Module extendhash::sha256

Compute SHA-256 hashes and hash extensions.

Example

let secret_data = "This is a secret!".as_bytes();
let hash = sha256::compute_hash(secret_data);
let secret_data_length = secret_data.len();

// Now we try computing a hash extension, assuming that
// `secret_data` is not available. We only need `hash` and
// `secret_data_length`.
let appended_message = "Appended message.".as_bytes();
let combined_hash = sha256::extend_hash(
    hash, secret_data_length, appended_message);

// Now we verify that `combined_hash` matches the
// concatenation (note the intermediate padding):
let mut combined_data = Vec::<u8>::new();
combined_data.extend_from_slice(secret_data);
let padding = sha256::padding_for_length(secret_data_length);
combined_data.extend_from_slice(padding.as_slice());
combined_data.extend_from_slice(appended_message);
assert_eq!(
    combined_hash,
    sha256::compute_hash(combined_data.as_slice()));

Functions

compute_hash	Compute the SHA-256 hash of the input data
extend_hash	Calculate a SHA-256 hash extension.
padding_for_length	Compute the SHA-256 padding for the given input length.
padding_length_for_input_length	Compute the SHA-256 padding length (in bytes) for the given input length.