add Rosenpass, the tool

Initial implementation of the Rosenpass tool, implemented by @koraa.
Includes contributions and some lints from @wucke13.

Co-authored-by: wucke13 <wucke13@gmail.com>

benches/handshake.rs

@@ -0,0 +1,82 @@
+use anyhow::Result;
+use rosenpass::{
+    pqkem::{CCAKEM, KEM},
+    protocol::{CcaPk, CcaSk, HandleMsgResult, MsgBuf, PeerPtr, Server, SymKey},
+    sodium::sodium_init,
+};
+
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+fn handle(
+    tx: &mut Server,
+    msgb: &mut MsgBuf,
+    msgl: usize,
+    rx: &mut Server,
+    resb: &mut MsgBuf,
+) -> Result<(Option<SymKey>, Option<SymKey>)> {
+    let HandleMsgResult {
+        exchanged_with: xch,
+        resp,
+    } = rx.handle_msg(&msgb[..msgl], &mut **resb)?;
+    assert!(matches!(xch, None | Some(PeerPtr(0))));
+
+    let xch = xch.map(|p| rx.osk(p).unwrap());
+    let (rxk, txk) = resp
+        .map(|resl| handle(rx, resb, resl, tx, msgb))
+        .transpose()?
+        .unwrap_or((None, None));
+
+    assert!(rxk.is_none() || xch.is_none());
+    Ok((txk, rxk.or(xch)))
+}
+
+fn hs(ini: &mut Server, res: &mut Server) -> Result<()> {
+    let (mut inib, mut resb) = (MsgBuf::zero(), MsgBuf::zero());
+    let sz = ini.initiate_handshake(PeerPtr(0), &mut *inib)?;
+    let (kini, kres) = handle(ini, &mut inib, sz, res, &mut resb)?;
+    assert!(kini.unwrap().secret() == kres.unwrap().secret());
+    Ok(())
+}
+
+fn keygen() -> Result<(CcaSk, CcaPk)> {
+    let (mut sk, mut pk) = (CcaSk::zero(), CcaPk::zero());
+    CCAKEM::keygen(sk.secret_mut(), pk.secret_mut())?;
+    Ok((sk, pk))
+}
+
+fn make_server_pair() -> Result<(Server, Server)> {
+    let psk = SymKey::random();
+    let ((ska, pka), (skb, pkb)) = (keygen()?, keygen()?);
+    let (mut a, mut b) = (Server::new(ska, pka.clone()), Server::new(skb, pkb.clone()));
+    a.add_peer(Some(psk.clone()), pkb)?;
+    b.add_peer(Some(psk), pka)?;
+    Ok((a, b))
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    sodium_init().unwrap();
+    let (mut a, mut b) = make_server_pair().unwrap();
+    c.bench_function("cca_secret_alloc", |bench| {
+        bench.iter(|| {
+            CcaSk::zero();
+        })
+    });
+    c.bench_function("cca_public_alloc", |bench| {
+        bench.iter(|| {
+            CcaPk::zero();
+        })
+    });
+    c.bench_function("keygen", |bench| {
+        bench.iter(|| {
+            keygen().unwrap();
+        })
+    });
+    c.bench_function("handshake", |bench| {
+        bench.iter(|| {
+            hs(black_box(&mut a), black_box(&mut b)).unwrap();
+        })
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);