Struct orion::auth::Tag

pub struct Tag { /* fields omitted */ }

A type to represent the Tag output by BLAKE2b-256 in keyed mode.

Errors:

An error will be returned if:

• slice is not 32 bytes.

Security:

• Avoid using unprotected_as_bytes() whenever possible, as it breaks all protections that the type implements.

• The trait PartialEq<&'_ [u8]> is implemented for this type so that users are not tempted to call unprotected_as_bytes to compare this sensitive value to a byte slice. The trait is implemented in such a way that the comparison happens in constant time. Thus, users should prefer SecretType == &[u8] over SecretType.unprotected_as_bytes() == &[u8]. Examples are shown below. The examples apply to any type that implements PartialEq<&'_ [u8]>.

use orion::hazardous::mac::hmac::Tag;

// Initialize an arbitrary, 64-byte tag.
let tag = Tag::from_slice(&[1; 64])?;

// Secure, constant-time comparison with a byte slice
assert!(tag == &[1; 64][..]);

// Secure, constant-time comparison with another Tag
assert!(tag == Tag::from_slice(&[1; 64])?);

Methods

impl Tag

#[must_use = "SECURITY WARNING: Ignoring a Result can have real security implications."] pub fn from_slice(slice: &[u8]) -> Result<Tag, UnknownCryptoError>

Construct from a given byte slice.

pub fn unprotected_as_bytes(&self) -> &[u8]

Return the object as byte slice. Warning: Should not be used unless strictly needed. This breaks protections that the type implements.

pub fn len(&self) -> usize

Return the length of the object.

Trait Implementations

impl Clone for Tag

fn clone(&self) -> Tag

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Tag

impl Debug for Tag

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

Formats the value using the given formatter.

impl Eq for Tag

impl From<[u8; 32]> for Tag

fn from(bytes: [u8; 32]) -> Tag

Make an object from a byte array.

impl<'_> PartialEq<&'_ [u8]> for Tag

fn eq(&self, other: &&[u8]) -> bool

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

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Tag> for Tag

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

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

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.