Hashing

Default: BLAKE3 (blake3_hash). Use SHA-256 for interop. Use sha256ni_hash for hardware acceleration. It’s immune to cache timing since it runs register-only with no table lookups.

thistle.sha256_hash

def sha256_hash(data: Span[UInt8, ...]) -> List[UInt8]

var d = sha256_hash(String("abc").as_bytes())
# hex(d) == "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"

thistle.sha256ni_hash

def sha256ni_hash(data: Span[UInt8, ...]) -> List[UInt8]

Same output as sha256_hash. Dispatches to SHA-NI or ARMv8 crypto ext at compile time. Falls back to the scalar transform if neither is present.

• Note: output is always correct. This is a pure perf switch.

thistle.sha3_256 / sha3_512

def sha3_256(data: Span[UInt8, ...]) -> List[UInt8]
def sha3_512(data: Span[UInt8, ...]) -> List[UInt8]

var d = sha3_256(data)
# hex(d) == "3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532" for "abc"

thistle.shake128 / shake256

def shake256(data: Span[UInt8, ...], output_len_bytes: Int) -> List[UInt8]

var out = shake256(data, 100)   # arbitrary output length

thistle.blake3_hash / blake3_parallel_hash

def blake3_hash(input: Span[UInt8, ...], out_len: Int = 32) -> List[UInt8]
def blake3_parallel_hash(input: Span[UInt8, ...], out_len: Int = 32) -> List[UInt8]

var d = blake3_hash(data)
# hex(d) == "6437b3ac38465133ffb63b75273a8db548c558465d79db03fd359c6cd5bd9d85" for "abc"

var d2 = blake3_parallel_hash(large_data)   # ~10 GB/s, multi-threaded, same output as blake3_hash

thistle.blake2b_hash / blake2b_hash_keyed

def blake2b_hash(data: Span[UInt8, ...], out_len: Int = 64) raises -> List[UInt8]
def blake2b_hash_keyed(data: Span[UInt8, ...], key: Span[UInt8, ...], out_len: Int = 64) raises -> List[UInt8]

var d = blake2b_hash(data, out_len=32)
var mac = blake2b_hash_keyed(data, key)

• Note: raises if out_len not in 1..64.
• Note: raises if key is longer than 64 bytes.

Streaming SHA-256

from thistle import SHA256Context
from thistle.sha2 import sha256_update, sha256_final_to_buffer

var ctx = SHA256Context()
sha256_update(ctx, chunk1)
sha256_update(ctx, chunk2)
var out = InlineArray[UInt8, 32](uninitialized=True)
sha256_final_to_buffer(ctx, out.unsafe_ptr())

• SHA256Context/SHA512Context have .wipe(). Call it if the context absorbed secret input.