mox/vendor/golang.org/x/text/cases/icu.go
Mechiel Lukkien c57aeac7f0
prevent unicode-confusion in password by applying PRECIS, and username/email address by applying unicode NFC normalization
an é (e with accent) can also be written as e+\u0301. the first form is NFC,
the second NFD. when logging in, we transform usernames (email addresses) to
NFC. so both forms will be accepted. if a client is using NFD, they can log
in too.

for passwords, we apply the PRECIS "opaquestring", which (despite the name)
transforms the value too: unicode spaces are replaced with ascii spaces. the
string is also normalized to NFC. PRECIS may reject confusing passwords when
you set a password.
2024-03-09 09:20:29 +01:00

61 lines
1.4 KiB
Go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build icu
package cases
// Ideally these functions would be defined in a test file, but go test doesn't
// allow CGO in tests. The build tag should ensure either way that these
// functions will not end up in the package.
// TODO: Ensure that the correct ICU version is set.
/*
#cgo LDFLAGS: -licui18n.57 -licuuc.57
#include <stdlib.h>
#include <unicode/ustring.h>
#include <unicode/utypes.h>
#include <unicode/localpointer.h>
#include <unicode/ucasemap.h>
*/
import "C"
import "unsafe"
func doICU(tag, caser, input string) string {
err := C.UErrorCode(0)
loc := C.CString(tag)
cm := C.ucasemap_open(loc, C.uint32_t(0), &err)
buf := make([]byte, len(input)*4)
dst := (*C.char)(unsafe.Pointer(&buf[0]))
src := C.CString(input)
cn := C.int32_t(0)
switch caser {
case "fold":
cn = C.ucasemap_utf8FoldCase(cm,
dst, C.int32_t(len(buf)),
src, C.int32_t(len(input)),
&err)
case "lower":
cn = C.ucasemap_utf8ToLower(cm,
dst, C.int32_t(len(buf)),
src, C.int32_t(len(input)),
&err)
case "upper":
cn = C.ucasemap_utf8ToUpper(cm,
dst, C.int32_t(len(buf)),
src, C.int32_t(len(input)),
&err)
case "title":
cn = C.ucasemap_utf8ToTitle(cm,
dst, C.int32_t(len(buf)),
src, C.int32_t(len(input)),
&err)
}
return string(buf[:cn])
}