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 
15 use super::{der::*, writer::*, *};
16 use alloc::boxed::Box;
17 
write_positive_integer(output: &mut dyn Accumulator, value: &Positive)18 pub(crate) fn write_positive_integer(output: &mut dyn Accumulator, value: &Positive) {
19     let first_byte = value.first_byte();
20     let value = value.big_endian_without_leading_zero_as_input();
21     write_tlv(output, Tag::Integer, |output| {
22         if (first_byte & 0x80) != 0 {
23             output.write_byte(0); // Disambiguate negative number.
24         }
25         write_copy(output, value)
26     })
27 }
28 
write_all(tag: Tag, write_value: &dyn Fn(&mut dyn Accumulator)) -> Box<[u8]>29 pub(crate) fn write_all(tag: Tag, write_value: &dyn Fn(&mut dyn Accumulator)) -> Box<[u8]> {
30     let length = {
31         let mut length = LengthMeasurement::zero();
32         write_tlv(&mut length, tag, write_value);
33         length
34     };
35 
36     let mut output = Writer::with_capacity(length);
37     write_tlv(&mut output, tag, write_value);
38 
39     output.into()
40 }
41 
write_tlv<F>(output: &mut dyn Accumulator, tag: Tag, write_value: F) where F: Fn(&mut dyn Accumulator),42 fn write_tlv<F>(output: &mut dyn Accumulator, tag: Tag, write_value: F)
43 where
44     F: Fn(&mut dyn Accumulator),
45 {
46     let length: usize = {
47         let mut length = LengthMeasurement::zero();
48         write_value(&mut length);
49         length.into()
50     };
51 
52     output.write_byte(tag as u8);
53     if length < 0x80 {
54         output.write_byte(length as u8);
55     } else if length < 0x1_00 {
56         output.write_byte(0x81);
57         output.write_byte(length as u8);
58     } else if length < 0x1_00_00 {
59         output.write_byte(0x82);
60         output.write_byte((length / 0x1_00) as u8);
61         output.write_byte(length as u8);
62     } else {
63         unreachable!();
64     };
65 
66     write_value(output);
67 }
68