start working on encryption

src/crypto.rs

@@ -0,0 +1,69 @@
+use std::io::{self, Read};
+use std::path::PathBuf;
+use std::{fs::File, io::BufReader};
+
+use rcgen::KeyPair;
+use rustls::pki_types::CertificateDer;
+use thiserror::Error;
+use webrtc_dtls::crypto::{Certificate, CryptoPrivateKey};
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("block is not a private key, unable to load key")]
+    ErrBlockIsNotPrivateKey,
+    #[error("unknown key time in PKCS#8 wrapping, unable to load key")]
+    ErrUnknownKeyTime,
+    #[error("no private key found, unable to load key")]
+    ErrNoPrivateKeyFound,
+    #[error("block is not a certificate, unable to load certificates")]
+    ErrBlockIsNotCertificate,
+    #[error("no certificate found, unable to load certificates")]
+    ErrNoCertificateFound,
+
+    #[error(transparent)]
+    Io(#[from] io::Error),
+    #[error(transparent)]
+    Dtls(#[from] webrtc_dtls::Error),
+    #[error("{0}")]
+    Other(String),
+}
+
+/// load_key_and_certificate reads certificates or key from file
+pub fn load_key_and_certificate(
+    key_path: PathBuf,
+    certificate_path: PathBuf,
+) -> Result<Certificate, Error> {
+    let private_key = load_key(key_path)?;
+
+    let certificate = load_certificate(certificate_path)?;
+
+    Ok(Certificate {
+        certificate,
+        private_key,
+    })
+}
+
+/// load_key Load/read key from file
+pub fn load_key(path: PathBuf) -> Result<CryptoPrivateKey, Error> {
+    let f = File::open(path)?;
+    let mut reader = BufReader::new(f);
+    let mut buf = vec![];
+    reader.read_to_end(&mut buf)?;
+
+    let s = String::from_utf8(buf).expect("utf8 of file");
+
+    let key_pair = KeyPair::from_pem(s.as_str()).expect("key pair in file");
+
+    Ok(CryptoPrivateKey::from_key_pair(&key_pair).expect("crypto key pair"))
+}
+
+/// load_certificate Load/read certificate(s) from file
+pub fn load_certificate(path: PathBuf) -> Result<Vec<CertificateDer<'static>>, Error> {
+    let f = File::open(path)?;
+
+    let mut reader = BufReader::new(f);
+    match rustls_pemfile::certs(&mut reader).collect::<Result<Vec<_>, _>>() {
+        Ok(certs) => Ok(certs.into_iter().map(CertificateDer::from).collect()),
+        Err(_) => Err(Error::ErrNoCertificateFound),
+    }
+}