Struct orion::hazardous::mac::blake2b::Tag

pub struct Tag { /* private fields */ }

A type to represent the Tag that BLAKE2b returns.

Errors:

An error will be returned if:

• slice is empty.
• slice is greater than 64 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::sha512::Tag;

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

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

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

Implementations

impl Tag

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.

pub fn is_empty(&self) -> bool

Return true if this object does not hold any data, false otherwise.

NOTE: This method should always return false, since there shouldn’t be a way to create an empty instance of this 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 Debug for Tag

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Tag

Available on crate feature serde only.

This type tries to deserialize as a Vec<u8> would. If it succeeds, the digest will be built using Self::from_slice.

Note that this allocates once to store the referenced bytes on the heap.

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Drop for Tag

fn drop(&mut self)

Executes the destructor for this type.

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 ==.

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

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

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 ==.

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

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

impl Serialize for Tag

Available on crate feature serde only.

This type tries to serialize as a &[u8] would. Note that the serialized type likely does not have the same protections that Orion provides, such as constant-time operations. A good rule of thumb is to only serialize these types for storage. Don’t operate on the serialized types.

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>where S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<&[u8]> for Tag

Delegates to from_slice implementation

type Error = UnknownCryptoError

The type returned in the event of a conversion error.

fn try_from(slice: &[u8]) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for Tag