Struct der::asn1::ContextSpecific

pub struct ContextSpecific<T> {
    pub tag_number: TagNumber,
    pub tag_mode: TagMode,
    pub value: T,
}

Context-specific field which wraps an owned inner value.

This type decodes/encodes a field which is specific to a particular context and is identified by a TagNumber.

Fields

tag_number: TagNumber

Context-specific tag number sans the leading 0b10000000 class identifier bit and 0b100000 constructed flag.

tag_mode: TagMode

Tag mode: EXPLICIT VS IMPLICIT.

value: T

Value of the field.

Implementations

impl<T> ContextSpecific<T>

pub fn decode_explicit<'a, R: Reader<'a>>(
    reader: &mut R,
    tag_number: TagNumber
) -> Result<Option<Self>> where
    T: Decode<'a>, 

Attempt to decode an EXPLICIT ASN.1 CONTEXT-SPECIFIC field with the provided TagNumber.

This method has the following behavior which is designed to simplify handling of extension fields, which are denoted in an ASN.1 schema using the ... ellipsis extension marker:

• Skips over ContextSpecific fields with a tag number lower than the current one, consuming and ignoring them.
• Returns Ok(None) if a ContextSpecific field with a higher tag number is encountered. These fields are not consumed in this case, allowing a field with a lower tag number to be omitted, then the higher numbered field consumed as a follow-up.
• Returns Ok(None) if anything other than a ContextSpecific field is encountered.

pub fn decode_implicit<'a, R: Reader<'a>>(
    reader: &mut R,
    tag_number: TagNumber
) -> Result<Option<Self>> where
    T: DecodeValue<'a> + Tagged, 

Attempt to decode an IMPLICIT ASN.1 CONTEXT-SPECIFIC field with the provided TagNumber.

This method otherwise behaves the same as decode_explicit, but should be used in cases where the particular fields are IMPLICIT as opposed to EXPLICIT.

Trait Implementations

impl<'a, T> Choice<'a> for ContextSpecific<T> where
    T: Decode<'a> + Tagged, 

fn can_decode(tag: Tag) -> bool

Is the provided Tag decodable as a variant of this CHOICE?

impl<T: Clone> Clone for ContextSpecific<T>

fn clone(&self) -> ContextSpecific<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for ContextSpecific<T>

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

Formats the value using the given formatter.

impl<'a, T> Decode<'a> for ContextSpecific<T> where
    T: Decode<'a>, 

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

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<T> EncodeValue for ContextSpecific<T> where
    T: EncodeValue + Tagged, 

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

Compute the length of this value (sans Tag+Length header) when encoded as ASN.1 DER.

fn encode_value(&self, writer: &mut dyn Writer) -> Result<()>

Encode value (sans Tag+Length header) as ASN.1 DER using the provided Encoder.

fn header(&self) -> Result<Header> where
    Self: Tagged, 

Get the Header used to encode this value.

impl<T: Ord> Ord for ContextSpecific<T>

fn cmp(&self, other: &ContextSpecific<T>) -> Ordering

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq<ContextSpecific<T>> for ContextSpecific<T>

fn eq(&self, other: &ContextSpecific<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ContextSpecific<T>) -> bool

This method tests for !=.

impl<T: PartialOrd> PartialOrd<ContextSpecific<T>> for ContextSpecific<T>

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

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

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

This method tests less than (for self and other) and is used by the < operator.

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

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

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

This method tests greater than (for self and other) and is used by the > operator.

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

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

impl<T> Tagged for ContextSpecific<T> where
    T: Tagged, 

fn tag(&self) -> Tag

Get the ASN.1 tag that this type is encoded with.

impl<'a, T> TryFrom<AnyRef<'a>> for ContextSpecific<T> where
    T: Decode<'a>, 

type Error = Error

The type returned in the event of a conversion error.

fn try_from(any: AnyRef<'a>) -> Result<ContextSpecific<T>>

Performs the conversion.

impl<T> ValueOrd for ContextSpecific<T> where
    T: EncodeValue + ValueOrd + Tagged, 

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

Return an Ordering between value portion of TLV-encoded self and other when serialized as ASN.1 DER.

impl<T: Copy> Copy for ContextSpecific<T>

impl<T: Eq> Eq for ContextSpecific<T>

impl<T> StructuralEq for ContextSpecific<T>

impl<T> StructuralPartialEq for ContextSpecific<T>