如注释中所述，您已将字节替换为内部和外部填充.返回到***页面:

As mentioned in a comment, you have swapped the bytes for the inner and outer padding. Refer back to the Wikipedia page:

o_key_pad = key xor [0x5c * blockSize]   //Outer padded key
i_key_pad = key xor [0x36 * blockSize]   //Inner padded key

这就是我对该功能的看法.我相信它的分配较少:

Here's what my take on the function would look like. I believe it has less allocation:

extern crate ring;

use ring::{digest, test};

const BLOCK_SIZE: usize = 64;

pub fn hmac(k: &[u8], m: &[u8]) -> Vec<u8> {
    assert_eq!(k.len(), BLOCK_SIZE);

    let mut i_key_pad: Vec<_> = k.iter().map(|&k| k ^ 0x36).collect();
    let mut o_key_pad: Vec<_> = k.iter().map(|&k| k ^ 0x5C).collect();

    i_key_pad.extend_from_slice(m);

    let hash = |v| digest::digest(&digest::SHA256, v);

    let a = hash(&i_key_pad);

    o_key_pad.extend_from_slice(a.as_ref());

    hash(&o_key_pad).as_ref().to_vec()
}

#[test]
fn test_hmac_digest() {
    let k = [0x61; BLOCK_SIZE];
    let m = [0x62; BLOCK_SIZE];
    let actual = hmac(&k, &m);

    // Expected value taken from: https://www.freeformatter.com/hmac-generator.html#ad-output
    let expected = test::from_hex("f6cbb37b326d36f2f27d294ac3bb46a6aac29c1c9936b985576041bfb338ae70").unwrap();
    assert_eq!(actual, expected);
}