1// Copyright 2018 Brian Smith.
2//
3// Permission to use, copy, modify, and/or distribute this software for any
4// purpose with or without fee is hereby granted, provided that the above
5// copyright notice and this permission notice appear in all copies.
6//
7// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
8// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
10// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14
15use super::{der::*, writer::*, *};
16use alloc::boxed::Box;
17
18pub(crate) fn write_positive_integer(output: &mut dyn Accumulator, value: &Positive) {
19 let first_byte: u8 = value.first_byte();
20 let value: Input<'_> = value.big_endian_without_leading_zero_as_input();
21 write_tlv(output, Tag::Integer, |output: &mut dyn Accumulator| {
22 if (first_byte & 0x80) != 0 {
23 output.write_byte(0); // Disambiguate negative number.
24 }
25 write_copy(accumulator:output, to_copy:value)
26 })
27}
28
29pub(crate) fn write_all(tag: Tag, write_value: &dyn Fn(&mut dyn Accumulator)) -> Box<[u8]> {
30 let length: LengthMeasurement = {
31 let mut length: LengthMeasurement = LengthMeasurement::zero();
32 write_tlv(&mut length, tag, write_value);
33 length
34 };
35
36 let mut output: Writer = Writer::with_capacity(length);
37 write_tlv(&mut output, tag, write_value);
38
39 output.into()
40}
41
42#[allow(clippy::cast_possible_truncation)]
43fn write_tlv<F>(output: &mut dyn Accumulator, tag: Tag, write_value: F)
44where
45 F: Fn(&mut dyn Accumulator),
46{
47 let length: usize = {
48 let mut length: LengthMeasurement = LengthMeasurement::zero();
49 write_value(&mut length);
50 length.into()
51 };
52
53 output.write_byte(tag as u8);
54 if length < 0x80 {
55 output.write_byte(length as u8);
56 } else if length < 0x1_00 {
57 output.write_byte(0x81);
58 output.write_byte(length as u8);
59 } else if length < 0x1_00_00 {
60 output.write_byte(0x82);
61 output.write_byte((length / 0x1_00) as u8);
62 output.write_byte(length as u8);
63 } else {
64 unreachable!();
65 };
66
67 write_value(output);
68}
69