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fix(middleware): preserve escaped paths in slash middleware in v4 #3225

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Merged
vishr merged 1 commit into from
Nov 12, 2026
Merged

fix(middleware): preserve escaped paths in slash middleware in v4 #3225

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21 changes: 15 additions & 6 deletions middleware/slash.go
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Original file line number Diff line number Diff line change
Expand Up @@ -49,10 +49,12 @@ func AddTrailingSlashWithConfig(config TrailingSlashConfig) echo.MiddlewareFunc
req := c.Request()
url := req.URL
path := url.Path
rawPath := url.EscapedPath()
qs := c.QueryString()
if !strings.HasSuffix(path, "/") {
if !strings.HasSuffix(rawPath, "/") {
path += "/"
uri := path
rawPath += "/"
uri := rawPath
if qs != "" {
uri += "?" + qs
}
Expand All @@ -65,6 +67,9 @@ func AddTrailingSlashWithConfig(config TrailingSlashConfig) echo.MiddlewareFunc
// Forward
req.RequestURI = uri
url.Path = path
if url.RawPath != "" {
url.RawPath = rawPath
}
}
return next(c)
}
Expand Down Expand Up @@ -96,11 +101,12 @@ func RemoveTrailingSlashWithConfig(config TrailingSlashConfig) echo.MiddlewareFu
req := c.Request()
url := req.URL
path := url.Path
rawPath := url.EscapedPath()
qs := c.QueryString()
l := len(path) - 1
if l > 0 && strings.HasSuffix(path, "/") {
path = path[:l]
uri := path
if len(rawPath) > 1 && strings.HasSuffix(rawPath, "/") {
path = path[:len(path)-1]
rawPath = rawPath[:len(rawPath)-1]
uri := rawPath
if qs != "" {
uri += "?" + qs
}
Expand All @@ -113,6 +119,9 @@ func RemoveTrailingSlashWithConfig(config TrailingSlashConfig) echo.MiddlewareFu
// Forward
req.RequestURI = uri
url.Path = path
if url.RawPath != "" {
url.RawPath = rawPath
}
}
return next(c)
}
Expand Down
181 changes: 171 additions & 10 deletions middleware/slash_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -43,17 +43,17 @@ func TestAddTrailingSlashWithConfig(t *testing.T) {
{
whenURL: "http://localhost:1323/%5Cexample.com",
expectPath: `/\example.com`,
expectLocation: []string{`/example.com/`},
expectLocation: []string{`/%5Cexample.com/`},
},
{
whenURL: `http://localhost:1323/\example.com`,
expectPath: `/\example.com`,
expectLocation: []string{`/example.com/`},
expectLocation: []string{`/%5Cexample.com/`},
},
{
whenURL: `http://localhost:1323/\\%5C////%5C\\\example.com`,
expectPath: `/\\\////\\\\example.com`,
expectLocation: []string{`/example.com/`},
expectLocation: []string{`/%5C%5C%5C////%5C%5C%5C%5Cexample.com/`},
},
{
whenURL: "http://localhost:1323//example.com",
Expand All @@ -63,7 +63,7 @@ func TestAddTrailingSlashWithConfig(t *testing.T) {
{
whenURL: "http://localhost:1323/%5C%5C",
expectPath: `/\\`,
expectLocation: []string{`/`},
expectLocation: []string{`/%5C%5C/`},
},
// control characters that browsers strip from URLs must not hide a `//` prefix (GHSA-v753-g4cw-jm48)
{
Expand All @@ -74,7 +74,7 @@ func TestAddTrailingSlashWithConfig(t *testing.T) {
{
whenURL: "http://localhost:1323/%09%5Cevil.example/x",
expectPath: "/\t\\evil.example/x",
expectLocation: []string{`/%09\evil.example/x/`},
expectLocation: []string{`/%09%5Cevil.example/x/`},
},
{
whenURL: "http://localhost:1323/%09//evil.example/x",
Expand Down Expand Up @@ -200,17 +200,17 @@ func TestRemoveTrailingSlashWithConfig(t *testing.T) {
{
whenURL: "http://localhost:1323/%5Cexample.com/",
expectPath: `/\example.com/`,
expectLocation: []string{`/example.com`},
expectLocation: []string{`/%5Cexample.com`},
},
{
whenURL: `http://localhost:1323/\example.com/`,
expectPath: `/\example.com/`,
expectLocation: []string{`/example.com`},
expectLocation: []string{`/%5Cexample.com`},
},
{
whenURL: `http://localhost:1323/\\%5C////%5C\\\example.com/`,
expectPath: `/\\\////\\\\example.com/`,
expectLocation: []string{`/example.com`},
expectLocation: []string{`/%5C%5C%5C////%5C%5C%5C%5Cexample.com`},
},
{
whenURL: "http://localhost:1323//example.com/",
Expand All @@ -220,7 +220,7 @@ func TestRemoveTrailingSlashWithConfig(t *testing.T) {
{
whenURL: "http://localhost:1323/%5C%5C/",
expectPath: `/\\/`,
expectLocation: []string{`/`},
expectLocation: []string{`/%5C%5C`},
},
// control characters that browsers strip from URLs must not hide a `//` prefix (GHSA-v753-g4cw-jm48)
{
Expand All @@ -231,7 +231,7 @@ func TestRemoveTrailingSlashWithConfig(t *testing.T) {
{
whenURL: "http://localhost:1323/%09%5Cevil.example/x/",
expectPath: "/\t\\evil.example/x/",
expectLocation: []string{`/%09\evil.example/x`},
expectLocation: []string{`/%09%5Cevil.example/x`},
},
{
whenURL: "http://localhost:1323/%09//evil.example/x/",
Expand Down Expand Up @@ -344,3 +344,164 @@ func TestSanitizeURI(t *testing.T) {
})
}
}

func TestTrailingSlashRedirectEscapedPath(t *testing.T) {
for _, tc := range []struct{ path, add, remove string }{
{"/files/a%2Fb", "/files/a%2Fb/", "/files/a%2Fb"},
{"/files/a%3Fb?x=1", "/files/a%3Fb/?x=1", "/files/a%3Fb?x=1"},
{"/files/a%20b", "/files/a%20b/", "/files/a%20b"},
{"/files/a%23b", "/files/a%23b/", "/files/a%23b"},
{"/%5Cexample.com", "/%5Cexample.com/", "/%5Cexample.com"},
{"/%2f%2Fexample.com", "/%2f%2Fexample.com/", "/%2f%2Fexample.com"},
} {
for _, remove := range []bool{false, true} {
name := "add"
target, want := tc.path, tc.add
mw := AddTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
if remove {
name = "remove"
target, want = tc.add, tc.remove
// Keep the original escaping when constructing the remove request.
req := httptest.NewRequest(http.MethodGet, tc.path, nil)
target = req.URL.EscapedPath() + "/"
if req.URL.RawQuery != "" {
target += "?" + req.URL.RawQuery
}
mw = RemoveTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
}
t.Run(name+tc.path, func(t *testing.T) {
e := echo.New()
rec := httptest.NewRecorder()
req := httptest.NewRequest(http.MethodGet, target, nil)
assert.NoError(t, mw(func(echo.Context) error { return nil })(e.NewContext(req, rec)))
assert.Equal(t, want, rec.Header().Get(echo.HeaderLocation))
})
}
}
}

func TestRemoveTrailingSlashRedirectAfterEncodedSuffix(t *testing.T) {
for _, target := range []string{"/files/a%2Fb%2f", "/files/a%2Fb%2F"} {
t.Run(target, func(t *testing.T) {
e := echo.New()
rec := httptest.NewRecorder()
req := httptest.NewRequest(http.MethodGet, target+"/?x=1", nil)
mw := RemoveTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
assert.NoError(t, mw(func(echo.Context) error { return nil })(e.NewContext(req, rec)))
assert.Equal(t, target+"?x=1", rec.Header().Get(echo.HeaderLocation))
})
}
}

func TestTrailingSlashRedirectPreservesRoute(t *testing.T) {
for _, remove := range []bool{false, true} {
name, target, route := "add", "/files/a%2Fb", "/files/:id/"
mw := AddTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
if remove {
name, target, route = "remove", "/files/a%2Fb/", "/files/:id"
mw = RemoveTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
}
t.Run(name, func(t *testing.T) {
e := echo.New()
e.Pre(mw)
e.GET(route, func(c echo.Context) error { return c.String(http.StatusOK, c.Param("id")) })
first := httptest.NewRecorder()
e.ServeHTTP(first, httptest.NewRequest(http.MethodGet, target, nil))
if !assert.Equal(t, http.StatusMovedPermanently, first.Code) {
return
}
second := httptest.NewRecorder()
e.ServeHTTP(second, httptest.NewRequest(http.MethodGet, first.Header().Get(echo.HeaderLocation), nil))
assert.Equal(t, http.StatusOK, second.Code)
assert.Equal(t, "a%2Fb", second.Body.String())
})
}
}

func TestTrailingSlashForwardEscapedPath(t *testing.T) {
for _, tc := range []struct{ segment, want string }{
{"a%2Fb", "a%2Fb"},
{"a%20b", "a b"},
{"a%3Fb", "a?b"},
{"a%23b", "a#b"},
{"caf%C3%A9", "café"},
} {
for _, remove := range []bool{false, true} {
name, target, route := "add", "/files/"+tc.segment+"?q=1", "/files/:id/"
mw := AddTrailingSlash()
if remove {
name, target, route = "remove", "/files/"+tc.segment+"/?q=1", "/files/:id"
mw = RemoveTrailingSlash()
}
t.Run(name+"/"+tc.segment, func(t *testing.T) {
req := httptest.NewRequest(http.MethodGet, target, nil)
hadRawPath := req.URL.RawPath != ""
e := echo.New()
e.Pre(mw)
e.GET(route, func(c echo.Context) error {
assert.Equal(t, c.Request().URL.EscapedPath()+"?q=1", c.Request().RequestURI)
assert.Equal(t, hadRawPath, c.Request().URL.RawPath != "")
return c.String(http.StatusOK, c.Param("id"))
})
rec := httptest.NewRecorder()
e.ServeHTTP(rec, req)
assert.Equal(t, http.StatusOK, rec.Code)
assert.Equal(t, tc.want, rec.Body.String())
})
}
}
}

func TestTrailingSlashPreservesEncodedLeadingSeparators(t *testing.T) {
for _, path := range []string{"/%2Fdocs", "/%5Cdocs", "/%2f%2Fdocs"} {
t.Run(path, func(t *testing.T) {
for _, remove := range []bool{false, true} {
target, want := path, path+"/"
mw := AddTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
if remove {
target, want = path+"/", path
mw = RemoveTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})
}
e := echo.New()
rec := httptest.NewRecorder()
assert.NoError(t, mw(func(echo.Context) error { return nil })(e.NewContext(httptest.NewRequest(http.MethodGet, target, nil), rec)))
assert.Equal(t, want, rec.Header().Get(echo.HeaderLocation))
}
})
}
}

func TestTrailingSlashEncodedFinalSegment(t *testing.T) {
for _, tc := range []struct {
name, target, route, location string
remove bool
}{
{"add", "/files/a%2F", "/files/:id/", "/files/a%2F/", false},
{"remove", "/files/a%2F/", "/files/:id", "/files/a%2F", true},
{"already removed", "/files/a%2F", "/files/:id", "", true},
} {
for _, code := range []int{0, http.StatusMovedPermanently} {
t.Run(tc.name+map[bool]string{true: "/redirect", false: "/forward"}[code != 0], func(t *testing.T) {
e := echo.New()
mw := AddTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: code})
if tc.remove {
mw = RemoveTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: code})
}
e.Pre(mw)
e.GET(tc.route, func(c echo.Context) error { return c.String(http.StatusOK, c.Param("id")) })
rec := httptest.NewRecorder()
e.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, tc.target, nil))
if code != 0 && tc.location != "" {
if !assert.Equal(t, code, rec.Code) {
return
}
assert.Equal(t, tc.location, rec.Header().Get(echo.HeaderLocation))
rec = httptest.NewRecorder()
e.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, tc.location, nil))
}
assert.Equal(t, http.StatusOK, rec.Code)
assert.Equal(t, "a%2F", rec.Body.String())
})
}
}
}
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