From 74fe12f61d8ca33066d415005315783c4f9a12e0 Mon Sep 17 00:00:00 2001
From: soralit <soralitria@gmail.com>
Date: Tue, 28 Mar 2023 11:06:21 +0800
Subject: [PATCH] support no_std

---
 Cargo.toml            |  6 ++++--
 rust-toolchain        |  1 +
 src/derivation/mod.rs |  3 +++
 src/hex.rs            |  6 ++++++
 src/key.rs            |  3 +++
 src/lib.rs            | 10 +++++++++-
 src/securemem.rs      | 10 +++-------
 src/signature.rs      |  3 +++
 8 files changed, 32 insertions(+), 10 deletions(-)
 create mode 100644 rust-toolchain

diff --git a/Cargo.toml b/Cargo.toml
index 7be305f..f616e6f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,9 @@ categories = [ "cryptography" ]
 
 [dependencies]
 cryptoxide = "0.4"
+zeroize = "1.6.0"
 
 [features]
-default = []
-with-bench = []
+default = ["std"]
+std = []
+with-bench = []
\ No newline at end of file
diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 0000000..07ade69
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+nightly
\ No newline at end of file
diff --git a/src/derivation/mod.rs b/src/derivation/mod.rs
index e90f4a6..314fa9f 100644
--- a/src/derivation/mod.rs
+++ b/src/derivation/mod.rs
@@ -1,3 +1,6 @@
+#[cfg(not(feature = "std"))]
+use core as std;
+
 mod common;
 pub mod v2;
 
diff --git a/src/hex.rs b/src/hex.rs
index 73cfae6..7854afa 100644
--- a/src/hex.rs
+++ b/src/hex.rs
@@ -1,3 +1,9 @@
+#[cfg(not(feature = "std"))]
+use alloc::string::String;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+
 const ALPHABET: &'static [u8] = b"0123456789abcdef";
 
 pub fn encode(input: &[u8]) -> String {
diff --git a/src/key.rs b/src/key.rs
index 5e61650..668dd4c 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -1,3 +1,6 @@
+#[cfg(not(feature = "std"))]
+use core as std;
+
 use std::fmt;
 
 use cryptoxide::constant_time::CtEqual;
diff --git a/src/lib.rs b/src/lib.rs
index ad3fcab..2b64d08 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,12 +10,20 @@
 //! In soft derivation, the important property is that given the parent public key,
 //! one can derive all softly derived children public key.
 
-#![cfg_attr(feature = "with-bench", feature(test))]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(not(feature = "std"), feature(error_in_core))]
 
+#![cfg_attr(feature = "with-bench", feature(test))]
 #[cfg(test)]
 #[cfg(feature = "with-bench")]
 extern crate test;
 
+#[cfg(not(feature = "std"))]
+extern crate alloc;
+
+#[cfg(not(feature = "std"))]
+extern crate core;
+
 mod derivation;
 mod hex;
 mod key;
diff --git a/src/securemem.rs b/src/securemem.rs
index 109a608..602db10 100644
--- a/src/securemem.rs
+++ b/src/securemem.rs
@@ -1,9 +1,5 @@
+use zeroize::Zeroize;
+
 pub fn zero(to_zero: &mut [u8]) {
-    // the unsafety of this call is bounded to the existence of the pointer
-    // and the accuracy of the length of the array.
-    //
-    // since to_zero existence is bound to live at least as long as the call
-    // of this function and that we use the length (in bytes) of the given
-    // slice, this call is safe.
-    unsafe { ::std::ptr::write_bytes(to_zero.as_mut_ptr(), 0, to_zero.len()) }
+    to_zero.zeroize()
 }
diff --git a/src/signature.rs b/src/signature.rs
index 657ccc1..35845c2 100644
--- a/src/signature.rs
+++ b/src/signature.rs
@@ -1,3 +1,6 @@
+#[cfg(not(feature = "std"))]
+use core as std;
+
 use super::hex;
 use std::error::Error;
 use std::fmt;