packer-cn/builder/azure/pkcs12/bmp-string.go

27 lines
770 B
Go

package pkcs12
import (
"errors"
"unicode/utf16"
)
func bmpString(s string) ([]byte, error) {
// References:
// https://tools.ietf.org/html/rfc7292#appendix-B.1
// http://en.wikipedia.org/wiki/Plane_(Unicode)#Basic_Multilingual_Plane
// - non-BMP characters are encoded in UTF 16 by using a surrogate pair of 16-bit codes
// EncodeRune returns 0xfffd if the rune does not need special encoding
// - the above RFC provides the info that BMPStrings are NULL terminated.
rv := make([]byte, 0, 2*len(s)+2)
for _, r := range s {
if t, _ := utf16.EncodeRune(r); t != 0xfffd {
return nil, errors.New("string contains characters that cannot be encoded in UCS-2")
}
rv = append(rv, byte(r/256), byte(r%256))
}
rv = append(rv, 0, 0)
return rv, nil
}