From dc842c44d1d5c1eaa6e88e536ae3af4b82faad61 Mon Sep 17 00:00:00 2001
From: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Date: Wed, 25 Sep 2024 21:55:02 +0200
Subject: [PATCH] sasl: Make this crate no_std

We mostly had to import from alloc some structs that are part of the std
prelude, such as Vec and String.
---
 sasl/CHANGELOG.md                       |  4 ++++
 sasl/README.md                          |  2 ++
 sasl/src/client/mechanisms/plain.rs     |  2 ++
 sasl/src/client/mechanisms/scram.rs     | 23 ++++++++++++++---------
 sasl/src/client/mod.rs                  |  5 +++--
 sasl/src/common/mod.rs                  |  6 ++++--
 sasl/src/common/scram.rs                | 10 +++++++---
 sasl/src/error.rs                       |  1 +
 sasl/src/lib.rs                         |  5 +++++
 sasl/src/secret.rs                      |  3 +++
 sasl/src/server/mechanisms/anonymous.rs |  2 ++
 sasl/src/server/mechanisms/plain.rs     |  2 ++
 sasl/src/server/mechanisms/scram.rs     |  6 +++++-
 sasl/src/server/mod.rs                  |  5 +++--
 14 files changed, 57 insertions(+), 19 deletions(-)

diff --git a/sasl/CHANGELOG.md b/sasl/CHANGELOG.md
index f42fda32bfcef052a52e2a2da4256d52247a990a..c703b5f77b1d867daabfc9c699798ddea64eded3 100644
--- a/sasl/CHANGELOG.md
+++ b/sasl/CHANGELOG.md
@@ -1,3 +1,7 @@
+Version NEXT, released 20??-??-??:
+	* Improvements
+		- This crate is now `no_std`, you can use it even on platforms which don’t provide the `std` crate.
+
 Version 0.5.2, released 2024-07-22:
 	* Improvements
 		- Add SCRAM client extensions support (thanks to Lucas Kent)
diff --git a/sasl/README.md b/sasl/README.md
index 5972c5915932aacc3e975bf3fabc8464d57bb965..5eb2266e71794f8888055e6847008a0cdf7452b7 100644
--- a/sasl/README.md
+++ b/sasl/README.md
@@ -6,6 +6,8 @@ What's this?
 
 A crate which handles SASL authentication. Still unstable until 1.0.0.
 
+It can be used in `no_std` environments.
+
 Can I see an example?
 ---------------------
 
diff --git a/sasl/src/client/mechanisms/plain.rs b/sasl/src/client/mechanisms/plain.rs
index bc08fd85b711a5b8d035b98764e00573601750b8..05f4bd291d12ca3b47fa9f6220f4cfbde7f10a49 100644
--- a/sasl/src/client/mechanisms/plain.rs
+++ b/sasl/src/client/mechanisms/plain.rs
@@ -2,6 +2,8 @@
 
 use crate::client::{Mechanism, MechanismError};
 use crate::common::{Credentials, Identity, Password, Secret};
+use alloc::string::String;
+use alloc::vec::Vec;
 
 /// A struct for the SASL PLAIN mechanism.
 pub struct Plain {
diff --git a/sasl/src/client/mechanisms/scram.rs b/sasl/src/client/mechanisms/scram.rs
index 05f7874478ecec6cae4a6ed4e705fe6e665e06d9..2f8dc5019fe5ff3507076ca97d72ab37b9f4d06c 100644
--- a/sasl/src/client/mechanisms/scram.rs
+++ b/sasl/src/client/mechanisms/scram.rs
@@ -8,7 +8,10 @@ use crate::common::{parse_frame, xor, ChannelBinding, Credentials, Identity, Pas
 
 use crate::error::Error;
 
-use std::marker::PhantomData;
+use alloc::format;
+use alloc::string::String;
+use alloc::vec::Vec;
+use core::marker::PhantomData;
 
 enum ScramState {
     Init,
@@ -226,6 +229,8 @@ mod tests {
     use crate::client::mechanisms::Scram;
     use crate::client::Mechanism;
     use crate::common::scram::{Sha1, Sha256};
+    use alloc::borrow::ToOwned;
+    use alloc::string::String;
 
     #[test]
     fn scram_sha1_works() {
@@ -293,13 +298,13 @@ mod tests {
                 .with_first_extensions("tokenauth=true".to_owned());
         let init = mechanism.initial();
         assert_eq!(
-            std::str::from_utf8(&init).unwrap(),
-            std::str::from_utf8(client_init).unwrap()
+            core::str::from_utf8(&init).unwrap(),
+            core::str::from_utf8(client_init).unwrap()
         ); // depends on ordering…
         let resp = mechanism.response(server_init).unwrap();
         assert_eq!(
-            std::str::from_utf8(&resp).unwrap(),
-            std::str::from_utf8(client_final).unwrap()
+            core::str::from_utf8(&resp).unwrap(),
+            core::str::from_utf8(client_final).unwrap()
         ); // again, depends on ordering…
         mechanism.success(server_final).unwrap();
     }
@@ -318,13 +323,13 @@ mod tests {
                 .with_final_extensions("foo=true".to_owned());
         let init = mechanism.initial();
         assert_eq!(
-            std::str::from_utf8(&init).unwrap(),
-            std::str::from_utf8(client_init).unwrap()
+            core::str::from_utf8(&init).unwrap(),
+            core::str::from_utf8(client_init).unwrap()
         ); // depends on ordering…
         let resp = mechanism.response(server_init).unwrap();
         assert_eq!(
-            std::str::from_utf8(&resp).unwrap(),
-            std::str::from_utf8(client_final).unwrap()
+            core::str::from_utf8(&resp).unwrap(),
+            core::str::from_utf8(client_final).unwrap()
         ); // again, depends on ordering…
     }
 }
diff --git a/sasl/src/client/mod.rs b/sasl/src/client/mod.rs
index 8acca9ffbc200c86e19d89c60fb1fd3a2876ed74..c04eabf8b3db2b19d3acf46ef1c7525033e4b5c7 100644
--- a/sasl/src/client/mod.rs
+++ b/sasl/src/client/mod.rs
@@ -1,4 +1,5 @@
-use std::fmt;
+use alloc::vec::Vec;
+use core::fmt;
 
 use crate::common::Credentials;
 
@@ -84,7 +85,7 @@ impl fmt::Display for MechanismError {
     }
 }
 
-impl std::error::Error for MechanismError {}
+impl core::error::Error for MechanismError {}
 
 /// A trait which defines SASL mechanisms.
 pub trait Mechanism {
diff --git a/sasl/src/common/mod.rs b/sasl/src/common/mod.rs
index bcf6543087a28838121fb17ea6e577201ee84bef..7313c9ec539698ea4f9499d593ed9e5be5b7107e 100644
--- a/sasl/src/common/mod.rs
+++ b/sasl/src/common/mod.rs
@@ -1,5 +1,7 @@
-use std::collections::BTreeMap;
-use std::string::FromUtf8Error;
+use alloc::borrow::ToOwned;
+use alloc::collections::BTreeMap;
+use alloc::string::{FromUtf8Error, String};
+use alloc::vec::Vec;
 
 #[cfg(feature = "scram")]
 pub mod scram;
diff --git a/sasl/src/common/scram.rs b/sasl/src/common/scram.rs
index 689a4d7824318bae18bd0d7ac4a9c632084ebe95..652ac0795df24611a6b378412935ae4650fb0089 100644
--- a/sasl/src/common/scram.rs
+++ b/sasl/src/common/scram.rs
@@ -1,3 +1,7 @@
+use alloc::string::{String, ToString};
+use alloc::vec;
+use alloc::vec::Vec;
+use core::fmt;
 use getrandom::{getrandom, Error as RngError};
 use hmac::{digest::InvalidLength, Hmac, Mac};
 use pbkdf2::pbkdf2;
@@ -25,8 +29,8 @@ pub enum DeriveError {
     IncompatibleIterationCount(u32, u32),
 }
 
-impl std::fmt::Display for DeriveError {
-    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
+impl fmt::Display for DeriveError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match self {
             DeriveError::IncompatibleHashingMethod(one, two) => {
                 write!(fmt, "incompatible hashing method, {} is not {}", one, two)
@@ -40,7 +44,7 @@ impl std::fmt::Display for DeriveError {
     }
 }
 
-impl std::error::Error for DeriveError {}
+impl core::error::Error for DeriveError {}
 
 impl From<hmac::digest::InvalidLength> for DeriveError {
     fn from(_err: hmac::digest::InvalidLength) -> DeriveError {
diff --git a/sasl/src/error.rs b/sasl/src/error.rs
index eb8859092c993f0b266268f82786879d1911ee59..0347e8ac82ac04a203d7ca2051b81e6a6c4cf296 100644
--- a/sasl/src/error.rs
+++ b/sasl/src/error.rs
@@ -1,3 +1,4 @@
+use alloc::string::String;
 #[cfg(feature = "scram")]
 use getrandom::Error as RngError;
 
diff --git a/sasl/src/lib.rs b/sasl/src/lib.rs
index 0c99962d56c5125ea9f7eb26faa912847d29b40e..a776c8c3555f4928778f8a94781806b42dc2257f 100644
--- a/sasl/src/lib.rs
+++ b/sasl/src/lib.rs
@@ -1,8 +1,11 @@
 //#![deny(missing_docs)]
+#![no_std]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
 //! This crate provides a framework for SASL authentication and a few authentication mechanisms.
 //!
+//! It can be used in `no_std` environments.
+//!
 //! # Examples
 //!
 //! ## Simple client-sided usage
@@ -184,6 +187,8 @@
 //! sasl = "*"
 //! ```
 
+extern crate alloc;
+
 mod error;
 
 pub mod client;
diff --git a/sasl/src/secret.rs b/sasl/src/secret.rs
index d78e81f3122d7b6178792659460907865b077fe1..d663fb0fa29269a1b34a685976a7e8e2bbb81e04 100644
--- a/sasl/src/secret.rs
+++ b/sasl/src/secret.rs
@@ -1,5 +1,8 @@
 #[cfg(feature = "scram")]
 use crate::common::scram::DeriveError;
+use alloc::borrow::ToOwned;
+use alloc::string::String;
+use alloc::vec::Vec;
 
 pub trait Secret {}
 
diff --git a/sasl/src/server/mechanisms/anonymous.rs b/sasl/src/server/mechanisms/anonymous.rs
index 92031673b5a75616f31e7aabb6c18204175b3aca..c171f25d94cd3657cdf3221494307eee0f5e7369 100644
--- a/sasl/src/server/mechanisms/anonymous.rs
+++ b/sasl/src/server/mechanisms/anonymous.rs
@@ -1,5 +1,7 @@
 use crate::common::Identity;
 use crate::server::{Mechanism, MechanismError, Response};
+use alloc::format;
+use alloc::vec::Vec;
 
 use getrandom::getrandom;
 
diff --git a/sasl/src/server/mechanisms/plain.rs b/sasl/src/server/mechanisms/plain.rs
index eae74a17aea4f1533095275f48560718ffe9716c..0cba1d8406fdff6606a8b2bd7ba0332e9301f8d1 100644
--- a/sasl/src/server/mechanisms/plain.rs
+++ b/sasl/src/server/mechanisms/plain.rs
@@ -1,6 +1,8 @@
 use crate::common::Identity;
 use crate::secret;
 use crate::server::{Mechanism, MechanismError, Response, Validator};
+use alloc::string::String;
+use alloc::vec::Vec;
 
 pub struct Plain<V: Validator<secret::Plain>> {
     validator: V,
diff --git a/sasl/src/server/mechanisms/scram.rs b/sasl/src/server/mechanisms/scram.rs
index 7bc48edf81c9aefcd4307fdd65b73f8318fc1c8d..62aa165131de79aa4bb3fe4fb23af9814d392879 100644
--- a/sasl/src/server/mechanisms/scram.rs
+++ b/sasl/src/server/mechanisms/scram.rs
@@ -1,4 +1,8 @@
-use std::marker::PhantomData;
+use alloc::borrow::ToOwned;
+use alloc::format;
+use alloc::string::{String, ToString};
+use alloc::vec::Vec;
+use core::marker::PhantomData;
 
 use base64::{engine::general_purpose::STANDARD as Base64, Engine};
 
diff --git a/sasl/src/server/mod.rs b/sasl/src/server/mod.rs
index 889abac4a856e6f4b8bcf118a734f1836c8d3a22..5032bb5ddd3dfedfa4b7dcc2c42c535f796b003e 100644
--- a/sasl/src/server/mod.rs
+++ b/sasl/src/server/mod.rs
@@ -1,6 +1,8 @@
 use crate::common::Identity;
 use crate::secret::Secret;
-use std::fmt;
+use alloc::vec::Vec;
+use core::error::Error;
+use core::fmt;
 
 #[cfg(feature = "scram")]
 use crate::common::scram::DeriveError;
@@ -171,7 +173,6 @@ impl Error for ProviderError {}
 
 impl Error for ValidatorError {}
 
-use std::error::Error;
 impl Error for MechanismError {
     fn source(&self) -> Option<&(dyn Error + 'static)> {
         match self {