Enum KeyIdMethod 

pub enum KeyIdMethod {
    Rfc5280Sha1,
    Rfc7093Method1Sha256,
    Rfc7093Method2Sha384,
    Rfc7093Method3Sha512,
    Rfc7093Method4 {
        algorithm_oid: Vec<u32>,
    },
}

Method for computing an X.509 key identifier value.

RFC 5280 §4.2.1.2 originally defined a single method (SHA-1 of the subjectPublicKey BIT STRING value). RFC 7093 adds four supplementary methods covering stronger hash algorithms and the full SubjectPublicKeyInfo DER encoding as input:

Method	Input	Hash	Output
RFC 5280	BIT STRING value of subjectPublicKey	SHA-1	full 20 bytes
RFC 7093 §2 m1	BIT STRING value of subjectPublicKey	SHA-256	leftmost 160 bits (20 bytes)
RFC 7093 §2 m2	BIT STRING value of subjectPublicKey	SHA-384	leftmost 160 bits (20 bytes)
RFC 7093 §2 m3	BIT STRING value of subjectPublicKey	SHA-512	leftmost 160 bits (20 bytes)
RFC 7093 §2 m4	Full SubjectPublicKeyInfo DER encoding	configurable	full hash bytes

Variants

Rfc5280Sha1

RFC 5280 §4.2.1.2: SHA-1 of the BIT STRING value of subjectPublicKey (full 20 bytes).

Rfc7093Method1Sha256

RFC 7093 §2 method 1: SHA-256 of the BIT STRING value, leftmost 160 bits (20 bytes).

Rfc7093Method2Sha384

RFC 7093 §2 method 2: SHA-384 of the BIT STRING value, leftmost 160 bits (20 bytes).

Rfc7093Method3Sha512

RFC 7093 §2 method 3: SHA-512 of the BIT STRING value, leftmost 160 bits (20 bytes).

Rfc7093Method4

RFC 7093 §2 method 4: hash of the full SubjectPublicKeyInfo DER encoding.

algorithm_oid selects the hash algorithm; the full hash value is used (no truncation). The RFC recommends SHA-256 as the example algorithm.

Fields

algorithm_oid: Vec<u32>

Implementations

impl KeyIdMethod

pub fn algorithm_oid(&self) -> &[u32]

OID component array of the hash algorithm used by this method.

pub fn uses_full_spki_der(&self) -> bool

Whether this method hashes the full SubjectPublicKeyInfo DER encoding rather than the BIT STRING value of subjectPublicKey.

Returns true only for Rfc7093Method4.

pub fn apply_output_length(&self, hash: Vec<u8>) -> Vec<u8>

Apply the output-length rule for this method.

RFC 7093 methods 1–3 truncate the hash to its leftmost 160 bits (20 bytes). All other methods return the full hash unchanged.

Trait Implementations

impl Clone for KeyIdMethod

fn clone(&self) -> KeyIdMethod

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KeyIdMethod

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

Formats the value using the given formatter.