chore: Move Public and debug_crypto_array into secret-memory crate

Cargo.lock

@@ -1073,6 +1073,7 @@ dependencies = [
  "paste",
  "rosenpass-ciphers",
  "rosenpass-constant-time",
+ "rosenpass-secret-memory",
  "rosenpass-sodium",
  "rosenpass-to",
  "rosenpass-util",
@@ -1116,6 +1117,16 @@ dependencies = [
  "stacker",
 ]
 
+[[package]]
+name = "rosenpass-secret-memory"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "rosenpass-sodium",
+ "rosenpass-to",
+ "rosenpass-util",
+]
+
 [[package]]
 name = "rosenpass-sodium"
 version = "0.1.0"

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "sodium",
     "to",
     "fuzz",
+    "secret-memory",
 ]
 
 default-members = [
@@ -26,6 +27,7 @@ rosenpass-constant-time = { path = "constant-time" }
 rosenpass-sodium = { path = "sodium" }
 rosenpass-ciphers = { path = "ciphers" }
 rosenpass-to = { path = "to" }
+rosenpass-secret-memory = { path = "secret-memory" }
 criterion = "0.4.0"
 test_bin = "0.4.0"
 libfuzzer-sys = "0.4"

rosenpass/Cargo.toml

@@ -19,6 +19,7 @@ rosenpass-constant-time = { workspace = true }
 rosenpass-sodium = { workspace = true }
 rosenpass-ciphers = { workspace = true }
 rosenpass-to = { workspace = true }
+rosenpass-secret-memory = { workspace = true }
 anyhow = { workspace = true }
 static_assertions = { workspace = true }
 memoffset = { workspace = true }

rosenpass/src/coloring.rs

@@ -1,11 +1,3 @@
-//! Types types for dealing with (secret-) values
-//!
-//! These types use type level coloring to make accidential leackage of secrets extra hard. Both [Secret] and [Public] own their data, but the memory backing
-//! [Secret] is special:
-//! - as it is heap allocated, we can actively zeroize the memory before freeing it.
-//! - guard pages before and after each allocation trap accidential sequential reads that creep towards our secrets
-//! - the memory is mlocked, e.g. it is never swapped
-
 use anyhow::Context;
 use lazy_static::lazy_static;
 use libsodium_sys as libsodium;
@@ -13,17 +5,10 @@ use rosenpass_util::{
     b64::b64_reader,
     file::{fopen_r, LoadValue, LoadValueB64, ReadExactToEnd, StoreValue},
     functional::mutating,
-    mem::cpy,
 };
 use std::result::Result;
 use std::{
-    collections::HashMap,
-    convert::TryInto,
-    fmt,
-    ops::{Deref, DerefMut},
-    os::raw::c_void,
-    path::Path,
-    ptr::null_mut,
+    collections::HashMap, convert::TryInto, fmt, os::raw::c_void, path::Path, ptr::null_mut,
     sync::Mutex,
 };
 
@@ -216,81 +201,6 @@ impl<const N: usize> fmt::Debug for Secret<N> {
     }
 }
 
-/// Contains information in the form of a byte array that may be known to the
-/// public
-// TODO: We should get rid of the Public type; just use a normal value
-#[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
-#[repr(transparent)]
-pub struct Public<const N: usize> {
-    pub value: [u8; N],
-}
-
-impl<const N: usize> Public<N> {
-    /// Create a new [Public] from a byte slice
-    pub fn from_slice(value: &[u8]) -> Self {
-        mutating(Self::zero(), |r| cpy(value, &mut r.value))
-    }
-
-    /// Create a new [Public] from a byte array
-    pub fn new(value: [u8; N]) -> Self {
-        Self { value }
-    }
-
-    /// Create a zero initialized [Public]
-    pub fn zero() -> Self {
-        Self { value: [0u8; N] }
-    }
-
-    /// 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) {
-        rosenpass_sodium::helpers::randombytes_buf(&mut self.value);
-    }
-}
-
-/// Writes the contents of an `&[u8]` as hexadecimal symbols to a [std::fmt::Formatter]
-pub fn debug_crypto_array(v: &[u8], fmt: &mut fmt::Formatter) -> fmt::Result {
-    fmt.write_str("[{}]=")?;
-    if v.len() > 64 {
-        for byte in &v[..32] {
-            std::fmt::LowerHex::fmt(byte, fmt)?;
-        }
-        fmt.write_str("…")?;
-        for byte in &v[v.len() - 32..] {
-            std::fmt::LowerHex::fmt(byte, fmt)?;
-        }
-    } else {
-        for byte in v {
-            std::fmt::LowerHex::fmt(byte, fmt)?;
-        }
-    }
-    Ok(())
-}
-
-impl<const N: usize> fmt::Debug for Public<N> {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        debug_crypto_array(&self.value, fmt)
-    }
-}
-
-impl<const N: usize> Deref for Public<N> {
-    type Target = [u8; N];
-
-    fn deref(&self) -> &[u8; N] {
-        &self.value
-    }
-}
-
-impl<const N: usize> DerefMut for Public<N> {
-    fn deref_mut(&mut self) -> &mut [u8; N] {
-        &mut self.value
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::*;
@@ -422,22 +332,3 @@ impl<const N: usize> StoreSecret for Secret<N> {
         Ok(())
     }
 }
-
-impl<const N: usize> LoadValue for Public<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 Public<N> {
-    type Error = anyhow::Error;
-
-    fn store<P: AsRef<Path>>(&self, path: P) -> anyhow::Result<()> {
-        std::fs::write(path, **self)?;
-        Ok(())
-    }
-}

rosenpass/src/protocol.rs

@@ -76,6 +76,7 @@ use crate::{
 };
 use anyhow::{bail, ensure, Context, Result};
 use rosenpass_ciphers::{aead, xaead, KEY_LEN};
+use rosenpass_secret_memory::Public;
 use rosenpass_util::{cat, mem::cpy_min, ord::max_usize, time::Timebase};
 use std::collections::hash_map::{
     Entry::{Occupied, Vacant},

secret-memory/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "rosenpass-secret-memory"
+version = "0.1.0"
+authors = ["Karolin Varner <karo@cupdev.net>", "wucke13 <wucke13@gmail.com>"]
+edition = "2021"
+license = "MIT OR Apache-2.0"
+description = "Rosenpass internal utilities for storing secrets in memory"
+homepage = "https://rosenpass.eu/"
+repository = "https://github.com/rosenpass/rosenpass"
+readme = "readme.md"
+
+[dependencies]
+anyhow = { workspace = true }
+rosenpass-to = { workspace = true }
+rosenpass-sodium = { workspace = true }
+rosenpass-util = { workspace = true }

secret-memory/readme.md

@@ -0,0 +1,5 @@
+# Rosenpass secure memory library
+
+Rosenpass internal library providing utilities for securely storing secret data in memory.
+
+This is an internal library; not guarantee is made about its API at this point in time.

secret-memory/src/debug.rs

@@ -0,0 +1,20 @@
+use std::fmt;
+
+/// Writes the contents of an `&[u8]` as hexadecimal symbols to a [std::fmt::Formatter]
+pub fn debug_crypto_array(v: &[u8], fmt: &mut fmt::Formatter) -> fmt::Result {
+    fmt.write_str("[{}]=")?;
+    if v.len() > 64 {
+        for byte in &v[..32] {
+            std::fmt::LowerHex::fmt(byte, fmt)?;
+        }
+        fmt.write_str("…")?;
+        for byte in &v[v.len() - 32..] {
+            std::fmt::LowerHex::fmt(byte, fmt)?;
+        }
+    } else {
+        for byte in v {
+            std::fmt::LowerHex::fmt(byte, fmt)?;
+        }
+    }
+    Ok(())
+}

secret-memory/src/lib.rs

@@ -0,0 +1,4 @@
+mod public;
+pub use crate::public::Public;
+
+pub mod debug;

secret-memory/src/public.rs

@@ -0,0 +1,105 @@
+use crate::debug::debug_crypto_array;
+use rosenpass_to::{ops::copy_slice, To};
+use rosenpass_util::file::{fopen_r, LoadValue, ReadExactToEnd, StoreValue};
+use rosenpass_util::functional::mutating;
+use std::borrow::{Borrow, BorrowMut};
+use std::fmt;
+use std::ops::{Deref, DerefMut};
+use std::path::Path;
+
+/// Contains information in the form of a byte array that may be known to the
+/// public
+// TODO: We should get rid of the Public type; just use a normal value
+#[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(transparent)]
+pub struct Public<const N: usize> {
+    pub value: [u8; N],
+}
+
+impl<const N: usize> Public<N> {
+    /// Create a new [Public] from a byte slice
+    pub fn from_slice(value: &[u8]) -> Self {
+        copy_slice(value).to_this(|| Self::zero())
+    }
+
+    /// Create a new [Public] from a byte array
+    pub fn new(value: [u8; N]) -> Self {
+        Self { value }
+    }
+
+    /// Create a zero initialized [Public]
+    pub fn zero() -> Self {
+        Self { value: [0u8; N] }
+    }
+
+    /// 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) {
+        rosenpass_sodium::helpers::randombytes_buf(&mut self.value);
+    }
+}
+
+impl<const N: usize> fmt::Debug for Public<N> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        debug_crypto_array(&self.value, fmt)
+    }
+}
+
+impl<const N: usize> Deref for Public<N> {
+    type Target = [u8; N];
+
+    fn deref(&self) -> &[u8; N] {
+        &self.value
+    }
+}
+
+impl<const N: usize> DerefMut for Public<N> {
+    fn deref_mut(&mut self) -> &mut [u8; N] {
+        &mut self.value
+    }
+}
+
+impl<const N: usize> Borrow<[u8; N]> for Public<N> {
+    fn borrow(&self) -> &[u8; N] {
+        &self.value
+    }
+}
+impl<const N: usize> BorrowMut<[u8; N]> for Public<N> {
+    fn borrow_mut(&mut self) -> &mut [u8; N] {
+        &mut self.value
+    }
+}
+
+impl<const N: usize> Borrow<[u8]> for Public<N> {
+    fn borrow(&self) -> &[u8] {
+        &self.value
+    }
+}
+impl<const N: usize> BorrowMut<[u8]> for Public<N> {
+    fn borrow_mut(&mut self) -> &mut [u8] {
+        &mut self.value
+    }
+}
+
+impl<const N: usize> LoadValue for Public<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 Public<N> {
+    type Error = anyhow::Error;
+
+    fn store<P: AsRef<Path>>(&self, path: P) -> anyhow::Result<()> {
+        std::fs::write(path, **self)?;
+        Ok(())
+    }
+}