Struct Digest 

pub struct Digest(/* private fields */);

A cryptographically secure digest, implemented with SHA-256.

A Digest represents the cryptographic hash of some data. In this implementation, SHA-256 is used, which produces a 32-byte hash value. Digests are used throughout the crate for data verification and as unique identifiers derived from data.

CBOR Serialization

Digest implements the CBORTaggedCodable trait, which means it can be serialized to and deserialized from CBOR with a specific tag. The tag used is TAG_DIGEST defined in the tags module.

UR Serialization

When serialized as a Uniform Resource (UR), a Digest is represented as a binary blob with the type “digest”.

Examples

Creating a digest from data:

use bc_components::Digest;

// Create a digest from a string
let data = "hello world";
let digest = Digest::from_image(data.as_bytes());

// Validate that the digest matches the original data
assert!(digest.validate(data.as_bytes()));

Creating and using a digest with hexadecimal representation:

use bc_components::Digest;

// Create a digest from a hex string
let hex_string =
    "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9";
let digest = Digest::from_hex(hex_string);

// Retrieve the digest as hex
assert_eq!(digest.hex(), hex_string);

Implementations

impl Digest

pub const DIGEST_SIZE: usize = 32usize

pub fn from_data(data: [u8; 32]) -> Self

Create a new digest from data.

pub fn from_data_ref(data: impl AsRef<[u8]>) -> Result<Self>

Create a new digest from data.

Returns None if the data is not the correct length.

pub fn from_image(image: impl AsRef<[u8]>) -> Self

Create a new digest from the given image.

The image is hashed with SHA-256.

pub fn from_image_parts(image_parts: &[&[u8]]) -> Self

Create a new digest from an array of data items.

The image parts are concatenated and hashed with SHA-256.

pub fn from_digests(digests: &[Digest]) -> Self

Create a new digest from an array of Digests.

The image parts are concatenated and hashed with SHA-256.

pub fn data(&self) -> &[u8; 32]

Get the data of the digest.

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

Get the digest as a byte slice.

pub fn validate(&self, image: impl AsRef<[u8]>) -> bool

Validate the digest against the given image.

The image is hashed with SHA-256 and compared to the digest. Returns true if the digest matches the image.

pub fn from_hex(hex: impl AsRef<str>) -> Self

Create a new digest from the given hexadecimal string.

Panics

Panics if the string is not exactly 64 hexadecimal digits.

pub fn hex(&self) -> String

The data as a hexadecimal string.

pub fn short_description(&self) -> String

The first four bytes of the digest as a hexadecimal string.

pub fn validate_opt(image: impl AsRef<[u8]>, digest: Option<&Digest>) -> bool

Validate the given data against the digest, if any.

Returns true if the digest is None or if the digest matches the image’s digest. Returns false if the digest does not match the image’s digest.

Trait Implementations

impl AsRef<[u8]> for Digest

Allows using a Digest as a reference to a byte slice.

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<Digest> for Digest

Provides a self-reference, enabling API consistency with other types.

fn as_ref(&self) -> &Digest

Converts this type into a shared reference of the (usually inferred) input type.

impl CBORTagged for Digest

Identifies the CBOR tags used for Digest serialization.

fn cbor_tags() -> Vec<Tag>

Returns the CBOR tags associated with this type.

impl CBORTaggedDecodable for Digest

Defines how a Digest is decoded from CBOR.

fn from_untagged_cbor(cbor: CBOR) -> Result<Self>

Creates an instance of this type by decoding it from untagged CBOR.

fn from_tagged_cbor(cbor: CBOR) -> Result<Self, Error>

where Self: Sized,

Creates an instance of this type by decoding it from tagged CBOR.

fn from_tagged_cbor_data(data: impl AsRef<[u8]>) -> Result<Self, Error>

where Self: Sized,

Creates an instance of this type by decoding it from binary encoded tagged CBOR.

fn from_untagged_cbor_data(data: impl AsRef<[u8]>) -> Result<Self, Error>

where Self: Sized,

Creates an instance of this type by decoding it from binary encoded untagged CBOR.

impl CBORTaggedEncodable for Digest

Defines how a Digest is encoded as CBOR (as a byte string).

fn untagged_cbor(&self) -> CBOR

Returns the untagged CBOR encoding of this instance.

fn tagged_cbor(&self) -> CBOR

Returns the tagged CBOR encoding of this instance.

fn tagged_cbor_data(&self) -> Vec<u8>

Returns the tagged value in CBOR binary representation.

impl Clone for Digest

fn clone(&self) -> Digest

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Digest

Provides a debug representation showing the digest’s hexadecimal value.

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

Formats the value using the given formatter.

impl DigestProvider for Digest

Implements DigestProvider to return itself without copying, as a Digest is already a digest.

fn digest(&self) -> Cow<'_, Digest>

Returns a digest that uniquely characterizes the content of the implementing type.

impl Display for Digest

Provides a string representation showing the digest’s hexadecimal value.

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

Formats the value using the given formatter.

impl<'a> From<&'a Digest> for &'a [u8]

Allows accessing the underlying data as a byte slice reference.

fn from(value: &'a Digest) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Digest> for &'a [u8; 32]

Allows accessing the underlying data as a fixed-size byte array reference.

fn from(value: &'a Digest) -> Self

Converts to this type from the input type.

impl From<&Digest> for Digest

Enables cloning a Digest from a reference using From trait.

fn from(digest: &Digest) -> Self

Converts to this type from the input type.

impl From<&Digest> for Vec<u8>

Converts a Digest reference into a Vec<u8> containing the digest bytes.

fn from(digest: &Digest) -> Self

Converts to this type from the input type.

impl From<Digest> for CBOR

Enables conversion of a Digest into a tagged CBOR value.

fn from(value: Digest) -> Self

Converts to this type from the input type.

impl From<Digest> for Vec<u8>

Converts a Digest into a Vec<u8> containing the digest bytes.

fn from(digest: Digest) -> Self

Converts to this type from the input type.

impl Hash for Digest

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Digest

Enables total ordering of Digests by comparing their underlying bytes lexicographically.

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Digest

fn eq(&self, other: &Digest) -> 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 PartialOrd for Digest

Enables partial ordering of Digests by comparing their underlying bytes.

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<CBOR> for Digest

Enables conversion from CBOR to Digest, with proper error handling.

type Error = Error

The type returned in the event of a conversion error.

fn try_from(cbor: CBOR) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for Digest

impl StructuralPartialEq for Digest