1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348
use crate::error::*;
use crate::{Any, Class, Explicit, Implicit, Tag, TaggedParser};
use core::convert::{TryFrom, TryInto};
#[cfg(feature = "std")]
use std::io::Write;
/// Phantom type representing a BER parser
#[doc(hidden)]
#[derive(Debug)]
pub enum BerParser {}
/// Phantom type representing a DER parser
#[doc(hidden)]
#[derive(Debug)]
pub enum DerParser {}
#[doc(hidden)]
pub trait ASN1Parser {}
impl ASN1Parser for BerParser {}
impl ASN1Parser for DerParser {}
pub trait Tagged {
const TAG: Tag;
}
impl<T> Tagged for &'_ T
where
T: Tagged,
{
const TAG: Tag = T::TAG;
}
pub trait DynTagged {
fn tag(&self) -> Tag;
}
impl<T> DynTagged for T
where
T: Tagged,
{
fn tag(&self) -> Tag {
T::TAG
}
}
/// Base trait for BER object parsers
///
/// Library authors should usually not directly implement this trait, but should prefer implementing the
/// [`TryFrom<Any>`] trait,
/// which offers greater flexibility and provides an equivalent `FromBer` implementation for free.
///
/// # Examples
///
/// ```
/// use asn1_rs::{Any, Result, Tag};
/// use std::convert::TryFrom;
///
/// // The type to be decoded
/// #[derive(Clone, Copy, Debug, PartialEq, Eq)]
/// pub struct MyType(pub u32);
///
/// impl<'a> TryFrom<Any<'a>> for MyType {
/// type Error = asn1_rs::Error;
///
/// fn try_from(any: Any<'a>) -> Result<MyType> {
/// any.tag().assert_eq(Tag::Integer)?;
/// // for this fictive example, the type contains the number of characters
/// let n = any.data.len() as u32;
/// Ok(MyType(n))
/// }
/// }
///
/// // The above code provides a `FromBer` implementation for free.
///
/// // Example of parsing code:
/// use asn1_rs::FromBer;
///
/// let input = &[2, 1, 2];
/// // Objects can be parsed using `from_ber`, which returns the remaining bytes
/// // and the parsed object:
/// let (rem, my_type) = MyType::from_ber(input).expect("parsing failed");
/// ```
pub trait FromBer<'a, E = Error>: Sized {
/// Attempt to parse input bytes into a BER object
fn from_ber(bytes: &'a [u8]) -> ParseResult<Self, E>;
}
impl<'a, T, E> FromBer<'a, E> for T
where
T: TryFrom<Any<'a>, Error = E>,
E: From<Error>,
{
fn from_ber(bytes: &'a [u8]) -> ParseResult<T, E> {
let (i, any) = Any::from_ber(bytes).map_err(nom::Err::convert)?;
let result = any.try_into().map_err(nom::Err::Error)?;
Ok((i, result))
}
}
/// Base trait for DER object parsers
///
/// Library authors should usually not directly implement this trait, but should prefer implementing the
/// [`TryFrom<Any>`] + [`CheckDerConstraints`] traits,
/// which offers greater flexibility and provides an equivalent `FromDer` implementation for free
/// (in fact, it provides both [`FromBer`] and `FromDer`).
///
/// Note: if you already implemented [`TryFrom<Any>`] and [`CheckDerConstraints`],
/// you can get a free [`FromDer`] implementation by implementing the
/// [`DerAutoDerive`] trait. This is not automatic, so it is also possible to manually
/// implement [`FromDer`] if preferred.
///
/// # Examples
///
/// ```
/// use asn1_rs::{Any, CheckDerConstraints, DerAutoDerive, Result, Tag};
/// use std::convert::TryFrom;
///
/// // The type to be decoded
/// #[derive(Clone, Copy, Debug, PartialEq, Eq)]
/// pub struct MyType(pub u32);
///
/// impl<'a> TryFrom<Any<'a>> for MyType {
/// type Error = asn1_rs::Error;
///
/// fn try_from(any: Any<'a>) -> Result<MyType> {
/// any.tag().assert_eq(Tag::Integer)?;
/// // for this fictive example, the type contains the number of characters
/// let n = any.data.len() as u32;
/// Ok(MyType(n))
/// }
/// }
///
/// impl CheckDerConstraints for MyType {
/// fn check_constraints(any: &Any) -> Result<()> {
/// any.header.assert_primitive()?;
/// Ok(())
/// }
/// }
///
/// impl DerAutoDerive for MyType {}
///
/// // The above code provides a `FromDer` implementation for free.
///
/// // Example of parsing code:
/// use asn1_rs::FromDer;
///
/// let input = &[2, 1, 2];
/// // Objects can be parsed using `from_der`, which returns the remaining bytes
/// // and the parsed object:
/// let (rem, my_type) = MyType::from_der(input).expect("parsing failed");
/// ```
pub trait FromDer<'a, E = Error>: Sized {
/// Attempt to parse input bytes into a DER object (enforcing constraints)
fn from_der(bytes: &'a [u8]) -> ParseResult<Self, E>;
}
/// Trait to automatically derive `FromDer`
///
/// This trait is only a marker to control if a DER parser should be automatically derived. It is
/// empty.
///
/// This trait is used in combination with others:
/// after implementing [`TryFrom<Any>`] and [`CheckDerConstraints`] for a type,
/// a free [`FromDer`] implementation is provided by implementing the
/// [`DerAutoDerive`] trait. This is the most common case.
///
/// However, this is not automatic so it is also possible to manually
/// implement [`FromDer`] if preferred.
/// Manual implementation is generally only needed for generic containers (for ex. `Vec<T>`),
/// because the default implementation adds a constraint on `T` to implement also `TryFrom<Any>`
/// and `CheckDerConstraints`. This is problematic when `T` only provides `FromDer`, and can be
/// solved by providing a manual implementation of [`FromDer`].
pub trait DerAutoDerive {}
impl<'a, T, E> FromDer<'a, E> for T
where
T: TryFrom<Any<'a>, Error = E>,
T: CheckDerConstraints,
T: DerAutoDerive,
E: From<Error>,
{
fn from_der(bytes: &'a [u8]) -> ParseResult<T, E> {
// Note: Any::from_der checks than length is definite
let (i, any) = Any::from_der(bytes).map_err(nom::Err::convert)?;
<T as CheckDerConstraints>::check_constraints(&any)
.map_err(|e| nom::Err::Error(e.into()))?;
let result = any.try_into().map_err(nom::Err::Error)?;
Ok((i, result))
}
}
/// Verification of DER constraints
pub trait CheckDerConstraints {
fn check_constraints(any: &Any) -> Result<()>;
}
/// Common trait for all objects that can be encoded using the DER representation
///
/// # Examples
///
/// Objects from this crate can be encoded as DER:
///
/// ```
/// use asn1_rs::{Integer, ToDer};
///
/// let int = Integer::from(4u32);
/// let mut writer = Vec::new();
/// let sz = int.write_der(&mut writer).expect("serialization failed");
///
/// assert_eq!(&writer, &[0x02, 0x01, 0x04]);
/// # assert_eq!(sz, 3);
/// ```
///
/// Many of the primitive types can also directly be encoded as DER:
///
/// ```
/// use asn1_rs::ToDer;
///
/// let mut writer = Vec::new();
/// let sz = 4.write_der(&mut writer).expect("serialization failed");
///
/// assert_eq!(&writer, &[0x02, 0x01, 0x04]);
/// # assert_eq!(sz, 3);
/// ```
#[cfg(feature = "std")]
pub trait ToDer
where
Self: DynTagged,
{
/// Get the length of the object, when encoded
///
// Since we are using DER, length cannot be Indefinite, so we can use `usize`.
// XXX can this function fail?
fn to_der_len(&self) -> Result<usize>;
/// Write the DER encoded representation to a newly allocated `Vec<u8>`.
fn to_der_vec(&self) -> SerializeResult<Vec<u8>> {
let mut v = Vec::new();
let _ = self.write_der(&mut v)?;
Ok(v)
}
/// Similar to using `to_vec`, but uses provided values without changes.
/// This can generate an invalid encoding for a DER object.
fn to_der_vec_raw(&self) -> SerializeResult<Vec<u8>> {
let mut v = Vec::new();
let _ = self.write_der_raw(&mut v)?;
Ok(v)
}
/// Attempt to write the DER encoded representation (header and content) into this writer.
///
/// # Examples
///
/// ```
/// use asn1_rs::{Integer, ToDer};
///
/// let int = Integer::from(4u32);
/// let mut writer = Vec::new();
/// let sz = int.write_der(&mut writer).expect("serialization failed");
///
/// assert_eq!(&writer, &[0x02, 0x01, 0x04]);
/// # assert_eq!(sz, 3);
/// ```
fn write_der(&self, writer: &mut dyn Write) -> SerializeResult<usize> {
let sz = self.write_der_header(writer)?;
let sz = sz + self.write_der_content(writer)?;
Ok(sz)
}
/// Attempt to write the DER header to this writer.
fn write_der_header(&self, writer: &mut dyn Write) -> SerializeResult<usize>;
/// Attempt to write the DER content (all except header) to this writer.
fn write_der_content(&self, writer: &mut dyn Write) -> SerializeResult<usize>;
/// Similar to using `to_der`, but uses provided values without changes.
/// This can generate an invalid encoding for a DER object.
fn write_der_raw(&self, writer: &mut dyn Write) -> SerializeResult<usize> {
self.write_der(writer)
}
}
#[cfg(feature = "std")]
impl<'a, T> ToDer for &'a T
where
T: ToDer,
&'a T: DynTagged,
{
fn to_der_len(&self) -> Result<usize> {
(*self).to_der_len()
}
fn write_der_header(&self, writer: &mut dyn Write) -> SerializeResult<usize> {
(*self).write_der_header(writer)
}
fn write_der_content(&self, writer: &mut dyn Write) -> SerializeResult<usize> {
(*self).write_der_content(writer)
}
}
/// Helper trait for creating tagged EXPLICIT values
///
/// # Examples
///
/// ```
/// use asn1_rs::{AsTaggedExplicit, Class, Error, TaggedParser};
///
/// // create a `[1] EXPLICIT INTEGER` value
/// let tagged: TaggedParser<_, _, Error> = 4u32.explicit(Class::ContextSpecific, 1);
/// ```
pub trait AsTaggedExplicit<'a, E = Error>: Sized {
fn explicit(self, class: Class, tag: u32) -> TaggedParser<'a, Explicit, Self, E> {
TaggedParser::new_explicit(class, tag, self)
}
}
impl<'a, T, E> AsTaggedExplicit<'a, E> for T where T: Sized + 'a {}
/// Helper trait for creating tagged IMPLICIT values
///
/// # Examples
///
/// ```
/// use asn1_rs::{AsTaggedImplicit, Class, Error, TaggedParser};
///
/// // create a `[1] IMPLICIT INTEGER` value, not constructed
/// let tagged: TaggedParser<_, _, Error> = 4u32.implicit(Class::ContextSpecific, false, 1);
/// ```
pub trait AsTaggedImplicit<'a, E = Error>: Sized {
fn implicit(
self,
class: Class,
constructed: bool,
tag: u32,
) -> TaggedParser<'a, Implicit, Self, E> {
TaggedParser::new_implicit(class, constructed, tag, self)
}
}
impl<'a, T, E> AsTaggedImplicit<'a, E> for T where T: Sized + 'a {}
pub trait ToStatic {
type Owned: 'static;
fn to_static(&self) -> Self::Owned;
}