Support a new value type, with Booleans, Integers, and Null.

This commit is contained in:
2020-07-04 20:22:52 -07:00
parent 9dae809afa
commit d8e32f63a5
7 changed files with 977 additions and 460 deletions

View File

@@ -1,461 +1,7 @@
use crate::bitstring::BitString;
use alloc::vec::Vec;
use core::convert::TryFrom;
use core::fmt;
#[cfg(test)]
use quickcheck::{quickcheck, Arbitrary, Gen};
pub(crate) mod tag;
pub(crate) mod length;
pub(crate) mod value;
#[repr(u8)]
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum BasicTagType {
Boolean = 1,
Integer = 2,
BitString = 3,
OctetString = 4,
Null = 5,
ObjectIdentifier = 6,
ObjectDescriptor = 7,
External = 8,
Real = 9,
Enumerated = 10,
EmbeddedBDV = 11,
UTF8String = 12,
RelativeOID = 13,
Sequence = 16,
Set = 17,
NumericString = 18,
PrintableString = 19,
TeletexString = 20,
VideotexString = 21,
IA5String = 22,
UTCTime = 23,
GeneralizedTime = 24,
GraphicString = 25,
VisibleString = 26,
GeneralString = 27,
UniversalString = 28,
CharacterString = 29,
BMPString = 30,
}
#[cfg(test)]
impl Arbitrary for BasicTagType {
fn arbitrary<G: Gen>(g: &mut G) -> BasicTagType {
let options = vec![
BasicTagType::Boolean,
BasicTagType::Integer,
BasicTagType::BitString,
BasicTagType::OctetString,
BasicTagType::Null,
BasicTagType::ObjectIdentifier,
BasicTagType::ObjectDescriptor,
BasicTagType::External,
BasicTagType::Real,
BasicTagType::Enumerated,
BasicTagType::EmbeddedBDV,
BasicTagType::UTF8String,
BasicTagType::RelativeOID,
BasicTagType::Sequence,
BasicTagType::Set,
BasicTagType::NumericString,
BasicTagType::PrintableString,
BasicTagType::TeletexString,
BasicTagType::VideotexString,
BasicTagType::IA5String,
BasicTagType::UTCTime,
BasicTagType::GeneralizedTime,
BasicTagType::GraphicString,
BasicTagType::VisibleString,
BasicTagType::GeneralString,
BasicTagType::UniversalString,
BasicTagType::CharacterString,
BasicTagType::BMPString,
];
let index = usize::arbitrary(g) % options.len();
options[index]
}
}
#[derive(Debug, PartialEq)]
pub enum TagTypeParseError {
UsedReservedSlot,
UsedSignalSlot,
ValueTooLarge,
}
impl fmt::Display for TagTypeParseError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
TagTypeParseError::UsedReservedSlot => write!(
f,
"Tag type value was one marked reserved in our specification."
),
TagTypeParseError::UsedSignalSlot => write!(
f,
"Tag type value was the one that signals a multi-byte tag."
),
TagTypeParseError::ValueTooLarge => {
write!(f, "Tag type value was much too large for us.")
}
}
}
}
impl TryFrom<u8> for BasicTagType {
type Error = TagTypeParseError;
fn try_from(x: u8) -> Result<BasicTagType, TagTypeParseError> {
match x {
0 => Err(TagTypeParseError::UsedReservedSlot),
1 => Ok(BasicTagType::Boolean),
2 => Ok(BasicTagType::Integer),
3 => Ok(BasicTagType::BitString),
4 => Ok(BasicTagType::OctetString),
5 => Ok(BasicTagType::Null),
6 => Ok(BasicTagType::ObjectIdentifier),
7 => Ok(BasicTagType::ObjectDescriptor),
8 => Ok(BasicTagType::External),
9 => Ok(BasicTagType::Real),
10 => Ok(BasicTagType::Enumerated),
11 => Ok(BasicTagType::EmbeddedBDV),
12 => Ok(BasicTagType::UTF8String),
13 => Ok(BasicTagType::RelativeOID),
14 => Err(TagTypeParseError::UsedReservedSlot),
15 => Err(TagTypeParseError::UsedReservedSlot),
16 => Ok(BasicTagType::Sequence),
17 => Ok(BasicTagType::Set),
18 => Ok(BasicTagType::NumericString),
19 => Ok(BasicTagType::PrintableString),
20 => Ok(BasicTagType::TeletexString),
21 => Ok(BasicTagType::VideotexString),
22 => Ok(BasicTagType::IA5String),
23 => Ok(BasicTagType::UTCTime),
24 => Ok(BasicTagType::GeneralizedTime),
25 => Ok(BasicTagType::GraphicString),
26 => Ok(BasicTagType::VisibleString),
27 => Ok(BasicTagType::GeneralString),
28 => Ok(BasicTagType::UniversalString),
29 => Ok(BasicTagType::CharacterString),
30 => Ok(BasicTagType::BMPString),
31 => Err(TagTypeParseError::UsedSignalSlot),
_ => Err(TagTypeParseError::ValueTooLarge),
}
}
}
#[repr(u8)]
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum TagClass {
Universal = 0b00,
Application = 0b01,
ContextSpecific = 0b10,
Private = 0b11,
}
#[cfg(test)]
impl Arbitrary for TagClass {
fn arbitrary<G: Gen>(g: &mut G) -> TagClass {
let options = vec![
TagClass::Universal,
TagClass::Application,
TagClass::ContextSpecific,
TagClass::Private,
];
let index = usize::arbitrary(g) % options.len();
options[index]
}
}
#[derive(Debug, PartialEq)]
pub enum TagClassParseError {
TagClassTooLarge,
}
impl fmt::Display for TagClassParseError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
TagClassParseError::TagClassTooLarge => write!(f, "Tag class value is too big"),
}
}
}
impl TryFrom<u8> for TagClass {
type Error = TagClassParseError;
fn try_from(x: u8) -> Result<TagClass, TagClassParseError> {
match x {
0 => Ok(TagClass::Universal),
1 => Ok(TagClass::Application),
2 => Ok(TagClass::ContextSpecific),
3 => Ok(TagClass::Private),
_ => Err(TagClassParseError::TagClassTooLarge),
}
}
}
#[repr(u8)]
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum TagForm {
Primitive = 0,
Constructed = 1,
}
#[cfg(test)]
impl Arbitrary for TagForm {
fn arbitrary<G: Gen>(g: &mut G) -> TagForm {
let options = vec![TagForm::Primitive, TagForm::Constructed];
let index = usize::arbitrary(g) % options.len();
options[index]
}
}
#[derive(Debug, PartialEq)]
pub enum TagFormParseError {
TagFormTooLarge,
}
impl fmt::Display for TagFormParseError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
TagFormParseError::TagFormTooLarge => write!(f, "Tag form value is more than one bit"),
}
}
}
impl TryFrom<u8> for TagForm {
type Error = TagFormParseError;
fn try_from(x: u8) -> Result<TagForm, TagFormParseError> {
match x {
0 => Ok(TagForm::Primitive),
1 => Ok(TagForm::Constructed),
_ => Err(TagFormParseError::TagFormTooLarge),
}
}
}
#[derive(Clone, Debug, PartialEq)]
pub enum Tag {
Simple(TagClass, TagForm, BasicTagType),
Extended(TagClass, TagForm, Vec<u8>),
}
#[cfg(test)]
impl Arbitrary for Tag {
fn arbitrary<G: Gen>(g: &mut G) -> Tag {
if g.next_u32() & 1 == 0 {
Tag::Simple(
TagClass::arbitrary(g),
TagForm::arbitrary(g),
BasicTagType::arbitrary(g),
)
} else {
let mut basic_vec = Vec::<u8>::arbitrary(g);
basic_vec.push(u8::arbitrary(g)); // just to ensure there's at least one
Tag::Extended(TagClass::arbitrary(g), TagForm::arbitrary(g), basic_vec)
}
}
}
#[derive(Debug, PartialEq)]
pub enum TagReaderError {
NotEnoughData,
InappropriateExtendedLength,
TagClassProblem(TagClassParseError),
TagFormProblem(TagFormParseError),
TagTypeProblem(TagTypeParseError),
}
impl From<TagClassParseError> for TagReaderError {
fn from(x: TagClassParseError) -> TagReaderError {
TagReaderError::TagClassProblem(x)
}
}
impl From<TagFormParseError> for TagReaderError {
fn from(x: TagFormParseError) -> TagReaderError {
TagReaderError::TagFormProblem(x)
}
}
impl From<TagTypeParseError> for TagReaderError {
fn from(x: TagTypeParseError) -> TagReaderError {
TagReaderError::TagTypeProblem(x)
}
}
#[derive(Debug, PartialEq)]
pub enum TagSerializationError {
NoExtendedTag,
ExtendedTagTooSmall,
InternalError,
}
impl Tag {
pub fn read<I: Iterator<Item = u8>>(it: &mut I) -> Result<Tag, TagReaderError> {
match it.next() {
None => Err(TagReaderError::NotEnoughData),
Some(b) => {
let class = TagClass::try_from(b >> 6)?;
let form = TagForm::try_from((b >> 5) & 1)?;
let tag = b & 0b11111;
if tag == 31 {
let mut bitstr = BitString::new();
// OK, here's an example of what we have to do here.
// Imagine that this tag was four bytes [67,33,30,42]:
//
// 01000011_00100001_00011110_00101010
//
// To encode them, we're going to pad the front, and then
// group them into sevens:
//
// 0000100_0011001_0000100_0111100_0101010
// 4 25 4 60 42
//
// We'll then set the high bits on the first 4, giving us
// an input to this function of:
// 132 153 132 188 42
//
// On the flip side, to parse, we need to first turn these
// back into 8 bit quantities:
// 00001000_01100100_00100011_11000101_010
let mut ended_clean = false;
while let Some(b) = it.next() {
bitstr.push_bits(7, b);
if b & 0b1000_0000 == 0 {
ended_clean = true;
break;
}
}
if !ended_clean {
return Err(TagReaderError::NotEnoughData);
}
//
// which is off by three.
let padding = bitstr.len() % 8;
//
// So if we pull three bits off the front we get back to:
// 01000011_00100001_00011110_00101010
//
let mut bititer = bitstr.bits().skip(padding);
let mut res = Vec::new();
let mut work_byte = 0;
let mut count = 0;
while let Some(x) = bititer.next() {
work_byte = (work_byte << 1) | (x & 1);
count += 1;
if count == 8 {
res.push(work_byte);
count = 0;
work_byte = 0;
}
}
if count != 0 {
return Err(TagReaderError::InappropriateExtendedLength);
}
return Ok(Tag::Extended(class, form, res));
}
Ok(Tag::Simple(class, form, BasicTagType::try_from(tag)?))
}
}
}
pub fn write(&self, buffer: &mut Vec<u8>) -> Result<(), TagSerializationError> {
match self {
Tag::Simple(class, form, basic) => {
let class_val = (*class as u8) << 6;
let form_val = (*form as u8) << 5;
let basic_val = *basic as u8;
buffer.push(class_val | form_val | basic_val);
Ok(())
}
Tag::Extended(class, form, value) => {
let class_val = (*class as u8) << 6;
let form_val = (*form as u8) << 5;
let basic_val = 0b00011111;
if value.len() == 0 {
return Err(TagSerializationError::NoExtendedTag);
}
buffer.push(class_val | form_val | basic_val);
let original_length = value.len() * 8;
let mut work_byte = 0;
let mut bits_added = if original_length % 7 == 0 {
0
} else {
7 - (original_length % 7)
};
let mut bitstream = BitString::from(value.iter().map(|x| *x)).bits().peekable();
while bitstream.peek().is_some() {
while bits_added < 7 {
match bitstream.next() {
None => return Err(TagSerializationError::InternalError),
Some(b) => {
bits_added += 1;
work_byte = (work_byte << 1) | b;
}
}
}
buffer.push(0b1000_0000 | work_byte);
bits_added = 0;
work_byte = 0;
}
let last_idx = buffer.len() - 1;
buffer[last_idx] &= 0b0111_1111;
Ok(())
}
}
}
}
macro_rules! item_u8_item {
($name: ident, $type: ident) => {
#[cfg(test)]
quickcheck! {
fn $name(t: $type) -> bool {
let t8 = t as u8;
match $type::try_from(t8) {
Err(_) => false,
Ok(t2) => t == t2,
}
}
}
};
}
item_u8_item!(tag_u8_tag, BasicTagType);
item_u8_item!(form_u8_form, TagForm);
item_u8_item!(class_u8_class, TagClass);
#[cfg(test)]
quickcheck! {
fn tag_bytes_tag(t: Tag) -> bool {
let mut bytes = Vec::new();
let () = t.write(&mut bytes).unwrap();
let mut byteiter = bytes.iter().map(|x| *x);
match Tag::read(&mut byteiter) {
Err(e) => {
// println!("Error result: {:?}", e);
false
}
Ok(t2) => {
// println!("Result: {:?}", t2);
t == t2
}
}
}
}
pub use crate::ber::tag::*;
pub use crate::ber::length::*;
pub use crate::ber::value::*;