Struct crypto::hmac::HMAC

pub struct HMAC;

Implementations

impl HMAC

pub fn mac(input: &[u8], secret_key: &[u8]) -> [u8; 20]

This implements HMAC for SHA1. The function takes in the bytes to hash and a secret key used to hash. The high level overview looks like this: input: &u8: the message to hash secret_key: &u8: the secret key to use in hashing.

1. The secret key is sized appropriately. (64 bytes in SHA-1)

• If the key is too long or too short, it is set to 64 bytes.
• If too short, it is padded with zeroes on the right
• if too long, it is hashed and then padded with zeroes on the right

2. Two keys are generated

• An outer key, which takes the sized key and xors it with 0x5c
• And inner key, which is xored with 0x36.

3. The inner key is concatenated with the input and then hashed.
4. And then the hash is calculated of the outer key concatenated by that result.

fn block_size_key(secret_key: &[u8]) -> [u8; 64]