Add #![no_std] support

.github/workflows/rust.yml

@@ -46,8 +46,12 @@ jobs:
       run: echo RUSTFLAGS='-Dwarnings' >> $GITHUB_ENV
     - run: rustup update
     - run: cargo version
-    - run: cargo build --target ${{ matrix.target }}
-    - run: cargo test --target ${{ matrix.target }}
+    - uses: stellar/binaries@v30
+      with:
+        name: cargo-hack
+        version: 0.5.28
+    - run: cargo-hack hack build --feature-powerset --target ${{ matrix.target }}
+    - run: cargo-hack hack test --feature-powerset --target ${{ matrix.target }}
 
   publish-dry-run:
     if: startsWith(github.head_ref, 'release/')

Cargo.toml

@@ -20,12 +20,12 @@ path = "src/bin/stellar-strkey/main.rs"
 required-features = ["cli"]
 doctest = false
 
-[build_dependencies]
+[build-dependencies]
 crate-git-revision = "0.0.6"
 
 [dev-dependencies]
 proptest = "1.0.0"
 
 [dependencies]
-data-encoding = "2.6.0"
+data-encoding = { version = "2.6.0", default-features = false, features = ["alloc"] }
 clap = { version = "4.2.4", default-features = false, features = ["std", "derive", "usage", "help"], optional = true }

README.md

@@ -16,6 +16,9 @@ To use the library, include in your toml:
 stellar-strkey = "..."
 ```
 
+This crate can be used in `no_std` environments. 
+However, please note that it relies on the [`alloc`](https://docs.rust-embedded.org/book/collections/#using-alloc) crate for certain types such as `Vec`.
+
 #### CLI
 
 To use the CLI:

src/convert.rs

@@ -1,6 +1,9 @@
 // TODO: Could encode and decode, and the functions upstream that call them, be
 // const fn's?
 
+use alloc::string::String;
+use alloc::vec::Vec;
+
 use crate::{crc::checksum, error::DecodeError};
 
 pub fn encode(ver: u8, payload: &[u8]) -> String {

src/crc.rs

@@ -86,6 +86,7 @@ pub fn checksum(data: &[u8]) -> [u8; 2] {
 mod tests {
     use super::checksum;
     extern crate proptest;
+    use alloc::vec::Vec;
     use proptest::prelude::*;
 
     #[test]

src/ed25519.rs

@@ -1,19 +1,20 @@
-use std::{
-    fmt::{Debug, Display},
-    str::FromStr,
-};
-
 use crate::{
     convert::{decode, encode},
     error::DecodeError,
     version,
 };
 
+use alloc::{format, string::String, vec, vec::Vec};
+use core::{
+    fmt::{Debug, Display},
+    str::FromStr,
+};
+
 #[derive(Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct PrivateKey(pub [u8; 32]);
 
 impl Debug for PrivateKey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "PrivateKey(")?;
         write!(
             f,
@@ -51,7 +52,7 @@ impl PrivateKey {
 }
 
 impl Display for PrivateKey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }
@@ -68,7 +69,7 @@ impl FromStr for PrivateKey {
 pub struct PublicKey(pub [u8; 32]);
 
 impl Debug for PublicKey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "PublicKey(")?;
         write!(
             f,
@@ -106,7 +107,7 @@ impl PublicKey {
 }
 
 impl Display for PublicKey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }
@@ -126,7 +127,7 @@ pub struct MuxedAccount {
 }
 
 impl Debug for MuxedAccount {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "MuxedAccount(")?;
         write!(
             f,
@@ -174,7 +175,7 @@ impl MuxedAccount {
 }
 
 impl Display for MuxedAccount {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }
@@ -197,7 +198,7 @@ pub struct SignedPayload {
 }
 
 impl Debug for SignedPayload {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "MuxedAccount(")?;
         write!(
             f,
@@ -321,7 +322,7 @@ impl SignedPayload {
 }
 
 impl Display for SignedPayload {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }

src/lib.rs

@@ -1,3 +1,6 @@
+#![no_std]
+extern crate alloc;
+
 #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Hash)]
 pub struct Version<'a> {
     pub pkg: &'a str,

src/strkey.rs

@@ -1,4 +1,8 @@
-use std::{fmt::Debug, fmt::Display, str::FromStr};
+use alloc::{format, string::String};
+use core::{
+    fmt::{Debug, Display},
+    str::FromStr,
+};
 
 use crate::{
     convert::{decode, encode},
@@ -55,7 +59,7 @@ impl Strkey {
 }
 
 impl Display for Strkey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }
@@ -72,7 +76,7 @@ impl FromStr for Strkey {
 pub struct PreAuthTx(pub [u8; 32]);
 
 impl Debug for PreAuthTx {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "PreAuthTx(")?;
         write!(
             f,
@@ -107,7 +111,7 @@ impl PreAuthTx {
 }
 
 impl Display for PreAuthTx {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }
@@ -124,7 +128,7 @@ impl FromStr for PreAuthTx {
 pub struct HashX(pub [u8; 32]);
 
 impl Debug for HashX {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "HashX(")?;
         write!(
             f,
@@ -159,7 +163,7 @@ impl HashX {
 }
 
 impl Display for HashX {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }
@@ -176,7 +180,7 @@ impl FromStr for HashX {
 pub struct Contract(pub [u8; 32]);
 
 impl Debug for Contract {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "Contract(")?;
         write!(
             f,
@@ -211,7 +215,7 @@ impl Contract {
 }
 
 impl Display for Contract {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{}", self.to_string())
     }
 }

tests/tests.rs

@@ -1,8 +1,10 @@
-use stellar_strkey::*;
+#![no_std]
 
+extern crate alloc;
 extern crate proptest;
-
-use proptest::prelude::*;
+use alloc::{format, string::String, vec, vec::Vec};
+use proptest::proptest;
+use stellar_strkey::*;
 
 #[test]
 fn test_valid_public_keys() {