath)
cleanedPath := path.Join("/", unescapedPath)
// If the path refers to a directory, add a trailing slash.
if !strings.HasSuffix(cleanedPath, "/") && (strings.HasSuffix(unescapedPath, "/") || strings.HasSuffix(unescapedPath, "/.") || strings.HasSuffix(unescapedPath, "/..")) {
cleanedPath += "/"
}
return cleanedPath
}

View file

@ -11,3 +11,59 @@ func TestTrimHostPort(t *testing.T) {
assert.EqualValues(t, "", TrimHostPort(":")) assert.EqualValues(t, "", TrimHostPort(":"))
assert.EqualValues(t, "example.com", TrimHostPort("example.com:80")) assert.EqualValues(t, "example.com", TrimHostPort("example.com:80"))
} }
// TestCleanPath is mostly copied from fasthttp, to keep the behaviour we had before migrating away from it.
// Source (MIT licensed): https://github.com/valyala/fasthttp/blob/v1.48.0/uri_test.go#L154
// Copyright (c) 2015-present Aliaksandr Valialkin, VertaMedia, Kirill Danshin, Erik Dubbelboer, FastHTTP Authors
func TestCleanPath(t *testing.T) {
// double slash
testURIPathNormalize(t, "/aa//bb", "/aa/bb")
// triple slash
testURIPathNormalize(t, "/x///y/", "/x/y/")
// multi slashes
testURIPathNormalize(t, "/abc//de///fg////", "/abc/de/fg/")
// encoded slashes
testURIPathNormalize(t, "/xxxx%2fyyy%2f%2F%2F", "/xxxx/yyy/")
// dotdot
testURIPathNormalize(t, "/aaa/..", "/")
// dotdot with trailing slash
testURIPathNormalize(t, "/xxx/yyy/../", "/xxx/")
// multi dotdots
testURIPathNormalize(t, "/aaa/bbb/ccc/../../ddd", "/aaa/ddd")
// dotdots separated by other data
testURIPathNormalize(t, "/a/b/../c/d/../e/..", "/a/c/")
// too many dotdots
testURIPathNormalize(t, "/aaa/../../../../xxx", "/xxx")
testURIPathNormalize(t, "/../../../../../..", "/")
testURIPathNormalize(t, "/../../../../../../", "/")
// encoded dotdots
testURIPathNormalize(t, "/aaa%2Fbbb%2F%2E.%2Fxxx", "/aaa/xxx")
// double slash with dotdots
testURIPathNormalize(t, "/aaa////..//b", "/b")
// fake dotdot
testURIPathNormalize(t, "/aaa/..bbb/ccc/..", "/aaa/..bbb/")
// single dot
testURIPathNormalize(t, "/a/./b/././c/./d.html", "/a/b/c/d.html")
testURIPathNormalize(t, "./foo/", "/foo/")
testURIPathNormalize(t, "./../.././../../aaa/bbb/../../../././../", "/")
testURIPathNormalize(t, "./a/./.././../b/./foo.html", "/b/foo.html")
}
func testURIPathNormalize(t *testing.T, requestURI, expectedPath string) {
cleanedPath := CleanPath(requestURI)
if cleanedPath != expectedPath {
t.Fatalf("Unexpected path %q. Expected %q. requestURI=%q", cleanedPath, expectedPath, requestURI)
}
}