Update hs_ntor code.

// We want to use the exact variable names from the rend-spec-v3.txt proposal.

// This means that we allow variables to be named x (privkey) and X (pubkey).

#![allow(non_snake_case)]

// This crate is still unused so allow some dead code for now.

// This module is still unused: so allow some dead code for now.

#![allow(dead_code)]

#![allow(unreachable_pub)]

use crate::crypto::handshake::KeyGenerator;

use crate::crypto::ll::kdf::{Kdf, ShakeKdf};

use tor_llcrypto::pk::{curve25519, ed25519};

use tor_llcrypto::util::rand_compat::RngCompatExt;

use cipher::stream::{NewStreamCipher, StreamCipher};

use cipher::{NewCipher, StreamCipher};

use digest::Digest;

use generic_array::GenericArray;

use rand_core::{CryptoRng, RngCore};

    // Encrypt the introduction data using 'enc_key'

    let zero_iv = GenericArray::default();

    let mut cipher = Aes256Ctr::new(&enc_key.into(), &zero_iv);

    cipher.encrypt(&mut plaintext);

    cipher.apply_keystream(&mut plaintext);

    let ciphertext = plaintext; // it's now encrypted

    // Now staple the other INTRODUCE1 data right before the ciphertext to

    // Decrypt the ENCRYPTED_DATA from the intro cell

    let zero_iv = GenericArray::default();

    let mut cipher = Aes256Ctr::new(&enc_key.into(), &zero_iv);

    cipher.decrypt(ciphertext);

    cipher.apply_keystream(ciphertext);

    let plaintext = ciphertext; // it's now decrypted

    // Generate ephemeral keys for this handshake