Function calculate_signature 

pub fn calculate_signature(
    signing_key: impl AsRef<[u8]>,
    string_to_sign: &[u8],
) -> String

Available on crate feature sigv4a only.

Calculates a Sigv4a signature

signing_key is a big-endian P-256 private scalar, as produced by generate_signing_key.

Shorter input is accepted down to 24 bytes and left-padded with zeroes, which is what the SecretKey this used to go through did.

Panics

Panics if signing_key is not a valid P-256 private key.