chore: Move Public and debug_crypto_array into secret-memory crate

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

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+# 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

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+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

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+mod public;
+pub use crate::public::Public;
+
+pub mod debug;

secret-memory/src/public.rs

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+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(())
+    }
+}