chore: Use naming scheme without rosenpass- for crates

constant-time/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "rosenpass-constant-time"
+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 constant time crypto implementations"
+homepage = "https://rosenpass.eu/"
+repository = "https://github.com/rosenpass/rosenpass"
+readme = "readme.md"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

constant-time/readme.md

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+# Rosenpass constant time library
+
+Rosenpass internal library providing basic constant-time operations.
+
+This is an internal library; not guarantee is made about its API at this point in time.

constant-time/src/lib.rs

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+/// Xors a and b element-wise and writes the result into a.
+///
+/// # Examples
+///
+/// ```
+/// use rosenpass_constant_time::xor_into;
+/// let mut a = String::from("hello").into_bytes();
+/// let b = b"world";
+/// xor_into(&mut a, b);
+/// assert_eq!(&a, b"\x1f\n\x1e\x00\x0b");
+/// ```
+#[inline]
+pub fn xor_into(a: &mut [u8], b: &[u8]) {
+    assert!(a.len() == b.len());
+    for (av, bv) in a.iter_mut().zip(b.iter()) {
+        *av ^= *bv;
+    }
+}