chore: Move Public and debug_crypto_array into secret-memory crate

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(())
+    }
+}