Struct Length 

pub struct Length(u32);

ASN.1-encoded length.

Maximum length is defined by the Length::MAX constant (256 MiB).

Tuple Fields

0: u32

Implementations

impl Length

pub const ZERO: Self

Length of 0

pub const ONE: Self

Length of 1

pub const MAX: Self

Maximum length currently supported: 256 MiB

pub const fn new(value: u16) -> Self

Create a new Length for any value which fits inside of a u16.

This function is const-safe and therefore useful for Length constants.

pub fn is_zero(self) -> bool

Is this length equal to zero?

pub fn for_tlv(self) -> Result<Self>

Get the length of DER Tag-Length-Value (TLV) encoded data if self is the length of the inner “value” portion of the message.

pub fn saturating_add(self, rhs: Self) -> Self

Perform saturating addition of two lengths.

pub fn saturating_sub(self, rhs: Self) -> Self

Perform saturating subtraction of two lengths.

fn initial_octet(self) -> Option<u8>

Get initial octet of the encoded length (if one is required).

From X.690 Section 8.1.3.5:

In the long form, the length octets shall consist of an initial octet and one or more subsequent octets. The initial octet shall be encoded as follows:

a) bit 8 shall be one; b) bits 7 to 1 shall encode the number of subsequent octets in the length octets, as an unsigned binary integer with bit 7 as the most significant bit; c) the value 11111111₂ shall not be used.

Trait Implementations

impl Add<Length> for Result<Length>

type Output = Result<Length, Error>

The resulting type after applying the + operator.

fn add(self, other: Length) -> Self

Performs the + operation.

impl Add<u16> for Length

type Output = Result<Length, Error>

The resulting type after applying the + operator.

fn add(self, other: u16) -> Result<Self>

Performs the + operation.

impl Add<u32> for Length

type Output = Result<Length, Error>

The resulting type after applying the + operator.

fn add(self, other: u32) -> Result<Self>

Performs the + operation.

impl Add<u8> for Length

type Output = Result<Length, Error>

The resulting type after applying the + operator.

fn add(self, other: u8) -> Result<Self>

Performs the + operation.

impl Add<usize> for Length

type Output = Result<Length, Error>

The resulting type after applying the + operator.

fn add(self, other: usize) -> Result<Self>

Performs the + operation.

impl Add for Length

type Output = Result<Length, Error>

The resulting type after applying the + operator.

fn add(self, other: Self) -> Result<Self>

Performs the + operation.

impl Clone for Length

fn clone(&self) -> Length

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Length

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Decode<'a> for Length

fn decode<R: Reader<'a>>(reader: &mut R) -> Result<Length>

Attempt to decode this message using the provided decoder.

fn from_der(bytes: &'a [u8]) -> Result<Self>

Parse Self from the provided DER-encoded byte slice.

impl Default for Length

fn default() -> Length

Returns the “default value” for a type.

impl DerOrd for Length

fn der_cmp(&self, other: &Self) -> Result<Ordering>

Return an Ordering between self and other when serialized as ASN.1 DER.

impl Display for Length

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Encode for Length

fn encoded_len(&self) -> Result<Length>

Compute the length of this value in bytes when encoded as ASN.1 DER.

fn encode(&self, writer: &mut impl Writer) -> Result<()>

Encode this value as ASN.1 DER using the provided Writer.

fn encode_to_slice<'a>(&self, buf: &'a mut [u8]) -> Result<&'a [u8]>

Encode this value to the provided byte slice, returning a sub-slice containing the encoded message.

fn encode_to_vec(&self, buf: &mut Vec<u8>) -> Result<Length>

Encode this message as ASN.1 DER, appending it to the provided byte vector.

fn to_der(&self) -> Result<Vec<u8>>

Encode this type as DER, returning a byte vector.

impl From<Length> for IndefiniteLength

fn from(length: Length) -> IndefiniteLength

Converts to this type from the input type.

impl From<Length> for u32

fn from(length: Length) -> u32

Converts to this type from the input type.

impl From<u16> for Length

fn from(len: u16) -> Length

Converts to this type from the input type.

impl From<u8> for Length

fn from(len: u8) -> Length

Converts to this type from the input type.

impl Ord for Length

fn cmp(&self, other: &Length) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Length

fn eq(&self, other: &Length) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Length

fn partial_cmp(&self, other: &Length) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub<Length> for Result<Length>

type Output = Result<Length, Error>

The resulting type after applying the - operator.

fn sub(self, other: Length) -> Self

Performs the - operation.

impl Sub for Length

type Output = Result<Length, Error>

The resulting type after applying the - operator.

fn sub(self, other: Length) -> Result<Self>

Performs the - operation.

impl TryFrom<IndefiniteLength> for Length

type Error = Error

The type returned in the event of a conversion error.

fn try_from(length: IndefiniteLength) -> Result<Length>

Performs the conversion.

impl TryFrom<Length> for usize

type Error = Error

The type returned in the event of a conversion error.

fn try_from(len: Length) -> Result<usize>

Performs the conversion.

impl TryFrom<u32> for Length

type Error = Error

The type returned in the event of a conversion error.

fn try_from(len: u32) -> Result<Length>

Performs the conversion.

impl TryFrom<usize> for Length

type Error = Error

The type returned in the event of a conversion error.

fn try_from(len: usize) -> Result<Length>

Performs the conversion.

impl Copy for Length

impl Eq for Length

impl StructuralPartialEq for Length