kryptos/hash

Cryptographic hash functions.

Hash functions take arbitrary input data and produce a fixed-size digest. Use these for data integrity verification, fingerprinting, and as building blocks for other cryptographic constructs like HMAC.

Example

import kryptos/hash

let assert Ok(h) = hash.new(hash.Sha256)
let digest = h |> hash.update(<<"hello":utf8>>) |> hash.final()

Types

HashAlgorithm

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Supported cryptographic hash algorithms.

pub type HashAlgorithm {
  Blake2b
  Blake2s
  Md5
  Sha1
  Sha256
  Sha384
  Sha512
  Sha512x224
  Sha512x256
  Sha3x224
  Sha3x256
  Sha3x384
  Sha3x512
  Shake128(output_length: Int)
  Shake256(output_length: Int)
}

Constructors

```
Blake2b
```
BLAKE2b (512-bit output)
```
Blake2s
```
BLAKE2s (256-bit output)
```
Md5
```
MD5 (128-bit output), cryptographically broken - use only for legacy compatibility.
```
Sha1
```
SHA-1 (160-bit output)
```
Sha256
```
SHA-256 (256-bit output)
```
Sha384
```
SHA-384 (384-bit output)
```
Sha512
```
SHA-512 (512-bit output)
```
Sha512x224
```
SHA-512/224 (224-bit output), truncated SHA-512.
```
Sha512x256
```
SHA-512/256 (256-bit output), truncated SHA-512.
```
Sha3x224
```
SHA3-224 (224-bit output)
```
Sha3x256
```
SHA3-256 (256-bit output)
```
Sha3x384
```
SHA3-384 (384-bit output)
```
Sha3x512
```
SHA3-512 (512-bit output)
```
Shake128(output_length: Int)
```
SHAKE128 extendable-output function (128-bit security). The output_length parameter specifies the desired digest length in bytes. Prefer using the shake_128 smart constructor to validate the output length.
```
Shake256(output_length: Int)
```
SHAKE256 extendable-output function (256-bit security). The output_length parameter specifies the desired digest length in bytes. Prefer using the shake_256 smart constructor to validate the output length.

Hasher

</>

Represents an in-progress hash computation.

Use new to create a hasher, update to add data, and final to get the digest.

pub type Hasher

Values

byte_size

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pub fn byte_size(algorithm: HashAlgorithm) -> Int

Returns the output size in bytes for a hash algorithm.

Parameters

algorithm: The hash algorithm to get the size for

Returns

The digest size in bytes.

final

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pub fn final(hasher: Hasher) -> BitArray

Finalizes the hash computation and returns the digest.

After calling this function, the hasher should not be reused.

Parameters

hasher: The hasher to finalize

Returns

A BitArray containing the computed hash digest.

is_supported

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pub fn is_supported(algorithm: HashAlgorithm) -> Bool

Checks if a hash algorithm is supported by the current runtime.

Some algorithms may not be available depending on the platform or OpenSSL/crypto library version.

Parameters

algorithm: The hash algorithm to check

Returns

True if the algorithm is supported, False otherwise.

new

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pub fn new(algorithm: HashAlgorithm) -> Result(Hasher, Nil)

Creates a new hasher for incremental hashing.

Use this when you need to hash data in chunks, such as when streaming or when the full input isn’t available at once.

Parameters

algorithm: The hash algorithm to use

Returns

Ok(Hasher) on success, Error(Nil) if the hash algorithm is not supported by the runtime.

shake_128

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pub fn shake_128(
  output_length length: Int,
) -> Result(HashAlgorithm, Nil)

Creates a SHAKE128 hash algorithm with the given output length in bytes.

Parameters

output_length: The desired digest length in bytes (must be > 0)

Returns

Ok(HashAlgorithm) on success, Error(Nil) if the output length is invalid.

shake_256

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pub fn shake_256(
  output_length length: Int,
) -> Result(HashAlgorithm, Nil)

Creates a SHAKE256 hash algorithm with the given output length in bytes.

Parameters

output_length: The desired digest length in bytes (must be > 0)

Returns

Ok(HashAlgorithm) on success, Error(Nil) if the output length is invalid.

update

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pub fn update(hasher: Hasher, data: BitArray) -> Hasher

Adds data to an in-progress hash computation.

Can be called multiple times to incrementally hash data.

Parameters

hasher: The hasher to update
data: The data to add to the hash

Returns

The updated hasher.