Enum HashAlg 

pub enum HashAlg {
    Sha1,
    Sha256,
    Sha384,
    Sha512,
    Sha3_256,
    Sha3_384,
    Sha3_512,
    Ripemd160,
}

Hash algorithm identifiers for PKCS#1 v1.5 signatures.

Each variant carries the DER-encoded DigestInfo prefix that gets prepended to the hash output H to form T = prefix || H. Per RFC 8017 §9.2 Note 1 the prefix encodes

DigestInfo ::= SEQUENCE {
    digestAlgorithm  SEQUENCE { OID, NULL },
    digest           OCTET STRING
}

SHA-3 prefixes use the OIDs assigned by NIST CSOR (2.16.840.1.101.3.4.2.{8,9,10}) which were standardised after RFC 8017 was published, but follow the same template as the SHA-2 prefixes.

Note on RIPEMD-160: included for backwards compatibility with legacy systems (Bitcoin signatures, some X.509 CAs from the 2000s). Not recommended for new designs.

Variants

Sha1

SHA-1 (FIPS 180-4). 20-byte output. Legacy / collision-broken; included only for compatibility with old certificates and HMAC-SHA-1.

Sha256

SHA-256 (FIPS 180-4). 32-byte output.

Sha384

SHA-384 (FIPS 180-4). 48-byte output.

Sha512

SHA-512 (FIPS 180-4). 64-byte output.

Sha3_256

SHA3-256 (FIPS 202). 32-byte output.

Sha3_384

SHA3-384 (FIPS 202). 48-byte output.

Sha3_512

SHA3-512 (FIPS 202). 64-byte output.

Ripemd160

RIPEMD-160 (ISO/IEC 10118-3). 20-byte output. Legacy; included for Bitcoin and 2000s European X.509 CAs.

Trait Implementations

impl Clone for HashAlg

fn clone(&self) -> HashAlg

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HashAlg

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

Formats the value using the given formatter.

impl PartialEq for HashAlg

fn eq(&self, other: &HashAlg) -> 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 Copy for HashAlg

impl StructuralPartialEq for HashAlg