use crate::io::BufMut;
use crate::postgres::protocol::Encode;
use crate::Result;
use byteorder::NetworkEndian;
use hmac::{Hmac, Mac};
use sha2::Sha256;
pub struct SaslInitialResponse<'a>(pub &'a str);
impl<'a> Encode for SaslInitialResponse<'a> {
fn encode(&self, buf: &mut Vec<u8>) {
let len = self.0.as_bytes().len() as u32;
buf.push(b'p');
buf.put_u32::<NetworkEndian>(4u32 + len + 14u32 + 4u32);
buf.put_str_nul("SCRAM-SHA-256");
buf.put_u32::<NetworkEndian>(len);
buf.extend_from_slice(self.0.as_bytes());
}
}
pub struct SaslResponse<'a>(pub &'a str);
impl<'a> Encode for SaslResponse<'a> {
fn encode(&self, buf: &mut Vec<u8>) {
buf.push(b'p');
buf.put_u32::<NetworkEndian>(4u32 + self.0.as_bytes().len() as u32);
buf.extend_from_slice(self.0.as_bytes());
}
}
pub fn hi<'a>(s: &'a str, salt: &'a [u8], iter_count: u32) -> Result<[u8; 32]> {
let mut mac = Hmac::<Sha256>::new_varkey(s.as_bytes())
.map_err(|_| protocol_err!("HMAC can take key of any size"))?;
mac.input(&salt);
mac.input(&1u32.to_be_bytes());
let mut u = mac.result().code();
let mut hi = u;
for _ in 1..iter_count {
let mut mac = Hmac::<Sha256>::new_varkey(s.as_bytes())
.map_err(|_| protocol_err!(" HMAC can take key of any size"))?;
mac.input(u.as_slice());
u = mac.result().code();
hi = hi.iter().zip(u.iter()).map(|(&a, &b)| a ^ b).collect();
}
Ok(hi.into())
}