Struct Checksum

pub struct Checksum<D: Digest> {
    digest: Vec<u8>,
    _marker: PhantomData<D>,
}

A checksum using a supported algorithm

Checksums are created using one of the supported algorithms:

• Blake2b512
• Md5 (WARNING: Use of this algorithm is highly discouraged, because it is cryptographically unsafe)
• Sha1 (WARNING: Use of this algorithm is highly discouraged, because it is cryptographically unsafe)
• Sha224
• Sha256
• Sha384
• Sha512

Contrary to makepkg/pacman, this crate does not support using cksum-style CRC-32 as it is non-standard (different implementations throughout libraries) and cryptographically unsafe.

Note

There are two ways to use a checksum:

1. Generically over a digest (e.g. Checksum::<Blake2b512>)
2. Using the convenience type aliases (e.g. Blake2b512Checksum)

Examples

use std::str::FromStr;
use alpm_types::{digests::Blake2b512, Checksum};

let checksum = Checksum::<Blake2b512>::calculate_from("foo\n");
let digest = vec![
    210, 2, 215, 149, 29, 242, 196, 183, 17, 202, 68, 180, 188, 201, 215, 179, 99, 250, 66,
    82, 18, 126, 5, 140, 26, 145, 14, 192, 91, 108, 208, 56, 215, 28, 194, 18, 33, 192, 49,
    192, 53, 159, 153, 62, 116, 107, 7, 245, 150, 92, 248, 197, 195, 116, 106, 88, 51, 122,
    217, 171, 101, 39, 142, 119,
];
assert_eq!(checksum.inner(), digest);
assert_eq!(
    format!("{}", checksum),
    "d202d7951df2c4b711ca44b4bcc9d7b363fa4252127e058c1a910ec05b6cd038d71cc21221c031c0359f993e746b07f5965cf8c5c3746a58337ad9ab65278e77",
);

// create checksum from hex string
let checksum = Checksum::<Blake2b512>::from_str("d202d7951df2c4b711ca44b4bcc9d7b363fa4252127e058c1a910ec05b6cd038d71cc21221c031c0359f993e746b07f5965cf8c5c3746a58337ad9ab65278e77")?;
assert_eq!(checksum.inner(), digest);

Developer Note

In case you want to wrap this type and make the parent Serializeable, please note the following:

Serde automatically adds a Serialize trait bound on top of it trait bounds in wrapper types. However, that’s not needed as we use D simply as a phantom marker that isn’t serialized in the first place. To fix this in your wrapper type, make use of the [bound container attribute], e.g.:

use alpm_types::{Checksum, digests::Digest};
use serde::Serialize;

#[derive(Serialize)]
struct Wrapper<D: Digest> {
    #[serde(bound = "D: Digest")]
    checksum: Checksum<D>,
}

Fields

digest: Vec<u8>

_marker: PhantomData<D>

Implementations

impl<D: Digest> Checksum<D>

pub fn calculate_from(input: impl AsRef<[u8]>) -> Self

Calculate a new Checksum for data that may be represented as a list of bytes

Examples

use alpm_types::{digests::Blake2b512, Checksum};

assert_eq!(
    format!("{}", Checksum::<Blake2b512>::calculate_from("foo\n")),
    "d202d7951df2c4b711ca44b4bcc9d7b363fa4252127e058c1a910ec05b6cd038d71cc21221c031c0359f993e746b07f5965cf8c5c3746a58337ad9ab65278e77",
);

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

Return a reference to the inner type

Trait Implementations

impl<D: Clone + Digest> Clone for Checksum<D>

fn clone(&self) -> Checksum<D>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<D: Digest> Debug for Checksum<D>

Use Display as Debug impl, since the byte representation and PhantomData field aren’t relevant for debugging purposes.

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

Formats the value using the given formatter.

impl<'de, D: Digest> Deserialize<'de> for Checksum<D>

fn deserialize<De>(deserializer: De) -> Result<Self, De::Error>

where De: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<D: Digest> Display for Checksum<D>

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

Formats the value using the given formatter.

impl<D: Digest> FromStr for Checksum<D>

fn from_str(s: &str) -> Result<Checksum<D>, Self::Err>

Create a new Checksum from a hex string and return it in a Result

All whitespaces are removed from the input and it is processed as a lowercase string. An Error is returned, if the input length does not match the output size for the given supported algorithm, or if the provided hex string could not be converted to a list of bytes.

Examples

use std::str::FromStr;
use alpm_types::{digests::Blake2b512, Checksum};

assert!(Checksum::<Blake2b512>::from_str("d202d7951df2c4b711ca44b4bcc9d7b363fa4252127e058c1a910ec05b6cd038d71cc21221c031c0359f993e746b07f5965cf8c5c3746a58337ad9ab65278e77").is_ok());
assert!(Checksum::<Blake2b512>::from_str("d2 02 d7 95 1d f2 c4 b7 11 ca 44 b4 bc c9 d7 b3 63 fa 42 52 12 7e 05 8c 1a 91 0e c0 5b 6c d0 38 d7 1c c2 12 21 c0 31 c0 35 9f 99 3e 74 6b 07 f5 96 5c f8 c5 c3 74 6a 58 33 7a d9 ab 65 27 8e 77").is_ok());
assert!(Checksum::<Blake2b512>::from_str("d202d7951df2c4b711ca44b4bcc9d7b363fa4252127e058c1a910ec05b6cd038d71cc21221c031c0359f993e746b07f5965cf8c5c3746a58337ad9ab65278e7").is_err());
assert!(Checksum::<Blake2b512>::from_str("d202d7951df2c4b711ca44b4bcc9d7b363fa4252127e058c1a910ec05b6cd038d71cc21221c031c0359f993e746b07f5965cf8c5c3746a58337ad9ab65278e7x").is_err());

type Err = Error

The associated error which can be returned from parsing.

impl<D: Digest> PartialEq for Checksum<D>

fn eq(&self, other: &Self) -> 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<D: Digest> Serialize for Checksum<D>

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

where S: Serializer,

Serialize a Checksum into a hex String representation.

We chose hex as byte vectors are imperformant and considered bad practice for non-binary formats like JSON or YAML