std::crypto::hash

Source: std/crypto/hash.slk

This is the exact canonical documentation page for std::crypto::hash.

Role#

std::crypto::hash is a shipped nested module in the Silk standard library. It provides byte-oriented BLAKE2b and SHA-256 hashing through the bundled libsodium implementation.

Exported API#

export fn blake2b (
  mut out: &std::buffer::BufferU8,
  out_len: i64,
  msg: std::arrays::ByteSlice,
) -> std::crypto::CryptoError?;

export fn blake2b_keyed (
  mut out: &std::buffer::BufferU8,
  out_len: i64,
  msg: std::arrays::ByteSlice,
  key: std::arrays::ByteSlice,
) -> std::crypto::CryptoError?;

export fn sha256 (
  mut out: &std::buffer::BufferU8,
  msg: std::arrays::ByteSlice,
) -> std::crypto::CryptoError?;

All three functions initialize the crypto runtime, validate nonnegative slice lengths and non-null pointers for nonempty slices, grow out when necessary, and return None on success. Allocation, initialization, or input errors are returned as Some(CryptoError).

• blake2b computes an unkeyed BLAKE2b digest of out_len bytes.
• blake2b_keyed computes a keyed BLAKE2b digest of out_len bytes.
• sha256 computes the standard fixed 32-byte SHA-256 digest.

On success, each operation replaces the logical contents of out and sets its length to the digest length. Input-validation or crypto-initialization failure leaves out unchanged. Once hashing begins, a later allocation or crypto-call failure leaves out.len at zero. In every case, the buffer allocation remains owned by out and can be reused or dropped normally.

Example#

import arrays from "std/arrays";
import buffer from "std/buffer";
import hash from "std/crypto/hash";

fn digest_abc () -> buffer::BufferU8? {
  let mut out = buffer::BufferU8.empty();
  let msg: string = "abc";
  let err = hash::sha256(mut out, arrays::ByteSlice{
    ptr: msg as raw u64,
    len: (sizeof(msg)) as i64,
  });
  if err != None {
    out.drop();
    return None;
  }
  return Some(out);
}

The caller owns the output buffer and must eventually drop it or transfer that ownership to another value.

See Also#

• crypto
• buffer
• arrays