mirror of
https://github.com/larksuite/cli.git
synced 2026-07-07 00:55:53 +08:00
71 lines
2.3 KiB
Go
71 lines
2.3 KiB
Go
// Copyright (c) 2026 Lark Technologies Pte. Ltd.
|
|
// SPDX-License-Identifier: MIT
|
|
|
|
package validate
|
|
|
|
import (
|
|
"fmt"
|
|
"strings"
|
|
)
|
|
|
|
// RejectControlChars rejects C0 control characters (except \t and \n) and
|
|
// dangerous Unicode characters from user input.
|
|
//
|
|
// Control characters cause subtle security issues: null bytes truncate strings
|
|
// at the C layer, \r\n enables HTTP header injection
|
|
// Unicode characters allow visual spoofing (e.g. making "report.exe" display
|
|
// as "report.txt").
|
|
func RejectControlChars(value, flagName string) error {
|
|
for _, r := range value {
|
|
if r != '\t' && r != '\n' && (r < 0x20 || r == 0x7f) {
|
|
return fmt.Errorf("%s contains invalid control characters", flagName)
|
|
}
|
|
if isDangerousUnicode(r) {
|
|
return fmt.Errorf("%s contains dangerous Unicode characters", flagName)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// RejectCRLF rejects strings containing carriage return (\r) or line feed (\n).
|
|
// These characters enable MIME/HTTP header injection and must never appear in
|
|
// header field names, values, Content-ID, or filename parameters.
|
|
func RejectCRLF(value, fieldName string) error {
|
|
if strings.ContainsAny(value, "\r\n") {
|
|
return fmt.Errorf("%s contains invalid line break characters", fieldName)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// StripQueryFragment removes any ?query or #fragment suffix from a URL path.
|
|
// API parameters must go through structured --params flags, not embedded in
|
|
// the path, to prevent parameter injection and behaviour confusion.
|
|
func StripQueryFragment(path string) string {
|
|
for i := 0; i < len(path); i++ {
|
|
if path[i] == '?' || path[i] == '#' {
|
|
return path[:i]
|
|
}
|
|
}
|
|
return path
|
|
}
|
|
|
|
// isDangerousUnicode identifies Unicode code points used for visual spoofing attacks.
|
|
// These characters are invisible or alter text direction, allowing attackers to make
|
|
// "report.exe" display as "report.txt" (Bidi override) or insert hidden content
|
|
// (zero-width characters).
|
|
func isDangerousUnicode(r rune) bool {
|
|
switch {
|
|
case r >= 0x200B && r <= 0x200D: // zero-width space/non-joiner/joiner
|
|
return true
|
|
case r == 0xFEFF: // BOM / ZWNBSP
|
|
return true
|
|
case r >= 0x202A && r <= 0x202E: // Bidi: LRE/RLE/PDF/LRO/RLO
|
|
return true
|
|
case r >= 0x2028 && r <= 0x2029: // line/paragraph separator
|
|
return true
|
|
case r >= 0x2066 && r <= 0x2069: // Bidi isolates: LRI/RLI/FSI/PDI
|
|
return true
|
|
}
|
|
return false
|
|
}
|