Move static KEM public key to new PublicBox struct

rosenpass/src/cli.rs

@@ -6,7 +6,7 @@ use rosenpass_secret_memory::file::StoreSecret;
 use rosenpass_secret_memory::{
     secret_policy_try_use_memfd_secrets, secret_policy_use_only_malloc_secrets,
 };
-use rosenpass_util::file::{LoadValue, LoadValueB64};
+use rosenpass_util::file::{LoadValue, LoadValueB64, StoreValue};
 use rosenpass_wireguard_broker::brokers::native_unix::{
     NativeUnixBroker, NativeUnixBrokerConfigBaseBuilder, NativeUnixBrokerConfigBaseBuilderError,
 };
@@ -370,7 +370,7 @@ impl CliCommand {
 fn generate_and_save_keypair(secret_key: PathBuf, public_key: PathBuf) -> anyhow::Result<()> {
     let mut ssk = crate::protocol::SSk::random();
     let mut spk = crate::protocol::SPk::random();
-    StaticKem::keygen(ssk.secret_mut(), spk.secret_mut())?;
+    StaticKem::keygen(ssk.secret_mut(), &mut *spk)?;
     ssk.store_secret(secret_key)?;
     spk.store(public_key)
 }

rosenpass/src/protocol.rs

@@ -32,11 +32,11 @@
 //!
 //! // initialize secret and public key for peer a ...
 //! let (mut peer_a_sk, mut peer_a_pk) = (SSk::zero(), SPk::zero());
-//! StaticKem::keygen(peer_a_sk.secret_mut(), peer_a_pk.secret_mut())?;
+//! StaticKem::keygen(peer_a_sk.secret_mut(), &mut *peer_a_pk)?;
 //!
 //! // ... and for peer b
 //! let (mut peer_b_sk, mut peer_b_pk) = (SSk::zero(), SPk::zero());
-//! StaticKem::keygen(peer_b_sk.secret_mut(), peer_b_pk.secret_mut())?;
+//! StaticKem::keygen(peer_b_sk.secret_mut(), &mut *peer_b_pk)?;
 //!
 //! // initialize server and a pre-shared key
 //! let psk = SymKey::random();
@@ -88,7 +88,7 @@ use rosenpass_ciphers::hash_domain::{SecretHashDomain, SecretHashDomainNamespace
 use rosenpass_ciphers::kem::{EphemeralKem, StaticKem};
 use rosenpass_ciphers::{aead, xaead, KEY_LEN};
 use rosenpass_constant_time as constant_time;
-use rosenpass_secret_memory::{Public, Secret};
+use rosenpass_secret_memory::{Public, PublicBox, Secret};
 use rosenpass_util::{cat, mem::cpy_min, ord::max_usize, time::Timebase};
 use zerocopy::{AsBytes, FromBytes, Ref};
 
@@ -163,7 +163,7 @@ pub fn has_happened(ev: Timing, now: Timing) -> bool {
 
 // DATA STRUCTURES & BASIC TRAITS & ACCESSORS ////
 
-pub type SPk = Secret<{ StaticKem::PK_LEN }>; // Just Secret<> instead of Public<> so it gets allocated on the heap
+pub type SPk = PublicBox<{ StaticKem::PK_LEN }>;
 pub type SSk = Secret<{ StaticKem::SK_LEN }>;
 pub type EPk = Public<{ EphemeralKem::PK_LEN }>;
 pub type ESk = Secret<{ EphemeralKem::SK_LEN }>;
@@ -548,7 +548,7 @@ impl CryptoServer {
     pub fn pidm(&self) -> Result<PeerId> {
         Ok(Public::new(
             hash_domains::peerid()?
-                .mix(self.spkm.secret())?
+                .mix(&*self.spkm)?
                 .into_value()))
     }
 
@@ -708,7 +708,7 @@ impl Peer {
     pub fn pidt(&self) -> Result<PeerId> {
         Ok(Public::new(
             hash_domains::peerid()?
-                .mix(self.spkt.secret())?
+                .mix(&*self.spkt)?
                 .into_value()))
     }
 }
@@ -1016,9 +1016,7 @@ impl CryptoServer {
         );
 
         let cookie_value = active_cookie_value.unwrap();
-        let cookie_key = hash_domains::cookie_key()?
-            .mix(self.spkm.secret())?
-            .into_value();
+        let cookie_key = hash_domains::cookie_key()?.mix(&*self.spkm)?.into_value();
 
         let mut msg_out = truncating_cast_into::<CookieReply>(tx_buf)?;
 
@@ -1509,7 +1507,7 @@ where
     /// Calculate the message authentication code (`mac`) and also append cookie value
     pub fn seal(&mut self, peer: PeerPtr, srv: &CryptoServer) -> Result<()> {
         let mac = hash_domains::mac()?
-            .mix(peer.get(srv).spkt.secret())?
+            .mix(&*peer.get(srv).spkt)?
             .mix(&self.as_bytes()[span_of!(Self, msg_type..mac)])?;
         self.mac.copy_from_slice(mac.into_value()[..16].as_ref());
         self.seal_cookie(peer, srv)?;
@@ -1536,7 +1534,7 @@ where
     /// Check the message authentication code
     pub fn check_seal(&self, srv: &CryptoServer) -> Result<bool> {
         let expected = hash_domains::mac()?
-            .mix(srv.spkm.secret())?
+            .mix(&*srv.spkm)?
             .mix(&self.as_bytes()[span_of!(Self, msg_type..mac)])?;
         Ok(constant_time::memcmp(
             &self.mac,
@@ -1641,7 +1639,7 @@ impl HandshakeState {
 
         // calculate ad contents
         let ad = hash_domains::biscuit_ad()?
-            .mix(srv.spkm.secret())?
+            .mix(&*srv.spkm)?
             .mix(self.sidi.as_slice())?
             .mix(self.sidr.as_slice())?
             .into_value();
@@ -1676,7 +1674,7 @@ impl HandshakeState {
 
         // Calculate additional data fields
         let ad = hash_domains::biscuit_ad()?
-            .mix(srv.spkm.secret())?
+            .mix(&*srv.spkm)?
             .mix(sidi.as_slice())?
             .mix(sidr.as_slice())?
             .into_value();
@@ -1763,7 +1761,7 @@ impl CryptoServer {
         let mut hs = InitiatorHandshake::zero_with_timestamp(self);
 
         // IHI1
-        hs.core.init(peer.get(self).spkt.secret())?;
+        hs.core.init(&*peer.get(self).spkt)?;
 
         // IHI2
         hs.core.sidi.randomize();
@@ -1780,7 +1778,7 @@ impl CryptoServer {
         hs.core
             .encaps_and_mix::<StaticKem, { StaticKem::SHK_LEN }>(
                 ih.sctr.as_mut_slice(),
-                peer.get(self).spkt.secret(),
+                &*peer.get(self).spkt,
             )?;
 
         // IHI6
@@ -1788,9 +1786,7 @@ impl CryptoServer {
             .encrypt_and_mix(ih.pidic.as_mut_slice(), self.pidm()?.as_ref())?;
 
         // IHI7
-        hs.core
-            .mix(self.spkm.secret())?
-            .mix(peer.get(self).psk.secret())?;
+        hs.core.mix(&*self.spkm)?.mix(peer.get(self).psk.secret())?;
 
         // IHI8
         hs.core.encrypt_and_mix(ih.auth.as_mut_slice(), &[])?;
@@ -1807,7 +1803,7 @@ impl CryptoServer {
         core.sidi = SessionId::from_slice(&ih.sidi);
 
         // IHR1
-        core.init(self.spkm.secret())?;
+        core.init(&*self.spkm)?;
 
         // IHR4
         core.mix(&ih.sidi)?.mix(&ih.epki)?;
@@ -1815,7 +1811,7 @@ impl CryptoServer {
         // IHR5
         core.decaps_and_mix::<StaticKem, { StaticKem::SHK_LEN }>(
             self.sskm.secret(),
-            self.spkm.secret(),
+            &*self.spkm,
             &ih.sctr,
         )?;
 
@@ -1828,7 +1824,7 @@ impl CryptoServer {
         };
 
         // IHR7
-        core.mix(peer.get(self).spkt.secret())?
+        core.mix(&*peer.get(self).spkt)?
             .mix(peer.get(self).psk.secret())?;
 
         // IHR8
@@ -1848,7 +1844,7 @@ impl CryptoServer {
         // RHR5
         core.encaps_and_mix::<StaticKem, { StaticKem::SHK_LEN }>(
             &mut rh.scti,
-            peer.get(self).spkt.secret(),
+            &*peer.get(self).spkt,
         )?;
 
         // RHR6
@@ -1916,7 +1912,7 @@ impl CryptoServer {
         // RHI5
         core.decaps_and_mix::<StaticKem, { StaticKem::SHK_LEN }>(
             self.sskm.secret(),
-            self.spkm.secret(),
+            &*self.spkm,
             &rh.scti,
         )?;
 
@@ -2113,7 +2109,7 @@ impl CryptoServer {
                     ),
                 }?;
 
-                let spkt = peer.get(self).spkt.secret();
+                let spkt = &*peer.get(self).spkt;
                 let cookie_key = hash_domains::cookie_key()?.mix(spkt)?.into_value();
                 let cookie_value = peer.cv().update_mut(self).unwrap();
 
@@ -2255,7 +2251,7 @@ mod test {
     fn keygen() -> Result<(SSk, SPk)> {
         // TODO: Copied from the benchmark; deduplicate
         let (mut sk, mut pk) = (SSk::zero(), SPk::zero());
-        StaticKem::keygen(sk.secret_mut(), pk.secret_mut())?;
+        StaticKem::keygen(sk.secret_mut(), &mut *pk)?;
         Ok((sk, pk))
     }
 

rp/src/key.rs

@@ -5,7 +5,7 @@ use std::{
 };
 
 use anyhow::{anyhow, Result};
-use rosenpass_util::file::{LoadValueB64, StoreValueB64};
+use rosenpass_util::file::{LoadValueB64, StoreValue, StoreValueB64};
 use zeroize::Zeroize;
 
 use rosenpass::protocol::{SPk, SSk};
@@ -56,8 +56,8 @@ pub fn genkey(private_keys_dir: &Path) -> Result<()> {
     if !pqsk_path.exists() && !pqpk_path.exists() {
         let mut pqsk = SSk::random();
         let mut pqpk = SPk::random();
-        StaticKem::keygen(pqsk.secret_mut(), pqpk.secret_mut())?;
-        pqpk.store_secret(pqpk_path)?;
+        StaticKem::keygen(pqsk.secret_mut(), &mut *pqpk)?;
+        pqpk.store(pqpk_path)?;
         pqsk.store_secret(pqsk_path)?;
     } else {
         eprintln!(

secret-memory/src/lib.rs

@@ -6,6 +6,7 @@ pub mod alloc;
 
 mod public;
 pub use crate::public::Public;
+pub use crate::public::PublicBox;
 
 mod secret;
 pub use crate::secret::Secret;

secret-memory/src/public.rs

@@ -277,3 +277,152 @@ mod tests {
         }
     }
 }
+
+#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(transparent)]
+pub struct PublicBox<const N: usize> {
+    pub inner: Box<Public<N>>,
+}
+
+impl<const N: usize> PublicBox<N> {
+    /// Create a new [Public] from a byte slice
+    pub fn from_slice(value: &[u8]) -> Self {
+        copy_slice(value).to_this(Self::zero) // TODO: fix
+    }
+
+    /// Create a new [Public] from a byte array
+    pub fn new(value: [u8; N]) -> Self {
+        Self {
+            inner: Box::new(Public::new(value)),
+        }
+    }
+
+    /// Create a zero initialized [Public]
+    pub fn zero() -> Self {
+        Self {
+            inner: Box::new(Public::zero()),
+        }
+    }
+
+    /// Create a random initialized [Public]
+    pub fn random() -> Self {
+        mutating(Self::zero(), |r| r.randomize())
+    }
+
+    /// Randomize all bytes in an existing [Public]
+    pub fn randomize(&mut self) {
+        (**self).try_fill(&mut crate::rand::rng()).unwrap()
+    }
+}
+
+impl<const N: usize> Randomize for PublicBox<N> {
+    fn try_fill<R: Rng + ?Sized>(&mut self, rng: &mut R) -> Result<(), rand::Error> {
+        (**self).try_fill(rng)
+    }
+}
+
+impl<const N: usize> fmt::Debug for PublicBox<N> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        debug_crypto_array(&**self, fmt)
+    }
+}
+
+impl<const N: usize> Deref for PublicBox<N> {
+    type Target = [u8; N];
+
+    fn deref(&self) -> &[u8; N] {
+        &*self.inner
+    }
+}
+
+impl<const N: usize> DerefMut for PublicBox<N> {
+    fn deref_mut(&mut self) -> &mut [u8; N] {
+        &mut *self.inner
+    }
+}
+
+impl<const N: usize> Borrow<[u8]> for PublicBox<N> {
+    fn borrow(&self) -> &[u8] {
+        &**self
+    }
+}
+
+impl<const N: usize> BorrowMut<[u8]> for PublicBox<N> {
+    fn borrow_mut(&mut self) -> &mut [u8] {
+        &mut **self
+    }
+}
+
+impl<const N: usize> LoadValue for PublicBox<N> {
+    type Error = anyhow::Error;
+
+    fn load<P: AsRef<Path>>(path: P) -> anyhow::Result<Self> {
+        let mut v = Self::random();
+        fopen_r(path)?.read_exact_to_end(&mut *v)?;
+        Ok(v)
+    }
+}
+
+impl<const N: usize> StoreValue for PublicBox<N> {
+    type Error = anyhow::Error;
+
+    fn store<P: AsRef<Path>>(&self, path: P) -> anyhow::Result<()> {
+        std::fs::write(path, **self)?;
+        Ok(())
+    }
+}
+
+impl<const N: usize> LoadValueB64 for PublicBox<N> {
+    type Error = anyhow::Error;
+
+    fn load_b64<const F: usize, P: AsRef<Path>>(path: P) -> Result<Self, Self::Error>
+    where
+        Self: Sized,
+    {
+        let mut f = [0u8; F];
+        let mut v = PublicBox::zero();
+        let p = path.as_ref();
+
+        let len = fopen_r(p)?
+            .read_slice_to_end(&mut f)
+            .with_context(|| format!("Could not load file {p:?}"))?;
+
+        b64_decode(&f[0..len], &mut *v)
+            .with_context(|| format!("Could not decode base64 file {p:?}"))?;
+
+        Ok(v)
+    }
+}
+
+impl<const N: usize> StoreValueB64 for PublicBox<N> {
+    type Error = anyhow::Error;
+
+    fn store_b64<const F: usize, P: AsRef<Path>>(&self, path: P) -> anyhow::Result<()> {
+        let p = path.as_ref();
+        let mut f = [0u8; F];
+        let encoded_str = b64_encode(&**self, &mut f)
+            .with_context(|| format!("Could not encode base64 file {p:?}"))?;
+        fopen_w(p, Visibility::Public)?
+            .write_all(encoded_str.as_bytes())
+            .with_context(|| format!("Could not write file {p:?}"))?;
+        Ok(())
+    }
+}
+
+impl<const N: usize> StoreValueB64Writer for PublicBox<N> {
+    type Error = anyhow::Error;
+
+    fn store_b64_writer<const F: usize, W: std::io::Write>(
+        &self,
+        mut writer: W,
+    ) -> Result<(), Self::Error> {
+        let mut f = [0u8; F];
+        let encoded_str =
+            b64_encode(&**self, &mut f).with_context(|| "Could not encode secret to base64")?;
+
+        writer
+            .write_all(encoded_str.as_bytes())
+            .with_context(|| "Could not write base64 to writer")?;
+        Ok(())
+    }
+}