native_tls::TlsAcceptor from .key/.crt PEM files instead of .p12 file.

native-tls-acceptor-from-pem-files.rs

use std::io::{self,Error,ErrorKind};
use std::path::Path;

use openssl::pkey::PKey;
use openssl::x509::X509;
use openssl::pkcs12::Pkcs12;
use openssl::stack::Stack;
use native_tls::{self,Identity};

fn read_pems(key: impl AsRef<Path>, cert: impl AsRef<Path>, password: &str) -> io::Result<Vec<u8>> {
    let b = std::fs::read_to_string(key)?;
    let pkey = if password.len() > 0 {
        PKey::private_key_from_pem_passphrase(b.as_bytes(), password.as_bytes())
    } else {
        PKey::private_key_from_pem(b.as_bytes())
    }?;
    let b = std::fs::read_to_string(cert)?;
    let mut certs = X509::stack_from_pem(b.as_bytes())?;
    let cert = certs.remove(0);
    let mut stack = Stack::<X509>::new().unwrap();
    certs.into_iter().for_each(|x| stack.push(x).unwrap());
    let mut builder = Pkcs12::builder();
    builder.ca(stack);
    let nickname = "certfile";
    let pkcs12 = builder.build("", nickname, &pkey, &cert)?;
    Ok(pkcs12.to_der()?)
}

pub fn acceptor_from_pem_files(key: impl AsRef<Path>, cert: impl AsRef<Path>, password: &str) -> io::Result<native_tls::TlsAcceptor> {
    let der = read_pems(key, cert, password)?;
    let cert = Identity::from_pkcs12(&der, "").map_err(|e| Error::new(ErrorKind::Other, e))?;
    native_tls::TlsAcceptor::builder(cert).build().map_err(|e| Error::new(ErrorKind::Other, e))
}