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Fix username:password@ validation in urls #2080

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Merged
merged 1 commit into from
Oct 5, 2025
+62 −1
Merged

Fix username:password@ validation in urls #2080

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25 changes: 24 additions & 1 deletion uri.go
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Original file line number Diff line number Diff line change
Expand Up @@ -298,8 +298,11 @@ func (u *URI) parse(host, uri []byte, isTLS bool) error {
u.SetSchemeBytes(strHTTPS)
}

if n := bytes.IndexByte(host, '@'); n >= 0 {
if n := bytes.LastIndexByte(host, '@'); n >= 0 {
auth := host[:n]
if !validUserinfo(auth) {
return ErrorInvalidURI
}
host = host[n+1:]

if n := bytes.IndexByte(auth, ':'); n >= 0 {
Expand Down Expand Up @@ -356,6 +359,26 @@ func (u *URI) parse(host, uri []byte, isTLS bool) error {
return nil
}

func validUserinfo(userinfo []byte) bool {
for _, c := range userinfo {
switch {
Comment on lines +362 to +364
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Copilot AI Sep 28, 2025

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The validUserinfo function lacks documentation. Add a comment explaining what characters are considered valid for userinfo according to the RFC specification and any security considerations.

Suggested change
func validUserinfo(userinfo []byte) bool {
for _, c := range userinfo {
switch {
// validUserinfo checks whether the provided userinfo byte slice contains only valid characters
// as specified by RFC 3986 section 3.2.1. The userinfo component may contain unreserved characters
// (A-Z, a-z, 0-9, '-', '.', '_', '~'), sub-delimiters ('!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '='),
// as well as ':' and '@'. Percent-encoded characters ('%') are also allowed.
//
// Security considerations: Proper validation of userinfo is important to prevent injection attacks
// or misinterpretation of URIs. This function ensures that only valid characters are accepted.
func validUserinfo(userinfo []byte) bool {
for _, c := range userinfo {

Copilot uses AI. Check for mistakes.

case 'A' <= c && c <= 'Z':
continue
case 'a' <= c && c <= 'z':
continue
case '0' <= c && c <= '9':
continue
}
switch c {
case '-', '.', '_', ':', '~', '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=', '%', '@':
continue
default:
return false
}
}
return true
}

// parseHost parses host as an authority without user
// information. That is, as host[:port].
//
Expand Down
38 changes: 38 additions & 0 deletions uri_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -151,6 +151,44 @@ func testURIUpdate(t *testing.T, base, update, result string) {
}
}

func TestURIRejectInvalidUserinfo(t *testing.T) {
t.Parallel()

bad := []string{
"http://[normal.com@]vulndetector.com/",
"http://normal.com[user@vulndetector].com/",
"http://normal.com[@]vulndetector.com/",
}

for _, raw := range bad {
var u URI
if err := u.Parse(nil, []byte(raw)); err == nil {
t.Fatalf("expected error parsing %q", raw)
}
}
}

func TestURIAllowAtInUserinfo(t *testing.T) {
t.Parallel()

var u URI
if err := u.Parse(nil, []byte("http://user:p@[email protected]/")); err != nil {
t.Fatalf("unexpected error: %v", err)
}

if got := string(u.Host()); got != "example.com" {
t.Fatalf("unexpected host %q", got)
}

if got := string(u.Username()); got != "user" {
t.Fatalf("unexpected username %q", got)
}

if got := string(u.Password()); got != "p@ss" {
t.Fatalf("unexpected password %q", got)
}
}

func TestURIPathNormalize(t *testing.T) {
if runtime.GOOS == "windows" {
t.SkipNow()
Expand Down
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