pub struct Hash(_);
Expand description

An output of the default size, 32 bytes, which provides constant-time equality checking.

Hash implements From and Into for [u8; 32], and it provides an explicit as_bytes method returning &[u8; 32]. However, byte arrays and slices don’t provide constant-time equality checking, which is often a security requirement in software that handles private data. Hash doesn’t implement Deref or AsRef, to avoid situations where a type conversion happens implicitly and the constant-time property is accidentally lost.

Hash provides the to_hex method for converting to hexadecimal. It doesn’t directly support converting from hexadecimal, but here’s an example of doing that with the hex crate:

use std::convert::TryInto;

let hash_hex = "d74981efa70a0c880b8d8c1985d075dbcbf679b99a5f9914e5aaf96b831a9e24";
let hash_bytes = hex::decode(hash_hex)?;
let hash_array: [u8; 32] = hash_bytes[..].try_into()?;
let hash: Hash = hash_array.into();

Implementations

The bytes of the Hash. Note that byte arrays don’t provide constant-time equality checking, so if you need to compare hashes, prefer the Hash type.

The hexadecimal encoding of the Hash. The returned ArrayString is a fixed size and doesn’t allocate memory on the heap. Note that ArrayString doesn’t provide constant-time equality checking, so if you need to compare hashes, prefer the Hash type.

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Converts to this type from the input type.
Converts to this type from the input type.
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more

This implementation is constant-time.

This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

This implementation is constant-time.

This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.