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use crate::*;
use alloc::borrow::Cow;
use alloc::vec::Vec;
use core::convert::TryFrom;
mod iterator;
mod sequence_of;
mod vec;
pub use iterator::*;
pub use sequence_of::*;
pub use vec::*;
/// The `SEQUENCE` object is an ordered list of heteregeneous types.
///
/// Sequences can usually be of 2 types:
/// - a list of different objects (`SEQUENCE`, usually parsed as a `struct`)
/// - a list of similar objects (`SEQUENCE OF`, usually parsed as a `Vec<T>`)
///
/// The current object covers the former. For the latter, see the [`SequenceOf`] documentation.
///
/// The `Sequence` object contains the (*unparsed*) encoded representation of its content. It provides
/// methods to parse and iterate contained objects, or convert the sequence to other types.
///
/// # Building a Sequence
///
/// To build a DER sequence:
/// - if the sequence is composed of objects of the same type, the [`Sequence::from_iter_to_der`] method can be used
/// - otherwise, the [`ToDer`] trait can be used to create content incrementally
///
/// ```
/// use asn1_rs::{Integer, Sequence, SerializeResult, ToDer};
///
/// fn build_seq<'a>() -> SerializeResult<Sequence<'a>> {
/// let mut v = Vec::new();
/// // add an Integer object (construct type):
/// let i = Integer::from_u32(4);
/// let _ = i.write_der(&mut v)?;
/// // some primitive objects also implement `ToDer`. A string will be mapped as `Utf8String`:
/// let _ = "abcd".write_der(&mut v)?;
/// // return the sequence built from the DER content
/// Ok(Sequence::new(v.into()))
/// }
///
/// let seq = build_seq().unwrap();
///
/// ```
///
/// # Examples
///
/// ```
/// use asn1_rs::{Error, Sequence};
///
/// // build sequence
/// let it = [2, 3, 4].iter();
/// let seq = Sequence::from_iter_to_der(it).unwrap();
///
/// // `seq` now contains the serialized DER representation of the array
///
/// // iterate objects
/// let mut sum = 0;
/// for item in seq.der_iter::<u32, Error>() {
/// // item has type `Result<u32>`, since parsing the serialized bytes could fail
/// sum += item.expect("parsing list item failed");
/// }
/// assert_eq!(sum, 9);
///
/// ```
///
/// Note: the above example encodes a `SEQUENCE OF INTEGER` object, the [`SequenceOf`] object could
/// be used to provide a simpler API.
///
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Sequence<'a> {
/// Serialized DER representation of the sequence content
pub content: Cow<'a, [u8]>,
}
impl<'a> Sequence<'a> {
/// Build a sequence, given the provided content
pub const fn new(content: Cow<'a, [u8]>) -> Self {
Sequence { content }
}
/// Consume the sequence and return the content
#[inline]
pub fn into_content(self) -> Cow<'a, [u8]> {
self.content
}
/// Apply the parsing function to the sequence content, consuming the sequence
///
/// Note: this function expects the caller to take ownership of content.
/// In some cases, handling the lifetime of objects is not easy (when keeping only references on
/// data). Other methods are provided (depending on the use case):
/// - [`Sequence::parse`] takes a reference on the sequence data, but does not consume it,
/// - [`Sequence::from_der_and_then`] does the parsing of the sequence and applying the function
/// in one step, ensuring there are only references (and dropping the temporary sequence).
pub fn and_then<U, F, E>(self, op: F) -> ParseResult<'a, U, E>
where
F: FnOnce(Cow<'a, [u8]>) -> ParseResult<U, E>,
{
op(self.content)
}
/// Same as [`Sequence::from_der_and_then`], but using BER encoding (no constraints).
pub fn from_ber_and_then<U, F, E>(bytes: &'a [u8], op: F) -> ParseResult<'a, U, E>
where
F: FnOnce(&'a [u8]) -> ParseResult<U, E>,
E: From<Error>,
{
let (rem, seq) = Sequence::from_ber(bytes).map_err(Err::convert)?;
let data = match seq.content {
Cow::Borrowed(b) => b,
// Since 'any' is built from 'bytes', it is borrowed by construction
Cow::Owned(_) => unreachable!(),
};
let (_, res) = op(data)?;
Ok((rem, res))
}
/// Parse a DER sequence and apply the provided parsing function to content
///
/// After parsing, the sequence object and header are discarded.
///
/// ```
/// use asn1_rs::{FromDer, ParseResult, Sequence};
///
/// // Parse a SEQUENCE {
/// // a INTEGER (0..255),
/// // b INTEGER (0..4294967296)
/// // }
/// // and return only `(a,b)
/// fn parser(i: &[u8]) -> ParseResult<(u8, u32)> {
/// Sequence::from_der_and_then(i, |i| {
/// let (i, a) = u8::from_der(i)?;
/// let (i, b) = u32::from_der(i)?;
/// Ok((i, (a, b)))
/// }
/// )
/// }
/// ```
pub fn from_der_and_then<U, F, E>(bytes: &'a [u8], op: F) -> ParseResult<'a, U, E>
where
F: FnOnce(&'a [u8]) -> ParseResult<U, E>,
E: From<Error>,
{
let (rem, seq) = Sequence::from_der(bytes).map_err(Err::convert)?;
let data = match seq.content {
Cow::Borrowed(b) => b,
// Since 'any' is built from 'bytes', it is borrowed by construction
Cow::Owned(_) => unreachable!(),
};
let (_, res) = op(data)?;
Ok((rem, res))
}
/// Apply the parsing function to the sequence content (non-consuming version)
pub fn parse<F, T, E>(&'a self, mut f: F) -> ParseResult<'a, T, E>
where
F: FnMut(&'a [u8]) -> ParseResult<'a, T, E>,
{
let input: &[u8] = &self.content;
f(input)
}
/// Apply the parsing function to the sequence content (consuming version)
///
/// Note: to parse and apply a parsing function in one step, use the
/// [`Sequence::from_der_and_then`] method.
///
/// # Limitations
///
/// This function fails if the sequence contains `Owned` data, because the parsing function
/// takes a reference on data (which is dropped).
pub fn parse_into<F, T, E>(self, mut f: F) -> ParseResult<'a, T, E>
where
F: FnMut(&'a [u8]) -> ParseResult<'a, T, E>,
E: From<Error>,
{
match self.content {
Cow::Borrowed(b) => f(b),
_ => Err(nom::Err::Error(Error::LifetimeError.into())),
}
}
/// Return an iterator over the sequence content, attempting to decode objects as BER
///
/// This method can be used when all objects from the sequence have the same type.
pub fn ber_iter<T, E>(&'a self) -> SequenceIterator<'a, T, BerParser, E>
where
T: FromBer<'a, E>,
{
SequenceIterator::new(&self.content)
}
/// Return an iterator over the sequence content, attempting to decode objects as DER
///
/// This method can be used when all objects from the sequence have the same type.
pub fn der_iter<T, E>(&'a self) -> SequenceIterator<'a, T, DerParser, E>
where
T: FromDer<'a, E>,
{
SequenceIterator::new(&self.content)
}
/// Attempt to parse the sequence as a `SEQUENCE OF` items (BER), and return the parsed items as a `Vec`.
pub fn ber_sequence_of<T, E>(&'a self) -> Result<Vec<T>, E>
where
T: FromBer<'a, E>,
E: From<Error>,
{
self.ber_iter().collect()
}
/// Attempt to parse the sequence as a `SEQUENCE OF` items (DER), and return the parsed items as a `Vec`.
pub fn der_sequence_of<T, E>(&'a self) -> Result<Vec<T>, E>
where
T: FromDer<'a, E>,
E: From<Error>,
{
self.der_iter().collect()
}
/// Attempt to parse the sequence as a `SEQUENCE OF` items (BER) (consuming input),
/// and return the parsed items as a `Vec`.
///
/// Note: if `Self` is an `Owned` object, the data will be duplicated (causing allocations) into separate objects.
pub fn into_ber_sequence_of<T, U, E>(self) -> Result<Vec<T>, E>
where
for<'b> T: FromBer<'b, E>,
E: From<Error>,
T: ToStatic<Owned = T>,
{
match self.content {
Cow::Borrowed(bytes) => SequenceIterator::<T, BerParser, E>::new(bytes).collect(),
Cow::Owned(data) => {
let v1 = SequenceIterator::<T, BerParser, E>::new(&data)
.collect::<Result<Vec<T>, E>>()?;
let v2 = v1.iter().map(|t| t.to_static()).collect::<Vec<_>>();
Ok(v2)
}
}
}
/// Attempt to parse the sequence as a `SEQUENCE OF` items (DER) (consuming input),
/// and return the parsed items as a `Vec`.
///
/// Note: if `Self` is an `Owned` object, the data will be duplicated (causing allocations) into separate objects.
pub fn into_der_sequence_of<T, U, E>(self) -> Result<Vec<T>, E>
where
for<'b> T: FromDer<'b, E>,
E: From<Error>,
T: ToStatic<Owned = T>,
{
match self.content {
Cow::Borrowed(bytes) => SequenceIterator::<T, DerParser, E>::new(bytes).collect(),
Cow::Owned(data) => {
let v1 = SequenceIterator::<T, DerParser, E>::new(&data)
.collect::<Result<Vec<T>, E>>()?;
let v2 = v1.iter().map(|t| t.to_static()).collect::<Vec<_>>();
Ok(v2)
}
}
}
pub fn into_der_sequence_of_ref<T, E>(self) -> Result<Vec<T>, E>
where
T: FromDer<'a, E>,
E: From<Error>,
{
match self.content {
Cow::Borrowed(bytes) => SequenceIterator::<T, DerParser, E>::new(bytes).collect(),
Cow::Owned(_) => Err(Error::LifetimeError.into()),
}
}
}
impl<'a> ToStatic for Sequence<'a> {
type Owned = Sequence<'static>;
fn to_static(&self) -> Self::Owned {
Sequence {
content: Cow::Owned(self.content.to_vec()),
}
}
}
impl<'a, T, U> ToStatic for Vec<T>
where
T: ToStatic<Owned = U>,
U: 'static,
{
type Owned = Vec<U>;
fn to_static(&self) -> Self::Owned {
self.iter().map(|t| t.to_static()).collect()
}
}
impl<'a> AsRef<[u8]> for Sequence<'a> {
fn as_ref(&self) -> &[u8] {
&self.content
}
}
impl<'a> TryFrom<Any<'a>> for Sequence<'a> {
type Error = Error;
fn try_from(any: Any<'a>) -> Result<Sequence<'a>> {
TryFrom::try_from(&any)
}
}
impl<'a, 'b> TryFrom<&'b Any<'a>> for Sequence<'a> {
type Error = Error;
fn try_from(any: &'b Any<'a>) -> Result<Sequence<'a>> {
any.tag().assert_eq(Self::TAG)?;
any.header.assert_constructed()?;
Ok(Sequence {
content: Cow::Borrowed(any.data),
})
}
}
impl<'a> CheckDerConstraints for Sequence<'a> {
fn check_constraints(_any: &Any) -> Result<()> {
// TODO: iterate on ANY objects and check constraints? -> this will not be exhaustive
// test, for ex INTEGER encoding will not be checked
Ok(())
}
}
impl<'a> DerAutoDerive for Sequence<'a> {}
impl<'a> Tagged for Sequence<'a> {
const TAG: Tag = Tag::Sequence;
}
#[cfg(feature = "std")]
impl ToDer for Sequence<'_> {
fn to_der_len(&self) -> Result<usize> {
let sz = self.content.len();
if sz < 127 {
// 1 (class+tag) + 1 (length) + len
Ok(2 + sz)
} else {
// 1 (class+tag) + n (length) + len
let n = Length::Definite(sz).to_der_len()?;
Ok(1 + n + sz)
}
}
fn write_der_header(&self, writer: &mut dyn std::io::Write) -> SerializeResult<usize> {
let header = Header::new(
Class::Universal,
true,
Self::TAG,
Length::Definite(self.content.len()),
);
header.write_der_header(writer).map_err(Into::into)
}
fn write_der_content(&self, writer: &mut dyn std::io::Write) -> SerializeResult<usize> {
writer.write(&self.content).map_err(Into::into)
}
}
#[cfg(feature = "std")]
impl<'a> Sequence<'a> {
/// Attempt to create a `Sequence` from an iterator over serializable objects (to DER)
///
/// # Examples
///
/// ```
/// use asn1_rs::Sequence;
///
/// // build sequence
/// let it = [2, 3, 4].iter();
/// let seq = Sequence::from_iter_to_der(it).unwrap();
/// ```
pub fn from_iter_to_der<T, IT>(it: IT) -> SerializeResult<Self>
where
IT: Iterator<Item = T>,
T: ToDer,
T: Tagged,
{
let mut v = Vec::new();
for item in it {
let item_v = <T as ToDer>::to_der_vec(&item)?;
v.extend_from_slice(&item_v);
}
Ok(Sequence {
content: Cow::Owned(v),
})
}
}